On Tuesday, September 9, 2025 at 11:25:37 PM UTC-6 Brent Meeker wrote:
On 9/9/2025 9:57 PM, Alan Grayson wrote: On Tuesday, September 9, 2025 at 5:18:14 PM UTC-6 Brent Meeker wrote: On 9/8/2025 8:45 PM, Alan Grayson wrote: On Monday, September 8, 2025 at 9:35:09 PM UTC-6 Brent Meeker wrote: On 9/8/2025 11:19 AM, Alan Grayson wrote: On Monday, September 8, 2025 at 5:06:36 AM UTC-6 John Clark wrote: On Mon, Sep 8, 2025 at 7:00 AM Alan Grayson <agrays...@gmail.com> wrote: *> I'm not sure the impossibility of absolute simultaneity solves the problem,* *Watch the video! If you follow what he does step-by-step you will see that he is right. It's not difficult. * *I'll definitely watch it, very soon, but a-priori the impossibility of absolute simultaneity can't solve the paradox because it's not its cause. Can you succinctly state the cause of the paradox? It's the application of time dilation in SR, under the mistaken assumption that the twins take symmetric paths; that their situations are symmetric. This results in the situation that when they meet and compare clock readings, each concludes the other is younger. * No that's wrong. The stay at home twin has a clock that indicates a longer interval than the traveling twins clock. They agree that the traveling twin is younger. Brent *Can't you understand English? I was stating the paradox and its cause. With an accurate analysis, the traveling twin is younger. Also, FWIW, for the traveling twin to return for the clock comparison, some acceleration is necessary, although it can be minimized if the comparison is done by fly-by. a AG * But notice that the acceleration is entirely incidental, as illustrated by the case in which Red and Blue each accelerates the same amount. IT'S JUST GEOMETRY. ONE PATH IS LONGER THAN THE OTHER. *In the original statement of the "paradox', the traveling twin must accelerate to return so the clocks can be compared. Please explain how this can happen without acceleration. * I've shown two different ways without acceleration and I've also shown the paradox with equal accelerations by both twins. Why can't you just accept that it's geometry; that one path is longer than the other. *If both twins are accelerating, then you've redefined the TP. If you have two paths in spacetime, starting at the same point and ending at the same point, or at a different point, how can you tell which is longer? AG * *You seem to defying basic physics if this is your claim. I don't deny that the original problem can be restated in a way which avoids acceleration, and IMO this is what you've done. * But I've done more than that. I've done it while maintaining exactly the same paradox. 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 view this discussion visit https://groups.google.com/d/msgid/everything-list/e0e2ba43-d27e-4814-975c-5e49a6b83fa3n%40googlegroups.com.
