On Friday, October 25, 2024 at 4:58:47 PM UTC-6 Brent Meeker wrote:
On 10/25/2024 2:49 PM, Alan Grayson wrote:
On Friday, October 25, 2024 at 11:34:13 AM UTC-6 Jesse Mazer wrote:
On Fri, Oct 25, 2024 at 5:44 AM Alan Grayson
<[email protected]> wrote:
On Friday, October 25, 2024 at 2:44:06 AM UTC-6 Brent
Meeker wrote:
On 10/25/2024 1:36 AM, Alan Grayson wrote:
On Thursday, October 24, 2024 at 11:07:18 PM UTC-6
Brent Meeker wrote:
On 10/24/2024 5:46 PM, Alan Grayson wrote:
On Thursday, October 24, 2024 at 1:30:32 PM
UTC-6 Brent Meeker wrote:
Here's how a light-clock ticks in when in
motion. A light-clock is just two perfect
mirrors a fixed distance apart with a
photon bouncing back an forth between
them. It's a hypothetical ideal clock for
which the effect of motion is easily
visualized.
These are the spacetime diagrams of three
identical light-clocks moving at _+_c
relative to the blue one.
*Three clocks? Black diagram? If only this was
as clear as you claim. TY, AG*
*You can't handle more than two? The left clock
is black with a red photon. Is that hard to
comprehend? Didn't they teach spacetime
diagrams at your kindergarten?
Brent
*
*What makes you think you can teach? *
*That I have taught and my students came back for more.*
*I can handle dozens of clocks. I know what a
spacetime diagram. It was taught in pre-school. Why
did you introduce a red photon? A joke perhaps? How
can a clock move at light speed? *
*None of the clocks in the diagram are moving at
light speed. The black one and the red one are
moving at 0.5c as the label says. What is it you
don't understand about this diagram?
Brent
*
*One thing among several that I don't understand is how
the LT is applied. For example, if we transform from one
frame to another, say in E&M, IIUC we get what the fields
will actually be measured by an observer in the target or
primed frame. (I assume we're transferring from frame S
to frame S'). But when we use it to establish time
dilation say, we don't get what's actually measured in
the target frame, but rather how it appears from the pov
of the source or unprimed frame. Presumably, that's why
you say that after a LT, the internal situation in each
transformed frame remains unchanged (or something to that
effect). AG*
Can you give a concrete example? If you some coordinate-based
facts in frame S (source frame) and use the Lorentz
transformation to get to frame S' (target frame), the result
should be exactly what is measured in the target frame S'
using their own system of rulers and clocks at rest relative
to themselves (with their own clocks synchronized by the
Einstein synchronization convention).
Jesse
*Glad you asked that question. Yes, this is what I expect when we
use the LT. We measure some observable in S, use the LT to
calculate its value in S', and this what an observer in S' will
measure. But notice this, say for length contraction. Whereas
from the pov of S, a moving rod shrinks as calculated and viewed
from S, the observer in S' doesn't measure the rod as shortened!
This is why I claim that the LT sometimes just tells how things
appear in the source frame S, but not what an observer in S'
actually measures. AG*
*Yes, although "appear" can be misleading when you consider things
moving near light speed. More accurate is "measure", using the
invariant speed of light.*
*
*
*On another point concerning time dilation; I demonstrated that
given two inertial frames with relative velocity v < c, it's easy
to synchronize clocks in both frames provided we know the
distance of clocks from the location of juxtaposition, but I was
mistaken in concluding this alone shows time dilation doesn't
exist. It does, because we insist on using the LT as the only
transformation between these frames, and the reason we do this is
because the LT is presumably the only transformation that
guarantees the invariance of the velocity of light. So time
dilation is, so to speak, the price we pay for imposing the
invariance of the velocity of light on our frame transformation.
But I remain unclear how a breakdown in simultaneity resolves the
apparent paradox of two frames viewing a passing clock in another
frame, as running slower than its own clock. AG*
*Look at the diagram I provided. At the bottom (t=0) the three
clocks are passing by one another. The blue clock sees the other
two as running slower.*
*
*
*Finally, for Brent, a word about "snarky". _You_ get snarky when
I don't understand something, like your "kindergarten" reference
in one of your recent replies. And occasionally I am correct in
my criticisms. Moreover, if you have typos in your explanation of
your graph, you shouldn't be surprised if they make it hard to
understand your graphical explanation of time dilation. AG*
*So that one typo, which was correct elsewhere made it muddled for
you?
*
*In part yes. When I think an author doesn't know what he's expounding
about, I lose interest. Also, although I was a software engineer at
JPL, I don't know LISP, so it would be hard to see what assumptions
you made in generating the plot. And the plot is claimed to establish
time dilation, and I'm not sure how you developed the width of the
blue path say, to show time passes more rapidly compared to the other
plots. AG*
