0

From what I understand, we have not been able to measure unidirectional speed of light. It is said that theoretically it is possible for light to travel at $c/2$ in one direction and infinity speed in the opposite.

This brings me to the question if it is possible to measure this unidirectional speed of light by observing space in all directions. The direction where the speed of light is if $c/2$ should appear very old since we are just starting to receive it's light whereas the direction where it's infinite should appear extremely young.

Even if the difference in speed of light in opposite directions is not so extreme, is there a way to study patterns of space to identify which direction appears older and which younger?

Qmechanic
  • 220,844
Manish Sharma
  • 11

1 Answers1

2

The statement is really stronger. Not only have we not been able to measure the one-way speed of light. It is impossible to measure even in theory.

To make this measurement you would need synchronized clocks at the emission and reception points. There is no synchronization method that allows for this within the theory of relativity unless you assume that the speed of light is the same in both directions. Synchronizing the clocks at one end and them moving one of them to the other end will result in time dilation at some level, rendering them unsynchronized before you do the experiment. Synchronizing by exchanging signals with clocks that are prepositioned requires knowing the speed of light a priori. There aren't really any good third options.

Brick
  • 5,247