- #1

- 2,257

- 7

## Main Question or Discussion Point

suppose we start with a long line of stationary, evenly spaced and perfectly synchronized clocks along the x axis. if the stationary twin is at the origin and at t=0 the other twin passes the origin moving at relativistic speed with gamma=2 then from the point of view of the stationary twin the moving twin is length contracted to 1/2 his normal length. but despite this moving twin, due to loss of simultaneity, will see the line of clocks as no longer synchronized and therefore as being contracted to 1/2 its normal length. thats obvious. presumably, due to loss of simultaneity, each individual clock will seem to be running at 1/2 its normal speed even though the time read off as each individual clock passes would be running at twice normal speed. i think thats right.

but what happens when the moving twin suddenly stops? now all the clocks are synchronized and there is no length or time contraction. in particular, from the point of view of the moving twin, what time does the non-moving twins clock show just before and just after the moving twin suddenly stops?

what happens then when the moving twin begins moving back toward the origin? what does he see?

but what happens when the moving twin suddenly stops? now all the clocks are synchronized and there is no length or time contraction. in particular, from the point of view of the moving twin, what time does the non-moving twins clock show just before and just after the moving twin suddenly stops?

what happens then when the moving twin begins moving back toward the origin? what does he see?

Last edited: