Liz, But see my responses to John and Brent on this ..
The question I'd ask you is why "A's frame cannot be put into a single inertial frame of reference" if his 1g acceleration was exactly the same as B's 1g acceleration during the ENTIRE trip? Are you saying that the simple fact that the DIRECTION of A's 1g acceleration REVERSED at midpoint is the ONLY cause of A's clock slowing relative to B's? Thanks, Edgar On Friday, January 31, 2014 11:17:06 PM UTC-5, Liz R wrote: > > On 1 February 2014 07:59, John Clark <johnk...@gmail.com <javascript:>>wrote: > >> On Thu, Jan 30, 2014 at 4:36 PM, Edgar L. Owen <edga...@att.net<javascript:> >> > wrote: >> >> > A is traveling at near light speed most of the trip. That's why B sees >>> A's clock slow >>> >> >> Yes. And from A's point of view he's standing still and B is traveling at >> near light speed, so A sees B's clock running slow. Both would see the >> others clock as running slow. However if A decided to join B so they could >> shake hands and directly compare the times their clocks show then A is >> going to have to accelerate, and then things would no longer be >> symmetrical, then A would see B's clock running FAST but B would still see >> A's clock run SLOW. So when they joined up again and compared clocks they >> would not match, B's clock would be ahead and B would have aged more than A. >> >> > So my question is this: Why does A's clock slowing turn out to be >>> ACTUAL (agreed by both A and B) when he stops at the center of the galaxy, >>> and B's slow clock slowing doesn't? >>> >> >> Because A stopped, and that means A must have accelerated but B did not. >> >> That's true, and can be rephrased as A's trajectory cannot be put into a > single inertial frame of reference, while B's can. Hence the symmetry > between them has to be broken at some point. > > There's an even simpler way to view this. A's path through space-time > forms two sides of a triangle, while B's forms the base. Since the two > sides of any triangle must be longer than the base, A must have taken a > longer path through space-time, which according to SR means he experienced > less duration. The twin paradox comes down to 4D geometry! > > -- 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.
