On Thursday, October 17, 2024 at 8:48:08 AM UTC-6 John Clark wrote:
On Thu, Oct 17, 2024 at 8:14 AM Alan Grayson <[email protected]> wrote: *> You claimed from Bob's pov, Alice's clock is running slower (not running backwards)**,* *Yes, although he would see the clock running backwards IF things could go faster than light. * *> and when he sends his reply his clock reads 2, whereas Alice's clock reads 1,* *Before the experiment started Alice and Bob agreed that when Bob's clock reads 2 he would send a message to Alice. And from Bob's point of view that is exactly what happened. Bob knows that **when his clock read 2 and he sent the message her clock must've only read 1 because her clock was running at only half the speed of his clock. A*nd so she must've received the message when her clock said 1 *PLUS* however much time it took for the message to travel between the two spaceships, which have both been moving at *86.6% the speed of light* but in opposite directions *since the experiment began**, which was two hours ago according to both of the clocks. And because they both believe in special relativity, they both realize it would also be 2 hours **according to the clock of a **stationary observer that underwent no acceleration and was midway between the two spaceships. * *That stationary observer would say the spaceships were 1.732 light hours distant from each other after two hours when the message was sent. Thus IF the message does not travel faster than the speed of light THEN it's going to take LONGER than one hour to travel that distance. So Bob will receive Alice's message at time 1 plus some number that is greater than 1 depending on exactly how fast the message was going, and that would be sometime after 2. And 2 was the time when the message was sent. Cause proceeds affect, causality is preserved and Alice sees no Paradox. A similar argument could be made with regard to Bob's point of view.* *> **No one claimed her clock was running backwards.* *But that is exactly what you would see IF AND ONLY IF particles that move faster than light existed and you could observe things with it.* *What about the case of two observers moving toward each other, and each seeing the other's clock running slower as they pass each other? An apparent paradox? How is this situation resolved, assuming no FTL? AG* * John K Clark See what's on my new list at Extropolis <https://groups.google.com/g/extropolis>* poe -- 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 on the web visit https://groups.google.com/d/msgid/everything-list/d075a63f-c8a7-49bc-9fc0-6072256a3a0bn%40googlegroups.com.
