Re: Block Universes
On Fri, Mar 7, 2014 at 8:37 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, I guess I'm supposed to take that as a yes? You do agree that A's world line is actually shorter than C's (even though it is depicted as longer) because A's proper time along it is less than C's from parting to meeting? Correct? Strange how resistant you are to ever saying you agree when we actually do agree. Remember we are not counting points here, at least I'm not, we are trying to find the truth I'm not resistant in general, I have said I agree to a number of agree/disagree questions you asked in the past. But in this one case I was expressing irritation because from your question it seemed pretty obvious you either hadn't read, or hadn't paid any attention to, my discussion of lengths in the post you were responding to. If you really, really can't deduce my opinion on this from statements like this: in terms of proper times C B A which is the opposite of how it works with spatial lengths or: in spatial terms a straight line is the SHORTEST path between two points, but in spacetime a straight (constant-velocity) worldline is the one with the LARGEST proper time between points ...then just tell me why you think these statements are ambiguous and I will then tell you whether I agree that A's world line is actually shorter than C's (even though it is depicted as longer) because A's proper time along it is less than C's from parting to meeting. But if reading those statements does answer your question, then I would suggest that part of trying to find the truth is actually reading through the responses you get, not skimming/skipping over parts of it. First, note you don't actually have to calculate anything. A and C just compare clocks when they meet and that gives the actual world line lengths. Sure, but I'm talking about the theoretical analysis. But, if you want to calculate to predict what that comparison will be, then you have to be careful to do it correctly. C can't just use the Pythagorean theorem on A's world line from his perspective on the x and y distances, he has to use it on the time dimension as well squareroot((y2-y1)^2 + (x2-x1)^2 - c(t2-t1)^2). You have the right idea, although that formula (with c^2 rather than c) actually calculates proper length on a spacelike interval, if you want proper time on a timelike interval the equivalent formula would be squareroot((t2-t1)^2 - (1/c)^2*(x2-x1)^2 - (1/c)^2*(y2-y1)^2). And since we were talking about a 2D spacetime diagram where all motion was along a single spatial axis, I dropped the y-coordinate, and as I mentioned I was also assuming units where c=1, like years for time and light-years for distance. That's why I just wrote the formula as sqrt((t2 - t1)^2 - (x2 - x1)^2). It is the subtraction of this time term that will reduce the length of the slanting blue lines of A and B to THEIR PROJECTIONS ON C'S OWN WORLDLINE. That statement appears wrong, although you'd have to give me a definition of what you mean by projections on C's own worldline for me to be sure. It seems to me that by the normal definition of projection, projecting one of the slanted blue line segments onto the C's vertical worldline would give a new segment parallel to the vertical axis, whose length is just equal to the vertical separation between the ends of the original slanted blue segment. If so, the length of that sort of projection is NOT equal to the proper time of the original slanted blue segment, instead it's equal to the coordinate time between its endpoints, in C's rest frame. For example, looking at the diagram at http://www.jessemazer.com/images/tripletparadox.jpg , let's say the bottom blue segment on A's worldline begins in 2001 in C's rest frame, and ends in 2008, and it has a velocity of 0.6c. In that case, by the normal meaning of projection, projecting this segment onto C's vertical worldline would just create a vertical segment that goes from 2001 to 2008, and thus has a coordinate time of 7 years (and for any vertical segment of a worldline parallel to the time coordinate axis, proper time is supposed to be equal to coordinate time). But because of time dilation, the proper time along the original blue segment (before it was projected to make it vertical) is less than the coordinate time by a factor of sqrt(1 - (0.8c/c)^2) = sqrt(1 - 0.64) = sqrt(0.36) = 0.6, so relativity says the correct proper time along that original slanted blue segment is 7*0.6 = 4.2 years. Do you agree or disagree with these numbers? I think that is what you are saying as well, but my point is that that NULLIFIES any effect on the length of the world lines by the SLANTING of the blue lines NO MATTER WHAT THEIR LENGTHS, and LEAVES ONLY the effects of the red curves. No, you're simply wrong about this. Let's actually do a numerical example. Suppose that both A and B go through the same sequence of 3 accelerations: ACCELERATION 1: starting from
Re: Block Universes
On Sat, Mar 8, 2014 at 9:31 AM, Jesse Mazer laserma...@gmail.com wrote: And B's worldline consists of the following five segments: Segment 1 (blue): Remaining at rest in C's frame, from t=1999 to t=2009 Segment 2 (red): ACCELERATION 1 from t=2009 to t=2011 Segment 3 (blue): Moving inertially at 0.6c in the +x direction, from t=2011 to t=2013 Segment 4 (red): ACCELERATION 2 from t=2013 to t=2017 Segment 5 (blue): Moving inertially at 0.6c in the -x direction, from t=2017 to t=2019 Segment 6 (red): ACCELERATION 3 from t=2019 to t=2019 Correction--that last line for B's worldline should read Segment 6 (red): ACCELERATION 3 from t=2019 to t=2021 -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Block Universes
Jesse, OK, Assume c=1 and start with your sqrt((t2 - t1)^2 - (x2 - x1)^2) to calculate what you say is the proper time on a time-like interval. Using your method, which I assume is correct I do see that A's proper time will be greater than B's. The reason is basically that A has to travel further in space to get from t1 to t2 and consequently must also travel less far in time. Correct? To confirm, consider a simplified twin example with only straight lines so we can ignore accelerations. A remains at rest with a straight vertical line from t1 to t3. B travels away from t1 in a straight oblique line, reverses direction midpoint (call this t2) and travels in a straight oblique line back to t3. The two halves of B's trip are symmetric (have the same velocities away from and back towards A) therefore B's proper time, calculated by A, will be = 2 x sqrt((t2 - t1)^2 - (x2 - x1)^2). In other words we have to multiply by 2 to get the proper time of B for the entire trip. Correct? OK, now consider another case with A and B just moving with constant relative motion and their world lines crossing at t1 and then diverging. There is NO acceleration. In this case using the Lorentz transform both A and B will observe each other's time running slow relative to their own. And using your formula above both A and B will also observe each other's proper times SLOWED RELATIVE TO THEIR OWN. But doesn't this mean that since A and B get different results about each other's proper times that this method of calculating proper times is NOT INVARIANT, and thus is not actually calculating proper times which you say are invariant? I agree that this method correctly calculates how A and B observe each other's clock times, but not sure that's the same as the other's actual proper times. Edgar On Saturday, March 8, 2014 9:31:24 AM UTC-5, jessem wrote: On Fri, Mar 7, 2014 at 8:37 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, I guess I'm supposed to take that as a yes? You do agree that A's world line is actually shorter than C's (even though it is depicted as longer) because A's proper time along it is less than C's from parting to meeting? Correct? Strange how resistant you are to ever saying you agree when we actually do agree. Remember we are not counting points here, at least I'm not, we are trying to find the truth I'm not resistant in general, I have said I agree to a number of agree/disagree questions you asked in the past. But in this one case I was expressing irritation because from your question it seemed pretty obvious you either hadn't read, or hadn't paid any attention to, my discussion of lengths in the post you were responding to. If you really, really can't deduce my opinion on this from statements like this: in terms of proper times C B A which is the opposite of how it works with spatial lengths or: in spatial terms a straight li ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Block Universes
On Sat, Mar 8, 2014 at 2:03 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, OK, Assume c=1 and start with your sqrt((t2 - t1)^2 - (x2 - x1)^2) to calculate what you say is the proper time on a time-like interval. Using your method, which I assume is correct I do see that A's proper time will be greater than B's. The reason is basically that A has to travel further in space to get from t1 to t2 and consequently must also travel less far in time. Correct? It's true in C's rest frame that A travels a greater distance than B, but this needn't be true if you used a different frame. For example, if you analyze the problem using an inertial frame D in which A is at rest during the first blue leg of his trip, then A and B should travel the same distance between departing and reuniting, because neither ever turns around and travels in the wrong direction in this frame, they are both always at rest in this frame or traveling in the -x direction towards the position in this frame where they will reunite. So if you imagine that A and B are cars that are driving along a piece of flat ground at rest in frame D, and both start out with odometers reading 0 when A first departs from B, then A and B's odometer will show the same reading when they reunite, since they have both traveled in a consistent direction (but varying speed) along the same straight road between the position in frame D where they departed and the position where they reunited. To confirm, consider a simplified twin example with only straight lines so we can ignore accelerations. A remains at rest with a straight vertical line from t1 to t3. B travels away from t1 in a straight oblique line, reverses direction midpoint (call this t2) and travels in a straight oblique line back to t3. The two halves of B's trip are symmetric (have the same velocities away from and back towards A) therefore B's proper time, calculated by A, will be = 2 x sqrt((t2 - t1)^2 - (x2 - x1)^2). In other words we have to multiply by 2 to get the proper time of B for the entire trip. Correct? Yes, that's correct. OK, now consider another case with A and B just moving with constant relative motion and their world lines crossing at t1 and then diverging. There is NO acceleration. In this case using the Lorentz transform both A and B will observe each other's time running slow relative to their own. And using your formula above both A and B will also observe each other's proper times SLOWED RELATIVE TO THEIR OWN. But doesn't this mean that since A and B get different results about each other's proper times that this method of calculating proper times is NOT INVARIANT, and thus is not actually calculating proper times which you say are invariant? The method gives an invariant answer for the proper time between any two specific events on an inertial worldline, events which are known to have coordinates (x1,t1) and (x2,t2) in whatever frame you're using. But in your example, they haven't agreed on a specific pair of points on each worldline to calculate the proper time between. Suppose their worldlines cross at the moment of their births, when they are both 0 years old, and subsequently they move apart with arelative velocity of 0.6c so the time dilation factor is 0.8c. If A wants to use his own rest frame to predict how old B will be at the same moment that A turns 20, he is picking the event b1 on B's worldline that is SIMULTANEOUS IN A's REST FRAME with A turning 20, and calculate the proper time between the event of B's birth and b1, which is 16. On the other hand, if B wants to use his own rest frame to predict how old he'll be at the same moment that A turns 20, he must pick the event b2 on B's worldline that is SIMULTANEOUS IN B'S REST FRAME with A turning 20, and calculate the proper time between B's birth and b2, which is 25. Both frames agree that the proper time between B's birth and b1 is 16, and that the proper time between B's birth and b2 is 25, they just disagree about whether b1 or b2 is simultaneous with A turning 20. So that's why they disagree about whether A is older or younger than B at any specified point on A's worldline, like A turning 20 (and of course the logic works the same if you specify a point on B's worldline and ask about A's age at the same moment). Of course, this sort of ambiguity about what events to choose doesn't arise in a twin-paradox type scenario where the twins depart from each other at one specific point on their worldlines, and reunite at some other specific point on their worldlines. If you want further evidence that the method gives an invariant answer, you can use the Lorentz transformation to check that this is so. Pick two events on the worldline of an inertial clock of arbitrary velocity in the frame you're using, and assume that the spacetime origin is chosen so that the first event is labeled with coordinates x1=0, t1=0. Then the second event can be anything (so long as the
Re: Block Universes
Jesse, PS: And in your nice long numerical example, which I thank you for, it seems to me what you are doing is calculating the proper time length of every segment of A's trip in terms of C's proper time. Isn't that correct? But if so aren't you in fact establishing a 1:1 correlation of proper times between A and C with your method? And isn't that what you keep telling me CAN'T BE DONE? Edgar On Saturday, March 8, 2014 9:31:24 AM UTC-5, jessem wrote: On Fri, Mar 7, 2014 at 8:37 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, I guess I'm supposed to take that as a yes? You do agree that A's world line is actually shorter than C's (even though it is depicted as longer) because A's proper time along it is less than C's from parting to meeting? Correct? Strange how resistant you are to ever saying you agree when we actually do agree. Remember we are not counting points here, at least I'm not, we are trying to find the truth I'm not resistant in general, I have said I agree to a number of agree/disagree questions you asked in the past. But in this one case I was expressing irritation because from your question it seemed pretty obvious you either hadn't read, or hadn't paid any attention to, my discussion of lengths in the post you were responding to. If you really, really can't deduce my opinion on this from statements like this: in terms of proper times C B A which is the opposite of how it works with spatial lengths or: in spatial terms a stra ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Block Universes
On Sat, Mar 8, 2014 at 3:11 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, PS: And in your nice long numerical example, which I thank you for, it seems to me what you are doing is calculating the proper time length of every segment of A's trip in terms of C's proper time. Isn't that correct? No, it's in terms of coordinate time in C's rest frame. C's proper time can only be defined between pairs of events on C's own worldline. Of course if C is inertial as in this example, then the coordinate time of events on C's worldline is the same as the proper time between those events, but it doesn't make sense to talk about C's proper time between events that are NOT on C's worldline. But if so aren't you in fact establishing a 1:1 correlation of proper times between A and C with your method? And isn't that what you keep telling me CAN'T BE DONE? You can of course define a correlation in proper times of separated clocks A and B if you specify what frame's definition of simultaneity you want to use. Then you can find a pair of events a1 and b1 that are simultaneous in this frame, and a pair of events a2 and b2 that are simultaneous in this frame, and compare the proper time on A's worldline between a1 and a2 with the proper time on B's worldline between b1 and b2. But this sort of correlation will differ depending on what frame you choose (because the simultaneous events will differ), and what can't be done is find any basis in relativity for saying that one frame's correlation represents the real correlation while other frames' do not. Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Block Universes
Jesse, Finally hopefully getting a minute to respond to at least some of your posts. I'm looking at the two 2 world line diagram on your website and I would argue that the world lines of A and B are exactly the SAME LENGTH due to the identical accelerations of A and B rather than different lengths as you claim. The length of a world line is the PROPER TIME along that world line. Thus the length of a world line is INVARIANT. It is the length of the world line according to its proper clock and NOT the length according to C's clock which is what this diagram shows. So to calculate the length of A's and B's world lines in C's frame (which this diagram represents) we must take the apparent lengths as shown from C's frame view on the diagram, and SHORTEN each section by the apparent slowing of ITS CLOCK relative to C's CLOCK. In other words, the proper time LENGTHS of A's and B's world lines will NOT be as they appear in this diagram which displays their apparent length's relative to C's proper clock. To get the actual length we have to use the readings of A's and B's clock and shorten their apparent lengths by that amount. When we do this all the blue segments of A's and B's world lines become parallel to C's and thus add no length to A's or B's world lines. This is what we would expect since the pure NON-accelerated relative motion of the blue segments doesn't add length to a world line. So when we subtract the apparent length differences of the blue lines all we are left with is the red ones which are equal. Thus the actual LENGTHS of A's and B's world lines are equal. And the only effects which add length to world lines are in fact accelerations as I claimed. The point is that the TRAJECTORIES in spacetime of world lines from some frame like C's in this diagram do NOT properly represent the invariant LENGTHS of those world lines. Because to get the invariant proper time length we must shorten those trajectories by the apparent clock slowing along it to get the actual proper clock interval from start to finish. So when we do this we find that the different LENGTHS of world lines between any two spacetime points are due ONLY TO ACCELERATIONS OR GRAVITATION as I previously stated. Do you agree? Edgar On Thursday, March 6, 2014 12:01:53 PM UTC-5, jessem wrote: On Thu, Mar 6, 2014 at 11:02 AM, Edgar L. Owen edga...@att.netjavascript: wrote: Liz, Sure, but aren't the different lengths of world lines due only to acceleration and gravitational effects? So aren't you saying the same thing I was? Isn't that correct my little Trollette? (Note I wouldn't have included this except in response to your own Troll obsession.) Anyway let's please put our Troll references aside and give me an honest scientific answer for a change if you can... OK? It would be nice to get an answer from Brent or Jesse as well if they care to chime in.. In the case of the traditional twin paradox where one accelerates between meetings while the other does not, the one that accelerates always has the greater path length through spacetime, so in this case they are logically equivalent. But you can have a case in SR (no gravity) where two observers have identical accelerations (i.e. each acceleration lasts the same interval of proper time and involves the same proper acceleration throughout this interval), but because different proper times elapse *between* these accelerations, they end up with worldlines with different path lengths between their meetings (and thus different elapsed aging)...in an online discussion a while ago someone drew a diagram of such a case that I saved on my website: http://www.jessemazer.com/images/tripletparadox.jpg In this example A and B have identical red acceleration phases, but A will have aged less than B when they reunite (you can ignore the worldline of C, who is inertial and naturally ages more than either of them). You can also have cases in SR where twin A accelerates more than B (defined in terms of the amount of proper time spent accelerating, or the value of the proper acceleration experienced during this time, or both), but B has aged less than A when they reunite, rather than vice versa. As always the correct aging is calculated by looking at the overall path through spacetime in some coordinate system, and calculating its length (proper time) with an equation that's analogous to the one you'd use to calculate the spatial length of a path on a 2D plane. Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Block Universes
On Fri, Mar 7, 2014 at 4:02 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, Finally hopefully getting a minute to respond to at least some of your posts. I'm looking at the two 2 world line diagram on your website and I would argue that the world lines of A and B are exactly the SAME LENGTH due to the identical accelerations of A and B rather than different lengths as you claim. The length of a world line is the PROPER TIME along that world line. Thus the length of a world line is INVARIANT. It is the length of the world line according to its proper clock and NOT the length according to C's clock which is what this diagram shows. I don't understand what you mean by the length according to C's clock--are you just talking about the numbers on the vertical time axis, 2000-2020? That axis represents the coordinate time in C's rest frame, and obviously the coordinate time between 2000 at the bottom of the diagram and 2020 at the top is 20 years regardless of what path you're talking about, so I don't see how it makes sense to call this the length of any particular path. But you can also use C's rest frame to assign x and t coordinates to the endpoints of any straight blue segment, x1 and t1 for one endpoint and x2 and t2 for the other, and then C can calculate the proper time along that segment as squareroot[(t2 - t1)^2 - (x2 - x1)^2] and get the correct INVARIANT answer (note that I am using units of light-years and years where c=1 so it doesn't appear in the equation, otherwise the second term in the square root would have to be (1/c^2)*(x2 - x1)^2). What the diagram is trying to show is that even though the different paths have identical red acceleration curves, they have different SPATIAL lengths, i.e. the length you'd measure if you printed out the diagram and laid a flexible cloth tape measure along each path to measure the distance ALONG THE PATH between the point at the bottom of the diagram where the paths diverge and the point at the top where they rejoin. It is true that if you just look at the spatial lengths of each path on the diagram, the ratio between the spatial lengths doesn't actually match up with the ratio between the proper times that would be calculated using relativity. If you use any Cartesian spatial coordinate system to draw x-y axes on the diagram, then you can use this coordinate system to assign x and y coordinates to the endpoints of any straight blue segment, x1 and y1 for one endpoint and x2 and y2 for the other, and then calculate the spatial length of that segment using the Pythagorean theorem: squareroot[(y2 - y1)^2 + (x2 - x1)^2]. Note that you ADD the squares of the two terms in parentheses when calculating spatial length, but my earlier equation showed that you SUBTRACT the square of the two terms in parentheses when calculating proper time, which explains why this sort of spatial path length on a spacetime diagram can be misleading. For example, in spatial terms a straight line is the SHORTEST path between two points, but in spacetime a straight (constant-velocity) worldline is the one with the LARGEST proper time between points. Nevertheless, the math for calculating the invariant spatial path length using a Cartesian coordinate system is closely analogous to the math for calculating the invariant proper time using an inertial frame. The diagrams show the spatial length of the paths being different despite identical red acceleration segments, and this remains true if you actually calculate proper time, even though in terms of proper times C B A which is the opposite of how it works with spatial lengths. If you assign time coordinates to the beginning and end of each acceleration phase, and you specify the proper acceleration involved, then you can calculate the proper time along elapsed on each worldline during both the acceleration phases (using the relativistic rocket equations given at http://math.ucr.edu/home/baez/physics/Relativity/SR/rocket.html ) as well as the proper time during the constant-velocity phases (using the method I mentioned above with squareroot[(t2 - t1)^2 - (x2 - x1)^2] for each segment). If you do this, you do find that in a detailed numerical version of the scenario in the diagram, A ELAPSES LESS TOTAL PROPER TIME THAN B DESPITE HAVING IDENTICAL ACCELERATIONS. I can give the detailed calculations using the relativistic rocket equations if you want, or you can just take my word for it. So to calculate the length of A's and B's world lines in C's frame (which this diagram represents) we must take the apparent lengths as shown from C's frame view on the diagram, and SHORTEN each section by the apparent slowing of ITS CLOCK relative to C's CLOCK. Yes, that would be another way to calculate proper time along the blue constant-velocity segments: just take the times t2 and t1 of the beginning and end of each segment in C's frame, and multiply by the time dilation factor which depends on the speed v in C's frame during
Re: Block Universes
Jesse, Do you understand why the world line that is depicted as LONGER in the typical world line diagram is ACTUALLY SHORTER? E.g. in your diagram do you understand why even though A's world line looks longer than C's world line, it is ACTUALLY SHORTER? Edgar On Friday, March 7, 2014 5:15:57 PM UTC-5, jessem wrote: On Fri, Mar 7, 2014 at 4:02 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, Finally hopefully getting a minute to respond to at least some of your posts. I'm looking at the two 2 world line diagram on your website and I would argue that the world lines of A and B are exactly the SAME LENGTH due to the identical accelerations of A and B rather than different lengths as you claim. The length of a world line is the PROPER TIME along that world line. Thus the length of a world line is INVARIANT. It is the length of the world line according to its proper clock and NOT the length according to C's clock which is what this diagram shows. I don't understand what you mean by the length according to C's clock--are you just talking about the numbers on the vertical time axis, 2000-2020? That axis represents the coordinate time in C's rest frame, and obviously the coordinate time between 2000 at the bottom of the diagram and 2020 at the top is 20 years regardless of what path you're talking about, so I don't see how it makes sense to call this the length of any particular path. But you can also use C's ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Block Universes
On Fri, Mar 7, 2014 at 7:20 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, Do you understand why the world line that is depicted as LONGER in the typical world line diagram is ACTUALLY SHORTER? E.g. in your diagram do you understand why even though A's world line looks longer than C's world line, it is ACTUALLY SHORTER? Edgar Are you actually reading my posts carefully all the way through, or just skimming them or something? I spent a whole extended section of my post discussing just this point, read it again: 'It is true that if you just look at the spatial lengths of each path on the diagram, the ratio between the spatial lengths doesn't actually match up with the ratio between the proper times that would be calculated using relativity. If you use any Cartesian spatial coordinate system to draw x-y axes on the diagram, then you can use this coordinate system to assign x and y coordinates to the endpoints of any straight blue segment, x1 and y1 for one endpoint and x2 and y2 for the other, and then calculate the spatial length of that segment using the Pythagorean theorem: squareroot[(y2 - y1)^2 + (x2 - x1)^2]. Note that you ADD the squares of the two terms in parentheses when calculating spatial length, but my earlier equation showed that you SUBTRACT the square of the two terms in parentheses when calculating proper time, which explains why this sort of spatial path length on a spacetime diagram can be misleading. For example, in spatial terms a straight line is the SHORTEST path between two points, but in spacetime a straight (constant-velocity) worldline is the one with the LARGEST proper time between points. Nevertheless, the math for calculating the invariant spatial path length using a Cartesian coordinate system is closely analogous to the math for calculating the invariant proper time using an inertial frame. The diagrams show the spatial length of the paths being different despite identical red acceleration segments, and this remains true if you actually calculate proper time, even though in terms of proper times C B A which is the opposite of how it works with spatial lengths.' On Friday, March 7, 2014 5:15:57 PM UTC-5, jessem wrote: On Fri, Mar 7, 2014 at 4:02 PM, Edgar L. Owen edga...@att.net wrote: Jesse, Finally hopefully getting a minute to respond to at least some of your posts. I'm looking at the two 2 world line diagram on your website and I would argue that the world lines of A and B are exactly the SAME LENGTH due to the identical accelerations of A and B rather than different lengths as you claim. The length of a world line is the PROPER TIME along that world line. Thus the length of a world line is INVARIANT. It is the length of the world line according to its proper clock and NOT the length according to C's clock which is what this diagram shows. I don't understand what you mean by the length according to C's clock--are you just talking about the numbers on the vertical time axis, 2000-2020? That axis represents the coordinate time in C's rest frame, and obviously the coordinate time between 2000 at the bottom of the diagram and 2020 at the top is 20 years regardless of what path you're talking about, so I don't see how it makes sense to call this the length of any particular path. But you can also use C's ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Block Universes
This is why time has a minus sign in SR. (I believe the usual way this informally is put is that the space-traveller trades space for time.) On 8 March 2014 13:26, Jesse Mazer laserma...@gmail.com wrote: On Fri, Mar 7, 2014 at 7:20 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, Do you understand why the world line that is depicted as LONGER in the typical world line diagram is ACTUALLY SHORTER? E.g. in your diagram do you understand why even though A's world line looks longer than C's world line, it is ACTUALLY SHORTER? Edgar Are you actually reading my posts carefully all the way through, or just skimming them or something? I spent a whole extended section of my post discussing just this point, read it again: 'It is true that if you just look at the spatial lengths of each path on the diagram, the ratio between the spatial lengths doesn't actually match up with the ratio between the proper times that would be calculated using relativity. If you use any Cartesian spatial coordinate system to draw x-y axes on the diagram, then you can use this coordinate system to assign x and y coordinates to the endpoints of any straight blue segment, x1 and y1 for one endpoint and x2 and y2 for the other, and then calculate the spatial length of that segment using the Pythagorean theorem: squareroot[(y2 - y1)^2 + (x2 - x1)^2]. Note that you ADD the squares of the two terms in parentheses when calculating spatial length, but my earlier equation showed that you SUBTRACT the square of the two terms in parentheses when calculating proper time, which explains why this sort of spatial path length on a spacetime diagram can be misleading. For example, in spatial terms a straight line is the SHORTEST path between two points, but in spacetime a straight (constant-velocity) worldline is the one with the LARGEST proper time between points. Nevertheless, the math for calculating the invariant spatial path length using a Cartesian coordinate system is closely analogous to the math for calculating the invariant proper time using an inertial frame. The diagrams show the spatial length of the paths being different despite identical red acceleration segments, and this remains true if you actually calculate proper time, even though in terms of proper times C B A which is the opposite of how it works with spatial lengths.' On Friday, March 7, 2014 5:15:57 PM UTC-5, jessem wrote: On Fri, Mar 7, 2014 at 4:02 PM, Edgar L. Owen edga...@att.net wrote: Jesse, Finally hopefully getting a minute to respond to at least some of your posts. I'm looking at the two 2 world line diagram on your website and I would argue that the world lines of A and B are exactly the SAME LENGTH due to the identical accelerations of A and B rather than different lengths as you claim. The length of a world line is the PROPER TIME along that world line. Thus the length of a world line is INVARIANT. It is the length of the world line according to its proper clock and NOT the length according to C's clock which is what this diagram shows. I don't understand what you mean by the length according to C's clock--are you just talking about the numbers on the vertical time axis, 2000-2020? That axis represents the coordinate time in C's rest frame, and obviously the coordinate time between 2000 at the bottom of the diagram and 2020 at the top is 20 years regardless of what path you're talking about, so I don't see how it makes sense to call this the length of any particular path. But you can also use C's ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Block Universes
Jesse, I guess I'm supposed to take that as a yes? You do agree that A's world line is actually shorter than C's (even though it is depicted as longer) because A's proper time along it is less than C's from parting to meeting? Correct? Strange how resistant you are to ever saying you agree when we actually do agree. Remember we are not counting points here, at least I'm not, we are trying to find the truth First, note you don't actually have to calculate anything. A and C just compare clocks when they meet and that gives the actual world line lengths. But, if you want to calculate to predict what that comparison will be, then you have to be careful to do it correctly. C can't just use the Pythagorean theorem on A's world line from his perspective on the x and y distances, he has to use it on the time dimension as well squareroot((y2-y1)^2 + (x2-x1)^2 - c(t2-t1)^2). It is the subtraction of this time term that will reduce the length of the slanting blue lines of A and B to THEIR PROJECTIONS ON C'S OWN WORLDLINE. I think that is what you are saying as well, but my point is that that NULLIFIES any effect on the length of the world lines by the SLANTING of the blue lines NO MATTER WHAT THEIR LENGTHS, and LEAVES ONLY the effects of the red curves. This must be the case because NON-accelerated relative motion DOES NOT affect proper time rates. This is because it is exactly the same from the perspective of A and C moving relative to each other, thus it cannot affect the lengths of their world lines. I'm trying to parse your last paragraph. Your diagram shows ONLY how A's and B's world lines appear in C's comoving frame. It does NOT show the proper LENGTHS of A's and B's world lines. I think we agree the lengths depicted are NOT the actual world line lengths. I claim the blue slanting lines of A and B, one set longer than the other, have NO EFFECT on the actual lengths of A's and B's world lines. Because when we calculate just their proper lengths subtracting the time term as I do above, their proper lengths reduce to their VERTICAL PROJECTIONS on C's vertical world line. In other words there is no difference in proper time rates of A, B or C during the intervals of the slanting blue lines. Thus, in my view, we are left with ONLY the effects of the curving red accelerations, and these are exactly the same for A and B. And when the lengths of those red acceleration segments are calculated we find that A's and B's world lines will both be SHORTER than C's world line AND by the SAME AMOUNT and that A's and B's world line lengths will be EQUAL due only to their equal accelerations. Perhaps to make this clearer consider just two blue lines of A and B slanted with respect to each other and crossing at P. From A's perspective B's line will be slanted, but from B's perspective A's line will be slanted in the other direction by an equal amount AND since this is NON-accelerated inertial motion only, both views are EQUALLY VALID. When we do the Pythagorean world line length calculation we get EXACTLY THE SAME RESULTS from both frame views. So both world line lengths are exactly equal. Thus slanted blue lines of ANY LENGTH have NO EFFECT AT ALL on world line lengths, and only curved red line accelerations do. If you disagree I can give you another example. Edgar On Friday, March 7, 2014 7:26:38 PM UTC-5, jessem wrote: On Fri, Mar 7, 2014 at 7:20 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, Do you understand why the world line that is depicted as LONGER in the typical world line diagram is ACTUALLY SHORTER? E.g. in your diagram do you understand why even though A ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Block Universes
Liz, Sure, but aren't the different lengths of world lines due only to acceleration and gravitational effects? So aren't you saying the same thing I was? Isn't that correct my little Trollette? (Note I wouldn't have included this except in response to your own Troll obsession.) Anyway let's please put our Troll references aside and give me an honest scientific answer for a change if you can... OK? It would be nice to get an answer from Brent or Jesse as well if they care to chime in.. Edgar On Wednesday, March 5, 2014 3:56:56 PM UTC-5, Liz R wrote: On 6 March 2014 09:12, Edgar L. Owen edga...@att.net javascript:wrote: Jesse, PS: It is well known that accelerations and gravitation are the ONLY causes that produce real actual age rate changes. These real actual age rate changes are real and actual because 1. ALL OBSERVERS AGREE on them when they meet up and check them, and 2.BECAUSE THEY ARE PERMANENT. Having your worldlines be different lengths in spacetime will also cause differences in actual age, as Brent has explained (with diagrams). Consistently ignoring this point and others like it is one reason most people here consider you a troll, so please try to address it. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, Yes, from the point any two observers in the same inertial frame synchronize clocks, their clocks will be synchronized in p-time BUT ONLY FROM THEN ON (we can't know if they were previously synchronized unless we know their acceleration histories). And only SO LONG AS they continue in the same inertial frame OR undergo symmetric accelerations. Same ages is just a way to ensure synchronized clocks at the birth event and make examples simpler. It has nothing to do with p-time synchrony per se. So in your next paragraph your and Jimbo's proper clocks ARE synchronized in p-time from then on under the conditions stated. But I don't understand the rest of your example since you just stated that we are to ignore their PREVIOUS and SUBSEQUENT acceleration histories to preserve the synchronies but then you start giving an example with accelerations, which will obviously change their synchrony UNLESS they are symmetric. You seem to claim that the accelerations are symmetric but you keep describing them as stopping in different frames at different times which indicates they are NOT symmetric. The only way to ensure the accelerations are symmetric is for both A and B to have the same proper accelerations at the same proper times AFTER they synchronize clocks. Are you doing that? If not you are not using MY method. Also you seem to be switching from synchronized proper clocks which I assumed did NOT reflect actual ages to ACTUAL AGES which doesn't work. I used actual ages synchronized at birth (twins) to avoid that kind of misunderstanding. Edgar On Wednesday, March 5, 2014 4:23:54 PM UTC-5, jessem wrote: On Wed, Mar 5, 2014 at 2:42 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, Yes, but respectfully, what I'm saying is that your example doesn't represent my method OR results. In your example of A and B separated but moving at the same velocity and direction, and C and D separated but moving at the same velocity and direction, BUT the two PAIRS moving at different velocities, AND where B and C happen to pass each other at the same point in spacetime here is my result. Assuming the acceleration/gravitation histories of A and B are the same and they are twins; AND the acceleration/gravitation histories of C and D are the same and they are twins, then A(t1)=B(t1)=C(t2)=D(t2) which is clearly transitive between all 4 parties. You earlier agreed that if two observers are at rest relative to each other, then if they synchronize clocks in their rest frame, their clocks will also be synchronized in p-time from then on. In your post at http://www.mail-archive.com/everything-list%40googlegroups.com/msg48404.htmlyou responded to ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On Thu, Mar 6, 2014 at 11:02 AM, Edgar L. Owen edgaro...@att.net wrote: Liz, Sure, but aren't the different lengths of world lines due only to acceleration and gravitational effects? So aren't you saying the same thing I was? Isn't that correct my little Trollette? (Note I wouldn't have included this except in response to your own Troll obsession.) Anyway let's please put our Troll references aside and give me an honest scientific answer for a change if you can... OK? It would be nice to get an answer from Brent or Jesse as well if they care to chime in.. In the case of the traditional twin paradox where one accelerates between meetings while the other does not, the one that accelerates always has the greater path length through spacetime, so in this case they are logically equivalent. But you can have a case in SR (no gravity) where two observers have identical accelerations (i.e. each acceleration lasts the same interval of proper time and involves the same proper acceleration throughout this interval), but because different proper times elapse *between* these accelerations, they end up with worldlines with different path lengths between their meetings (and thus different elapsed aging)...in an online discussion a while ago someone drew a diagram of such a case that I saved on my website: http://www.jessemazer.com/images/tripletparadox.jpg In this example A and B have identical red acceleration phases, but A will have aged less than B when they reunite (you can ignore the worldline of C, who is inertial and naturally ages more than either of them). You can also have cases in SR where twin A accelerates more than B (defined in terms of the amount of proper time spent accelerating, or the value of the proper acceleration experienced during this time, or both), but B has aged less than A when they reunite, rather than vice versa. As always the correct aging is calculated by looking at the overall path through spacetime in some coordinate system, and calculating its length (proper time) with an equation that's analogous to the one you'd use to calculate the spatial length of a path on a 2D plane. Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, You are right about velocity intervals I think, but I do think there will be a mathematically rigorous way to compare the proper time correlation of any two observers from all frame views of that correlation and I do think they will cluster around my results. Each frame view will certainly give us an EXACT value for the difference in proper times between A and B and I think it will be possible to compare those in a meaningful way to see how they cluster WITHOUT weighting them. In any case this is a peripheral though interesting subject.. Edgar On Wednesday, March 5, 2014 4:41:17 PM UTC-5, jessem wrote: On Wed, Mar 5, 2014 at 2:52 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, Yes, the views are infinite on several axes, but that can be addressed simply by enumerating views at standard intervals on those axes. But velocity intervals which are equal when the velocit ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, I don't think this is correct. It is meaningless to try to TAKE THE FRAME VIEW OF ALL FRAME VIEWS. That's not the correct way to look at it. What we do is to take all frame views of any ONE proper time correlation. Every frame view will give one and only one EXACT answer of how close those proper times are to being equal. Once that's done we have the whole picture. We DO NOT HAVE TO TAKE FRAME VIEWS OF THOSE FRAME VIEWS because we already have ALL the frame views of that one situation. Edgar On Wednesday, March 5, 2014 5:01:10 PM UTC-5, jessem wrote: On Wed, Mar 5, 2014 at 4:47 PM, LizR liz...@gmail.com javascript:wrote: If you have a continuum of inertial frames with velocities ranging from +c to -c in all possible directions, how are you going to integrate over them? Isn't there a measure problem over an uncountably infinite set? There's no inherent problem with defining measures on uncountably infinite sets--for example, a bell curve is a continuous probability measure defined over the infinite real number line from -infinity to +infinity, which can be integrated over any specific range to define a probability that a result will fall in that range. But as I've said, the problem is that although you can define a measure over all frames in relativity, if it looks like a uniform distribution when you state the velocity of each frame relative to a particular reference frame A, then it will be a non-uniform distribution when you state the velocity of each frame relative to a different reference frame B, so any such measure will be privileging one frame from the start. Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On Thu, Mar 6, 2014 at 11:32 AM, Edgar L. Owen edgaro...@att.net wrote: Jesse, Yes, from the point any two observers in the same inertial frame synchronize clocks, their clocks will be synchronized in p-time BUT ONLY FROM THEN ON (we can't know if they were previously synchronized unless we know their acceleration histories). And only SO LONG AS they continue in the same inertial frame OR undergo symmetric accelerations. Same ages is just a way to ensure synchronized clocks at the birth event and make examples simpler. It has nothing to do with p-time synchrony per se. So in your next paragraph your and Jimbo's proper clocks ARE synchronized in p-time from then on under the conditions stated. But I don't understand the rest of your example since you just stated that we are to ignore their PREVIOUS and SUBSEQUENT acceleration histories to preserve the synchronies but then you start giving an example with accelerations, which will obviously change their synchrony UNLESS they are symmetric. I clearly stated that the reason I was giving an example of accelerations was in case you DIDN'T accept the clocks were synchronized in p-time in my example with Jimbo, which ignored my and Jimbo's past acceleration histories and ages. My words were: OK, I don't think it should be necessary to specify acceleration histories or ages if you agree with my statement about me and Jimbo above, but if you disagree with that statement I can give details about each pair's past history, though it makes the example a bit more complicated. Since you do accept my statement about p-time simultaneity in the Jimbo example, then there's really no NEED to assume anything about A/B and C/D's past accelerations being symmetric, we can just assume that at some point before the experiment happened, A and B came to rest in frame F and synchronized their clocks in frame F, and C and D came to rest in frame F' and synchronized their clocks in frame F', and subsequently their x(t) and T(t) functions in frame F were as I described. However, in the rest of your post you are responding to my example of a history where A and B had symmetrical accelerations before the experiment, and so did C and D, so I will discuss that example; maybe it makes the statements about p-time simultaneity conceptually clearer to think of their history that way, although if you think it'd be simpler I'd also be just as happy to make the assumption above that each pair synchronized clocks after they came to rest in the same frame. You seem to claim that the accelerations are symmetric but you keep describing them as stopping in different frames at different times which indicates they are NOT symmetric. In my example both accelerations were totally symmetric in the frames where the twins started out at rest next to each other with synchronized clocks. A and B's accelerations were totally symmetric in the unprimed frame F where they started out both at rest at position x=12.5, and C and D's accelerations were totally symmetric in the primed frame F' where they started out both at rest at position x'=7.5. Of course since C and D stopped accelerating simultaneously in the primed frame F' (at time t'=-12 in F'), they stopped accelerating at different times in the unprimed frame F which I had used to describe their x(t) and T(t) functions, but surely your criteria for symmetrical accelerations is just that there is ONE specific frame where all their proper accelerations are simultaneous, namely the frame where they started out at rest and next to each other with synchronized clocks? Assuming that's your criteria, then F' is that one specific frame for C and D (and note that according to relativity, C and D's proper times T also remain synchronized in frame F' at all coordinate times), and F is that one specific frame for A and B (and A and B's proper times T also remain synchronized in F at all coordinate times). The only way to ensure the accelerations are symmetric is for both A and B to have the same proper accelerations at the same proper times AFTER they synchronize clocks. Are you doing that? If not you are not using MY method. Yes, I was doing that. In my example I said that in the unprimed frame F, A and B were originally at rest at position x=12.5, with both having the same ages, and let's say that their proper time clocks have been set to read T = -18 years at the moment they were born. Since they were right next to each other with the same ages and their proper time clocks both showing a time that's just their age minus 18, naturally their clocks were originally synchronized. Then they accelerated in a completely symmetrical way in frame F, with all changes in acceleration being simultaneous in F, including the event of their both ceasing their acceleration and coming to rest again in F, which happened at t=-12 in F. Also you seem to be switching from synchronized proper clocks which I assumed did NOT reflect actual ages
Re: Block Universes
On 3/6/2014 9:01 AM, Jesse Mazer wrote: On Thu, Mar 6, 2014 at 11:02 AM, Edgar L. Owen edgaro...@att.net mailto:edgaro...@att.net wrote: Liz, Sure, but aren't the different lengths of world lines due only to acceleration and gravitational effects? So aren't you saying the same thing I was? Isn't that correct my little Trollette? (Note I wouldn't have included this except in response to your own Troll obsession.) Anyway let's please put our Troll references aside and give me an honest scientific answer for a change if you can... OK? It would be nice to get an answer from Brent or Jesse as well if they care to chime in.. In the case of the traditional twin paradox where one accelerates between meetings while the other does not, the one that accelerates always has the greater path length through spacetime, so in this case they are logically equivalent. But you can have a case in SR (no gravity) where two observers have identical accelerations (i.e. each acceleration lasts the same interval of proper time and involves the same proper acceleration throughout this interval), but because different proper times elapse *between* these accelerations, they end up with worldlines with different path lengths between their meetings (and thus different elapsed aging)...in an online discussion a while ago someone drew a diagram of such a case that I saved on my website: http://www.jessemazer.com/images/tripletparadox.jpg In this example A and B have identical red acceleration phases, but A will have aged less than B when they reunite (you can ignore the worldline of C, who is inertial and naturally ages more than either of them). Right. And you could also replace A's path with the broken line path formed by two clocks passing one another in opposite directions and just handing off the time reading (as in the diagram I posted earlier) so that there was no acceleration involved at all, yet the path would still have less proper time elapse than B's. Brent You can also have cases in SR where twin A accelerates more than B (defined in terms of the amount of proper time spent accelerating, or the value of the proper acceleration experienced during this time, or both), but B has aged less than A when they reunite, rather than vice versa. As always the correct aging is calculated by looking at the overall path through spacetime in some coordinate system, and calculating its length (proper time) with an equation that's analogous to the one you'd use to calculate the spatial length of a path on a 2D plane. Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com mailto:everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com mailto:everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On 7 March 2014 06:01, Jesse Mazer laserma...@gmail.com wrote: On Thu, Mar 6, 2014 at 11:02 AM, Edgar L. Owen edgaro...@att.net wrote: Liz, Sure, but aren't the different lengths of world lines due only to acceleration and gravitational effects? So aren't you saying the same thing I was? I'm ignoring gravitation for the sake of simplicity, so the differences in length of world lines is indeed due to acceleration. However the time difference is not directly caused by acceleration, which was my point. The same acceleration can be used to produce different lengths of world line, for example one twin can go back and forth within the solar system while the other one accelerates to near light-speed and travels to a nearby star and back. The resulting time difference will always be related to the lengths of the world lines, (which in special relativity is an absolute measure everyone will agree on). -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Just realized in retrospect that it was a very confusing choice of terminology to use reference frame to refer to the frame that's used to label other frame's relative velocities--I was thinking of the idea that other frame's velocities are labeled in reference to this one choice of frame, but somehow it didn't occur to me that reference frame is a synonym for frame of reference, which is what ALL frames are called. So I edited my post below to use the term index frame instead, since I'm indexing other frames by their velocity relative to this frame: On Thu, Mar 6, 2014 at 12:51 PM, Jesse Mazer laserma...@gmail.com wrote: I don't know what you mean by the frame view of all frame views. I agree that for a given pair of clocks A and B that are at rest relative to each other and synchronized in their rest frame, each frame has only ONE answer to how much clock A is ahead of B (a number which can be zero if the frame in question is their rest frame, and can also be negative if the frame in question sees clock A as having a time that's behind clock B's time). But if we want to LABEL each such frame by velocity (so we can do an integral or sum over frames with different velocities to take the average), then we must use some specific index frame, and label the velocity of every other frame relative to the index frame. So for example if a given frame X has a velocity of 0.9c relative to a pair of clocks that are 2 light-year apart in their own rest frame, then in X they are out-of-sync by 2*0.9 = 1.8 years. If we use as our index frame the rest frame of the clocks themselves, then X is labeled with v=0.9c since that's its velocity relative to the index frame, and thus our amount out of sync as a function of v function will have a value of 1.8 at v=0.9c. On the other hand, if we use as our index frame a frame moving at 0.8c relative to the clocks, then frame X will have to be labeled with v=0.357c since that's its velocity relative to the new index frame--it's still the same frame X, and it still has the same amount-out-of-sync of 1.8, but it just has a different velocity label. So using this index frame, our amount out of sync as a function of v function will have a value of 1.8 at v=0.357c. Point is, depending on the index frame we use to define the v of every other frame, our amount out of sync as a function of v function will look different, and thus if we integrate over that function to find some sort of average value for the amount the clocks are out of sync, or just do an average over a finite number of values of the function at regular intervals of v, then we'll get different answers depending on what index frame we chose. Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Block Universes
Jesse, First I see no conclusion that demonstrates INtransitivity here or any contradiction that I asked for. Did I miss that? But that really doesn't matter because second, you are NOT using MY method because you are using ANOTHER coordinate clock FRAME rather than the frame views of the parties of their OWN age relationships. So whatever proof you think you have, it is not a proof about my method. So, in spite of what you claim you just seem to be trying to prove there is no simultaneity of VIEWS of age relationships rather than addressing the ACTUAL age relationships of the parties themselves which is my whole point. Edgar . On Tuesday, March 4, 2014 8:03:57 PM UTC-5, jessem wrote: On Tue, Mar 4, 2014 at 5:45 PM, Jesse Mazer laser...@gmail.comjavascript: wrote: I promise you the example has nothing to do with any frames other than the ones in which each pair is at rest. Again, the only assumptions about p-time that I make in deriving the contradiction are: ASSUMPTION 1. If two observers are at rest in the same inertial frame, then events on their worldlines that are simultaneous in their rest frame are also simultaneous in p-time ASSUMPTION 2. If two observers cross paths at a single point in spacetime P, and observer #1's proper time at P is T1 while observer #2's proper time at P is T2, then the event of observer #1's clock showing T1 is simultaneous in p-time with the event of observer #2's clock showing T2. ASSUMPTION 3. p-time simultaneity is transitive That's it! I make no other assumptions about p-time simultaneity. But if you want to actually see how the contradiction is derived, there's really no shortcut besides looking at the math. If you are willing to do that, can we just start with the last 2 questions I asked about the scenario? Here's what I asked again, with a few cosmetic modifications: Please have another look at the specific numbers I gave for x(t), coordinate position as a function of coordinate time, and T(t), proper time as a function of coordinate time, for each observer (expressed using the inertial frame where A and B are at rest, and C and D are moving at 0.8c), and then tell me if you agree or disagree with the following two statements: For A: x(t) = 25, T(t) = t For B: x(t) = 0, T(t) = t For C: x(t) = 0.8c * t, T(t) = 0.6*t For D: x(t) = [0.8c * t] + 9, T(t) = 0.6*t - 12 --given the x(t) functions for B and C, we can see that they both pass through the point in spacetime with coordinates x=0, t=0. Given their T(t) functions, we can see that B has a proper time T=0 at those coordinates, and C also has a proper time T=0 at those coordinates. Therefore, by ASSUMPTION 1 above, the event of B's proper time clock reading T=0 is simultaneous in p-time with the event of C's proper time clock reading T=0. Agree or disagree? --given the x(t) functions for A and D, we can see that they both pass through the point in spacetime with coordinates x=25, t=20. Given their T(t) functions, we can see that A has a proper time T=20 at those coordinates, and D has a proper time T=0 at those coordinates. Therefore, by ASSUMPTION 1 above, the event of A's proper time clock reading T=20 is simultaneous in p-time with the event of D's proper time clock reading T=0. Agree or disagree? Another little correction--in the last two paragraphs there, where I said Therefore, by ASSUMPTION 1 above, I should have written ASSUMPTION 2, since in both cases I was deriving p-time simultaneity from the fact that two clock readings happened at the same point in spacetime. Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, Here's another point for you to ponder: You claim that all frame views are equally valid. What would you say the weighted mean of all frame views is? I would suspect that it converges towards my solution. It is clear from your own analysis that it does converge to my solution as separation and relative motion diminishes, so I strongly suspect it converges towards my solution in all cases. Correct? And if so I would argue that this also tends to validate my solution as the actual correct 1:1 correlation of proper ages, even though I agree completely that all observers cannot direct observe this correlation... In fact this is tantalizingly similar to the notion of a wavefunction representing the probabilities of all possible locations of a particle. If we take all possible frame views as a continuous 'wavefunction' of the actual age correlation can we begin to assign probabilities based on their weighted mean, and if so isn't that going to be my solution? Edgar On Tuesday, March 4, 2014 8:03:57 PM UTC-5, jessem wrote: On Tue, Mar 4, 2014 at 5:45 PM, Jesse Mazer laser...@gmail.comjavascript: wrote: div ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On Wed, Mar 5, 2014 at 8:19 AM, Edgar L. Owen edgaro...@att.net wrote: Jesse, First I see no conclusion that demonstrates INtransitivity here or any contradiction that I asked for. Did I miss that? No, I was just asking if you agreed with those two steps, which show that different pairs of readings are simultaneous using ASSUMPTION 2. If you agreed with those, I would show that several further pairs of readings must also be judged simultaneous in p-time using ASSUMPTION 1, and then all these individual simultaneity judgments would together lead to a contradiction via the transitivity assumption, ASSUMPTION 3. I already laid this out in the original Alice/Bob/Arlene/Bart post, but since you apparently didn't understand that post I wanted to go over everything more carefully with the exact x(t) and T(t) functions given, and every point about simultaneity stated more carefully. I thought you would be more likely to answer if I just gave you two statements to look over and verify rather than a large collection of them, but if you are going to stubbornly refuse to answer the opening questions until I lay out the whole argument, here it is in full: ASSUMPTION 1. If two observers are at rest in the same inertial frame, then events on their worldlines that are simultaneous in their rest frame are also simultaneous in p-time ASSUMPTION 2. If two observers cross paths at a single point in spacetime P, and observer #1's proper time at P is T1 while observer #2's proper time at P is T2, then the event of observer #1's clock showing T1 is simultaneous in p-time with the event of observer #2's clock showing T2. ASSUMPTION 3. p-time simultaneity is transitive Please have another look at the specific numbers I gave for x(t), coordinate position as a function of coordinate time, and T(t), proper time as a function of coordinate time, for each observer (expressed using the inertial frame where A and B are at rest, and C and D are moving at 0.8c), and then tell me if you agree or disagree with the following two statements: For A: x(t) = 25, T(t) = t For B: x(t) = 0, T(t) = t For C: x(t) = 0.8c * t, T(t) = 0.6*t For D: x(t) = [0.8c * t] + 9, T(t) = 0.6*t - 12 STATEMENT 1. Given the x(t) functions for B and C, we can see that they both pass through the point in spacetime with coordinates x=0, t=0. Given their T(t) functions, we can see that B has a proper time T=0 at those coordinates, and C also has a proper time T=0 at those coordinates. Therefore, by ASSUMPTION 2 above, the event of B's proper time clock reading T=0 is simultaneous in p-time with the event of C's proper time clock reading T=0. Agree or disagree? STATEMENT 2. Given the x(t) functions for A and D, we can see that they both pass through the point in spacetime with coordinates x=25, t=20. Given their T(t) functions, we can see that A has a proper time T=20 at those coordinates, and D has a proper time T=0 at those coordinates. Therefore, by ASSUMPTION 2 above, the event of A's proper time clock reading T=20 is simultaneous in p-time with the event of D's proper time clock reading T=0. Agree or disagree? STATEMENT 3. At t=0 in this frame, both A and B have a proper time of T=0; these readings are simultaneous in this frame. Since A and B are both at rest in this frame, by ASSUMPTION 1 above, the event of A's proper time clock reading T=0 is simultaneous in p-time with the event of B's proper time clock reading T=0. Agree or disagree? STATEMENT 4. C's worldline passes through the point x=0, t=0, and at this point C's proper time clock reads T=0. D's worldline passes through the point x=25, t=20, and at this point D's proper time clock reads T=0. These events are not simultaneous in this frame, but using the Lorentz transformation we can see that they ARE simultaneous in the frame where C and D are at rest. Therefore, by ASSUMPTION 1 above, the event of C's proper time clock reading T=0 is simultaneous in p-time with the event of D's proper time clock reading T=0. Agree or disagree? Note: This statement is perhaps the subtlest if you aren't too familiar with the math of SR--in case you didn't know, the Lorentz transformation is used when we know the coordinates x,t of an event in one inertial frame, and we want to find the coordinates x',t' of the SAME event in a second inertial frame which is moving at speed v relative to the first (a good intro to various aspects of SR including the Lorentz transform can be found at http://en.wikibooks.org/wiki/Special_Relativity ). Assuming that the spatial origins of the two frames coincide when t=0 in the first frame and t'=0 in the second, and assuming that the first frame subsequently sees the origin of the second frame moving at speed v along the first frame's x-axis, the transformation equations are: x' = gamma*(x - v*t) t' = gamma*(t - (v*x)/c^2 ) Where gamma is the commonly-used relativistic factor 1/sqrt(1 - (v/c)^2). So with v=0.8c in this example, gamma works out to 1/sqrt(1 - 0.64) =
Re: Block Universes
On Wed, Mar 5, 2014 at 8:38 AM, Edgar L. Owen edgaro...@att.net wrote: Jesse, Here's another point for you to ponder: You claim that all frame views are equally valid. What would you say the weighted mean of all frame views is? Weighted how? I can't see any weighing that doesn't itself depend on privileging one frame over others. For example, suppose I label frames using velocity relative to my rest frame, and use a uniform distribution on velocity values as my weight function, which implies that the collection of frames with velocities between 0.1c and 0.1c + dV will have the same total weight as the collection of frames with velocities between 0.9c and 0.9c + dV, since these are equal-sized velocity intervals (for example, if dV=0.05c then we are looking at the frames from 0.1c to 0.15c, and the frames from 0.9c to 0.95c). But if we look at all the frames in these two intervals, and translate from their velocities relative to ME to their velocities relative to another frame B that is moving at say 0.8c relative to me, then these two bunches of frames do NOT occupy equal-sized velocity intervals when we look at their velocities relative to frame B (an interval from 0.1c to 0.15c in my frame translates to the interval from -0.761c to -0.739c in B's frame, while an interval of 0.9c to 0.95c in my frame translates to an interval from 0.357c to 0.625c in B's frame). So if we weigh them equally using MY velocity labels, that would translate to an unequal weighing relative to B's velocity labels, so we are privileging my frame's definitions over the definitions of other frames like B. I would suspect that it converges towards my solution. It is clear from your own analysis that it does converge to my solution as separation and relative motion diminishes, so I strongly suspect it converges towards my solution in all cases. Correct? And if so I would argue that this also tends to validate my solution as the actual correct 1:1 correlation of proper ages, even though I agree completely that all observers cannot direct observe this correlation... In fact this is tantalizingly similar to the notion of a wavefunction representing the probabilities of all possible locations of a particle. If we take all possible frame views as a continuous 'wavefunction' of the actual age correlation can we begin to assign probabilities based on their weighted mean, and if so isn't that going to be my solution? This doesn't really help your case unless you can find a weight function for the continuous infinity of different possible frames that doesn't itself privilege one frame's definitions from the start. Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, Yes, you are right. I phrased it incorrectly. What I meant to say was not that each individual view was somehow weighted, but that all views considered together would tend to cluster around my results for any distance and motion difference pairs. In other words there would be a lot more views that were close to my solution, than views that were far from my solution. And that we can see this because, as you yourself pointed out, as distance separation and relative motion differences decrease all other frame views DO tend to converge on my results. Thus the aggregate WEIGHT OF ALL VIEWS tends to converge on my solution, which is what I meant to say. Sort of like a Bell curve distribution with a point at top representing my solution Would you agree to that? Edgar On Wednesday, March 5, 2014 11:00:19 AM UTC-5, jessem wrote: On Wed, Mar 5, 2014 at 8:38 AM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, Here's another point for you to ponder: You claim that all frame views are equally valid. What would you say the weighted mean of all frame views is? Weighted how? I can't see any weighing that doesn't itself depend on privileging one frame over others. For example, suppose I label frames using velocity relative to my rest frame, and use a uniform distribution on velocity values as my weight function, which implies that the collection of frames with velocities between 0.1c and 0.1c + dV will have the same total weight as the collection of frames with velocities between 0.9c and 0.9c + dV, since these are equal-sized velocity intervals (for example, if dV=0.05c then we are looking at the frames from 0.1c to 0.15c, and the frames from 0.9c to 0.95c). But if we look at all the frames in these two intervals, and translate from their velocities relative to ME to their velocities relative to another frame B that is moving at say 0.8c relative to me, then these two bunches of frames do NOT occupy equal-sized velocity intervals when we look at their velocities relative to frame B (an interval from 0.1c to 0.15c in my frame translates to the interval from -0.761c to -0.739c in B's frame, while an interval of 0.9c to 0.95c in my frame translates to an interval from 0.357c to 0.625c in B's frame). So if we weigh them equally using MY velocity labels, that would translate to an unequal weighing relative to B's velocity labels, so we are privileging my frame's definitions over the definitions of other frames like B. I would suspect that it converges towards my solution. It is clear from your own analysis that it does converge to my solution as separation and relative motion diminishes, so I strongly suspect it converges towards my solution in all cases. Correct? And if so I would argue that this also tends to validate my solution as the actual correct 1:1 correlation of proper ages, even though I agree completely that all observers cannot direct observe this correlation... In fact this is tantalizingly similar to the notion of a wavefunction representing the probabilities of all possible locations of a particle. If we take all possible frame views as a continuous 'wavefunction' of the actual age correlation can we begin to assign probabilities based on their weighted mean, and if so isn't that going to be my solution? This doesn't really help your case unless you can find a weight function for the continuous infinity of different possible frames that doesn't itself privilege one frame's definitions from the start. Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On Wed, Mar 5, 2014 at 1:27 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, Yes, you are right. I phrased it incorrectly. What I meant to say was not that each individual view was somehow weighted, but that all views considered together would tend to cluster around my results for any distance and motion difference pairs. Too vague. What does all views considered together mean mathematically, if not a weighted average using some specific weighting function? In other words there would be a lot more views that were close to my solution, than views that were far from my solution. How do you count more when there are a continuous infinity of frame's views? The only way to count different subsets of an infinite set is using some sort of measure function (see https://en.wikipedia.org/wiki/Measure_(mathematics) ), which is equivalent to a weighting function--whatever you choose to call it, the idea would be that if you want to compare the number or weight of frames with velocity between v1 and v2 (the velocities defined relative to some other specific frame, of course) vs. the number or weight with velocity between v3 and v4, you use a measure/weight function W(v) which gives a value for every specific frame velocity v, and you integrate the function W(v) from v1 to v2, and compare the result to integrating W(v) between v3 and v4 (and if you want to do a weighted average of some specific quantity Q(v) that varies from one frame to another, like the amount by which two clocks are out-of-sync, you would integrate Q(v)*W(v) over the frame velocity interval over which you want the weighted average of Q). And that we can see this because, as you yourself pointed out, as distance separation and relative motion differences decrease all other frame views DO tend to converge on my results. Thus the aggregate WEIGHT OF ALL VIEWS tends to converge on my solution, which is what I meant to say. Sort of like a Bell curve distribution with a point at top representing my solution Would you agree to that? In the case of two clocks at rest and synchronized in a common frame, the only convergence I think we agree on is if you consider a series of cases where the distance between the two clocks approaches 0, or where the velocity of the frame whose opinion you're considering relative to the rest frame of the two clocks approaches 0 (which may be what you meant by as distance separation and relative motion differences decrease all other frame views DO tend to converge on my results). If you are talking about a FIXED value for the distance between two clocks in their rest frame, and doing a weighted average of larger and larger sets of different frame's opinions about the time difference between the two clocks (eventually including frames with a very large velocity relative to the clocks), then what value this average would converge to would depend entirely on the weighting function. As I said a weighting function that looks uniform in one frame (equal velocity intervals have equal weight when you integrate over the integral) will look non-uniform in other frames, so I can't see a way to define a weighting function that doesn't privilege one frame at the outset. Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, Yes, but respectfully, what I'm saying is that your example doesn't represent my method OR results. In your example of A and B separated but moving at the same velocity and direction, and C and D separated but moving at the same velocity and direction, BUT the two PAIRS moving at different velocities, AND where B and C happen to pass each other at the same point in spacetime here is my result. Assuming the acceleration/gravitation histories of A and B are the same and they are twins; AND the acceleration/gravitation histories of C and D are the same and they are twins, then A(t1)=B(t1)=C(t2)=D(t2) which is clearly transitive between all 4 parties. We don't know what t1 and t2 are because you haven't specified their acceleration histories or birth dates, but whatever they are the equation above will hold. The problem is that your careful analysis simply DOES NOT use MY method which depends on the actual real physical causes (acceleration histories) to deternine 1:1 age correlations between any two observers. It uses YOUR method to prove the standard lack of simultaneity between VIEWS of pairs of actual physical events. This is a WELL KNOWN result of relativity WITH WHICH I AGREE! But for the nth time, my method concentrates on the ACTUAL RELATIONSHIP, rather than VIEWS of that actual relationship. This is a simple, well accepted logical distinction which most certainly applies here to the ACTUAL age correlations of people.. If a man and a wife love each other that is a real actual physical relationship. The fact that someone else thinks they don't love each other may well be his real VIEW, but it does NOT change or affect the ACTUAL love between the man and his wife. No matter how many times I state this it doesn't seem to sink in Edgar On Wednesday, March 5, 2014 10:36:10 AM UTC-5, jessem wrote: On Wed, Mar 5, 2014 at 8:19 AM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, First I see no conclusion that demonstrates INtransitivity here or any contradiction that I asked for. Did I miss that? No, I was just asking if you agreed with those two steps, which show that different pairs of readings are simultaneous using ASSUMPTION 2. If you agreed with those, I would show that several further pairs of readings must also be judged simultaneous in p-time using ASSUMPTION 1, and then all these individual simultaneity judgments would together lead to a contradiction via the transitivity assumption, ASSUMPTION 3. I already laid this out in the original Alice/Bob/Arlene/Bart post, but since you apparently didn't understand that post I wanted to go over everything more carefully with the exact x(t) and T(t) functions given, and every point about simultaneity stated more carefully. I thought you would be more likely to answer if I just gave you two statements to look over and verify rather than a large collection of them, but if you are going to stubbornly refuse to answer the opening questions until I lay out the whole argument, here it is in full:/d ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, Yes, the views are infinite on several axes, but that can be addressed simply by enumerating views at standard intervals on those axes. Or you could equally integrate over the continuous functions. Considered together simply means you plot the correlation each frame view (at the standard intervals as above) gives and see how they cluster. Which I'm pretty sure will be around my result. You don't need to view the resulting graph from any frame as you seem to suggest, because the graph is OF the actual all frame view results. For every frame you simply calculate the apparent lack of simultaneity between two events Nonsiimultaneity=(t1-t2) and plot it relative to the simultaneity that my method claims is actual. Edgar On Wednesday, March 5, 2014 2:13:24 PM UTC-5, jessem wrote: On Wed, Mar 5, 2014 at 1:27 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, Yes, you are right. I phrased it incorrectly. What I meant to say was not that each individual view was somehow weighted, but that all views considered together would tend to cluster around m ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, PS: It is well known that accelerations and gravitation are the ONLY causes that produce real actual age rate changes. These real actual age rate changes are real and actual because 1. ALL OBSERVERS AGREE on them when they meet up and check them, and 2.BECAUSE THEY ARE PERMANENT. Relativity agrees on this when the parties MEET. All my method does is to give a method to calculate these real actual changes BEFORE they meet, when the parties are still separated or in relative motion or acceleration or gravitation. This is incredibly simple to understand if you can just escape the notion that all VIEWS of an age relationship are somehow the same as the ACTUAL relationship itself. The views DO differ and these VIEWS ARE VALID VIEWS, but they don't affect the actual RELATIONSHIP THEY ARE VIEWING which is what my method calculates. Again, this is a difference in INTERPRETATIONS of relativity. It does NOT contradict the equations of relativity itself. It simply uses the one that describes the actual relationship rather than ones that describe VIEWS of that relationship. Aren't you at least able to understand what I'm saying even if you don't agree with it? I see no evidence you are even able to do that Edgar On Wednesday, March 5, 2014 2:13:24 PM UTC-5, jessem wrote: On Wed, Mar 5, 2014 at 1:27 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, Yes, you are right. I phrased it incorrectly. What I meant to say was not that each individual view was somehow weighted, but that all views considered together would tend to cluster around m ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On 6 March 2014 09:12, Edgar L. Owen edgaro...@att.net wrote: Jesse, PS: It is well known that accelerations and gravitation are the ONLY causes that produce real actual age rate changes. These real actual age rate changes are real and actual because 1. ALL OBSERVERS AGREE on them when they meet up and check them, and 2.BECAUSE THEY ARE PERMANENT. Having your worldlines be different lengths in spacetime will also cause differences in actual age, as Brent has explained (with diagrams). Consistently ignoring this point and others like it is one reason most people here consider you a troll, so please try to address it. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On Wed, Mar 5, 2014 at 2:42 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, Yes, but respectfully, what I'm saying is that your example doesn't represent my method OR results. In your example of A and B separated but moving at the same velocity and direction, and C and D separated but moving at the same velocity and direction, BUT the two PAIRS moving at different velocities, AND where B and C happen to pass each other at the same point in spacetime here is my result. Assuming the acceleration/gravitation histories of A and B are the same and they are twins; AND the acceleration/gravitation histories of C and D are the same and they are twins, then A(t1)=B(t1)=C(t2)=D(t2) which is clearly transitive between all 4 parties. You earlier agreed that if two observers are at rest relative to each other, then if they synchronize clocks in their rest frame, their clocks will also be synchronized in p-time from then on. In your post at http://www.mail-archive.com/everything-list%40googlegroups.com/msg48404.htmlyou responded to one of my questions in this way: 'Yes is the answer to your question if two clocks are at rest relative to one another and synchronized according to the definition of simultaneity in their mutual rest frame, do you automatically assume this implies they are synchronized in p-time? ' You didn't say anything about their ages having to be equal, or about their needing to have had identical acceleration histories before this. For example, if I and some stranger named Jimbo are at rest relative to each other in an inertial frame in flat SR spacetime (no gravity), and in this frame my 37th birthday is simultaneous with Jimbo's 20th birthday, then if I set my clock to T=0 on my 37th birthday and he sets his clock to T=0 on his 20th birthday, isn't this sufficient to demonstrate that our clocks will be synchronized in p-time from then on (provided we both remain at rest in this frame), regardless of how either of us may have accelerated *before* we came to rest in this frame? (assuming of course that I came to rest before my 37th birthday, and Jimbo came to rest before his 20th) Even if you somehow don't agree with this, I can easily fill in some details about the past history of my example to give A/B and C/D symmetrical accelerations, if you wish--see below. We don't know what t1 and t2 are because you haven't specified their acceleration histories or birth dates, but whatever they are the equation above will hold. OK, I don't think it should be necessary to specify acceleration histories or ages if you agree with my statement about me and Jimbo above, but if you disagree with that statement I can give details about each pair's past history, though it makes the example a bit more complicated. Say that in the frame F where A and B are at rest during the period I described, A and B were originally at rest at position x=12.5, with both having the same ages, and let's say that their proper time clocks have been set to read T = -18 years at the moment they were born (it is the custom in their society to have their proper time clock tell how far from voting age they are, so for example when they turn 15 their clock reads T=-3, when they turn 28 their clock reads T=10, etc.). Then each of them simultaneously began to accelerate in opposite directions with a fixed proper acceleration of 1 light year/year^2, and after each had traveled a distance of 6.25 light years from their starting position in this frame, they began to decelerate (i.e. turn their rockets around and accelerate in the opposite direction, lowering their speed in this frame) at the same proper acceleration of 1 light year/year^2. After they each had traveled another 6.25 light years and come to rest in this frame, they stopped decelerating and simply remained at rest. Each of them will have then traveled a distance of 12.5 light years from their original starting position of x=12.5 light years, with A at position x=25 light years, and B at position x=0 light years. Hopefully you agree that because their accelerations are completely symmetrical in the frame where they were originally at rest with the same ages, in this frame identical ages will still be simultaneous after they finish the acceleration/deceleration phase and come to rest. So, let's just say that they come to rest simultaneously at t=-12 in this frame, and at this moment their clocks both read T=-12, meaning they are both turning 6 at the moment they stop accelerating. After this, their x(t) and T(t) functions are just as I described. As for C and D, let's switch over to the frame F' where THEY are at rest during the period I describe, whose coordinates I had previously labeled as x' and t' (and given the Lorentz transformation equations for converting from x,t to x',t'). Say that in frame F', they were both originally at rest at position x'=7.5, again with both having the same ages, and both having their proper time clocks read a time of T
Re: Block Universes
On Wed, Mar 5, 2014 at 2:52 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, Yes, the views are infinite on several axes, but that can be addressed simply by enumerating views at standard intervals on those axes. But velocity intervals which are equal when the velocities are defined relative to one frame are not equal when the velocities are defined relative to a different frame. I already mentioned an example where if a frame 1 has velocity v=0.1c relative to me and another frame 2 has velocity v=0.15c relative to me, then the interval between them is 0.05c from my perspective, and likewise if a frame 3 has velocity v=0.9c relative to me and another frame 4 has velocity v=0.95c relative to me, then they have the same interval of 0.05c from my perspective; but for another observer moving at v=0.8c relative to me, frame 1 has a velocity of -0.761c and frame 2 has a velocity of -0.739c (so the interval between 1 and 2 is 0.022 for this observer), whereas frame 3 has a velocity of 0.357c and frame 4 has a velocity of 0.625c (so the interval between 3 and 4 is 0.268c for this observer, more than ten times larger than the interval between 1 and 2). These velocities are calculated using the relativistic velocity formula at http://math.ucr.edu/home/baez/physics/Relativity/SR/velocity.html where u = -0.8c is my velocity relative to the second observer, and v is the velocity of any given frame 1,2,3, or 4 relative to me. Point is, if your intervals are equal relative to one frame but unequal relative to all other frames, then you are privileging a particular frame's perspective from the start. Or you could equally integrate over the continuous functions. As I said, the only way to do this is to use some sort of weight/measure function, and a weight/measure function which is uniform when plotted against velocity in one frame will be non-uniform when plotted against velocity in other frames, so there doesn't seem to be a way of picking such a function that doesn't privilege one frame from the start. Considered together simply means you plot the correlation each frame view (at the standard intervals as above) gives and see how they cluster. Which I'm pretty sure will be around my result. The will cluster around the judgment of whatever frame you choose to privilege from the start, either by your definition of equal intervals or by your weighting/measure function. So, using this to conclude anything about the actual correlation would just be another piece of circular reasoning. Jesse You don't need to view the resulting graph from any frame as you seem to suggest, because the graph is OF the actual all frame view results. For every frame you simply calculate the apparent lack of simultaneity between two events Nonsiimultaneity=(t1-t2) and plot it relative to the simultaneity that my method claims is actual. Edgar On Wednesday, March 5, 2014 2:13:24 PM UTC-5, jessem wrote: On Wed, Mar 5, 2014 at 1:27 PM, Edgar L. Owen edga...@att.net wrote: Jesse, Yes, you are right. I phrased it incorrectly. What I meant to say was not that each individual view was somehow weighted, but that all views considered together would tend to cluster around m ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
If you have a continuum of inertial frames with velocities ranging from +c to -c in all possible directions, how are you going to integrate over them? Isn't there a measure problem over an uncountably infinite set? -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On Wed, Mar 5, 2014 at 3:12 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, PS: It is well known that accelerations and gravitation are the ONLY causes that produce real actual age rate changes. These real actual age rate changes are real and actual because 1. ALL OBSERVERS AGREE on them when they meet up and check them, and 2.BECAUSE THEY ARE PERMANENT. No, they produce real actual differences in TOTAL ELAPSED PROPER TIME BETWEEN MEETINGS, which all frames agree on. This tells us nothing about the moment-by-moment rates of each clock between meetings, unless you are simply talking about the AVERAGE ticking rate between meetings (and all frames do agree on the ratio between two clock's AVERAGE ticking rate between meetings, since the average ticking rate for clock #1 between meetings in any frame is [proper time elapsed on #1 between meetings / coordinate time between meetings] and the average ticking rate for clock #2 is [proper time elapsed on #2 between meetings / coordinate time between meetings], thus the ratio of the two averages is [proper time elapsed on #1 between meetings / proper time elapsed on #2 between meetings] which all frames will agree on). Relativity agrees on this when the parties MEET. All my method does is to give a method to calculate these real actual changes BEFORE they meet, when the parties are still separated or in relative motion or acceleration or gravitation. It gives a method which is based on simply ASSUMING FROM THE START that the clock rates behave a certain way between the meetings, without ever deriving or demonstrating this from more basic premises. Even a fellow presentist could easily disagree with your assumptions, and you would have no ARGUMENT for convincing him that your assumptions are correct, using starting premises that you both could agree on. And as always, my example with two pairs of twins demonstrates that your methods lead to a direct contradiction where two different ages of A have to labeled simultaneous in p-time--if you disagree, the only intellectually honest way to show I'm wrong is to go through my numbered STATEMENTs about p-time simultaneity, and tell me which is the first that is not a valid inference using your method. This is incredibly simple to understand if you can just escape the notion that all VIEWS of an age relationship are somehow the same as the ACTUAL relationship itself. The views DO differ and these VIEWS ARE VALID VIEWS, but they don't affect the actual RELATIONSHIP THEY ARE VIEWING which is what my method calculates. Again, this is a difference in INTERPRETATIONS of relativity. It does NOT contradict the equations of relativity itself. It simply uses the one that describes the actual relationship rather than ones that describe VIEWS of that relationship. Aren't you at least able to understand what I'm saying even if you don't agree with it? I see no evidence you are even able to do that I understand that your method gives a way of deciding which events are simultaneous in p-time in your theory, it just that: a) I don't think you have any argument for the validity of your method that doesn't simply assume p-time simultaneity works the way you want it to from the start, something that even another presentist who believes in absolute simultaneity could reasonably disagree with b) I think your method can be used to derive a contradiction, even though you don't understand that yet and seem to be refusing to engage with the nitty-gritty details of my example. Jesse On Wednesday, March 5, 2014 2:13:24 PM UTC-5, jessem wrote: On Wed, Mar 5, 2014 at 1:27 PM, Edgar L. Owen edga...@att.net wrote: Jesse, Yes, you are right. I phrased it incorrectly. What I meant to say was not that each individual view was somehow weighted, but that all views considered together would tend to cluster around m ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On Wed, Mar 5, 2014 at 4:47 PM, LizR lizj...@gmail.com wrote: If you have a continuum of inertial frames with velocities ranging from +c to -c in all possible directions, how are you going to integrate over them? Isn't there a measure problem over an uncountably infinite set? There's no inherent problem with defining measures on uncountably infinite sets--for example, a bell curve is a continuous probability measure defined over the infinite real number line from -infinity to +infinity, which can be integrated over any specific range to define a probability that a result will fall in that range. But as I've said, the problem is that although you can define a measure over all frames in relativity, if it looks like a uniform distribution when you state the velocity of each frame relative to a particular reference frame A, then it will be a non-uniform distribution when you state the velocity of each frame relative to a different reference frame B, so any such measure will be privileging one frame from the start. Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On 6 March 2014 11:01, Jesse Mazer laserma...@gmail.com wrote: On Wed, Mar 5, 2014 at 4:47 PM, LizR lizj...@gmail.com wrote: If you have a continuum of inertial frames with velocities ranging from +c to -c in all possible directions, how are you going to integrate over them? Isn't there a measure problem over an uncountably infinite set? There's no inherent problem with defining measures on uncountably infinite sets--for example, a bell curve is a continuous probability measure defined over the infinite real number line from -infinity to +infinity, which can be integrated over any specific range to define a probability that a result will fall in that range. But as I've said, the problem is that although you can define a measure over all frames in relativity, if it looks like a uniform distribution when you state the velocity of each frame relative to a particular reference frame A, then it will be a non-uniform distribution when you state the velocity of each frame relative to a different reference frame B, so any such measure will be privileging one frame from the start. Ah, yes, I know you can integrate some continuous function from + to - infinity, but I was assuming that cases like Bell curves were privileging one particular point (e.g. starting from or centred on 0) - but I guess I got that wrong. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, I'm interested in finding the truth, not in assigning blame. The important thing is we both now agree that there IS ALWAYS A CORRELATION OF ACTUAL AGES between any two observers. The difference is I think it's an EXACT correlation, and you think that it's ALMOST EXACT except for cases of extreme separation or motion. I think we have to analyze the age correlation from a POV that preserves the actual relationship of the accelerations that are the ONLY cause of age rate differences. Whereas you think we have to consider all possible views irrespective of whether they properly preserve the relationship of causes of age rate differences. My method provides an EXACT correlation. Your method provides an ALMOST EXACT correlation in all but extreme cases. Also now that I have pointed out the error in your Alice, Bob, Arlene, Bart example do you agree my method does produce consistent, unambiguous and transitive 1:1 correlations of proper ages among all observers? To address your new questions: Do you deny acceleration and gravitation produce real actual slowings of clock rates and thus of real actual aging rates? Of course we can VIEW these slowings differently from different frames, but the ACTUAL effects they produce on the observer who experiences them are exact. It is these exact actual effects that my method explains, and yours doesn't. We know these effects are real and actual when twins meet up with different ages. Thus we know they were ALSO REAL AND ACTUAL BEFORE the twins met. That is pure simple logic. How many times do I have to explain. The twins exchange flight plans for EXACT SAME ACCLERATIONS AT THE EXACT SAME TIMES before they part. This ABSOLUTELY ENSURES that their age rates will slow EXACTLY THE SAME during their trip. There is no way around that. Another observer can VIEW that differently but from the POV of the twins themselves it IS EXACT AND ABSOLUTE. Thus it is clear to anyone that to properly analyze the REAL ACTUAL CORRELATION OF THE TWINS' AGES WE MUST PRESERVE THE REAL ACTUAL RELATIONSHIP OF THE ACCELERATIONS THAT ARE THE ONLY CAUSE OF AGE RATE CHANGES. Jeez, how difficult is that to understand? And your different frame to exchange flight plans in is an oxymoron because it would make their actual symmetric flight plans appear to be NON symmetric. Only a pair of idiots would do that You are just endlessly repeating what you read in some relativity textbook without using simple logic to determine its proper application Edgar On Monday, March 3, 2014 5:51:25 PM UTC-5, jessem wrote: On Mon, Mar 3, 2014 at 3:45 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, No, it was you that said there was NO correlation. Jeez Edgar, you really need to work on your reading comprehension. I just got through AGREEING that I had said that there wasn't a correlation, but I explained that this was because I was using correlation in the way YOU had consistently been using it up until now, to refer to a 1:1 correlation in which each proper age of a twin is matched up to one unique proper age of the other twin. The archive at http://www.mail-archive.com/everything-list@googlegroups.com/ has a better search function than google's archive (returning individual posts rather than threads), so I searched for posts from Edgar L. Owen with correlate or correlation in them, results here: http://www.mail-archive.com/search?a=1l=everything-list%40googlegroups.comhaswords=correlatefrom=Edgar+L.+Owennotwords=subject=datewithin=1ddate=order=datenewestsearch=Search http://www.mail-archive.com/search?a=1l=everything-list%40googlegroups.comhaswords=correlationfrom=Edgar+L.+Owennotwords=subject=datewithin=1ddate=order=datenewestsearch=Search Earliest posts on the block time thread I could find in these searches (that were directed at me, and not some other poster) were these from Feb. 12 and 13 (shown in order below), where you can see from the quotes that you were talking specifically about 1:1 correlations that map clock times of one to specific clock times of the other: http://www.mail-archive.com/everything-list%40googlegroups.com/msg48613.html So all observers are always in the same p-time moment. Now it's just a matter of correlating their clock times to see which clock times occurred in any particular current moment of p-time. http://www.mail-archive.com/everything-list%40googlegroups.com/msg48716.html Do you see how this mutual agreed on understanding of how each's clock time varies in the other's frame always allows each to correlate their own comoving clock time with the comoving (own) clock time of the other? In other words for A to always know what B's clock time was reading when A's clock time was reading t, and for B to always know what A's clock time was reading when B's clock time was reading t'?
Re: Block Universes
On Tue, Mar 4, 2014 at 12:19 PM, Jesse Mazer laserma...@gmail.com wrote: So you are just going to COMPLETELY IGNORE my response, which pointed out that your supposed error relied on using the ambiguous phrase B's and C's proper ages are simultaneous in p-time because they are at the same place in spacetime to describe my views, and interpreting it in a way that I would never had agreed with? Again, this phrase could be interpreted two possible ways: 1. If B's proper age at this point in spacetime in T, then C's proper age at this point in spacetime must be T as well (i.e. their proper ages are simultaneous in the sense that they must reach the same age simultaneously). 2. If B and C's worldlines both pass through a specific point in spacetime P, and B's age is T1 when she passes through P, while C's age is T2 when she passes through P, then B must be at age T1 simultaneously with C being at age T2 (i.e. whatever two specific ages they have at P, they must reach those two ages simultaneously, even if the two ages are different) Minor typo in #1 there, it should read If B's proper age at this point in spacetime is T, not in T. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, You ask me to choose between 1. and 2. 1. If B's proper age at this point in spacetime is T, then C's proper age at this point in spacetime must be T as well (i.e. their proper ages are simultaneous in the sense that they must reach the same age simultaneously). 2. If B and C's worldlines both pass through a specific point in spacetime P, and B's age is T1 when she passes through P, while C's age is T2 when she passes through P, then B must be at age T1 simultaneously with C being at age T2 (i.e. whatever two specific ages they have at P, they must reach those two ages simultaneously, even if the two ages are different) First I assume that by passing through the same point in spacetime you mean that the worldlines cross at P simultaneously by the operational definition of no light delay. 1. is true only in a SYMMETRIC case. In the symmetric case they would have the same ages as they pass through the same point P, but in that case they have the same ages during the WHOLE trip so no big surprise. 2. is true in all cases. The actual ages T1 and T2 at which they simultaneously cross will stand in a 1:1 correlation, but ONLY AT THAT POINT P because their ages could be different due to acceleration differences either before or after. There are two equivalent ways they can confirm their actual 1:1 age correlations in both (all cases) when they cross paths. First they can directly observe this 1:1 correlation by simply looking at each other's clocks as they pass. Normally this is not possible if two observers have relative motion with respect to each other, but in this case there is no time delay and the looking only takes a SINGLE MOMENT OF TIME, so even though the time RATES of each other's proper clocks are dilated in each other's frames, each can still actually read the correct proper time on the other's clock as they cross. (One might initially think it is impossible to read each others' clocks correctly due to the dilation of relative motion, or even if they passed with different accelerations, but this is not true in the case where they read as they cross. Each proper clock is ALWAYS reading the actual proper age. The apparent dilation effect is just due to the longer interval it takes for signals from that clock to reach the observer. But the signals received always display the real and actual proper age of the clock WHEN the signals were sent. So in the crossing case where there is only a single signal with NO time delay the clock reading received = the actual clock reading when the signal was sent. Note that this analysis points out that all proper clocks continually show the actual proper age of the clock when the signal was sent. So that real actual age is REALLY OUT THERE. Your imaginary 1:1 correlation problem just doesn't take into proper account the transmission time from the clock to the receiver. Just subtract the transmission time and you will get the actual 1:1 age correlation between when any proper age signal was sent and what proper time it was received.) Second they CAN CONFIRM the actual age correlation in ALL cases simply by exchanging light messages as they cross telling each other their actual ages which is an equivalent method. As they cross the light signal has no appreciable delay so whatever actual age they report will correlate to the actual age the other receives the signal. In this way crossing observers CAN UNambiguously determine the 1:1 correlation of their actual ages even if they are in relative motion. With this understanding your 1. is true of symmetric cases, and 2. is true of all cases... Edgar On Tuesday, March 4, 2014 12:19:27 PM UTC-5, jessem wrote: On Tue, Mar 4, 2014 at 8:37 AM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, I'm interested in finding the truth, not in assigning blame. The important thing is we both now agree that there IS ALWAYS A CORRELATION OF ACTUAL AGES between any two observers. The difference is I think it's an EXACT correlation, and you think that it's ALMOST EXACT except for cases of extreme separation or motion. I think we have to analyze the age correlation from a POV that preserves the actual relationship of the accelerations that are the ONLY cause of age rate differences. Whereas you think we have to consider all possible views irrespective of whether they properly preserve the relationship of causes of age rate differences. My method provides an EXACT correlation. Your method provides an ALMOST EXACT correlation in all but extreme cases. Also now that I have pointed out the error in your Alice, Bob, Arlene, Bart example do you agree my method does produce consistent, unambiguous and transitive 1:1 correlations of proper ages among all observers? So you are just going to COMPLETELY IGNORE my response, which pointed out that your supposed error relied on using the ambiguous phrase B's and C's proper ages are
Re: Block Universes
On 3/4/2014 11:19 AM, Jesse Mazer wrote: On Tue, Mar 4, 2014 at 2:02 PM, Edgar L. Owen edgaro...@att.net mailto:edgaro...@att.net wrote: Jesse, You ask me to choose between 1. and 2. 1. If B's proper age at this point in spacetime is T, then C's proper age at this point in spacetime must be T as well (i.e. their proper ages are simultaneous in the sense that they must reach the same age simultaneously). 2. If B and C's worldlines both pass through a specific point in spacetime P, and B's age is T1 when she passes through P, while C's age is T2 when she passes through P, then B must be at age T1 simultaneously with C being at age T2 (i.e. whatever two specific ages they have at P, they must reach those two ages simultaneously, even if the two ages are different) First I assume that by passing through the same point in spacetime you mean that the worldlines cross at P simultaneously by the operational definition of no light delay. 1. is true only in a SYMMETRIC case. In the symmetric case they would have the same ages as they pass through the same point P, but in that case they have the same ages during the WHOLE trip so no big surprise. This isn't true. In the inertial frame of a third party passing by, B and C age at different rates in different segments of their world lines even though those rates integrate to the same total aging between their two meetings. Brent -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, BTW, in spite of your claim it can't be done, here is another simple way for any two observers at rest with respect to each other but separated by any arbitrary distance in space to determine their 1:1 age correlation. If A and B are separated at any distance but at rest with respect to each other A sends B a light message telling B what A's current age is, and B immediately reflects that light message back to A with B's current age reading attached. Because they are at rest A knows that the actual age difference is A's CURRENT age - B's REPORTED age + 1/2 delta c (half the light signal's round trip time). In this way A determines a unique 1:1 age correlation between his and B's age that will hold for as long as they are at rest. B can use the same method to determine his 1:1 age correlation with A. A and B do NOT have to synchronize the signals to do this. This gives both A and B their single correct 1:1 age correlation at any distance which holds so long as they are at rest with respect to each other. Of course other observers may see this differently but IT'S NOT THEIR AGE CORRELATION, IT'S ONLY A'S AND B'S AGE CORRELATION and A and B can determine exactly what that correlation is. Do you agree? I know you will claim it's not valid since other observers may view it differently, but frankly A and B's age correlation is NONE OF THEIR BUSINESS! I'll respond to the rest of your post later when I have more time... Edgar On Tuesday, March 4, 2014 2:19:46 PM UTC-5, jessem wrote: On Tue, Mar 4, 2014 at 2:02 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, You ask me to choose between 1. and 2. 1. If B's proper age at this point in spacetime is T, then C's proper age at this point in spacetime must be T as well (i.e. their proper ages are simultaneous in the sense that they must reach the same age simultaneously). 2. If B and C's worldlines both pass through a specific point in spacetime P, and B's age is T1 when she passes through P, while C's age is T2 when she passes through P, then B must be at age T1 simultaneously with C being at age T2 (i.e. whatever two specific ages they have at P, they must reach those two ages simultaneously, even if the two ages are different) First I assume that by passing through the same point in spacetime you mean that the worldlines cross at P simultaneously by the operational definition of no light delay. 1. is true only in a SYMMETRIC case. In the symmetric case they would have the same ages as they pass through the same point P, but in that case they have the same ages during the WHOLE trip so no big surprise. 2. is true in all cases. The actual ages T1 and T2 at which they simultaneously cross will stand in a 1:1 correlation, but ONLY AT THAT POINT P because their ages could be different due to acceleration differences either before or after. Thanks for the clear answer. So now you hopefully see that you must retract your claim that there's an error in my comments about the scenario with the two pairs of twins A/B and C/D, since I never asserted anything remotely resembling #1, my point about ages that occur at the same point in spacetime being simultaneous in p-time referred SOLELY to #2. Now, can you please address the follow-up questions that I asked you to address if you did agree with #2? I will requote them below: 'On the other hand, if you would answer no, statement #2 is not in error, I agree that in this case T1 and T2 are simultaneous in absolute terms, then please have another look at the specific numbers I gave for x(t), coordinate position as a function of coordinate time, and T(t), proper time as a function of coordinate time, for each observer, and then tell me if you agree or disagree with the following two statements: For A: x(t) = 25, T(t) = t For B: x(t) = 0, T(t) = t For C: x(t) = 0.8c * t, T(t) = 0.6*t For D: x(t) = [0.8c * t] + 9, T(t) = 0.6*t - 12 --given the x(t) functions for B and C, we can see that they both pass through the point in spacetime with coordinates x=0, t=0. Given their T(t) functions, we can see that B has a proper time T=0 at those coordinates, and C also has a proper time T=0 at those coordinates. Agree or disagree? --given the x(t) functions for A and D, we can see that they both pass through the point in spacetime with coordinates x=25, t=20. Given their T(t) functions, we can see that A has a proper time T=20 at those coordinates, and D has a proper time T=0 at those coordinates. Agree or disagree?' (if you don't understand the math of how to use x(t) to determine whether someone passed through a given point in spacetime with known x and t coordinates, or how to determine their proper time T at this point, then just ask and I will elaborate) There are two equivalent ways they can confirm their actual 1:1 age correlations in both (all cases) when they cross paths.
Re: Block Universes
On Tue, Mar 4, 2014 at 4:04 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, BTW, in spite of your claim it can't be done, here is another simple way for any two observers at rest with respect to each other but separated by any arbitrary distance in space to determine their 1:1 age correlation. If A and B are separated at any distance but at rest with respect to each other A sends B a light message telling B what A's current age is, and B immediately reflects that light message back to A with B's current age reading attached. Because they are at rest A knows that the actual age difference is A's CURRENT age - B's REPORTED age + 1/2 delta c (half the light signal's round trip time). In this way A determines a unique 1:1 age correlation between his and B's age that will hold for as long as they are at rest. B can use the same method to determine his 1:1 age correlation with A. A and B do NOT have to synchronize the signals to do this. This is a valid method for determining what ages are simultaneous in the inertial frame where they are both at rest. But there is no basis in relativity for judging this frame's views on simultaneity to be any more valid than another frame's. This gives both A and B their single correct 1:1 age correlation at any distance which holds so long as they are at rest with respect to each other. Again, you present no argument for why this is the single correct correlation, you just assert it. Of course other observers may see this differently but IT'S NOT THEIR AGE CORRELATION, IT'S ONLY A'S AND B'S AGE CORRELATION and A and B can determine exactly what that correlation is. Do you agree? No. You already agreed in an earlier post that for an inertial observer to label the frame where they are at rest as their own frame is purely a matter of HUMAN CONVENTION, not an objective reality that is forced on them by nature. So even if we ignore these other observers, there is nothing stopping A and B from using a different convention to define their own frame, such as the inertial frame where they both have a velocity of 0.99c along the x-axis. I know you will claim it's not valid since other observers may view it differently, but frankly A and B's age correlation is NONE OF THEIR BUSINESS! Again, you are conflating observers with frames, even though you earlier acknowledged that any link between particular observers and particular frames is just a matter of convention. I'll respond to the rest of your post later when I have more time... OK, thanks. Please prioritize my latest post discussing the scenario with A/B and C/D and statement #1 vs. statement #2, since it seems that your original argument for an error in my analysis was based on falsely imagining I was asserting statement #1 rather than statement #2. Since the analysis really only depends on #2 which you seem to agree with, I would like to proceed with the analysis of this scenario to see if you can find any other reason to object to any other step in the reasoning--if you can't, then presumably you will have no basis for denying the final conclusion that two different ages of the same observer A would have to be simultaneous in p-time, according to your own rules. Jesse On Tuesday, March 4, 2014 2:19:46 PM UTC-5, jessem wrote: On Tue, Mar 4, 2014 at 2:02 PM, Edgar L. Owen edga...@att.net wrote: Jesse, You ask me to choose between 1. and 2. 1. If B's proper age at this point in spacetime is T, then C's proper age at this point in spacetime must be T as well (i.e. their proper ages are simultaneous in the sense that they must reach the same age simultaneously). 2. If B and C's worldlines both pass through a specific point in spacetime P, and B's age is T1 when she passes through P, while C's age is T2 when she passes through P, then B must be at age T1 simultaneously with C being at age T2 (i.e. whatever two specific ages they have at P, they must reach those two ages simultaneously, even if the two ages are different) First I assume that by passing through the same point in spacetime you mean that the worldlines cross at P simultaneously by the operational definition of no light delay. 1. is true only in a SYMMETRIC case. In the symmetric case they would have the same ages as they pass through the same point P, but in that case they have the same ages during the WHOLE trip so no big surprise. 2. is true in all cases. The actual ages T1 and T2 at which they simultaneously cross will stand in a 1:1 correlation, but ONLY AT THAT POINT P because their ages could be different due to acceleration differences either before or after. Thanks for the clear answer. So now you hopefully see that you must retract your claim that there's an error in my comments about the scenario with the two pairs of twins A/B and C/D, since I never asserted anything remotely resembling #1, my point about ages that occur at the same point in spacetime being
Re: Block Universes
Brent, First thanks for your comment. I think Jesse and I are both aware of that, but we are considering the age relationship JUST BETWEEN A and B and so must consider only how they see it in their OWN frames, not the view of a 3rd observer of that relationship. Though Jesse would probably disagree. The current discussion is about choice of frames though. Check my latest post for a synopsis of one case.. Edgar On Tuesday, March 4, 2014 2:56:49 PM UTC-5, Brent wrote: On 3/4/2014 11:19 AM, Jesse Mazer wrote: On Tue, Mar 4, 2014 at 2:02 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, You ask me to choose between 1. and 2. 1. If B's proper age at this point in spacetime is T, then C's proper age at this point in spacetime must be T as well (i.e. their proper ages are simultaneous in the sense that they must reach the same age simultaneously). 2. If B and C's worldlines both pass through a specific point in spacetime P, and B's age is T1 when she passes through P, while C's age is T2 when she passes through P, then B must be at age T1 simultaneously with C being at age T2 (i.e. whatever two specific ages they have at P, they must reach those two ages simultaneously, even if the two ages are different) First I assume that by passing through the same point in spacetime you mean that the worldlines cross at P simultaneously by the operational definition of no light delay. 1. is true only in a SYMMETRIC case. In the symmetric case they would have the same ages as they pass through the same point P, but in that case they have the same ages during the WHOLE trip so no big surprise. This isn't true. In the inertial frame of a third party passing by, B and C age at different rates in different segments of their world lines even though those rates integrate to the same total aging between their two meetings. Brent -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, Good, we agree it's a valid method for determining 1:1 age correlations in a common inertial frame in which they are both at rest. I claim that frame is the correct one to determine the actual age correlation because it expresses the actual relation in a manner both A and B agree, is transitive among all observers, AND is the exact same method that gives the correct answer WHEN A AND B MEET and everyone, even you, agrees on the 1:1 age correlation. Our disagreement over choice of frames is spinning its wheels and not getting anywhere. It's a matter of how to INTERPRET relativity, rather than relativity itself. And I have given very convincing reasons why a privileged frame that preserves the actual physical facts that affect age changes is appropriate. You just don't agree with them. As to your example claiming to prove my method leads to a contradiction, just give me the bottom line, a simple synopsis. I don't have the time to wade through a detailed example only to find the only disagreement is over choice of frames again. On the other hand if you ASSUME privileged frames the way I do and think my method of using them leads to a contradiction that isn't just another disagreement over choice of frames that were assumed, then give me a simple example, the simplest you can come up with. Edgar On Tuesday, March 4, 2014 4:37:32 PM UTC-5, jessem wrote: On Tue, Mar 4, 2014 at 4:04 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, BTW, in spite of your claim it can't be done, here is another simple way for any two observers at rest with respect to each other but separated by any arbitrary distance in space to determine their 1:1 age correlation. If A and B are separated at any distance but at rest with respect to each other A sends B a light message telling B what A's current age is, and B immediately reflects that light message back to A with B's current age reading attached. Because they are at rest A knows that the actual age difference is A's CURRENT age - B's REPORTED age + 1/2 delta c (half the light signal's round trip time). In this way A determines a unique 1:1 age correlation between his and B's age that will hold for as long as they are at rest. B can use the same method to determine his 1:1 age correlation with A. A and B do NOT have to synchronize the signals to do this. This is a valid method for determining what ages are simultaneous in the inertial frame where they are both at rest. But there is no basis in relativity for judging this frame's views on simultaneity to be any more valid than another frame's. This gives both A and B their single correct 1:1 age correlation at any distance which holds so long as they are at rest with respect to each other. Again, you present no argument for why this is the single correct correlation, you just assert it. Of course other observers may see this differently but IT'S NOT THEIR AGE CORRELATION, IT'S ONLY A'S AND B'S AGE CORRELATION and A and B can determine exactly what that correlation is. Do you agree? No. You already agreed in an earlier post that for an inertial observer to label the frame where they are at rest as their own frame is purely a matter of HUMAN CONVENTION, not an objective reality that is forced on them by nature. So even if we ignore these other observers, there is nothing stopping A and B from using a different convention to define their own frame, such as the inertial frame where they both have a velocity of 0.99c along the x-axis. I know you will claim it's not valid since other observers may view it differently, but frankly A and B's age correlation is NONE OF THEIR BUSINESS! Again, you are conflating observers with frames, even though you earlier acknowledged that any link between particular observers and particular frames is just a matter of convention. I'll respond to the rest of your post later when I have more time... OK, thanks. Please prioritize my latest post discussing the scenario with A/B and C/D and statement #1 vs. statement #2, since it seems that your original argument for an error in my analysis was based on falsely imagining I was asserting statement #1 rather than statement #2. Since the analysis really only depends on #2 which you seem to agree with, I would like to proceed with the analysis of this scenario to see if you can find any other reason to object to any other step in the reasoning--if you can't, then presumably you will have no basis for denying the final conclusion that two different ages of the same observer A would have to be simultaneous in p-time, according to your own rules. Jesse On Tuesday, March 4, 2014 2:19:46 PM UTC-5, jessem wrote: On Tue, Mar 4, 2014 at 2:02 PM, Edgar L. Owen edga...@att.net wrote: Jesse, You ask me to choose between 1. and 2. 1. If B's proper age at this point in spacetime is T, then
Re: Block Universes
On Tue, Mar 4, 2014 at 4:57 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, Good, we agree it's a valid method for determining 1:1 age correlations in a common inertial frame in which they are both at rest. I claim that frame is the correct one to determine the actual age correlation because it expresses the actual relation in a manner both A and B agree You are avoiding my question of whether identifying this frame with A and B's view or perspective is just a matter of convention as you previously seemed to agree, or whether it is tied to them in some more fundamental way. If it's just a matter of convention, then A and B could equally well agree to define any other frame as their own view of the situation. is transitive among all observers, AND is the exact same method that gives the correct answer WHEN A AND B MEET and everyone, even you, agrees on the 1:1 age correlation. Our disagreement over choice of frames is spinning its wheels and not getting anywhere. It's a matter of how to INTERPRET relativity, rather than relativity itself. And I have given very convincing reasons why a privileged frame that preserves the actual physical facts that affect age changes is appropriate. You just don't agree with them. But you refuse to answer my very simple questions about your reasons, like my question about whether you ASSUME FROM THE START that a particular definition of simultaneity (the one you prefer) is the actual reality, or whether you claim to have convincing reasons for this definition of simultaneity representing reality that don't simply assume it from the start. As to your example claiming to prove my method leads to a contradiction, just give me the bottom line, a simple synopsis. I don't have the time to wade through a detailed example only to find the only disagreement is over choice of frames again. I promise you the example has nothing to do with any frames other than the ones in which each pair is at rest. Again, the only assumptions about p-time that I make in deriving the contradiction are: ASSUMPTION 1. If two observers are at rest in the same inertial frame, then events on their worldlines that are simultaneous in their rest frame are also simultaneous in p-time ASSUMPTION 2. If two observers cross paths at a single point in spacetime P, and observer #1's proper time at P is T1 while observer #2's proper time at P is T2, then the event of observer #1's clock showing T1 is simultaneous in p-time with the event of observer #2's clock showing T2. ASSUMPTION 3. p-time simultaneity is transitive That's it! I make no other assumptions about p-time simultaneity. But if you want to actually see how the contradiction is derived, there's really no shortcut besides looking at the math. If you are willing to do that, can we just start with the last 2 questions I asked about the scenario? Here's what I asked again, with a few cosmetic modifications: Please have another look at the specific numbers I gave for x(t), coordinate position as a function of coordinate time, and T(t), proper time as a function of coordinate time, for each observer (expressed using the inertial frame where A and B are at rest, and C and D are moving at 0.8c), and then tell me if you agree or disagree with the following two statements: For A: x(t) = 25, T(t) = t For B: x(t) = 0, T(t) = t For C: x(t) = 0.8c * t, T(t) = 0.6*t For D: x(t) = [0.8c * t] + 9, T(t) = 0.6*t - 12 --given the x(t) functions for B and C, we can see that they both pass through the point in spacetime with coordinates x=0, t=0. Given their T(t) functions, we can see that B has a proper time T=0 at those coordinates, and C also has a proper time T=0 at those coordinates. Therefore, by ASSUMPTION 1 above, the event of B's proper time clock reading T=0 is simultaneous in p-time with the event of C's proper time clock reading T=0. Agree or disagree? --given the x(t) functions for A and D, we can see that they both pass through the point in spacetime with coordinates x=25, t=20. Given their T(t) functions, we can see that A has a proper time T=20 at those coordinates, and D has a proper time T=0 at those coordinates. Therefore, by ASSUMPTION 1 above, the event of A's proper time clock reading T=20 is simultaneous in p-time with the event of D's proper time clock reading T=0. Agree or disagree? (if you don't understand the math of how to use x(t) to determine whether someone passed through a given point in spacetime with known x and t coordinates, or how to determine their proper time T at this point, then just ask and I will elaborate) If you agree with both of these, then I will proceed to the next few agree/disagree statements that follow from the three assumptions, and if you agree with them all you'll have no way to avoid the contradiction. On the other hand if you ASSUME privileged frames the way I do and think my method of using them leads to a contradiction that isn't just another disagreement over
Re: Block Universes
On Tue, Mar 4, 2014 at 5:45 PM, Jesse Mazer laserma...@gmail.com wrote: I promise you the example has nothing to do with any frames other than the ones in which each pair is at rest. Again, the only assumptions about p-time that I make in deriving the contradiction are: ASSUMPTION 1. If two observers are at rest in the same inertial frame, then events on their worldlines that are simultaneous in their rest frame are also simultaneous in p-time ASSUMPTION 2. If two observers cross paths at a single point in spacetime P, and observer #1's proper time at P is T1 while observer #2's proper time at P is T2, then the event of observer #1's clock showing T1 is simultaneous in p-time with the event of observer #2's clock showing T2. ASSUMPTION 3. p-time simultaneity is transitive That's it! I make no other assumptions about p-time simultaneity. But if you want to actually see how the contradiction is derived, there's really no shortcut besides looking at the math. If you are willing to do that, can we just start with the last 2 questions I asked about the scenario? Here's what I asked again, with a few cosmetic modifications: Please have another look at the specific numbers I gave for x(t), coordinate position as a function of coordinate time, and T(t), proper time as a function of coordinate time, for each observer (expressed using the inertial frame where A and B are at rest, and C and D are moving at 0.8c), and then tell me if you agree or disagree with the following two statements: For A: x(t) = 25, T(t) = t For B: x(t) = 0, T(t) = t For C: x(t) = 0.8c * t, T(t) = 0.6*t For D: x(t) = [0.8c * t] + 9, T(t) = 0.6*t - 12 --given the x(t) functions for B and C, we can see that they both pass through the point in spacetime with coordinates x=0, t=0. Given their T(t) functions, we can see that B has a proper time T=0 at those coordinates, and C also has a proper time T=0 at those coordinates. Therefore, by ASSUMPTION 1 above, the event of B's proper time clock reading T=0 is simultaneous in p-time with the event of C's proper time clock reading T=0. Agree or disagree? --given the x(t) functions for A and D, we can see that they both pass through the point in spacetime with coordinates x=25, t=20. Given their T(t) functions, we can see that A has a proper time T=20 at those coordinates, and D has a proper time T=0 at those coordinates. Therefore, by ASSUMPTION 1 above, the event of A's proper time clock reading T=20 is simultaneous in p-time with the event of D's proper time clock reading T=0. Agree or disagree? Another little correction--in the last two paragraphs there, where I said Therefore, by ASSUMPTION 1 above, I should have written ASSUMPTION 2, since in both cases I was deriving p-time simultaneity from the fact that two clock readings happened at the same point in spacetime. Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, Your position becomes more and more absurd. You claim they DO have a unique 1:1 correlation of their ages when they are together but they DON'T when they separate. So how far do they have to separate before this correlation is lost? 1 meter? 1 kilometer, 1 light year? And is the correlation lost all at once as they separate or gradually? And if all at once, what is the threshold distance where correlation is lost? And if gradually what is the relativistic formula that determines how much the correlation falls off with distance? The fact is that both twins DO HAVE AN ACTUAL AGE AT ALL TIMES. You've already agreed to this obvious fact. Thus there absolutely MUST be an actual correlation of those ages. That is pure logic, not relativity. All you are saying is that relativity does not give a unique answer for what that correlation is. Sure, I agree completely. But my point is that if we choose the correct frame that preserves the relationship between ONLY the twins themselves we do get a unique unambiguous answer. And so that is the only correct answer. And it is consistent and transitive among all observers. Therefore it qualifies as an actual physical fact. All you are saying is that relativity doesn't have a way to calculate an age correlation. But not having a way to calculate something DOES NOT MEAN it doesn't actually exist, it just means it can't be calculated. Do you agree with that? So to falsify p-time you can't just say a correlation can't be calculated, you have to actually prove there is an actual CONTRADICTION between p-time and relativity. You haven't yet done that and I don't think you can... Note also that the GPS system DOES establish actual 1:1 correlations of proper times between satellites and ground based receivers both moving relative to each other and at distance from each other. if it didn't, it couldn't work. So even relativity tells us this is possible. Edgar On Sunday, March 2, 2014 7:52:12 PM UTC-5, jessem wrote: On Sun, Mar 2, 2014 at 7:44 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, OK good, that's what I assumed you meant. BUT now take the two twins at rest standing on opposite sides of the earth, and then they each start walking in different directions. By your criterion you then have to say that suddenly and instantly there is NO more 1:1 correlation of their ages, that they COMPLETELY AND ABSOLUTELY lose their 1:1 age correlation they had at rest even if they take a SINGLE STEP! You seem to have misunderstood me, although I thought I was pretty clear--I said that they did NOT have a unique actual correlation in their ages when they were at rest relative to each other but at different positions in space, so nothing changes if they start walking, they still don't have any unique actual correlation in their ages. Try reading what I wrote again (with the correction I mentioned that 'any unique actual truth about their ages' has been changed to 'any unique actual truth about the correlation between their ages'): 'No, of course I wouldn't agree that there is any unique actual truth about the correlation between their ages in this case, nor would any mainstream physicist. What part of all frames are equally valid don't you understand? Or do you not get that if we use an inertial frame where the twins are both moving with the same constant velocity, they do NOT have identical ages at any given moment in this frame? (assuming they had identical ages at any given moment in their rest frame)' Jesse On Sunday, March 2, 2014 7:13:31 PM UTC-5, jessem wrote: On Sun, Mar 2, 2014 at 7:01 PM, Jesse Mazer laser...@gmail.com wrote: ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On Mon, Mar 3, 2014 at 10:03 AM, Edgar L. Owen edgaro...@att.net wrote: Jesse, Your position becomes more and more absurd. My position is simply that for any question on which different frames give different answers, there is no physical basis for judging one frame's judgments to be reality while others are not. I guarantee you that any physicist would agree with this. You claim they DO have a unique 1:1 correlation of their ages when they are together but they DON'T when they separate. So how far do they have to separate before this correlation is lost? 1 meter? 1 kilometer, 1 light year? Any finite number--one trillionth of a nanometer, say. The theory says that no matter how small the distance D you choose, if you have an inertial frame where two clocks are at rest and synchronized a distance D apart, then in another inertial frame where the two clocks are moving along the axis between them at speed v, at any given moment in this new frame one clock's time will be ahead of the other's by vD/c^2. There is a maximum to how far their times can be out-of-sync since v must be smaller than c, this implies that no inertial frame will see them as being out-of-sync by a time greater than or equal to D/c (so if the two clocks are 1 light-second apart in their rest frame, or 299792458 meters apart, any other frame will see them out-of-sync by less than a second). And this means that if you are rounding ages off at some point, in practice you may not have to worry about disagreements in simultaneity between frames--if two people are precisely the same age in their rest frame and are standing only a meter apart in their inertial rest frame, all other frames will say their ages differ by less than 1/299792458 of a second, so obviously if you're rounding their ages to the nearest second you'll still say they're the same age no matter what inertial frame you're using. But if you want to talk about physical reality rather than mere practical approximations, the fact remains that different frames will disagree somewhat on which ages are simultaneous for ANY finite separation, and in relativity there can NEVER be a physical basis for saying that one frame's judgments are a true representation of physical reality while other's are not. And is the correlation lost all at once as they separate or gradually? And if all at once, what is the threshold distance where correlation is lost? And if gradually what is the relativistic formula that determines how much the correlation falls off with distance? See above, if the clocks are at rest a distance D apart and synchronized in their own rest frame, then in another frame moving at speed v along the axis between the two clocks, at any given moment in this new frame the clocks are out-of-sync by vD/c^2. This can be derived directly from the Lorentz transformation which tells you the coordinates of any event in frame #2 if you already have its coordinates in frame #1. The fact is that both twins DO HAVE AN ACTUAL AGE AT ALL TIMES. You've already agreed to this obvious fact. Thus there absolutely MUST be an actual correlation of those ages. That is pure logic, not relativity. That isn't logical at all, in fact it's a complete non sequitur (note that you make no attempt to actually explain the 'logic' that leads you from the premise to the conclusion here). Once again I would mention the geometric analogy: --If you have two spatial paths between points A and B on a 2D plane, then at any given point P on a specific path, there is an actual distance along the path between point A and point P, which could be measured by a flexible measuring tape laid along the path. This distance along the path from A to P--call it the proper path distance from A to P--is totally coordinate-independent, in the sense that if different Cartesian coordinate systems have different coordinate descriptions of the same path, they can each use their own coordinates to calculate this proper path distance from A to P and they will all get the same answer. But if you use different Cartesian coordinate systems to assign x,y coordinates to points on the plane, two points P1 and P2 on *different* paths may have the same y-coordinate in one coordinate system, but different y-coordinates in another coordinate system. So the question do two points on different paths share a common y-coordinate?, unlike the question what is the proper path distance between two points on a single path?, is one that different Cartesian coordinate systems answer differently. But I don't think anyone would ever claim that one Cartesian coordinate system's answer to the latter question would be physically correct while other coordinate systems are objectively physically wrong--the notion of separated points in space having the same y-coordinate is an INTRINSICALLY coordinate-based idea, it HAS no physical reality independent of an arbitrary choice of coordinate system. All of this is exactly analogous
Re: Block Universes
Jesse, OK, this is some progress. Now you've gone from saying there is NO correlation at all, to the ages ARE CORRELATED WITHIN SOME LIMIT. In other words we DO know that for any set of twins we can always say that their ages ARE the same within some limits. Correct? This is a VERY BIG CHANGE in your stated position, from NO correlation at all to SOME correlation... You though continue to claim that all frames are equally valid, even if they DO NOT preserve the actual age changing acceleration effects between the twins, while I claim that IF we properly choose a frame that DOES preserve the actual age changing acceleration effects that we narrow that limit to zero resulting in an EXACT 1:1 age correlation. You, in fact, have previously agreed that IF we choose the frame in which the symmetric accelerations were preserved that we DO get an exact 1:1 correlation, you just disagree that that frame is privileged because it preserves the actual age changing symmetric accelerations like I claim. So I suggest that for the moment we ASSUME we should choose that frame, and then see if it can be consistently applied in a transitive manner to achieve a common age correlation between ALL observers. If it can't my theory is falsified. If it can then we can still agree to disagree about how frames should be applied to analyze specific physical relationships. Edgar On Monday, March 3, 2014 11:39:10 AM UTC-5, jessem wrote: On Mon, Mar 3, 2014 at 10:03 AM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, Your position becomes more and more absurd. My position is simply that for any question on which different frames give different answers, there is no physical basis for judging one frame's judgments to be reality while others are not. I guarantee you that any physicist would agree with this. You claim they DO have a unique 1:1 correlation of their ages when they are together but they DON'T when they separate. So how far do they have to separate before this correlation is lost? 1 meter? 1 kilometer, 1 light year? Any finite number--one trillionth of a nanometer, say. The theory says that no matter how small the distance D you choose, if you have an inertial frame where two clocks are at rest and synchronized a distance D apart, then in another inertial frame where the two clocks are moving along the axis between them at speed v, at any given moment in this new frame one clock's time will be ahead of the other's by vD/c^2. There is a maximum to how far their times can be out-of-sync since v must be smaller than c, this implies that no inertial frame will see them as being out-of-sync by a time greater than or equal to D/c (so if the two clocks are 1 light-second apart in their rest frame, or 299792458 meters apart, any other frame will see them out-of-sync by less than a second). And this means that if you are rounding ages off at some point, in practice you may not have to worry about disagreements in simultaneity between frames--if two people are precisely the same age in their rest frame and are standing only a meter apart in their inertial rest frame, all other frames will say their ages differ by less than 1/299792458 of a second, so obviously if you're rounding their ages to the nearest second you'll still say they're the same age no matter what inertial frame you're using. But if you want to talk about physical reality rather than mere practical approximations, the fact remains that different frames will disagree somewhat on which ages are simultaneous for ANY finite separation, and in relativity there can NEVER be a physical basis for saying that one frame's judgments are a true representation of physical reality while other's are not. And is the correlation lost all at once as they separate or gradually? And if all at once, what is the threshold distance where correlation is lost? And if gradually what is the relativistic formula that determines how much the correlation falls off with distance? See above, if the clocks are at rest a distance D apart and synchronized in their own rest frame, then in another frame moving at speed v along the axis between the two clocks, at any given moment in this new frame the clocks are out-of-sync by vD/c^2. This can be derived directly from the Lorentz transformation which tells you the coordinates of any event in frame #2 if you already have its coordinates in frame #1. The fact is that both twins DO HAVE AN ACTUAL AGE AT ALL TIMES. You've already agreed to this obvious fact. Thus there absolutely MUST be an actual correlation of those ages. That is pure logic, not relativity. That isn't logical at all, in fact it's a complete non sequitur (note that you make no attempt to actually explain the 'logic' that leads you from the premise to the conclusion here). Once again I would mention the geometric analogy: --If you
Re: Block Universes
By the way, a friend suggested how Edgar's p-time could be rescued from relativity. If the universe is a simulation running on a game of life, which is itself running in a Newtonian universe with separate space and time dimensions (and assuming the simulation can handle relativity - we weren't sure how easily it would manage QM) then it becomes at least possible to envisage how it might exist. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On Mon, Mar 3, 2014 at 12:36 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, OK, this is some progress. Now you've gone from saying there is NO correlation at all, to the ages ARE CORRELATED WITHIN SOME LIMIT. In other words we DO know that for any set of twins we can always say that their ages ARE the same within some limits. Correct? This is a VERY BIG CHANGE in your stated position, from NO correlation at all to SOME correlation... Once again your argument turns on vague use of language. You were consistently talking about a 1:1 correlation, so naturally I was using correlation in this sense too. If we say all inertial frames agree that my age T' is simultaneous with my twin's age having some value between T1 and T2, but they disagree on the precise value that is NOT a 1:1 correlation, period. So there's been no change in my position, it's you whose changing the meaning of correlation in mid-argument in an attempt to prove me wrong. You though continue to claim that all frames are equally valid, even if they DO NOT preserve the actual age changing acceleration effects between the twins, What do you mean by actual age changing acceleration effect? If you're talking about things that are directly measurable without use of a particular frame--like each twin's proper age at any specific event on his worldline (including their identical proper ages at the point in spacetime where they reunite), or each twin's proper acceleration as a function of proper age, then all frames DO preserve these effects. If instead you mean the idea that identical ages of separated symmetrically-accelerating twins are simultaneous in absolute, non-frame-dependent terms, then YOUR ARGUMENT IS TOTALLY CIRCULAR--you are simply assuming from the start that symmetrical acceleration implies that identical ages are simultaneous in actual, absolute terms, WITHOUT DERIVING THIS IDEA FROM ANY MORE BASIC PREMISES. while I claim that IF we properly choose a frame that DOES preserve the actual age changing acceleration effects that we narrow that limit to zero resulting in an EXACT 1:1 age correlation. Yep, that sounds pretty circular all right. As near as I can tell, the structure of your argument is this: 1. Assume without any prior argument that for symmetrically-accelerating twins, the actual truth about simultaneity is that identical ages are simultaneous. 2. Observe that there is only one frame that preserves this actual truth. 3. Therefore, only this frame is valid, other frames are not. 4. If we use this valid frame we can find a unique 1:1 correlation in their ages--and that is supposed to demonstrate the validity of premise #1 above! Hopefully you can see that this argument would be completely circular. If you think this isn't a fair representation of your own argument, then perhaps you can lay your argument out in a step-by-step manner as above, with each successive step being obviously derivable from only the previous steps. You, in fact, have previously agreed that IF we choose the frame in which the symmetric accelerations were preserved All frames agree the proper accelerations as a function of each twin's proper time are symmetric. By the frame in which symmetric accelerations were preserved do you mean that each twin's acceleration as a function of COORDINATE time in that frame is symmetric? that we DO get an exact 1:1 correlation, you just disagree that that frame is privileged because it preserves the actual age changing symmetric accelerations like I claim. Do you have any argument to DERIVE the conclusion that one frame's acceleration and aging as a function of COORDINATE time is actual, or is this just something you assume from the start and have no way to derive from any more basic premises? So I suggest that for the moment we ASSUME we should choose that frame, and then see if it can be consistently applied in a transitive manner to achieve a common age correlation between ALL observers. If it can't my theory is falsified. If it can then we can still agree to disagree about how frames should be applied to analyze specific physical relationships. Would you consider it a falsification of your theory to show that your assumption about simultaneity for symmetrically-moving observers (combined with transitivity and the idea that events at the same space and time coordinates in some inertial frame are automatically simultaneous in p-time) can lead in certain scenarios to a situation where we are forced to conclude that two different proper times of the SAME observer (Bob's proper time clock reading 0 and Bob's proper time clock reading 20, say) are simultaneous in p-time? If so, this sort of falsification is exactly what I have derived in my Alice/Bob/Arlene/Bart scenario from Feb. 9 at https://groups.google.com/d/msg/everything-list/jFX-wTm_E_Q/pxg0VAAHJRQJwhich you have CONSISTENTLY FAILED TO ADDRESS on all the myriad occasions I have reminded you of
Re: Block Universes
Liz, Thanks but P-time doesn't need to be rescued from relativity since it's completely consistent with relativity, though apparently not with some people's interpretation of relativity. Edgar On Monday, March 3, 2014 1:42:48 PM UTC-5, Liz R wrote: By the way, a friend suggested how Edgar's p-time could be rescued from relativity. If the universe is a simulation running on a game of life, which is itself running in a Newtonian universe with separate space and time dimensions (and assuming the simulation can ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, No, it was you that said there was NO correlation. In any case that's irrelevant if we know you now accept that there is a very LARGE correlation in most situations, and a definable correlation in ALL situations. That there is always SOME correlation. By actual age changing effect I mean proper accelerations and gravitations measurable by a comoving scale at specific clock tick events on his proper clock. There is no doubt these are real actual CAUSES with specific measurable values that thus must have real actual EFFECTS with specific actual values. So you are now saying that all frames DO preserve these effects? Your 4 point representation of my method MAY BE circular, but my actual method is NOT circular. Your statement 1. is an incorrect statement of my theory. What I assume FIRST in the symmetric case is NOT simultaneity of ages but simultaneity of the AGE CHANGING EFFECTS that relativity itself identifies, namely acceleration and gravitation. And in the general case the ages are NOT simultaneous nor are the age changing effects, yet my method still works. Would you claim that in the NON-symmetric case I start by assuming that NON-identical ages are NOT simultaneous. No, of course not, so your statement 1. does NOT represent an assumption my theory makes. I've defined this before but here it is again. The frame in which the accelerations are symmetric is a frame in which the same proper accelerations of BOTH twins occur at the same proper ages of both twins AND in which the proper ages of both twins have the same t value in that symmetry preserving frame. They have the same t value because the twins exchanged flight plans and agreed they would, and we know that their proper clocks MUST run at the same rates under the same accelerations at the same proper times. Therefore we must choose a frame that reflects that agreed upon symmetry. To address your two pair moving relative to each other example if A's proper time comes out both 0 and 20 at the same point in spacetime that sounds like a falsification. Let me paraphrase it for clarity in terms of a pair of observers A and B, and another pair C and D. If I understand it correctly A and B have the same proper ages, are at rest with respect to each other but separated in space. And C and D have the same proper ages, are at rest with respect to each other but also separated in space. However B and C are initially at the SAME position in space as the pairs move past each other. A's and B's proper ages are simultaneous in p-time because they are simultaneous in the A/B rest frame. C's and D's proper ages are simultaneous in p-time because they are simultaneous in the C/D rest frame. B's and C's proper ages are simultaneous in p-time because they are at the same place in spacetime. NO. for that to be true we have to assume that B's and C's proper ages were INITIALLY THE SAME AND THERE WAS NO SUBSEQUENT PROPER ACCELERATION OR GRAVITATIONAL DIFFERENCES. The simple fact that B and C are at the same point in spacetime DOES NOT require their proper ages to be the same. Obviously not since the twins in general are at DIFFERENT proper ages when they meet at the same point in spacetime. How could you believe differently? So this is the ERROR in your example. Therefore it does NOT generate a result in which A's proper age is both 0 and 20 at the same point in spacetime. Edgar On Monday, March 3, 2014 1:50:40 PM UTC-5, jessem wrote: On Mon, Mar 3, 2014 at 12:36 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, OK, this is some progress. Now you've gone from saying there is NO correlation at all, to the ages ARE CORRELATED WITHIN SOME LIMIT. In other words we DO know that for any set of twins we can always say that their ages ARE the same within some limits. Correct? This is a VERY BIG CHANGE in your stated position, from NO correlation at all to SOME correlation... Once again your argument turns on vague use of language. You were consistently talking about a 1:1 correlation, so naturally I was using correlation in this sense too. If we say all inertial frames agree that my age T' is simultaneous with my twin's age having some value between T1 and T2, but they disagree on the precise value that is NOT a 1:1 correlation, period. So there's been no change in my position, it's you whose changing the meaning of correlation in mid-argument in an attempt to prove me wrong. You though continue to claim that all frames are equally valid, even if they DO NOT preserve the actual age changing acceleration effects between the twins, What do you mean by actual age changing acceleration effect? If you're talking about things that are directly measurable without use of a particular frame--like each twin's proper age at any specific event on his worldline (including their identical proper ages at the point in spacetime where they reunite), or
Re: Block Universes
On Mon, Mar 3, 2014 at 3:45 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, No, it was you that said there was NO correlation. Jeez Edgar, you really need to work on your reading comprehension. I just got through AGREEING that I had said that there wasn't a correlation, but I explained that this was because I was using correlation in the way YOU had consistently been using it up until now, to refer to a 1:1 correlation in which each proper age of a twin is matched up to one unique proper age of the other twin. The archive at http://www.mail-archive.com/everything-list@googlegroups.com/ has a better search function than google's archive (returning individual posts rather than threads), so I searched for posts from Edgar L. Owen with correlate or correlation in them, results here: http://www.mail-archive.com/search?a=1l=everything-list%40googlegroups.comhaswords=correlatefrom=Edgar+L.+Owennotwords=subject=datewithin=1ddate=order=datenewestsearch=Search http://www.mail-archive.com/search?a=1l=everything-list%40googlegroups.comhaswords=correlationfrom=Edgar+L.+Owennotwords=subject=datewithin=1ddate=order=datenewestsearch=Search Earliest posts on the block time thread I could find in these searches (that were directed at me, and not some other poster) were these from Feb. 12 and 13 (shown in order below), where you can see from the quotes that you were talking specifically about 1:1 correlations that map clock times of one to specific clock times of the other: http://www.mail-archive.com/everything-list%40googlegroups.com/msg48613.html So all observers are always in the same p-time moment. Now it's just a matter of correlating their clock times to see which clock times occurred in any particular current moment of p-time. http://www.mail-archive.com/everything-list%40googlegroups.com/msg48716.html Do you see how this mutual agreed on understanding of how each's clock time varies in the other's frame always allows each to correlate their own comoving clock time with the comoving (own) clock time of the other? In other words for A to always know what B's clock time was reading when A's clock time was reading t, and for B to always know what A's clock time was reading when B's clock time was reading t'? http://www.mail-archive.com/everything-list%40googlegroups.com/msg48750.html Do you understand that if we have equations for t' in terms of t in A's frame, and t in terms of t' in B's frame, that we can always establish a 1: 1 correlation between t in A's frame and t' in B's frame? And in subsequent posts I'm pretty sure you always used correlation in the same manner, repeating the phrase 1:1 correlation many times (you may have gotten this phrase from ghibbsa, who used it in a Feb. 6 post at http://www.mail-archive.com/everything-list%40googlegroups.com/msg48264.htmlthat you quoted in one of your posts that came up in the search results). A similar search for posts by me that use correlate or correlation doesn't show any posts of mine using these words on the thread prior to your three posts to me above, and subsequently I always used correlation in the same sense that YOU had been consistently using it, to refer to a precise 1:1 correlation in ages/proper times. In any case that's irrelevant if we know you now accept that there is a very LARGE correlation in most situations, and a definable correlation in ALL situations. That there is always SOME correlation. By actual age changing effect I mean proper accelerations and gravitations measurable by a comoving scale at specific clock tick events on his proper clock. There is no doubt these are real actual CAUSES with specific measurable values that thus must have real actual EFFECTS with specific actual values. So you are now saying that all frames DO preserve these effects? What EFFECTS do you think they cause? Can you name a SPECIFIC effect on a SPECIFIC variable used in relativity? As I've told you before, if you are talking about some notion of a change in clock rate, then in relativity there is no frame-independent way to assign a specific actual value to the concept of a clock rate, the clock rate can only be defined relative to a particular coordinate system, so the clock rate at a particular event on the clock's worldline can have DIFFERENT values depending on what coordinate system you use. So, if this is in fact what you mean by effects, then I would DENY that proper accelerations have real actual EFFECTS with specific actual values. If you mean something else by real actual EFFECTS, you'll have to name the specific effect or your argument will be hopelessly vague. Your 4 point representation of my method MAY BE circular, but my actual method is NOT circular. Your statement 1. is an incorrect statement of my theory. What I assume FIRST in the symmetric case is NOT simultaneity of ages but simultaneity of the AGE CHANGING EFFECTS that relativity itself identifies, namely acceleration and gravitation. Not
Re: Block Universes
Jesse, much as I admire your attempt to engage with Edgar and his theory, I suspect you will eventually have to accept that he isn't arguing rationally - it looks to me as thought he will just pounce on some word you use, and twist it around to try and make a case. He is, in other words, a troll. On 4 March 2014 11:51, Jesse Mazer laserma...@gmail.com wrote: On Mon, Mar 3, 2014 at 3:45 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, No, it was you that said there was NO correlation. Jeez Edgar, you really need to work on your reading comprehension. I just got through AGREEING that I had said that there wasn't a correlation, but I explained that this was because I was using correlation in the way YOU had consistently been using it up until now, to refer to a 1:1 correlation in which each proper age of a twin is matched up to one unique proper age of the other twin. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On 04 Mar 2014, at 00:01, LizR wrote: Jesse, much as I admire your attempt to engage with Edgar and his theory, I suspect you will eventually have to accept that he isn't arguing rationally - it looks to me as thought he will just pounce on some word you use, and twist it around to try and make a case. He is, in other words, a troll. He certainly behave like a troll. If only by the way he does not answer question. The list self-moderation principle is a bit sick those days. Bruno On 4 March 2014 11:51, Jesse Mazer laserma...@gmail.com wrote: On Mon, Mar 3, 2014 at 3:45 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, No, it was you that said there was NO correlation. Jeez Edgar, you really need to work on your reading comprehension. I just got through AGREEING that I had said that there wasn't a correlation, but I explained that this was because I was using correlation in the way YOU had consistently been using it up until now, to refer to a 1:1 correlation in which each proper age of a twin is matched up to one unique proper age of the other twin. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, To answer your final question. If I understand your 3 points correctly then I agree with all 3. Though I suspect we understand them differently. When you spring your 'proof' we will find that out. And to your first points. I agree completely that there is no objective or actual truth about VIEWS of simultaneity from different frames. That is standard relativity which I accept completely. But you still find it impossible to understand we can DEDUCE or calculate an ACTUAL physical simultaneity irrespective of VIEWS of it. And just as proper time invariance is NOT ANY VIEW but a deduction or calculation, we CAN use deductions and calculations that DO NOT correspond to any particular view to determine relativistic truth That such a methodology is permissible? Do you agree that the symmetric relationship defined by the twins executing the exact same proper accelerations at their exact same proper times is a meaningful physical concept? That we can speak meaningfully about a symmetric relationship? You've been referring to it as if you do. Note that the twins certainly consider it a meaningful physical scenario because they can exchange and execute specific flight plans on that basis. If so you agree that some frames preserve that real physical relationship and some don't? If so please tell me why if we want to analyze that ACTUAL real physical relationship we should not choose a frame that preserves it? And second, do you agree my method is consistently calculating something, and that something is transitive, even if you don't agree it's a physically meaningful concept? If not then please try to prove it's not unambiguous and transitive, using MY definitions of MY theory rather than your 3 points. In other words assume it and then try to disprove it works. Edgar On Saturday, March 1, 2014 5:51:37 PM UTC-5, jessem wrote: On Sat, Mar 1, 2014 at 5:35 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, Let me ask you one simple question. In the symmetric case where the twins part and then meet up again with the exact same real actual ages isn't it completely logical to conclude they must also have been the exact same real actual ages all during the trip? If, as you claim, the same exact proper accelerations do NOT result in the exact same actual ages all during the trip then how in hell can the twins actually have the exact same actual ages when they meet up? It's not that I'm claiming that there's an objective truth that they DON'T have the same ages during the trip. I'm just saying that as far as physics is concerned, there simply IS NO OBJECTIVE OR ACTUAL TRUTH ABOUT SIMULTANEITY, and thus there is neither an actual truth that they are the same age or an actual truth that they are different ages. These things are purely a matter of human coordinate conventions, like the question of which pairs of points on different measuring-tapes have the same y coordinates in any given Cartesian coordinate system. Similarly, questions of simultaneity reduce to questions about which pairs of points on different worldlines have the same t coordinate in any given inertial coordinate system, nothing more. What is the mysterious mechanism you propose that causes twins that do not have the same actual ages during the trip to just happen to end up with the exact same actual ages when they meet? Again, I do not say there is any objective truth that they do not have the same actual ages, I simply say there is no objective truth about which ages are actually simultaneous in some sense that is more than just an arbitrary coordinate convention. But if you're just asking about how things work in FRAMES where they don't have the same actual ages during the trip, the answer is that in such a frame you always find that the answer to which twin's clock is ticking faster changes at some point during the trip, so the twin whose clock was formerly ticking faster is now ticking slower after a certain time coordinate t, and it always balances out exactly ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On Sat, Mar 1, 2014 at 7:09 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, To address your points in order: 1. Yes, you said that proper ages are invariant. But note the important point that the proper age of A to himself is a direct observation (he looks at his age clock), but to anyone else is a computation and NOT an observation. If he looks at his age clock, that's a direct measurement that is not specifically tied to ANY frame, including his own comoving frame. And there's nothing stopping an observer who is moving relative to him from stealing a glance at his age clock too as she passes him nearby (or looks at him through her telescope), so she can make a direct measurement of his age just as easily. A reference frame only needs to be used when you want to PREDICT some fact you don't already know through direct measurement, given some other known facts. For example, if you know that someone has a coordinate velocity v at coordinate time t0 in some frame, and you know their proper age is T0 at coordinate time t0, then as long as they move inertially, you can PREDICT that at some later coordinate time t1, their proper age T1 will be equal to T0 + (t1 - t0)*sqrt[1 - (v/c)^2]. Of course if you happen to be using the person's inertial rest frame where v=0, this formula reduces to the simple one T1 = T0 + (t1 - t0), but this still qualifies as a CALCULATION to predict his proper age at a later coordinate time t1, not a direct measurement. In fact from their native comoving frames they will observe A at some other age than their calculation. So the calculations trump the views. Huh? You're not making any sense--you just got through agreeing proper ages are invariant, how can you still maintain they'll observe A at some other age than their calculation if you agree all frames will predict exactly the same age for him at any event on his worldline, and this will also be the age that he will be observed to have on his personal clock at that event? Do you just mean that the time coordinate they assign to that event may be different than his proper age? That would be true, but no one familiar with relativity would conflate a time coordinate with an age, and anyway it's quite possible to have an inertial coordinate system where he's at rest but his age still doesn't match the coordinate time, because his birth is assigned some time coordinate different from t=0. Thus it is valid in relativity to CALCULATE things we CANNOT OBSERVE from our frame. Actual physical measurements can be seen by any observer, like the example of looking at the age clock of someone you're in motion relative to, so there's nothing that one person can observe that someone else cannot observe just because they're in a different rest frame, if by observe you mean measure using a physical instrument. Of course, actual physical measurements may be interpreted differently depending on what frame we use--for example, if I see an object pass the x=10 meters mark on some ruler when the clock there reads t=5 seconds, and later pass the x=20 meters mark on the same ruler when the clock there reads t=6 seconds, then if I am using a frame that defines the ruler and clocks to be at rest and the clocks to be synchronized, I'll say these measurements imply the object had a velocity of 10 meters per second, but if I'm using a frame where the ruler itself is moving and the clocks are out of sync, I can say that the velocity of the object itself was larger or smaller. That's what I do to establish 1:1 correlations of actual ages. I use calculations that trump Views, that trump observations. We don't always have to use frame views to establish relativistic truth. Do you agree with that? You must if you accept proper age invariance. Of course, you can determine relativistic truth by direct measurement, like looking at someone's clock. But this only applies to quantities that are frame-invariant, like proper time or proper acceleration. Other quantities are DEFINED with respect to reference frames, there's absolutely no way to determine them in a way that doesn't involve a frame. The x-coordinate of an event would be an example of a quantity that's defined in terms of a reference frame, you can't determine some object's x-coordinate except in reference to a particular coordinate system that has a particular spatial origin and its x-axis oriented in a particular direction. Likewise, the t-coordinate of an event can only be defined relative to a particular frame, and since simultaneity is DEFINED in relativity to mean nothing more than events that have the same t-coordinate, simultaneity can only be defined relative to a particular frame (talking specifically about physical definitions of simultaneity in relativity--this doesn't preclude the possibility of some metaphysical truth about simultaneity that's impossible to demonstrate experimentally, and of course it's conceivable that relativity will turn out to be
Re: Block Universes
On Sun, Mar 2, 2014 at 12:13 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, To answer your final question. If I understand your 3 points correctly then I agree with all 3. Though I suspect we understand them differently. When you spring your 'proof' we will find that out. Thanks for addressing the question. As I mentioned in my previous comment to you, the proof has already been sprung--it is the Alice/Bob/Arlene/Bart example from Feb. 9 at https://groups.google.com/d/msg/everything-list/jFX-wTm_E_Q/pxg0VAAHJRQJwhich I have asked you to address in at least ten different posts since then. And to your first points. I agree completely that there is no objective or actual truth about VIEWS of simultaneity from different frames. That is standard relativity which I accept completely. But you still find it impossible to understand we can DEDUCE or calculate an ACTUAL physical simultaneity irrespective of VIEWS of it. And just as proper time invariance is NOT ANY VIEW but a deduction or calculation, we CAN use deductions and calculations that DO NOT correspond to any particular view to determine relativistic truth That such a methodology is permissible? Do you agree that the symmetric relationship defined by the twins executing the exact same proper accelerations at their exact same proper times is a meaningful physical concept? That we can speak meaningfully about a symmetric relationship? Only in terms of coordinate-invariant characterizations of their paths, like the proper acceleration as a function of proper time, or the total proper time elapsed between departing and reuniting. There is no logical reason that this symmetry in coordinate-invariant aspects of their trips somehow forces us to say that a coordinate system where coordinate-dependent aspects of their trips are symmetrical too represents actual physical reality where other coordinate systems do not. Suppose we lay out two measuring tapes on different paths between two intersection points A and B, and these paths are geometrically symmetrical in the sense that each one looks like a mirror image of the other if your mirror is laid out straight between points A and B. Both tapes have their 0 markings coincide with the first intersection point A, and obviously since the two paths are symmetrical, both measuring tapes will have the same marking coincide with the second intersection point B. Obviously we could draw different spatial coordinate axes on the plane, and in some coordinate systems their paths would be symmetrical in coordinate terms--for example, a pair of identical markings on each tape would have the same y-coordinates, and their slopes at these markings would have the same absolute value--while in others they would not. I can sketch out a diagram if you can't visualize what I'm talking about, but assuming you can, do you think that coordinate-based statements based on a symmetrical coordinate system, like the 4-centimeter marks on each measuring tape have the same y-coordinate would represent actual reality, whereas coordinate-based statements in other coordinate systems would not? You've been referring to it as if you do. Note that the twins certainly consider it a meaningful physical scenario because they can exchange and execute specific flight plans on that basis. If so you agree that some frames preserve that real physical relationship and some don't? No, I don't agree. ALL frames preserve the only symmetries I would recognize as objective ones--same proper acceleration as a function of proper time, same proper time when the twins reunite--while other coordinate-depedent statements are not ones I would call a real physical relationship. Note that they are perfectly free to agree to use a coordinate system where the coordinate descriptions of their paths are not symmetrical, and exchange and execute specific flight plans on that basis. If so please tell me why if we want to analyze that ACTUAL real physical relationship we should not choose a frame that preserves it? And second, do you agree my method is consistently calculating something, and that something is transitive, even if you don't agree it's a physically meaningful concept? If you consider more than one pair of twins whose paths cross one another, as I do in my Alice/Bob/Arlene/Bart scenario, then either your method leads to a contradiction where two different ages of the same observer are judged simultaneous, or else you'd have to drop one of the assumptions in your method (meaning it'd no longer be quite the same method). One of those assumptions was transitivity, so in principle you could drop that if you wanted to avoid the contradiction I describe, but as I said in my previous comment, it seems like a much more reasonable assumption to drop is the one that says inertial clocks at rest relative to one another that are synchronized in their rest frame must also be synchronized in p-time. Though as I
Re: Block Universes
Jesse, I'll address your points in a later post, but first let me run this simple new case by you. Imagine the symmetric trips of the twins continually criss cross each other at 1 second intervals (of their own proper clocks) for the duration of the entire trip. At each 1 second meeting I'm sure you would agree their proper times are in a 1:1 correlation so their proper times are in a 1:1 correlation every second of the duration of the trip and both twins agree on that. There is a 1:1 correlation of proper age clocks at the criss crosses because they are in the same point of space and time by your operational reflected light definition AND they both compute both their 1 second proper time intervals since the last criss cross as the same invariant number as each other, AND they BOTH HAVE AGREED TO CRISS CROSS WHEN EACH OF THEIR PROPER TIMES READS 1 SECOND INTERVALS which in itself ensures the 1:1 correlation of proper times. Now just take the limit of that and imagine a vanishingly small interval for the criss crosses. If we do that then clearly we can say the twins have a 1:1 correlation of their proper ages at EVERY MOMENT during the entire trip to any limit of accuracy we wish. Since a criss cross symmetric trip is no different in principle than our previous symmetric trip (only a single meeting) it is clear that we have proven there is a 1:1 proper age correlation for any symmetric trip during EVERY MOMENT of the trip. Edgar On Sunday, March 2, 2014 1:18:27 PM UTC-5, jessem wrote: On Sat, Mar 1, 2014 at 7:09 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, To address your points in order: 1. Yes, you said that proper ages are invariant. But note the important point that the proper age of A to himself is a direct observation (he looks at his age clock), but to anyone else is a computation and NOT an observation. If he looks at his age clock, that's a direct measurement that is not specifically tied to ANY frame, including his own comoving frame. And there's nothing stopping an observer who is moving relative to him from stealing a glance at his age clock too as she passes him nearby (or looks at him through her telescope), so she can make a direct measurement of his age just as easily. A reference frame only needs to be used when you want to PREDICT some fact you don't already know through direct measurement, given some other known facts. For example, if you know that someone has a coordinate velocity v at coordinate time t0 in some frame, and you know their proper age is T0 at coordinate time t0, then as long as they move inertially, you can PREDICT that at some later coordinate time t1, their proper age T1 will be equal to T0 + (t1 - t0)*sqrt[1 - (v/c)^2]. Of course if you happen to be using the person's inertial rest frame where v=0, this formula reduces to the simple one T1 = T0 + (t1 - t0), but this still qualifies as a CALCULATION to predict his proper age at a later coordinate time t1, not a direct measurement. In fact from their native comoving frames they will observe A at some other age than their calculation. So the calculations trump the views. Huh? You're not making any sense--you just got through agreeing proper ages are invariant, how can you still maintain they'll observe A at some other age than their calculation if you agree all frames will predict exactly the same age for him at any event on his worldline, and this will also be the age that he will be observed to have on his personal clock at that event? Do you just mean that the time coordinate they assign to that event may be different than his proper age? That would be true, but no one familiar with relativity would conflate a time coordinate with an age, and anyway it's quite possible to have an inertial coordinate system where he's at rest but his age still doesn't match the coordinate time, because his birth is assigned some time coordinate different from t=0. Thus it is valid in relativity to CALCULATE things we CANNOT OBSERVE from our frame. Actual physical measurements can be seen by any observer, like the example of looking at the age clock of someone you're in motion relative to, so there's nothing that one person can observe that someone else cannot observe just because they're in a different rest frame, if by observe you mean measure using a physical instrument. Of course, actual physical measurements may be interpreted differently depending on what frame we use--for example, if I see an object pass the x=10 meters mark on some ruler when the clock there reads t=5 seconds, and later pass the x=20 meters mark on the same ruler when the clock there reads t=6 seconds, then if I am using a frame that defines the ruler and clocks to be at rest and the clocks to be synchronized, I'll say these measurements imply the object had a velocity of 10 meters per second, but if
Re: Block Universes
On Sun, Mar 2, 2014 at 2:25 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, I'll address your points in a later post, but first let me run this simple new case by you. Imagine the symmetric trips of the twins continually criss cross each other at 1 second intervals (of their own proper clocks) for the duration of the entire trip. At each 1 second meeting I'm sure you would agree their proper times are in a 1:1 correlation so their proper times are in a 1:1 correlation every second of the duration of the trip and both twins agree on that. There is a 1:1 correlation of proper age clocks at the criss crosses because they are in the same point of space and time by your operational reflected light definition AND they both compute both their 1 second proper time intervals since the last criss cross as the same invariant number as each other, AND they BOTH HAVE AGREED TO CRISS CROSS WHEN EACH OF THEIR PROPER TIMES READS 1 SECOND INTERVALS which in itself ensures the 1:1 correlation of proper times. Sure, there is complete agreement about their respective ages at each crossing-point. Now just take the limit of that and imagine a vanishingly small interval for the criss crosses. If we do that then clearly we can say the twins have a 1:1 correlation of their proper ages at EVERY MOMENT during the entire trip to any limit of accuracy we wish. The problem is that in this limit, they also approach a state of simply moving right alongside each other (since the spatial separation they can achieve between crossings approaches zero), remaining at exactly the same point in space at any given time, so their worldlines are identical. Of course it is true in such a case that their ages will remain the same at every moment in a frame-invariant sense, but this tell us anything about simultaneity in a case where they have a finite spatial separation throughout the trip. Since a criss cross symmetric trip is no different in principle than our previous symmetric trip (only a single meeting) it is clear that we have proven there is a 1:1 proper age correlation for any symmetric trip during EVERY MOMENT of the trip. Edgar On Sunday, March 2, 2014 1:18:27 PM UTC-5, jessem wrote: On Sat, Mar 1, 2014 at 7:09 PM, Edgar L. Owen edga...@att.net wrote: Jesse, To address your points in order: 1. Yes, you said that proper ages are invariant. But note the important point that the proper age of A to himself is a direct observation (he looks at his age clock), but to anyone else is a computation and NOT an observation. If he looks at his age clock, that's a direct measurement that is not specifically tied to ANY frame, including his own comoving frame. And there's nothing stopping an observer who is moving relative to him from stealing a glance at his age clock too as she passes him nearby (or looks at him through her telescope), so she can make a direct measurement of his age just as easily. A reference frame only needs to be used when you want to PREDICT some fact you don't already know through direct measurement, given some other known facts. For example, if you know that someone has a coordinate velocity v at coordinate time t0 in some frame, and you know their proper age is T0 at coordinate time t0, then as long as they move inertially, you can PREDICT that at some later coordinate time t1, their proper age T1 will be equal to T0 + (t1 - t0)*sqrt[1 - (v/c)^2]. Of course if you happen to be using the person's inertial rest frame where v=0, this formula reduces to the simple one T1 = T0 + (t1 - t0), but this still qualifies as a CALCULATION to predict his proper age at a later coordinate time t1, not a direct measurement. In fact from their native comoving frames they will observe A at some other age than their calculation. So the calculations trump the views. Huh? You're not making any sense--you just got through agreeing proper ages are invariant, how can you still maintain they'll observe A at some other age than their calculation if you agree all frames will predict exactly the same age for him at any event on his worldline, and this will also be the age that he will be observed to have on his personal clock at that event? Do you just mean that the time coordinate they assign to that event may be different than his proper age? That would be true, but no one familiar with relativity would conflate a time coordinate with an age, and anyway it's quite possible to have an inertial coordinate system where he's at rest but his age still doesn't match the coordinate time, because his birth is assigned some time coordinate different from t=0. Thus it is valid in relativity to CALCULATE things we CANNOT OBSERVE from our frame. Actual physical measurements can be seen by any observer, like the example of looking at the age clock of someone you're in motion relative to, so there's nothing that one person can observe that someone
Re: Block Universes
Jesse, Glad we agree on the first point but, even if there is some minimum time limit to the criss crosses, you miss the real point of my example. Let me restate it: Since a criss cross symmetric trip is NO DIFFERENT IN PRINCIPLE than our previous symmetric trip (only a single meeting) it is clear that we have proven there is a 1:1 proper age correlation for any symmetric trip during EVERY minimum time interval of the trip EVEN IF THERE ARE NO CRISS CROSSES. We have confirmed there are proper age correlations (at every second) for the criss cross trip but it's exactly the same in principle as any non criss cross trip. Therefore there must also be proper age correlations (at every second) for ALL symmetric trips. Edgar On Sunday, March 2, 2014 2:37:13 PM UTC-5, jessem wrote: On Sun, Mar 2, 2014 at 2:25 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, I'll address your points in a later post, but first let me run this simple new case by you. Imagine the symmetric trips of the twins continually criss cross each other at 1 second intervals (of their own proper clocks) for the duration of the entire trip. At each 1 second meeting I'm sure you would agree their proper times are in a 1:1 correlation so their proper times are in a 1:1 correlation every second of the duration of the trip and both twins agree on that. There is a 1:1 correlation of proper age clocks at the criss crosses because they are in the same point of space and time by your operational reflected light definition AND they both compute both their 1 second proper time intervals since the last criss cross as the same invariant number as each other, AND they BOTH HAVE AGREED TO CRISS CROSS WHEN EACH OF THEIR PROPER TIMES READS 1 SECOND INTERVALS which in itself ensures the 1:1 correlation of proper times. Sure, there is complete agreement about their respective ages at each crossing-point. Now just take the limit of that and imagine a vanishingly small interval for the criss crosses. If we do that then clearly we can say the twins have a 1:1 correlation of their proper ages at EVERY MOMENT during the entire trip to any limit of accuracy we wish. The problem is that in this limit, they also approach a state of simply moving right alongside each other (since the spatial separation they can achieve between crossings approaches zero), remaining at exactly the same point in space at any given time, so their worldlines are identical. Of course it is true in such a case that their ages will remain the same at every moment in a frame-invariant sense, but this tell us anything about simultaneity in a case where they have a finite spatial separation throughout the trip. Since a criss cross symmetric trip is no different in principle than our previous symmetric trip (only a single meeting) it is clear that we have proven there is a 1:1 proper age correlation for any symmetric trip during EVERY MOMENT of the trip. Edgar On Sunday, March 2, 2014 1:18:27 PM UTC-5, jessem wrote: On Sat, Mar 1, 2014 at 7:09 PM, Edgar L. Owen edga...@att.net wrote: Jesse, To address your points in order: 1. Yes, you said that proper ages are invariant. But note the important point that the proper age of A to himself is a direct observation (he looks at his age clock), but to anyone else is a computation and NOT an observation. If he looks at his age clock, that's a direct measurement that is not specifically tied to ANY frame, including his own comoving frame. And there's nothing stopping an observer who is moving relative to him from stealing a glance at his age clock too as she passes him nearby (or looks at him through her telescope), so she can make a direct measurement of his age just as easily. A reference frame only needs to be used when you want to PREDICT some fact you don't already know through direct measurement, given some other known facts. For example, if you know that someone has a coordinate velocity v at coordinate time t0 in some frame, and you know their proper age is T0 at coordinate time t0, then as long as they move inertially, you can PREDICT that at some later coordinate time t1, their proper age T1 will be equal to T0 + (t1 - t0)*sqrt[1 - (v/c)^2]. Of course if you happen to be using the person's inertial rest frame where v=0, this formula reduces to the simple one T1 = T0 + (t1 - t0), but this still qualifies as a CALCULATION to predict his proper age at a later coordinate time t1, not a direct measurement. In fact from their native comoving frames they will observe A at some other age than their calculation. So the calculations trump the views. Huh? You're not making any sense--you just got through agreeing proper ages are invariant, how can you still maintain they'll observe A at some other age than their calculation if you agree all frames will predict exactly the
Re: Block Universes
Jesse, Just checking but I'm sure you would agree that twins AT REST with respect to each other are the same actual age (have a 1:1 proper age correlation) even if they are SEPARATED by distance? You just don't agree that if they are separated by distance AND in symmetric acceleration that there is any correlation of actual ages possible. Is that correct? Edgar On Sunday, March 2, 2014 2:37:13 PM UTC-5, jessem wrote: On Sun, Mar 2, 2014 at 2:25 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, I'll address your points in a later post, but first let me run this simple new case by you. Imagine the symmetric trips of the twins continually criss cross each other at 1 second intervals (of their own proper clocks) for the duration of the entire trip. At each 1 second meeting I'm sure you would agree their proper times are in a 1:1 correlation so their proper times are in a 1:1 correlation every second of the duration of the trip and both twins agree on that. There is a 1:1 correlation of proper age clocks at the criss crosses because they are in the same point of space and time by your operational reflected light definition AND they both compute both their 1 second proper time intervals since the last criss cross as the same invariant number as each other, AND they BOTH HAVE AGREED TO CRISS CROSS WHEN EACH OF THEIR PROPER TIMES READS 1 SECOND INTERVALS which in itself ensures the 1:1 correlation of proper times. Sure, there is complete agreement about their respective ages at each crossing-point. Now just take the limit of that and imagine a vanishingly small interval for the criss crosses. If we do that then clearly we can say the twins have a 1:1 correlation of their proper ages at EVERY MOMENT during the entire trip to any limit of accuracy we wish. The problem is that in this limit, they also approach a state of simply moving right alongside each other (since the spatial separation they can achieve between crossings approaches zero), remaining at exactly the same point in space at any given time, so their worldlines are identical. Of course it is true in such a case that their ages will remain the same at every moment in a frame-invariant sense, but this tell us anything about simultaneity in a case where they have a finite spatial separation throughout the trip. Since a criss cross symmetric trip is no different in principle than our previous symmetric trip (only a single meeting) it is clear that we have proven there is a 1:1 proper age correlation for any symmetric trip during EVERY MOMENT of the trip. Edgar On Sunday, March 2, 2014 1:18:27 PM UTC-5, jessem wrote: On Sat, Mar 1, 2014 at 7:09 PM, Edgar L. Owen edga...@att.net wrote: Jesse, To address your points in order: 1. Yes, you said that proper ages are invariant. But note the important point that the proper age of A to himself is a direct observation (he looks at his age clock), but to anyone else is a computation and NOT an observation. If he looks at his age clock, that's a direct measurement that is not specifically tied to ANY frame, including his own comoving frame. And there's nothing stopping an observer who is moving relative to him from stealing a glance at his age clock too as she passes him nearby (or looks at him through her telescope), so she can make a direct measurement of his age just as easily. A reference frame only needs to be used when you want to PREDICT some fact you don't already know through direct measurement, given some other known facts. For example, if you know that someone has a coordinate velocity v at coordinate time t0 in some frame, and you know their proper age is T0 at coordinate time t0, then as long as they move inertially, you can PREDICT that at some later coordinate time t1, their proper age T1 will be equal to T0 + (t1 - t0)*sqrt[1 - (v/c)^2]. Of course if you happen to be using the person's inertial rest frame where v=0, this formula reduces to the simple one T1 = T0 + (t1 - t0), but this still qualifies as a CALCULATION to predict his proper age at a later coordinate time t1, not a direct measurement. In fact from their native comoving frames they will observe A at some other age than their calculation. So the calculations trump the views. Huh? You're not making any sense--you just got through agreeing proper ages are invariant, how can you still maintain they'll observe A at some other age than their calculation if you agree all frames will predict exactly the same age for him at any event on his worldline, and this will also be the age that he will be observed to have on his personal clock at that event? Do you just mean that the time coordinate they assign to that event may be different than his proper age? That would be true, but no one familiar with relativity would conflate a time coordinate with an age, and
Re: Block Universes
On Sun, Mar 2, 2014 at 6:49 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, Just checking but I'm sure you would agree that twins AT REST with respect to each other are the same actual age (have a 1:1 proper age correlation) even if they are SEPARATED by distance? You just don't agree that if they are separated by distance AND in symmetric acceleration that there is any correlation of actual ages possible. Is that correct? No, of course I wouldn't agree that there is any unique actual truth about their ages in this case, nor would any mainstream physicist. What part of all frames are equally valid don't you understand? Or do you not get that if we use an inertial frame where the twins are both moving with the same constant velocity, they do NOT have identical ages at any given moment in this frame? (assuming they had identical ages at any given moment in their rest frame) Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On Sun, Mar 2, 2014 at 6:40 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, Glad we agree on the first point but, even if there is some minimum time limit to the criss crosses, you miss the real point of my example. Let me restate it: Since a criss cross symmetric trip is NO DIFFERENT IN PRINCIPLE than our previous symmetric trip (only a single meeting) it is clear that we have proven there is a 1:1 proper age correlation for any symmetric trip during EVERY minimum time interval of the trip EVEN IF THERE ARE NO CRISS CROSSES. Nonsense. We both agree that in case A where they are right next to each other throughout the whole trip (same spatial position at every single moment), there is an objective 1:1 correlation in their ages throughout the trip. We disagree about whether there is a 1:1 correlation throughout the trip in case B, where they do NOT occupy the same position through the trip. So now you think you can prove your belief about CASE B by considering a series of cases that IN THE LIMIT would have a 1:1 correlation throughout the trip, even though IN THE LIMIT this just reduces to CASE A, which we already agreed on? Sorry, but this fails basic logic. Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On Sun, Mar 2, 2014 at 7:01 PM, Jesse Mazer laserma...@gmail.com wrote: No, of course I wouldn't agree that there is any unique actual truth about their ages in this case, nor would any mainstream physicist. Sorry, I wrote too quickly here--what I meant is that I don't agree there is any unique actual truth about the CORRELATION between their ages, i.e. whether or not they reach the same age simultaneously (of course there is still a unique truth about each one's age at any specific event on his worldline). They do reach the same age simultaneously in their comoving inertial frame, but this frame's judgments can't be considered any more valid than a different inertial frame. Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, OK good, that's what I assumed you meant. BUT now take the two twins at rest standing on opposite sides of the earth, and then they each start walking in different directions. By your criterion you then have to say that suddenly and instantly there is NO more 1:1 correlation of their ages, that they COMPLETELY AND ABSOLUTELY lose their 1:1 age correlation they had at rest even if they take a SINGLE STEP! The way you state it this is EITHER OR. Either there is a 1:1 at rest, but if they are NOT at rest in the very slightest amount then they COMPLETELY AND ABSOLUTELY lose any 1:1 age correlation. Now if you do NOT agree to that then you are forced to try to claim that it's a matter of degree then you have to come up with some mathematical function that tells us what VARYING AMOUNT of 1:1 age correlation holds with what amount of relative motion. What defines the degree of 1:1 age correlation or lack thereof? I certainly don't think relativity theory has any such function. For relativity it is absolutely either or. Is this not correct? Or, on the other hand if you use simple logic from my many proofs you just admit that any two twins ALWAYS have a 1:1 actual real proper age correlation in all situations. And that is is always unambiguously calculable in a manner that all observers agree to, but that is not in general observable. And this problem and all the other problems simply go away Which is it? Edgar On Sunday, March 2, 2014 7:13:31 PM UTC-5, jessem wrote: On Sun, Mar 2, 2014 at 7:01 PM, Jesse Mazer laser...@gmail.comjavascript: wrote: No, of course I wouldn't agree that there is any unique actual truth about their ages in this case, nor would any mainstream physicist. Sorry, I wrote too quickly here--what I meant is that I don't agree there is any unique actual truth about the CORRELATION between their ages, i.e. whether or not they reach the same age simultaneously (of course there is still a unique truth about each one's age at any specific event on his worldline). They do reach the same age simultaneously in their comoving inertial frame, but this frame's judgments can't be considered any more valid than a different inertial frame. Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On Sun, Mar 2, 2014 at 7:44 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, OK good, that's what I assumed you meant. BUT now take the two twins at rest standing on opposite sides of the earth, and then they each start walking in different directions. By your criterion you then have to say that suddenly and instantly there is NO more 1:1 correlation of their ages, that they COMPLETELY AND ABSOLUTELY lose their 1:1 age correlation they had at rest even if they take a SINGLE STEP! You seem to have misunderstood me, although I thought I was pretty clear--I said that they did NOT have a unique actual correlation in their ages when they were at rest relative to each other but at different positions in space, so nothing changes if they start walking, they still don't have any unique actual correlation in their ages. Try reading what I wrote again (with the correction I mentioned that 'any unique actual truth about their ages' has been changed to 'any unique actual truth about the correlation between their ages'): 'No, of course I wouldn't agree that there is any unique actual truth about the correlation between their ages in this case, nor would any mainstream physicist. What part of all frames are equally valid don't you understand? Or do you not get that if we use an inertial frame where the twins are both moving with the same constant velocity, they do NOT have identical ages at any given moment in this frame? (assuming they had identical ages at any given moment in their rest frame)' Jesse On Sunday, March 2, 2014 7:13:31 PM UTC-5, jessem wrote: On Sun, Mar 2, 2014 at 7:01 PM, Jesse Mazer laser...@gmail.com wrote: No, of course I wouldn't agree that there is any unique actual truth about their ages in this case, nor would any mainstream physicist. Sorry, I wrote too quickly here--what I meant is that I don't agree there is any unique actual truth about the CORRELATION between their ages, i.e. whether or not they reach the same age simultaneously (of course there is still a unique truth about each one's age at any specific event on his worldline). They do reach the same age simultaneously in their comoving inertial frame, but this frame's judgments can't be considered any more valid than a different inertial frame. Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
A little consideration of trains travelling at half lightspeed with photons bouncing between parallel mirrors, and people observing lights being turned on in the station should suffice to demonstrate that there is no objective truth about the order of spatially separated events. This margin is too narrow to contain the exact proof, but maybe Brent can oblige? -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On 01 Mar 2014, at 02:18, Russell Standish wrote: On Fri, Feb 28, 2014 at 04:14:29PM +0100, Bruno Marchal wrote: Isn't it crazy to reject what there is enormous evidence for and accept what there is NO evidence for? That is what you do. There are no evidence for any universe, and indeed, as you assume comp, you could understand that there is no universe. The notion is close to inconsistent, and explanatively empty. Physicists measure numbers, and infer relation among numbers. Then even cosmological theories usually avoid metaphysical commitment. This is done by physicalist philosophers, and can make sense, but then not together with the assumption that the brain functions mechanically at some level. Sorry to be pernicketty, but if you are working in a theory that makes no ontologicical commitment (or metaphysical, which I assume is the same thing), then how does that contradict your reversal result? Because it is theology, but done scientifically, and so can assume an ontology with the only goal to refute it by absurdo, although here, as in any applied theory, we need Occam razor. It is only a theory _about_ phenomena, not about what's ontologically real. Theology is concerned with ontology, but does not commit itself on any of them, except for refuting them by absurdo. But that is not a commitment, only a temporary assumption. bruno -- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, Of course there is a rational justification for selecting one frame over another in many cases. All frames are NOT equal when it comes to representing ACTUAL physical facts. E.g. we can choose various frames to make someone's age pretty much any number we like but nevertheless they are still actually the age they think they are. If Alice is really 30 we can choose a frame in which she is all sorts of different ages but she is still actually 30. Different VIEWS of her age don't change her actual age. Isn't that obvious, and don't you agree with this? Your expertise in relativity is clear but you don't seem to understand that all frames are NOT equal when it comes to representing actual physical fact. You don't understand the fundamental notion in relativity that some frames represent actual physical fact, but others represent only HOW OTHER OBSERVERS VIEW those physical facts. This is quite obvious from the age example above, but it also applies to the actual relationship BETWEEN TWINS in my examples. The relationship between twins is exactly that, it is a RELATIONSHIP BETWEEN ONLY THOSE TWINS. Of course you can come up with frames in which that relationship is VIEWED differently, but that DOES NOT CHANGE the actual relationship between the twins TO THEMSELVES which is what my theory is based on because that is the ACTUAL REALITY of that physical situation. It is not just some arbitrary VIEW of that reality, it is the REALITY ITSELF. My theory recognizes the need to concentrate on actual physical fact as opposed to VIEWS of physical facts. There is a simple CRITERION to determine whether we are talking about PHYSICAL FACT or a VIEW of a physical fact. If the parties TO THE FACT AGREE on their views of the fact then that agreed view probably represents the actual physical fact. If they DO NOT agree then this disagreement represents VIEWS of physical facts rather than the FACTS THEMSELVES. I can perhaps think of a few explainable exceptions but this is the generally applicable criterion. For example the different ages of the twins when they meet is AGREED by both twins. Thus it is a physical fact. But the different ages of twins in relative motion is NOT AGREED by both twins. Thus those are VIEWS OF FACTS, RATHER THAN THE FACTS THEMSELVES. An absolutely crucial distinction in understanding what relativity is all about. If we can agree on this obvious point, and that we CAN establish a 1:1 proper time correlation on this basis, then I look forward to considering your example which you claim PROVES this 1:1 proper time correlation is not transitive. I'm pretty sure it is transitive when properly understood but am certainly willing to consider your 'proof'. Edgar On Friday, February 28, 2014 11:55:40 AM UTC-5, jessem wrote: On Fri, Feb 28, 2014 at 11:18 AM, Edgar L. Owen edga...@att.netjavascript: wrote: You point out that from the POV of all arbitrary frames they won't be, BUT the point is we MUST use a frame that MAINTAINS the real and actual symmetry to determine the ACTUAL REALITY of this situation. Why? You give no rational justification for why reality should coincide with the frame where the coordinates assigned to their paths are symmetrical as opposed to any other frame which makes the same physical predictions, this just seems like a quasi-aesthetic intuition on your part. But I also have a more definitive argument against identifying simultaneity in the frame where their paths look symmetrical with any sort of absolute simultaneity--because, as I have said over and over, it leads directly to contradictions when we consider multiple symmetrical pairs of observers, and the transitive nature of absolute simultaneity/p-time. If you will just respond to my Feb 24 post at https://groups.google.com/d/msg/everything-list/jFX-wTm_E_Q/dM2tcGYspfMJas you promised to do earlier, then as soon as we are completely settled on the matter of whether events that have the same space and time coordinates in an inertial frame must have happened at the same p-time, we can go back and look at the Alice/Bob/Arlene/Bart example at https://groups.google.com/d/msg/everything-list/jFX-wTm_E_Q/pxg0VAAHJRQJwhich PROVES that a contradiction follows fr ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, To address your questions: 1. Yes, of course the choice of their own frame is a matter of convention. But that does NOT mean that all frames are equal when it comes to accurately representing some particular physical fact or relationship. 2. The their experience in my symmetric example is the actual physical fact that they know their accelerations are symmetric because they exchanged flight plans to ensure that. And because their ACTUAL EXPERIENCE is the fact that they both can feel their proper accelerations AND time them by their own proper clocks to ensure they are in accordance with the flight plans they exchanged. By simple logic they then KNOW BEYOND DOUBT that their proper times are always in synch. AND they confirm this by meeting with the exact same clock readings that they AGREE upon. It is true their OBSERVATIONAL experiences of each other do not reflect this 1:1 proper time correlation but they are SMART ENOUGH TO UNDERSTAND that these are NON agreed VIEWS which do NOT reflect the actual physical FACTS of the relationship on which they DO AGREE and thus which is an actual physical fact rather than just views of facts. 3. I DO want to address your 'proof of non-transitivity. But for the sake of clarity and saving time can you please just restate it in the simplest possible terms? I'll make it easier by restating my thesis concisely. I claim: a. That any two observers can always establish an agreed 1:1 correlation of their proper times BETWEEN THEMSELVES. (This does NOT MEAN that A's t is always = B's t'. It means there is a 1:1 correlation that both A and B agree upon.) b. That this 1:1 relationship will be transitive in the sense that if A's t :: B's t', and B's t' :: C's t'', then C's t'' :: A's t. Assuming my method of establishing the 1:1 correlation what's your proof this is incorrect? Edgar On Friday, February 28, 2014 1:28:01 PM UTC-5, jessem wrote: On Fri, Feb 28, 2014 at 12:38 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, First I would appreciate it if you didn't snip my proximate post that you are replying to... Anyway we MUST choose a frame that preserves the symmetry because remember we are trying to establish a 1:1 proper time correlation BETWEEN THE TWINS THEMSELVES (not them and anyone else), and it is only a symmetric frame that preserves the facts as EXPERIENCED BY THE TWINS THEMSELVES. ALL we need to do in my p-time theory is demonstrate that each twin can correlate his OWN proper time with that of the other twin. But you agreed earlier (in your post at https://groups.google.com/d/msg/everything-list/jFX-wTm_E_Q/PYrVLII1ClYJ) that the idea of calling the comoving inertial frame of an observer their own frame is purely a matter of CONVENTION, not anything imposed on them by reality. So, we could easily choose a different convention--one in which each twin defines their own frame, or what they experience themselves, as the inertial frame in which they have a velocity of 0.99c along the x-axis. If they both agreed to define the facts as experienced by the twins themselves in this way, by convention, they could also agree on a 1:1 correlation between their proper times, one that would be different from the 1:1 correlation they'd get if they used the comoving frame. Do you wish to take back your earlier agreement that phrases like their own frame, their view, what they observe/experience are only by CONVENTION understood to refer to the comoving inertial frame, that this isn't something forced on us by reality? If you still agree this is a matter of convention, then it seems to me that trying to use something that's merely a matter of human linguistic convention to prove something absolute about reality is obviously silly, like trying to prove something about the essential nature of God by noting that according to the spelling conventions of English, God is dog spelled backwards. All the other frames are the views of OTHER observers, not the views of the twins themselves which is all that we need to consider to establish whether the TWINS THEMSELVES can establish a 1:1. Obviously if all observers agreed on an invariant 1:1 correlation we never would have to establish the 1:1 on a successive observer pair basis and then try to prove it transitive as I've consistently worked on doing. MY theory establishes this 1:1 correlation BETWEEN THE ACTUAL TWINS THEMSELVES on a pairwise basis, not on the basis of any invariance. Therefore it obviously uses a symmetric frame that is consistent with how those two twins experience their own and each other's realities and doesn't require input from any other frames to do that. That isn't obvious at all--I don't see how the symmetric frame reflects their experience in any way that isn't purely a matter of convention, they certainly don't experience their proper times and velocities being equal
Re: Block Universes
On Sat, Mar 1, 2014 at 9:55 AM, Edgar L. Owen edgaro...@att.net wrote: Jesse, Of course there is a rational justification for selecting one frame over another in many cases. All frames are NOT equal when it comes to representing ACTUAL physical facts. E.g. we can choose various frames to make someone's age pretty much any number we like but nevertheless they are still actually the age they think they are. If Alice is really 30 we can choose a frame in which she is all sorts of different ages I've already told you that proper time at an event on Alice's worldline is frame-independent, did you forget already? If one frame says Alice is 30 at a particular event in her worldline, like the event of her passing a particular object or observer (or her age when she reunites with her twin), then ALL frames say this, there is no need to use her comoving frame to get the correct answer. Different frames may disagree about simultaneity--what Alice's age is at the same moment that Bob turns 40, at a distant spatial location--but this is precisely why physicists don't believe there is any actual physical fact about simultaneity in relativity (this doesn't rule out presentism since there could still be a metaphysical fact about simultaneity, but no physical experiment would be able to determine it if there was, unless relativity turns out to be incorrect in its physical predictions). but she is still actually 30. Different VIEWS of her age don't change her actual age. Isn't that obvious, and don't you agree with this? Don't change her actual age WHEN? Doesn't change her age at some specific event on her worldline, or doesn't change what her age is now at the same moment that some distant observer like Bob reaches a particular age, say 40? If the first I agree that she has an actual age at any given event on her wrodline, but there ARE no different views of this since all frames agree on her proper age at any specific event on her worldline. If the latter I don't agree there is any physical basis for saying she has a unique actual age when Bob is 40, since relativity doesn't give any physical basis for a preferred definition of simultaneity. Your expertise in relativity is clear but you don't seem to understand that all frames are NOT equal when it comes to representing actual physical fact. You don't understand the fundamental notion in relativity that some frames represent actual physical fact, but others represent only HOW OTHER OBSERVERS VIEW those physical facts. Not a physicist in the world would agree with you that there is a fundamental notion in relativity that some frames represent actual physical facts, you appear to be completely confused about the difference between your own p-time views and mainstream relativity. In special relativity there can NEVER be a basis for considering one inertial frame more correct than any other. There are only two kinds of facts in relativity: 1. Facts about frame-independent matters like the proper time of an observer at a particular event on their worldline; all frames agree in their predictions about these, so they don't give any reason to prefer one frame over another. 2. Facts about frame-dependent matters like the coordinate velocity of an object at a particular event on its worldline, or the question of which point on worldline B is simultaneous with a particular point on worldline A; different frames disagree on these matters, and in relativity NO FRAME'S STATEMENTS ABOUT FRAME-DEPENDENT MATTERS ARE CONSIDERED MORE VALID THAN ANY OTHER FRAME'S. If you don't believe me that it's a basic principle of relativity that all frames are considered equally valid and none are preferred over others, here are some quotes from books written by physicists that I found on google books: If one reference frame moves uniformly relative to another, then the two are equally good frames for observing nature, and two identical experiments performed in the two frames will give identical results. --From Relativity for the Questioning Mind by Daniel Styer, at http://books.google.com/books?id=Ebr7YhJcUd0Clpg=PP1pg=PA13 The descriptions of the two sets of observers are equally real and equally valid, each within their own frame of reference. Since no preferred frame exists, there is no objective basis for ascribing any more reality to one description than the other. --From Understanding Relativity: A Simplified Approach to Einstein's Theories by Leo Sartori, at http://books.google.com/books?id=gV6kgxrZjL8Clpg=PP1pg=PA173 If Albert and Betty clap nearly simultaneously, one observer may report that Albert clapped first, whereas a second observer, in motion with respect to the first, may report that Betty clapped first. It makes no sense to ask, 'Who really clapped first?' The question assumes that one viewpoint, one reference frame, is valid or 'real' and the other is not. But time is not absolute; it is a property of a particular frame of reference. Both
Re: Block Universes
On 2 March 2014 05:42, Jesse Mazer laserma...@gmail.com wrote: On Sat, Mar 1, 2014 at 9:55 AM, Edgar L. Owen edgaro...@att.net wrote: Jesse, Of course there is a rational justification for selecting one frame over another in many cases. All frames are NOT equal when it comes to representing ACTUAL physical facts. E.g. we can choose various frames to make someone's age pretty much any number we like but nevertheless they are still actually the age they think they are. If Alice is really 30 we can choose a frame in which she is all sorts of different ages Edgar I'm sorry, but this sort of comment shows that your grasp of relativity theory is about as good as your understanding of block universes - which is to say that yet again, you're completely missing the point. All frames are equal when it comes to representing physical facts, some are just more convenient than others for doing the maths (hence relativity). And you can't make Alice's age whatever you like, you can only obtain different values by measuring it from frames moving at different velocities, because the planes of simultaneity attached to those frames intersect Alice's worldline at different points in space-time. Why not go away and read up on the subject before you pontificate about it? -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Liz, Hmmm, that's exactly what I said. So why are you disagreeing with yourself again? Looks like you are out of touch both with reality and English comprehension... Edgar On Saturday, March 1, 2014 3:51:18 PM UTC-5, Liz R wrote: On 2 March 2014 05:42, Jesse Mazer laser...@gmail.com javascript:wrote: On Sat, Mar 1, 2014 at 9:55 AM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, Of course there is a rational justification for selecting one frame over another in many cases. All frames are NOT equal when it comes to representing ACTUAL physical facts. E.g. we can choose various frames to make someone's age pretty much any number we like but nevertheless they are still actually the age they think they are. If Alice is really 30 we can choose a frame in which she is all sorts of different ages Edgar div class=gmail_e ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On Sat, Mar 1, 2014 at 5:35 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, Let me ask you one simple question. In the symmetric case where the twins part and then meet up again with the exact same real actual ages isn't it completely logical to conclude they must also have been the exact same real actual ages all during the trip? If, as you claim, the same exact proper accelerations do NOT result in the exact same actual ages all during the trip then how in hell can the twins actually have the exact same actual ages when they meet up? It's not that I'm claiming that there's an objective truth that they DON'T have the same ages during the trip. I'm just saying that as far as physics is concerned, there simply IS NO OBJECTIVE OR ACTUAL TRUTH ABOUT SIMULTANEITY, and thus there is neither an actual truth that they are the same age or an actual truth that they are different ages. These things are purely a matter of human coordinate conventions, like the question of which pairs of points on different measuring-tapes have the same y coordinates in any given Cartesian coordinate system. Similarly, questions of simultaneity reduce to questions about which pairs of points on different worldlines have the same t coordinate in any given inertial coordinate system, nothing more. What is the mysterious mechanism you propose that causes twins that do not have the same actual ages during the trip to just happen to end up with the exact same actual ages when they meet? Again, I do not say there is any objective truth that they do not have the same actual ages, I simply say there is no objective truth about which ages are actually simultaneous in some sense that is more than just an arbitrary coordinate convention. But if you're just asking about how things work in FRAMES where they don't have the same actual ages during the trip, the answer is that in such a frame you always find that the answer to which twin's clock is ticking faster changes at some point during the trip, so the twin whose clock was formerly ticking faster is now ticking slower after a certain time coordinate t, and it always balances out exactly so that their clocks have elapsed the same total time when they reunite. If you like I could give you a simple numerical example where I analyze a symmetric trip both from the frame where their velocities are symmetrical, and a different frame where their velocities are non-symmetrical, and show that it does work out that the second frame predicts their ages will be the same when they reunite despite them aging at different rates during different phases of the trip in this frame. Meanwhile, are you going to address the question about whether you agree with the 3 premises that I claim together lead to a contradiction? I'll repost the question from my last post: 'Again, the 3 premises are: 1. If a pair of inertial observers are at rest relative to one another, then events (like clock readings) that are simultaneous in their comoving frame are also simultaneous in p-time 2. Any two events that happen at precisely the same position and time coordinate in a particular inertial frame must be simultaneous in p-time 3. p-time simultaneity is transitive So to start with, please just tell me if you do agree with all these premises, or if there is one or more you disagree with or aren't sure about and require clarification on. And if you disagree with or are not sure about #2, this is the same point in spacetime issue we had been discussing earlier before you stopped responding, so in this case please go back to my last post on the subject at https://groups.google.com/d/msg/everything-list/jFX-wTm_E_Q/dM2tcGYspfMJand respond to that.' Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On 2 March 2014 11:51, Jesse Mazer laserma...@gmail.com wrote: On Sat, Mar 1, 2014 at 5:35 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, Let me ask you one simple question. In the symmetric case where the twins part and then meet up again with the exact same real actual ages isn't it completely logical to conclude they must also have been the exact same real actual ages all during the trip? If, as you claim, the same exact proper accelerations do NOT result in the exact same actual ages all during the trip then how in hell can the twins actually have the exact same actual ages when they meet up? The same answer as usual. Because the lengths of their worldlines through space-time between the start and end points are the same. Do pay attention, 007. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On Monday, February 24, 2014 10:57:14 PM UTC, Edgar L. Owen wrote: Ghibbsa, I apologize, but I'm a little unsure as to what you are actually asking of me here, but I'll try to answer. First P-time and relativity are NOT causally isolated. A proper interpretation of relativity actually implies the necessity of P-time. i've demonstrated why. Please read to my proximate reply to Quentin for an explanation of some of it. So because they are causally connected, there could be an inconsistency, which would be fatal, but there isn't any such consistency that has arisen even after many have tried to find one. Edgar They actually are not causally connected Edgar. p-time doesn't infer from within itself the layer above will be relativistic. And Relativity calculates everything and theoretically carries its own weight too without ever once depending on a p-time. What you do is, propose a common shared moment at the point of a handshake in a local space. Relativity explains how they got there independently of that, but because your proposition is inherently not causal, in that, it's an encapsulating dimension. Which it would be possible to propose a further encapsulation of that too, without changing anything. Because that's the nature of your proposition, there is no definitive, resolvable inconsistency. By the way that's the right way to do it IMHO. It's correct to introduce a theory that way. It's super robust. No one can refuse it. However the approach method is that of the tautology. It's the very best way to begin. But the introduction is then worth nothing in and of itself. Everything hangs on what you construct from that tautological foundation. The two problems I've pointed out in your efforts, have been, this one. And the one where you argue you can correlate moment for moment between twins, and that as a proof for p-time. Unfortunately it's not legitimate, what you say, because - remembering you are doing this correlating from absolute time, it's always going to be possible to 1:1 correlate, moment for moment, literally any two objects in the universe, if you are allowed to stretch or contract one of them in the dimension of measurement. Which is what you allow yourself to do to handle relativistic effects. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, To address your points in order: 1. Yes, you said that proper ages are invariant. But note the important point that the proper age of A to himself is a direct observation (he looks at his age clock), but to anyone else is a computation and NOT an observation. In fact from their native comoving frames they will observe A at some other age than their calculation. So the calculations trump the views. Thus it is valid in relativity to CALCULATE things we CANNOT OBSERVE from our frame. That's what I do to establish 1:1 correlations of actual ages. I use calculations that trump Views, that trump observations. We don't always have to use frame views to establish relativistic truth. Do you agree with that? You must if you accept proper age invariance. Also note that the ticks of the symmetric twins' own comoving clocks serve as event markers. So if the proper ages of the twins are invariant to all observers, then all observers can simply observe their clock tick markers reading exactly the same for the same proper ages of both twins. That PROVES the 1:1 correlation that the real actual ages of the symmetric twins always occur at the same clock tick markers and thus they are the same proper ages at the same times. Thus all observers agree that the proper ages of both twins occur at the same clock tick marker readings of the twins own proper clocks. This is one more proof the actual ages of the symmetric twins are equal during the trip, and EVERY OBSERVER AGREES ON THIS. Thus it is a real physical fact. 2. What all these quotes mean in saying that all frames are equally valid is that all observer VIEWS are real actual VIEWS of reality. That they are what the observer actually observes. I certainly agree with that. However as I've pointed out they don't all preserve the actual physical reality of SPECIFIC facts. I just pointed out how they don't with respect to the invariance of proper times which are not observable views but calculations. Proper age invariance is a physical fact at odds with the notion that all frames are equally valid as anything else than VIEWS. 3. No. By the different ages of twins in relative motion are not agreed and thus are views rather than actual physical facts I mean just that, and just what I've always said. The 1:1 correlation is NOT the VIEW of one twin of the other's clock. It is a logical calculation and not a view that establishes that 1:1. 4. **You now say you DON'T CLAIM YOU PROVE P-TIME SIMULTANEITY IS NOT TRANSITIVE!. OK, great. Wonderful! That's progress, and a complete change from what you said previously. You then are apparently trying to prove something else. But please, respectfully, you are trying to disprove MY theory, so please let ME state MY theory and then try to disprove that rather than trying to disprove something that isn't my actual theory. I just gave a concise statement of my theory earlier today. Can you disprove it or can't you? Edgar On Saturday, March 1, 2014 11:42:18 AM UTC-5, jessem wrote: On Sat, Mar 1, 2014 at 9:55 AM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, Of course there is a rational justification for selecting one frame over another in many cases. All frames are NOT equal when it comes to representing ACTUAL physical facts. E.g. we can choose various frames to make someone's age pretty much any number we like but nevertheless they are still actually the age they think they are. If Alice is really 30 we can choose a frame in which she is all sorts of different ages I've already told you that proper time at an event on Alice's worldline is frame-independent, did you forget already? If one frame says Alice is 30 at a particular event in her worldline, like the event of her passing a particular object or observer (or her age when she reunites with her twin), then ALL frames say this, there is no need to use her comoving frame to get the correct answer. Different frames may disagree about simultaneity--what Alice's age is at the same moment that Bob turns 40, at a distant spatial location--but this is precisely why physicists don't believe there is any actual physical fact about simultaneity in relativity (this doesn't rule out presentism since there could still be a metaphysical fact about simultaneity, but no physical experiment would be able to determine it if there was, unless relativity turns out to be incorrect in its physical predictions). but she is still actually 30. Different VIEWS of her age don't change her actual age. Isn't that obvious, and don't you agree with this? Don't change her actual age WHEN? Doesn't change her age at some specific event on her worldline, or doesn't change what her age is now at the same moment that some distant observer like Bob reaches a particular age, say 40? If the first I agree that she has an actual age at any given event on her wrodline, but there ARE no
Re: Block Universes
Jesse, Yes, but what you are saying here is just that it is impossible to unambiguously OBSERVE that the proper ages are the same. I agree. But it is possible to unambiguously DEDUCE and CALCULATE that they MUST be the same, which is all my theory says. If we can use calculation and deduction with respect to an invariant notion of proper ages that we CANNOT unambiguously observe, why can't we use calculation and deduction with proper age simultaneity as well? Edgar On Saturday, March 1, 2014 5:51:37 PM UTC-5, jessem wrote: On Sat, Mar 1, 2014 at 5:35 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, Let me ask you one simple question. In the symmetric case where the twins part and then meet up again with the exact same real actual ages isn't it completely logical to conclude they must also have been the exact same real actual ages all during the trip? If, as you claim, the same exact proper accelerations do NOT result in the exact same actual ages all during the trip then how in hell can the twins actually have the exact same actual ages when they meet up? It's not that I'm claiming that there's an objective truth that they DON'T have the same ages during the trip. I'm just saying that as far as physics is concerned, there simply IS NO OBJECTIVE OR ACTUAL TRUTH ABOUT SIMULTANEITY, and thus there is neither an actual truth that they are the same age or an actual truth that they are different ages. These things are purely a matter of human coordinate conventions, like the question of which pairs of points on different measuring-tapes have the same y coordinates in any given Cartesian coordinate system. Similarly, questions of simultaneity reduce to questions about which pairs of points on different worldlines have the same t coordinate in any given inertial coordinate system, nothing more. What is the mysterious mechanism you propose that causes twins that do not have the same actual ages during the trip to just happen to end up with the exact same actual ages when they meet? Again, I do not say there is any objective truth that they do not have the same actual ages, I simply say there is no objective truth about which ages are actually simultaneous in some sense that is more than just an arbitrary coordinate convention. But if you're just asking about how things work in FRAMES where they don't have the same actual ages during the trip, the answer is that in such a frame you always find that the answer to which twin's clock is ticking faster changes at some point during the trip, so the twin whose clock was formerly ticking faster is now ticking slower after a certain time coordinate t, and it always balances out exactly ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On 26 Feb 2014, at 15:32, Edgar L. Owen wrote: Stathis, At least we AGREE there is NO empirical evidence for a block universe. There is no evidence for a universe. (in the usual aristotelian sense of the word). But there is OVERWHELMING evidence for flowing time and a present moment. Not 3p evidences, and the relativity theory makes it senseless (as Jesse made rather clear here). Your p-time seems transitive, and this implies p-time is block-time. The experience of our existence in a present moment is the most fundamental empirical observation of our existence. It is a 1p evidence. It is not sharable. Using that type of evidence is not allow in polite conversation. And all science, all knowledge, is based on empirical observation. OK. But consciousness and flowing time are not empirical evidence. They are complex data top explain, but cannot be taken for granted, or even well defined. So, in the face of this obvious weight of evidence, why do you insist on a block universe instead of a universe in which time flows? Isn't it crazy to reject what there is enormous evidence for and accept what there is NO evidence for? That is what you do. There are no evidence for any universe, and indeed, as you assume comp, you could understand that there is no universe. The notion is close to inconsistent, and explanatively empty. Physicists measure numbers, and infer relation among numbers. Then even cosmological theories usually avoid metaphysical commitment. This is done by physicalist philosophers, and can make sense, but then not together with the assumption that the brain functions mechanically at some level. If you doubt this, then you must find a flaw in the UD Argument. Bruno Edgar On Tuesday, February 25, 2014 5:39:21 PM UTC-5, stathisp wrote: On 26 February 2014 08:07, Edgar L. Owen edga...@att.net wrote: Stathis, I know that's your point. You are just restating it once again, but you are completely UNABLE TO DEMONSTRATE IT without using some example in which time is already FLOWING. Since you can't demonstrate it, there is no reason to believe it. Belief in a block universe becomes a matter of blind faith, rather than a logical consequence of anything, and it is certainly NOT based on any empirical evidence whatsoever. I'm not arguing that there is empirical evidence for a block universe, just that a block universe is consistent with our experience. -- Stathis Papaioannou -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Bruno, Your contention that there is no evidence for a universe is simply delusional. The very fact you can make any statement absolutely PROVES a universe of some kind. Your contention is so absurd it's laughable.. Edgar On Friday, February 28, 2014 10:14:29 AM UTC-5, Bruno Marchal wrote: On 26 Feb 2014, at 15:32, Edgar L. Owen wrote: Stathis, At least we AGREE there is NO empirical evidence for a block universe. There is no evidence for a universe. (in the usual aristotelian sense of the word). But there is OVERWHELMING evidence for flowing time and a present moment. Not 3p evidences, and the relativity theory makes it senseless (as Jesse made rather clear here). Your p-time seems transitive, and this implies p-time is block-time. The experience of our existence in a present moment is the most fundamental empirical observation of our existence. It is a 1p evidence. It is not sharable. Using that type of evidence is not allow in polite conversation. And all science, all knowledge, is based on empirical observation. OK. But consciousness and flowing time are not empirical evidence. They are complex data top explain, but cannot be taken for granted, or even well defined. So, in the face of this obvious weight of evidence, why do you insist on a block universe instead of a universe in which time flows? Isn't it crazy to reject what there is enormous evidence for and accept what there is NO evidence for? That is what you do. There are no evidence for any universe, and indeed, as you assume comp, you could understand that there is no universe. The notion is close to inconsistent, and explanatively empty. Physicists measure numbers, and infer relation among numbers. Then even cosmological theories usually avoid metaphysical commitment. This is done by physicalist philosophers, and can make sense, but then not together with the assumption that the brain functions mechanically at some level. If you doubt this, then you must find a flaw in the UD Argument. Bruno Edgar On Tuesday, February 25, 2014 5:39:21 PM UTC-5, stathisp wrote: On 26 February 2014 08:07, Edgar L. Owen edga...@att.net wrote: Stathis, I know that's your point. You are just restating it once again, but you are completely UNABLE TO DEMONSTRATE IT without using some example in which time is already FLOWING. Since you can't demonstrate it, there is no reason to believe it. Belief in a block universe becomes a matter of blind faith, rather t ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, With regards to your contention in your first paragraph below it may express the correct view of frame DEPENDENT simultaneity, but that is NOT the point I'm making. I'll try to explain more clearly. This example is revised to attempt to conform with your previous objections so please bear with me. I'll keep it short... Take twins who start and finish a trip with the same proper ages. Define their trips as symmetric in the sense they both experience exactly equivalent proper accelerations at the exact same moments by their own proper clocks. (This is a new definition of symmetric.) This is why their ages must be the same when they meet. Now first I still maintain that in this case it is simple logic to conclude that there is a 1:1 correlation of their proper times during the trip, but I think we can now do better than that. Take the beginnings and ends of every phase of their acceleration changes, beginning with the start of the trip, as event markers. Now you, yourself, tell us that the proper times between every one of these markers is invariant. Now the question is whether these two invariant proper time sequences are synchronized or not. Whether there is a 1:1 correlation of proper times as each twin passes through these event markers that are defined identically in terms of each twin's proper acceleration? You point out that from the POV of all arbitrary frames they won't be, BUT the point is we MUST use a frame that MAINTAINS the real and actual symmetry to determine the ACTUAL REALITY of this situation. In any frame that PRESERVES that symmetry the observer WILL conclude that the proper times of both twins between all markers will be exactly the same, and thus the proper times of the twins at every one of these symmetric markers will be equal. Thus we do have a natural 1:1 correlation between the proper times of the twins that is also consistent with the direct observational agreement of proper times at start and finish, which we must account for in any accurate analysis. So my point is that there is a REAL AND ACTUAL SYMMETRY between the trips of the twins, and thus to get an accurate view of that real symmetry we must analyze it in a frame that preserves that symmetry. And when we do this we DO achieve a 1:1 correlation of proper ages during the trip, which must obviously be correct if they are to meet with the same ages. My whole approach depends on recognizing the difference between what is REALLY HAPPENING to someone as opposed to how any other observer may VIEW what is happening to that OTHER person. It is always what is actually happening to someone that is the reality irrespective of other's VIEWS of that reality. You consistently present the correct relativistic analysis of relativistic VIEWS without recognizing there is an ACTUAL REALITY involved that can be properly analyzed only by frames that recognize and preserve that reality. Do you agree that if we choose a frame that preserves the real and actual symmetry of the trip that we do get EQUAL proper times between all markers on the twins respective trips? And thus that we CAN establish a 1:1 correlation of proper times in this case? Edgar On Thursday, February 27, 2014 7:11:08 PM UTC-5, jessem wrote: On Thu, Feb 27, 2014 at 6:43 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, My understanding of the first part of your reply is though proper time is ONLY one's reading of one's own clock (as I stated) it IS possible for any other observer to calculate that proper time and always come up with the same answer. Is that correct? For a given clock C, it is possible for any observer to calculate the proper time between events ON C'S OWN WORLDLINE, and everyone will get the same answer (it is frame-invariant). But what is NOT frame-invariant is the answer to a question like what is the proper time on that distant clock RIGHT NOW, at the same moment that my own clock shows some specific time T--in that case you aren't talking about a specific event on C's worldline, you're talking about a specific event on your worldline (the event of your clock showing time T), and asking which event on C's worldline is simultaneous with that. Since simultaneity is frame-dependent in relativity, there is no frame-invariant answer to this second type of question. If so that's precisely what I've been claiming all along! That it's always possible for any observer to calculate any other observer's PROPER TIME. Why did I get the strong impression you were claiming that wasn't so from your previous replies? That is precisely the whole crux of my case, and precisely what I've been claiming In my view that is exactly what is necessary to establish a 1:1 correlation between proper times. If everyone can always calculate everyone's proper times including their own in an UNAMBIGUOUS INVARIANT WAY then why isn't it possible to
Re: Block Universes
On Fri, Feb 28, 2014 at 11:18 AM, Edgar L. Owen edgaro...@att.net wrote: You point out that from the POV of all arbitrary frames they won't be, BUT the point is we MUST use a frame that MAINTAINS the real and actual symmetry to determine the ACTUAL REALITY of this situation. Why? You give no rational justification for why reality should coincide with the frame where the coordinates assigned to their paths are symmetrical as opposed to any other frame which makes the same physical predictions, this just seems like a quasi-aesthetic intuition on your part. But I also have a more definitive argument against identifying simultaneity in the frame where their paths look symmetrical with any sort of absolute simultaneity--because, as I have said over and over, it leads directly to contradictions when we consider multiple symmetrical pairs of observers, and the transitive nature of absolute simultaneity/p-time. If you will just respond to my Feb 24 post at https://groups.google.com/d/msg/everything-list/jFX-wTm_E_Q/dM2tcGYspfMJ as you promised to do earlier, then as soon as we are completely settled on the matter of whether events that have the same space and time coordinates in an inertial frame must have happened at the same p-time, we can go back and look at the Alice/Bob/Arlene/Bart example at https://groups.google.com/d/msg/everything-list/jFX-wTm_E_Q/pxg0VAAHJRQJwhich PROVES that a contradiction follows from your assumptions, given the premise that events with the same space and time coordinates in an inertial frame happened at the same p-time. Do you agree that if we choose a frame that preserves the real and actual symmetry of the trip that we do get EQUAL proper times between all markers on the twins respective trips? And thus that we CAN establish a 1:1 correlation of proper times in this case? The real and actual symmetry is that they have symmetrical proper accelerations as a function of proper time, but ALL frames preserve this symmetry. I agree that we are free to use a frame where their coordinate velocities and proper time as a function of coordinate time are ALSO symmetrical, but these are simply statements about coordinates, I see no reason to consider them any more real and actual than the coordinates assigned to their paths in any other frame. Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, First I would appreciate it if you didn't snip my proximate post that you are replying to... Anyway we MUST choose a frame that preserves the symmetry because remember we are trying to establish a 1:1 proper time correlation BETWEEN THE TWINS THEMSELVES (not them and anyone else), and it is only a symmetric frame that preserves the facts as EXPERIENCED BY THE TWINS THEMSELVES. ALL we need to do in my p-time theory is demonstrate that each twin can correlate his OWN proper time with that of the other twin. All the other frames are the views of OTHER observers, not the views of the twins themselves which is all that we need to consider to establish whether the TWINS THEMSELVES can establish a 1:1. Obviously if all observers agreed on an invariant 1:1 correlation we never would have to establish the 1:1 on a successive observer pair basis and then try to prove it transitive as I've consistently worked on doing. MY theory establishes this 1:1 correlation BETWEEN THE ACTUAL TWINS THEMSELVES on a pairwise basis, not on the basis of any invariance. Therefore it obviously uses a symmetric frame that is consistent with how those two twins experience their own and each other's realities and doesn't require input from any other frames to do that. MY theory then attempts to prove these correlations are transitive on a pair by pair basis, not by considering all irrelevant frames and trying to establish some invariance that I agree is impossible. Does this make it clear what my theory is trying to do? The theory is based on pair wise correlations, not invariance Edgar On Friday, February 28, 2014 11:55:40 AM UTC-5, jessem wrote: On Fri, Feb 28, 2014 at 11:18 AM, Edgar L. Owen edga...@att.netjavascript: wrote: You point out that from the POV of all arbitrary frames they won't be, BUT the point is we MUST use a frame that MAINTAINS the real and actual symmetry to determine the ACTUAL REALITY of this situation. Why? You give no rational justification for why reality should coincide with the frame where the coordinates assigned to their paths are symmetrical as opposed to any other frame which makes the same physical predictions, this just seems like a quasi-aesthetic intuition on your part. But I also have a more definitive argument against identifying simultaneity in the frame where their paths look symmetrical with any sort of absolute simultaneity--because, as I have said over and over, it leads directly to contradictions when we consider multiple symmetrical pairs of observers, and the transitive nature of absolute simultaneity/p-time. If you will just respond to my Feb 24 post at https://groups.google.com/d/msg/everything-list/jFX-wTm_E_Q/dM2tcGYspfMJas you promised to do earlier, then as soon as we are completely settled on the matter of whether events that have the same space and time coordinates in an inertial frame must have happened at the same p-time, we can go back and look at the Alice/Bob/Arlene/Bart example at https://groups.google.com/d/msg/everything-list/jFX-wTm_E_Q/pxg0VAAHJRQJwhich PROVES that a contradiction follows from your assumptions, given ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On 27 Feb 2014, at 04:45, Jesse Mazer wrote: On Wed, Feb 26, 2014 at 8:52 PM, Edgar L. Owen edgaro...@att.net wrote: Can you agree to this at least? To repeat what I said in my second-to-last post: 'If you continue to ask me Do you agree? type questions while ignoring the similar questions I ask you, I guess I'll have to take that as a sign of contempt, in which case as I said I won't be responding to further posts of yours. Any response is better than just completely ignoring questions, even if it's something like I find your questions ambiguous or you've asked too many questions and I don't have time for them all right now, please narrow it down to one per post.' If you decide to treat me with the same basic level of respect I have treated you, rather than making a show of asking me questions while you contemptuously ignore my requests that you address mine, then I will keep going with this. If not, I have better things to do. I think some people does not argue, they fake it only. Edgar does not answer the question asked. Bruno Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On 28 Feb 2014, at 00:10, LizR wrote: Any attempt to separate out time from space-time and remain within the context of special relativity is bound to fail, because SR is the unification of space and time. In Newtonian theory there was absolute space and absolute time. In SR there is only absolute space- time (in the sense of invariant distances through space-time). In SR, time is relative, and lunch time doubly so. :) http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On Fri, Feb 28, 2014 at 12:38 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, First I would appreciate it if you didn't snip my proximate post that you are replying to... Anyway we MUST choose a frame that preserves the symmetry because remember we are trying to establish a 1:1 proper time correlation BETWEEN THE TWINS THEMSELVES (not them and anyone else), and it is only a symmetric frame that preserves the facts as EXPERIENCED BY THE TWINS THEMSELVES. ALL we need to do in my p-time theory is demonstrate that each twin can correlate his OWN proper time with that of the other twin. But you agreed earlier (in your post at https://groups.google.com/d/msg/everything-list/jFX-wTm_E_Q/PYrVLII1ClYJ ) that the idea of calling the comoving inertial frame of an observer their own frame is purely a matter of CONVENTION, not anything imposed on them by reality. So, we could easily choose a different convention--one in which each twin defines their own frame, or what they experience themselves, as the inertial frame in which they have a velocity of 0.99c along the x-axis. If they both agreed to define the facts as experienced by the twins themselves in this way, by convention, they could also agree on a 1:1 correlation between their proper times, one that would be different from the 1:1 correlation they'd get if they used the comoving frame. Do you wish to take back your earlier agreement that phrases like their own frame, their view, what they observe/experience are only by CONVENTION understood to refer to the comoving inertial frame, that this isn't something forced on us by reality? If you still agree this is a matter of convention, then it seems to me that trying to use something that's merely a matter of human linguistic convention to prove something absolute about reality is obviously silly, like trying to prove something about the essential nature of God by noting that according to the spelling conventions of English, God is dog spelled backwards. All the other frames are the views of OTHER observers, not the views of the twins themselves which is all that we need to consider to establish whether the TWINS THEMSELVES can establish a 1:1. Obviously if all observers agreed on an invariant 1:1 correlation we never would have to establish the 1:1 on a successive observer pair basis and then try to prove it transitive as I've consistently worked on doing. MY theory establishes this 1:1 correlation BETWEEN THE ACTUAL TWINS THEMSELVES on a pairwise basis, not on the basis of any invariance. Therefore it obviously uses a symmetric frame that is consistent with how those two twins experience their own and each other's realities and doesn't require input from any other frames to do that. That isn't obvious at all--I don't see how the symmetric frame reflects their experience in any way that isn't purely a matter of convention, they certainly don't experience their proper times and velocities being equal at each coordinate time if they don't CHOOSE to use a particular coordinate system. All that they directly experience in a way that doesn't depend on coordinate systems is the way that their proper acceleration varied as a function of their proper time. MY theory then attempts to prove these correlations are transitive on a pair by pair basis, not by considering all irrelevant frames and trying to establish some invariance that I agree is impossible. Does this make it clear what my theory is trying to do? The theory is based on pair wise correlations, not invariance My proof of a contradiction in your ideas about p-time doesn't consider the other frames you consider irrelevant either, it is based SOLELY on the following premises: 1. If a pair of inertial observers are at rest relative to one another, then events (like clock readings) that are simultaneous in their comoving frame are also simultaneous in p-time 2. Any two events that happen at precisely the same position and time coordinate in a particular inertial frame must be simultaneous in p-time 3. p-time simultaneity is transitive Your only response was to dispute premise #2, but subsequent discussion suggested you were originally misunderstanding what I meant by same position and time coordinate and that properly understood, you would most like agree with premise #2 after all. That's why I want you to address my last few questions about the same position and time coordinate issue at https://groups.google.com/d/msg/everything-list/jFX-wTm_E_Q/dM2tcGYspfMJwhich you promised to address earlier, but have subsequently ignored all my requests to get back to. Once again, if you continue to just ignore the requests, that indicates a lack of respect for me and for the two-way nature of discussions. Here, I'll even repost those questions to save you the time of going back through your inbox to find the original post to reply to: On Mon, Feb 24, 2014 at 6:53 PM, Edgar L. Owen edgaro...@att.netwrote: Jesse, Well, I
Re: Block Universes
On 28 Feb 2014, at 16:20, Edgar L. Owen wrote: Bruno, Your contention that there is no evidence for a universe is simply delusional. I meant the Aristotelian universe, where physics is supposed to describe the fundamental ontology, or what is. Of course I believe in something, and I take very seriously the appearance of some physical reality into account. The very fact you can make any statement absolutely PROVES a universe of some kind. I agree. And I tend to believe in the arithmetical reality. The computable is a part of the arithmetical reality, which is larger. It happens that the arithmetical computable part can infer and even mirror larger and larger part of the non computable. See the book by Matiyasevich to see how diophantine relations can simulate Turing machines. Bruno Your contention is so absurd it's laughable.. Edgar On Friday, February 28, 2014 10:14:29 AM UTC-5, Bruno Marchal wrote: On 26 Feb 2014, at 15:32, Edgar L. Owen wrote: Stathis, At least we AGREE there is NO empirical evidence for a block universe. There is no evidence for a universe. (in the usual aristotelian sense of the word). But there is OVERWHELMING evidence for flowing time and a present moment. Not 3p evidences, and the relativity theory makes it senseless (as Jesse made rather clear here). Your p-time seems transitive, and this implies p-time is block-time. The experience of our existence in a present moment is the most fundamental empirical observation of our existence. It is a 1p evidence. It is not sharable. Using that type of evidence is not allow in polite conversation. And all science, all knowledge, is based on empirical observation. OK. But consciousness and flowing time are not empirical evidence. They are complex data top explain, but cannot be taken for granted, or even well defined. So, in the face of this obvious weight of evidence, why do you insist on a block universe instead of a universe in which time flows? Isn't it crazy to reject what there is enormous evidence for and accept what there is NO evidence for? That is what you do. There are no evidence for any universe, and indeed, as you assume comp, you could understand that there is no universe. The notion is close to inconsistent, and explanatively empty. Physicists measure numbers, and infer relation among numbers. Then even cosmological theories usually avoid metaphysical commitment. This is done by physicalist philosophers, and can make sense, but then not together with the assumption that the brain functions mechanically at some level. If you doubt this, then you must find a flaw in the UD Argument. Bruno Edgar On Tuesday, February 25, 2014 5:39:21 PM UTC-5, stathisp wrote: On 26 February 2014 08:07, Edgar L. Owen edga...@att.net wrote: Stathis, I know that's your point. You are just restating it once again, but you are completely UNABLE TO DEMONSTRATE IT without using some example in which time is already FLOWING. Since you can't demonstrate it, there is no reason to believe it. Belief in a block universe becomes a matter of blind faith, rather t ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Bruno, Nonsense. You continually ask the exact same questions which I answered several times but just ignore my answers and keep asking the same questions, and when you rarely do respond to my answers you do so incoherently and only in terms of your own very rigid worldview. Well perhaps that's the way that 1p zombies 1p clones operate? Anyway I do answer all serious questions... Edgar On Friday, February 28, 2014 12:42:26 PM UTC-5, Bruno Marchal wrote: On 27 Feb 2014, at 04:45, Jesse Mazer wrote: On Wed, Feb 26, 2014 at 8:52 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Can you agree to this at least? To repeat what I said in my second-to-last post: 'If you continue to ask me Do you agree? type questions while ignoring the similar questions I ask you, I guess I'll have to take that as a sign of contempt, in which case as I said I won't be responding to further posts of yours. Any response is better than just completely ignoring questions, even if it's something like I find your questions ambiguous or you've asked too many questions and I don't have time for them all right now, please narrow it down to one per post.' If you decide to treat me with the same basic level of respect I have treated you, rather than making a show of asking me questions while you contemptuously ignore my requests that you address mine, then I will keep going with this. If not, I have better things to do. I think some people does not argue, they fake it only. Edgar does not answer the question asked. Bruno Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscribe javascript: ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On 1 March 2014 04:14, Bruno Marchal marc...@ulb.ac.be wrote: On 26 Feb 2014, at 15:32, Edgar L. Owen wrote: Stathis, At least we AGREE there is NO empirical evidence for a block universe. There is no evidence for a universe. (in the usual Aristotelian sense of the word). True. If only because evidence isn't for things. But in any case, Edgar doesn't appear to grasp what a block universe is, as he proves by his continual meaningless comments about it. He has some weird idea that has nothing to do with the scientific concept expounded in relativity, and that's what he's arguing against. So, rather like the discussion Jesse has been having with him about p-time, this is a pointless discussion. As I mentioned (it must have been some weeks ago now) with regard to Edgar-ism, you can't argue with a religious fanatic who refuses to consider any opposing viewpoint, and who sees everything you say through the lens of his own fantasy. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On 1 March 2014 06:42, Bruno Marchal marc...@ulb.ac.be wrote: On 27 Feb 2014, at 04:45, Jesse Mazer wrote: On Wed, Feb 26, 2014 at 8:52 PM, Edgar L. Owen edgaro...@att.net wrote: Can you agree to this at least? To repeat what I said in my second-to-last post: 'If you continue to ask me Do you agree? type questions while ignoring the similar questions I ask you, I guess I'll have to take that as a sign of contempt, in which case as I said I won't be responding to further posts of yours. Any response is better than just completely ignoring questions, even if it's something like I find your questions ambiguous or you've asked too many questions and I don't have time for them all right now, please narrow it down to one per post.' If you decide to treat me with the same basic level of respect I have treated you, rather than making a show of asking me questions while you contemptuously ignore my requests that you address mine, then I will keep going with this. If not, I have better things to do. I think some people does not argue, they fake it only. Edgar does not answer the question asked. On most forums he would have been banned as a troll, because either (a) he is too stupid to grasp the arguments of his opponents and give a rational response or (b) he is deliberately refusing to do so. The polite assumption is (b), which makes him a troll - someone who deliberately tries to provoke arguments for their own malicious amusement. If this forum wasn't full of saints, everyone would by now have given up talking to him. Instead, because we tend to believe that everyone is rational and can be educated if we try hard enough, we keep trying (I did for quite a while). But of course a troll is, in game-theoretic terms, a defector in what is mostly a community of co-operators. Hence they flourish for a while, until everyone gets tired of hitting their head against a brick wall. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On Fri, Feb 28, 2014 at 04:14:29PM +0100, Bruno Marchal wrote: Isn't it crazy to reject what there is enormous evidence for and accept what there is NO evidence for? That is what you do. There are no evidence for any universe, and indeed, as you assume comp, you could understand that there is no universe. The notion is close to inconsistent, and explanatively empty. Physicists measure numbers, and infer relation among numbers. Then even cosmological theories usually avoid metaphysical commitment. This is done by physicalist philosophers, and can make sense, but then not together with the assumption that the brain functions mechanically at some level. Sorry to be pernicketty, but if you are working in a theory that makes no ontologicical commitment (or metaphysical, which I assume is the same thing), then how does that contradict your reversal result? It is only a theory _about_ phenomena, not about what's ontologically real. -- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On 28 Feb 2014, at 21:05, Edgar L. Owen wrote: Bruno, Nonsense. You continually ask the exact same questions which I answered several times but just ignore my answers and keep asking the same questions, and when you rarely do respond to my answers you do so incoherently and only in terms of your own very rigid worldview. Define what you mean by computation. you did not answer this, or give me the link. What you did is to repeat things like reality computes, which add more mystery to the notion. You never answered if you are OK with Church thesis. Bruno Well perhaps that's the way that 1p zombies 1p clones operate? Anyway I do answer all serious questions... Edgar On Friday, February 28, 2014 12:42:26 PM UTC-5, Bruno Marchal wrote: On 27 Feb 2014, at 04:45, Jesse Mazer wrote: On Wed, Feb 26, 2014 at 8:52 PM, Edgar L. Owen edga...@att.net wrote: Can you agree to this at least? To repeat what I said in my second-to-last post: 'If you continue to ask me Do you agree? type questions while ignoring the similar questions I ask you, I guess I'll have to take that as a sign of contempt, in which case as I said I won't be responding to further posts of yours. Any response is better than just completely ignoring questions, even if it's something like I find your questions ambiguous or you've asked too many questions and I don't have time for them all right now, please narrow it down to one per post.' If you decide to treat me with the same basic level of respect I have treated you, rather than making a show of asking me questions while you contemptuously ignore my requests that you address mine, then I will keep going with this. If not, I have better things to do. I think some people does not argue, they fake it only. Edgar does not answer the question asked. Bruno Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscribe ... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
Jesse, I haven't answered those questions out of any disrespect or rudeness but because I was working on a new explanation which I think does specifically address and answer all of them which I present in this post. I will be happy to answer any of your questions if you think they are still relevant after reading this post which I think solves the 1:1 age correlation to your satisfaction. If you find any of the terminology confusing please let me know what you think it SHOULD be rather than just saying it's wrong. Twins A and B start at the same location in deep space. No acceleration, no gravitation. Their ages are obviously the same, and their age clocks are running at the same rate. They exchange flight plans and embark on their separate trips according to those flight plans. Now the only effects that will alter the rates of their age clocks are acceleration or gravitation. But each twin can continually measure the amount of acceleration or gravitation he experiences with a scale. So each twin can always calculate how much his age has slowed relative to what his age WOULD HAVE BEEN had he NOT experienced any gravitation or acceleration. Let's call that his 'inertial age', the age he WOULD have been had he NOT experienced any acceleration or gravitation. So each twin always knows what inertial age corresponds to his actual age. And because each twin has the exact flight plan of the other twin, he also can calculate what inertial age corresponds to the actual age of the other twin at any point on his trip because the flight plan tells him what all accelerations and gravitational effects will be. Thus it is a simple, frame independent matter for both twins to get a 1:1 correspondence between their respective actual ages in terms of their inertial ages since their inertial ages will always be the same. If A is age a' when his inertial age is I', and B is age a'' when his inertial age is I', then A will be actual age a' when B is actual age a'', and we can always establish such a 1:1 correspondence of actual ages for any actual age of either. And both twins will always AGREE on this 1:1 correlation of their actual ages. Note it is not even necessary to exchange flight plans. Each twin can just continually transmit a light signal to the other giving his current actual age in terms of his inertial age. That again allows both twins to correlate their actual ages. So this gives us a frame independent way for any two observers who initially synchronize their inertial ages to the same arbitrary value to always establish an UN-ambiguous, AGREED 1:1 correlation of their actual ages. Do you agree? Edgar On Wednesday, February 26, 2014 10:45:51 PM UTC-5, jessem wrote: On Wed, Feb 26, 2014 at 8:52 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Can you agree to this at least? To repeat what I said in my second-to-last post: 'If you continue to ask me Do you agree? type questions while ignoring the similar questions I ask you, I guess I'll have to take that as a sign of contempt, in which case as I said I won't be responding to further posts of yours. Any response is better than just completely ignoring questions, even if it's something like I find your questions ambiguous or you've asked too many questions and I don't have time for them all right now, please narrow it down to one per post.' If you decide to treat me with the same basic level of respect I have treated you, rather than making a show of asking me questions while you contemptuously ignore my requests that you address mine, then I will keep going with this. If not, I have better things to do. Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
Re: Block Universes
On Thu, Feb 27, 2014 at 9:25 AM, Edgar L. Owen edgaro...@att.net wrote: Jesse, I haven't answered those questions out of any disrespect or rudeness but because I was working on a new explanation which I think does specifically address and answer all of them which I present in this post. I will be happy to answer any of your questions if you think they are still relevant after reading this post which I think solves the 1:1 age correlation to your satisfaction. That's the problem, you continually come up with new arguments and explanations that you think resolve the questions I asked and therefore mean you don't need to address them, but inevitably I disagree. Please just respect my judgment about what's relevant TO ME, and answer the questions that I ask ALONGSIDE any new arguments or explanations you might want to supply. You say above I will be happy to answer any of your questions if you think they are still relevant after reading this post, so I will hold you to that by repeating a question I'd like you to answer at the end of this post. If you find any of the terminology confusing please let me know what you think it SHOULD be rather than just saying it's wrong. Twins A and B start at the same location in deep space. No acceleration, no gravitation. Their ages are obviously the same, and their age clocks are running at the same rate. They exchange flight plans and embark on their separate trips according to those flight plans. Now the only effects that will alter the rates of their age clocks are acceleration or gravitation. But each twin can continually measure the amount of acceleration or gravitation he experiences with a scale. Let's consider just the issue of accelerations in flat SR spacetime for now, since it's simpler. The problem with this statement is that although it's true each twin can measure their proper acceleration, there is no FRAME-INDEPENDENT equation in relativity for how a given acceleration affects the rates of their age clocks, the only equations dealing with clock rates and acceleration in SR deal with how changes in coordinate velocity (determined by acceleration) affect the rate a clock is ticking relative to coordinate time in some specific coordinate system. So each twin can always calculate how much his age has slowed relative to what his age WOULD HAVE BEEN had he NOT experienced any gravitation or acceleration. Let's call that his 'inertial age', the age he WOULD have been had he NOT experienced any acceleration or gravitation. I see no way to define this in any frame-independent way. The only version of this that relativity would allow you to calculate is what your age would have been at a PARTICULAR COORDINATE TIME if you had remained inertial, and you can compare that to what your age is at that SAME COORDINATE TIME given your acceleration history. But this comparison obviously gives different results in different coordinate systems. So, I don't agree with your subsequent conclusion that this allows two twins to define a 1:1 correlation in their ages in a frame-independent way. There are a number of questions I asked in the last few posts that none of your answers have addressed, but I'll restrict myself to repeating one for now: 'Also, do you understand that even for inertial observers, the idea that an observer's own rest frame can be labeled his view or taken to describe his observations is PURELY A MATTER OF CONVENTION, not something that is forced on us by the laws of nature? Physicists just don't want to have to write out in the observer's comoving inertial frame all the time, so they just adopt a linguistic convention that lets them write simpler things like from this observer's perspective or in his frame as a shorthand for the observer's comoving inertial frame. Physically there is no reason an observer can't assign coordinates to events using rulers and clocks that are moving relative to himself though, lots of real-world experiments involve measuring-instruments that move relative to the people carrying out the experiment.' Do you agree with the above paragraph? Jesse On Wednesday, February 26, 2014 10:45:51 PM UTC-5, jessem wrote: On Wed, Feb 26, 2014 at 8:52 PM, Edgar L. Owen edga...@att.net wrote: Can you agree to this at least? To repeat what I said in my second-to-last post: 'If you continue to ask me Do you agree? type questions while ignoring the similar questions I ask you, I guess I'll have to take that as a sign of contempt, in which case as I said I won't be responding to further posts of yours. Any response is better than just completely ignoring questions, even if it's something like I find your questions ambiguous or you've asked too many questions and I don't have time for them all right now, please narrow it down to one per post.' If you decide to treat me with the same basic level of respect I have treated you, rather than making a show of asking me questions while you
Re: Block Universes
Jesse, First the answer to your question at the end of your post. Yes, of course I agree. Again that's just standard relativity theory. However as you point out by CONVENTION it means the observer's comoving inertial frame which is the way I was using it. Now to your replies to my post beginning with your first paragraph. Certainly there are equations that do what you say they do, but I don't see why what I say isn't correct based on that. Why do you claim it is impossible to just take proper acceleration and calculate what my age would have been if there was not any proper acceleration? An observer knows what his proper acceleration is, and he knows how much various accelerations are slowing his proper time relative to what it would be if those accelerations didn't happen. He has a frame independent measure of acceleration. He knows that particular acceleration will slow his proper time by 1/2 so he can define and calculate an 'inertial time' whose rate is 2x his proper rate. You seem to think it would be necessary to MEASURE THIS FROM SOME FRAME for the concept to be true. It's not an observable measure, it's the CALCULATION of a useful variable. Therefore there is NO requirement that it's measurable in any frame because it's a frame independent concept, a calculation rather than an observable. Therefore I don't see any reason to accept your criticism in this paragraph. If you disagree, which I'm sure you will, then explain why this concept of inertial time is not frame independent and valid. Perhaps a clear example would help? Another way to approach this is do you deny that if we drop a coordinate grid on an area of EMPTY space that the coordinate clocks at the grid intersections all run at the same rate? And if not, why? And don't start making up other frames on me here. Just compare the proper times of those coordinate clocks. Do they all run at the same rate or not? Edgar On Thursday, February 27, 2014 11:56:08 AM UTC-5, jessem wrote: On Thu, Feb 27, 2014 at 9:25 AM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, I haven't answered those questions out of any disrespect or rudeness but because I was working on a new explanation which I think does specifically address and answer all of them which I present in this post. I will be happy to answer any of your questions if you think they are still relevant after reading this post which I think solves the 1:1 age correlation to your satisfaction. That's the problem, you continually come up with new arguments and explanations that you think resolve the questions I asked and therefore mean you don't need to address them, but inevitably I disagree. Please just respect my judgment about what's relevant TO ME, and answer the questions that I ask ALONGSIDE any new arguments or explanations you might want to supply. You say above I will be happy to answer any of your questions if you think they are still relevant after reading this post, so I will hold you to that by repeating a question I'd like you to answer at the end of this post. If you find any of the terminology confusing please let me know what you think it SHOULD be rather than just saying it's wrong. Twins A and B start at the same location in deep space. No acceleration, no gravitation. Their ages are obviously the same, and their age clocks are running at the same rate. They exchange flight plans and embark on their separate trips according to those flight plans. Now the only effects that will alter the rates of their age clocks are acceleration or gravitation. But each twin can continually measure the amount of acceleration or gravitation he experiences with a scale. Let's consider just the issue of accelerations in flat SR spacetime for now, since it's simpler. The problem with this statement is that although it's true each twin can measure their proper acceleration, there is no FRAME-INDEPENDENT equation in relativity for how a given acceleration affects the rates of their age clocks, the only equations dealing with clock rates and acceleration in SR deal with how changes in coordinate velocity (determined by acceleration) affect the rate a clock is ticking relative to coordinate time in some specific coordinate system. So each twin can always calculate how much his age has slowed relative to what his age WOULD HAVE BEEN had he NOT experienced any gravitation or acceleration. Let's call that his 'inertial age', the age he WOULD have been had he NOT experienced any acceleration or gravitation. I see no way to define this in any frame-independent way. The only version of this that relativity would allow you to calculate is what your age would have been at a PARTICULAR COORDINATE TIME if you had remained inertial, and you can compare that to what your age is at that SAME COORDINATE TIME given your acceleration history. But this comparison obviously
Re: Block Universes
On Thu, Feb 27, 2014 at 2:38 PM, Edgar L. Owen edgaro...@att.net wrote: Jesse, First the answer to your question at the end of your post. Yes, of course I agree. Again that's just standard relativity theory. However as you point out by CONVENTION it means the observer's comoving inertial frame which is the way I was using it. Thanks, it seemed like you might have been suggesting there was some natural truth to calculations done in the comoving frame of two obserervers at rest relative to each other, even though they could equally well agree to calculate things from the perspective of a totally different frame. Now to your replies to my post beginning with your first paragraph. Certainly there are equations that do what you say they do, but I don't see why what I say isn't correct based on that. Why do you claim it is impossible to just take proper acceleration and calculate what my age would have been if there was not any proper acceleration? I don't claim it's impossible, just that it can only be done relative to a particular frame. I can make statements like I am now 30, but in frame A, if I hadn't accelerated I would now be 20 and I am now 30, but in frame B, if I hadn't accelerated I would now be 25. An observer knows what his proper acceleration is, and he knows how much various accelerations are slowing his proper time relative to what it would be if those accelerations didn't happen. Slowing his proper time only has meaning relative to a particular frame, there is no frame-independent sense in which clocks slow down (or speed up) due to acceleration in relativity. He has a frame independent measure of acceleration. He knows that particular acceleration will slow his proper time by 1/2 so he can define and calculate an 'inertial time' whose rate is 2x his proper rate. Given the exact same proper acceleration, there may be one frame A where at the end of the acceleration his clock has slowed by 1/2 (relative to the time coordinate of that frame), and another frame B where it has slowed by 1/3, and even another frame where it has *sped up* by a factor of 10. Do you disagree? You seem to think it would be necessary to MEASURE THIS FROM SOME FRAME for the concept to be true. It's not an observable measure, it's the CALCULATION of a useful variable. Therefore there is NO requirement that it's measurable in any frame because it's a frame independent concept, a calculation rather than an observable. Calculations are always calculations of the values of particular numerical quantities, like the rate a clock is ticking. So, what matters is whether the quantity in question is frame-dependent (like velocity, or rate of clock ticking) or frame-independent (like proper time at a specific event on someone's worldine), there is nothing inherent in the notion of calculations that make them frame-independent. Also, *all* calculated quantities in relativity can also be observables--it's straightforward to observe frame-independent quantities like proper time (just look at the clock the observer carries), and frame-dependent ones can also be observed if you have a physical grid of rulers and coordinate clocks as I have described before (for example, to find the rate a clock is ticking relative to a coordinate system, you look at the time T1 it reads as it passes next to a coordinate clock that reads t1, and the time T2 it reads as it passes next to another coordinate clock that reads t2, and then you can just define the average rate over that interval as [T2 - T1]/[t2 - t1], and if the difference between T2 and T1 approaches 0 this approaches the *instantaneous* rate at T1). Therefore I don't see any reason to accept your criticism in this paragraph. If you disagree, which I'm sure you will, then explain why this concept of inertial time is not frame independent and valid. Perhaps a clear example would help? If you disagree with my statement above that different frames can disagree on the amount that a clock slowed down (or sped up) after a given proper acceleration, I can give you a numerical example. Another way to approach this is do you deny that if we drop a coordinate grid on an area of EMPTY space that the coordinate clocks at the grid intersections all run at the same rate? And if not, why? Are you talking about an inertial coordinate grid of rigid rulers, or an arbitrary non-inertial coordinate grid where we can imagine different grid points connected by rubbery rulers that can stretch and compress over time? In the simpler case of an inertial grid, obviously all inertial coordinate clocks tick at the same rate relative to any other inertial coordinate system, though not necessarily relative to an arbitrary non-inertial system. And the clocks of an arbitrary non-inertial coordinate system need not tick at a constant rate relative to inertial systems. And don't start making up other frames on me here. Just compare the proper times of those
Re: Block Universes
Jesse, Remember we are talking ONLY about PROPER TIMES, or actual ages. These DO NOT HAVE any MEANING IN OTHER FRAMES than that of the actual frame of the observer in question. So your comments that an observer's age will be measured differently in other frames, while obviously true, is NOT the observer's PROPER AGE or PROPER TIME. Every observer has one and only one proper age, that is his proper age to himself, NOT to anyone else, not in any other frame. That holds for all your comments about age effects of acceleration being different in different frames. Of course they can be but that is NOT PROPER ACTUAL AGE. So I have to disregard all those comments because they don't apply to PROPER TIMES OR ACTUAL AGES. Proper time is ONLY one's reading of one's own clock, NOT one's own clock viewed from some other frame. Correct? Now a very basic question. Do you agree or disagree that all PROPER TIMES run at the same rate unless some effect causes them to run at different rates? Again this is NOT how clocks appear to run in any other frames but their OWN. If you do not agree then please explain why not and please PROVE to me that PROPER TIMES do not run at the same rate unless there is some actual effect that causes them to run at different rates. Edgar On Thursday, February 27, 2014 3:07:41 PM UTC-5, jessem wrote: On Thu, Feb 27, 2014 at 2:38 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Jesse, First the answer to your question at the end of your post. Yes, of course I agree. Again that's just standard relativity theory. However as you point out by CONVENTION it means the observer's comoving inertial frame which is the way I was using it. Thanks, it seemed like you might have been suggesting there was some natural truth to calculations done in the comoving frame of two obserervers at rest relative to each other, even though they could equally well agree to calculate things from the perspective of a totally different frame. Now to your replies to my post beginning with your first paragraph. Certainly there are equations that do what you say they do, but I don't see why what I say isn't correct based on that. Why do you claim it is impossible to just take proper acceleration and calculate what my age would have been if there was not any proper acceleration? I don't claim it's impossible, just that it can only be done relative to a particular frame. I can make statements like I am now 30, but in frame A, if I hadn't accelerated I would now be 20 and I am now 30, but in frame B, if I hadn't accelerated I would now be 25. An observer knows what his proper acceleration is, and he knows how much various accelerations are slowing his proper time relative to what it would be if those accelerations didn't happen. Slowing his proper time only has meaning relative to a particular frame, there is no frame-independent sense in which clocks slow down (or speed up) due to acceleration in relativity. He has a frame independent measure of acceleration. He knows that particular acceleration will slow his proper time by 1/2 so he can define and calculate an 'inertial time' whose rate is 2x his proper rate. Given the exact same proper acceleration, there may be one frame A where at the end of the acceleration his clock has slowed by 1/2 (relative to the time coordinate of that frame), and another frame B where it has slowed by 1/3, and even another frame where it has *sped up* by a factor of 10. Do you disagree? You seem to think it would be necessary to MEASURE THIS FROM SOME FRAME for the concept to be true. It's not an observable measure, it's the CALCULATION of a useful variable. Therefore there is NO requirement that it's measurable in any frame because it's a frame independent concept, a calculation rather than an observable. Calculations are always calculations of the values of particular numerical quantities, like the rate a clock is ticking. So, what matters is whether the quantity in question is frame-dependent (like velocity, or rate of clock ticking) or frame-independent (like proper time at a specific event on someone's worldine), there is nothing inherent in the notion of calculations that make them frame-independent. Also, *all* calculated quantities in relativity can also be observables--it's straightforward to observe frame-independent quantities like proper time (just look at the clock the observer carries), and frame-dependent ones can also be observed if you have a physical grid of rulers and coordinate clocks as I have described before (for example, to find the rate a clock is ticking relative to a coordinate system, you look at the time T1 it reads as it passes next to a coordinate clock that reads t1, and the time T2 it reads as it passes next to another coordinate clock that reads t2, and then you can just define the average rate over that
