Le lun. 6 janv. 2025, 22:58, Alan Grayson <[email protected]> a écrit :
> > > On Monday, January 6, 2025 at 2:44:56 PM UTC-7 Quentin Anciaux wrote: > > Last try. > > So as you agreed, the two observers being in different frame, they don't > share the simultaneity plane. > > The key to understanding the situation is that the two observers (the > person in the garage and the person in the car) don’t share the same idea > of what events happen at the same time. This is because, in relativity, the > concept of "simultaneity" depends on the observer’s motion. > > What does "fit into the garage" mean? > > For the car to "fit into" the garage, we’re asking if: > > The back of the car has passed the entrance of the garage and > > The front of the car is at, or before, the exit of the garage > at the same time. > > Why is there disagreement? > > 1. For the garage’s observer: > > The car looks shorter because of Lorentz contraction. > > They can say: "At the same time, the back of the car has passed the > entrance, and the front is at or before the exit." So, for them, the car > fits. > > 2. For the car’s observer: > > The garage looks shorter because of Lorentz contraction. > > They see events differently. For them, the back of the car passes the > entrance before the front reaches the exit. So, they say: "The car never > fits inside the garage." > > Why no contradiction? > > The disagreement comes from the fact that the two observers don’t share > the same plane of simultaneity: > > In the garage’s frame, the "fit" happens because the events (back passing > entrance and front at exit) occur simultaneously. > > In the car’s frame, those events don’t happen at the same time. The car > sees the garage’s doors acting at different times to avoid a crash. > > Conclusion: > > The paradox is resolved because "fitting into the garage" depends on when > you decide to check if the car fits, and different observers disagree about > what "at the same time" means. This is a direct result of how special > relativity changes our understanding of simultaneity. > > Quentin > > > *As I've previously stated, the issue, if there is one, is that the frames > disagree about whether the car fits in the garage, not when it fits, or how > good or bad the fit is. This is obvious from length contraction alone, that > the frames disagree. This fact is unchanged by the disagreement about > simultaneity. So if you or anyone want to use the disagreement on > simultaneity and length contraction, to put some numbers on this problem, > that's fine. But it shouldn't be concluded that the underlying enigma has > been solved. AG* > The confusion here seems to stem from treating "fits" as if it were an absolute property, independent of the observer's frame of reference. However, in the context of special relativity, "fits" is not absolute, it’s inherently dependent on the observer's definition of simultaneity. Here’s why: 1. The concept of "fits" requires simultaneity: For the car to "fit" in the garage, you need to compare two events: (1) the back of the car passing the entrance and (2) the front of the car being at or before the exit. Whether these two events happen "at the same time" depends on the observer’s frame of reference. The disagreement about simultaneity between the two frames directly leads to a disagreement about whether the car fits. It’s not just an added detail—it’s fundamental. 2. Length contraction alone doesn’t explain the full scenario: Yes, length contraction makes the car appear shorter in the garage’s frame and the garage appear shorter in the car’s frame. But without simultaneity, "fits" remains undefined because it depends on when you compare the positions of the car’s front and back relative to the garage. 3. There’s no "underlying enigma" left to solve: The disagreement between frames is entirely explained by relativity: the garage’s observer uses their simultaneity to conclude the car fits, while the car’s observer uses a different simultaneity to conclude it doesn’t. Both are correct within their own frames. This is not a paradox, it’s how spacetime works. 4. "Fits" cannot be absolute: If you’re treating "fits" as a frame-independent property, you’re implicitly ignoring the core of special relativity, where space and time are not absolute. This perspective is incompatible with the theory. In short: The disagreement about simultaneity is not a side effect, it’s the very reason frames disagree about whether the car fits. To claim the problem is unsolved is to misunderstand how relativity defines spatial relationships and simultaneity. Quentin > Le lun. 6 janv. 2025, 22:37, Quentin Anciaux <[email protected]> a écrit : > > A troll feels absolutely no shame. > > > > Le lun. 6 janv. 2025, 22:25, Alan Grayson <[email protected]> a écrit : > > > > On Monday, January 6, 2025 at 11:46:52 AM UTC-7 Alan Grayson wrote: > > On Monday, January 6, 2025 at 3:11:47 AM UTC-7 Alan Grayson wrote: > > On Sunday, January 5, 2025 at 10:02:28 PM UTC-7 Alan Grayson wrote: > > On Sunday, January 5, 2025 at 9:43:47 PM UTC-7 Brent Meeker wrote: > > On 1/5/2025 7:44 PM, Alan Grayson wrote: > > You claim there is no objective fact. The car fitted in the garage. > > But that's only from the garage frame. > If it's from only one frame and not another, that's the definition of > "not objective". It's not fact. It's subjective perception. > > Brent > > > You truncated my statement. You showed the car fits in one frame > and not the other (the car frame). The paradox is based on the belief > that this is impossible. Disproving this belief is required to resolve > the paradox. AG > > > *Here is something to consider to prove what I believe needs to be proven;* > *that the two frames under consideration are not in relative motion as the* > *case of two inertial frames in empty space where nothing exists other > than* > *these two frames. In the paradox the car is in real detectable motion if > one* > *views its background, whereas the garage is fixed by the same > observation.* > *In fact, the garage and its surroundings can be considered a rigid body > from* > *the pov of the car frame, entirely in motion, not just the garage. I do > not say* > *t**his will work in possibly eliminating the relative motion of garage > from * > *the pov of the car frame and thus resolving the paradox, but it's a > possibility* > *worth **considering. AG * > > > *Maybe you can explain this: we started with an apparent paradox based on > length* > *contraction. Then, to allegedly resolve it, several MB members including > yourself, * > *applied both length contraction and disagreement about simultaneity to > get the* > *SAME result which was patently obvious with nothing more than length > contraction.* > *At which point victory was declared; the alleged paradox was resolved! > Praise the* > *Lord! Can you tell me what I'm missing? And please; don't tell me that > adding doors* > *on the garage was needed or necessary. Without those doors it was obvious > that* > *the frames would disagree about whether the car would fit at some high > speed. * > *Maybe Jesse and Quentin could explain this as well. TY, AG* > > > *I'd also like to hear from Clark on this issue. He was another great > advocate of putting* > *doors on the garage and thinking the problem was solved. As I see it, all > that's been * > *accomplished is to put some numbers on the problem, to calculate how good > the fit* > *is or isn't, without touching on the underlying problem. As for > falsifying relativity, that's* > *definitely not my preference. It seems to have worked for more than a > century, so it's* > *highly likely to be correct. But when all the experts here give their > opinions, ISTM that * > *none **are in the ballpark of actually shedding light on this problem. > Of course, we can* > *always adopt the "shut up and calculate" pov and conclude that that's > what SR says, and * > *be done with it. So, Clark, what do you think? AG * > > > > It doesn't fit from the car frame, regardless of the doors, which IMO > > can be dispensed with. So, as I see it, the paradox follows from the > > belief that there can't be disagreement about what the frames > > conclude. Isn't this the claim that must be disproven to resolve the > > paradox, and a constructive proof that the frames disagree using the > > LT is insufficient? AG > > -- > 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 [email protected]. > To view this discussion visit > https://groups.google.com/d/msgid/everything-list/ac4d026b-0d85-47f7-8714-0bc5042bc213n%40googlegroups.com > <https://groups.google.com/d/msgid/everything-list/ac4d026b-0d85-47f7-8714-0bc5042bc213n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- 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 [email protected]. To view this discussion visit https://groups.google.com/d/msgid/everything-list/CAMW2kAoHum7TJGTRDmBWAup6OtxZi92OoqLEBkD0z1FwQGtuMQ%40mail.gmail.com.
