On Tue, Feb 11, 2014 at 7:46 PM, Jesse Mazer <laserma...@gmail.com> wrote: > > "Instantaneously pause" has no frame-independent meaning in relativity, do > you disagree? If A and B are in relative motion, and unlike my example > above, B is *not* at the same point in spacetime as A when A turns some age > (say 60), then different frames disagree on what age B is "at the same > instant" that B turns 60. So if one frame said B was 48 at the same instant > A turned 50, and another frame said B was 75 at the same instant A turned > 50, then at what age should B's motion relative to A be "paused"? We don't > have an "objective instantaneous pause machine" that can settle the > question empirically, it has to be *our choice* when to subject B to a > sudden acceleration to instantaneously bring him to rest relative to A. > Again, do you disagree? >
Sorry, I got the numbers and letters a little mixed up here, the paragraph should read: "Instantaneously pause" has no frame-independent meaning in relativity, do you disagree? If A and B are in relative motion, and unlike my example above, B is *not* at the same point in spacetime as A when A turns some age (say 60), then different frames disagree on what age B is "at the same instant" that A turns 60. So if one frame said B was 48 at the same instant A turned 60, and another frame said B was 75 at the same instant A turned 60, then at what age should B's motion relative to A be "paused"? We don't have an "objective instantaneous pause machine" that can settle the question empirically, it has to be *our choice* when to subject B to a sudden acceleration to instantaneously bring him to rest relative to A. Again, do you disagree? -- 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.
