/sci/ - Science & Math

https://www.youtube.com/watch?v=pTn6Ewhb27k

Derek seems to believe that only way to measure the speed of light is to emit light and observe how long it takes to reflect back to the source OR by throwing multiple time dilated clocks at the problem. No matter what he does, he cannot measure the "one-way" speed of light.

The setup to measuring the one-way speed of light is simple. The setup requires:

>3 objects spaced 1km apart from each other. (See pic related.)
>2 photons emitted simultaneously.
>1 clock.

The 3 objects are an emitter, a reflector and a detector.

>The emitter emits two signals simultaneously, one directed at the detector and another towards the reflector.

>The reflector reflects all incoming signals towards the detector.

>The detector starts a clock when it detects a signal arriving from the emitter and then stops the clock when it detects a signal arriving from the reflector. Intuitively this would mean that the detector starts the clock when the signal begins it's 1km journey from the reflector to the detector.

This is all you need to solve the one-way speed of light using speed = distance / time. You can do this experiment in the vacuum of space, in atmosphere, underwater or using fiber-optic cables. With this setup, it is impossible to measure anything other than the one-way speed of light in any medium.

There are two scenarios on what could be observed:
>As expected, the signal from the emitter is detected first and then about 0.0000033 seconds later the signal from the reflector is detected, proving the one-way speed of light is exactly c.
>Unexpectedly, the signal from the emitter and reflector are detected at the same time. This could only occur if the one-way speed of light is infinitely fast.