Does anyone have any ideas about this scenario? I'm having trouble comparing what happens at the different speeds. It has to do with simultaneity
Suppose Al is at rest standing in between two sets of railroad tracks. Bob goes by in one direction at a speed u, as measured by Al, and Carl goes by on the other tracks going in the opposite direction at the same speed. Al, Bob, and Carl all have meter sticks and whatever other instruments needed to compare their length.
Suppose that u = 1/1000 c (one thousandth of the speed of light). Approximately how fast is Bob going according to Carl?
Suppose that u = 9/10 c. What does Al say about Bob's and Carl's meter sticks? What does Bob say regarding Al's and Carl's meter sticks? How are these two different accounts compatible?
Suppose Einstein's theory of relativity is true. Now consider what happens if light moves with infinite speed rather than the speed c. In particular, explain what would then be true regarding the relativistic effects we have considered in class -- length contraction, time dilation, and the relativity of simultaneity.