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If this (very similar) experiment didn't give the speed of light (in optical fibre) then people would have noticed.https://www.picotech.com/library/experiment/speed-of-light
The speed of light can be determined with marshmallows and a microwave. https://wonders.physics.wisc.edu/measure-the-speed-of-light/This is technically neither a two-way measurement nor a one-way measurement but a zero-way since it is measuring the (half) wavelength of a standing wave. The speed of light (EM radiation, which includes microwaves) is calculated by wavelength times frequency of the microwave oven.
Quote from: Malamute Lover on 24/07/2020 01:44:46The speed of light can be determined with marshmallows and a microwave. https://wonders.physics.wisc.edu/measure-the-speed-of-light/This is technically neither a two-way measurement nor a one-way measurement but a zero-way since it is measuring the (half) wavelength of a standing wave. The speed of light (EM radiation, which includes microwaves) is calculated by wavelength times frequency of the microwave oven.We still have to measure the actual frequency instead of taking the value on the nameplate for granted.
Quote from: Bored chemist on 23/07/2020 11:41:33If this (very similar) experiment didn't give the speed of light (in optical fibre) then people would have noticed.https://www.picotech.com/library/experiment/speed-of-lightPeople could assume that the refractive index of the optical fibre deviates from what is stated by its manufacturer.
We are now looking for the increasing speed of the distance between a single/identified photon and its source; so, our problem is this.
Quote from: xersanozgen on 24/07/2020 10:56:18We are now looking for the increasing speed of the distance between a single/identified photon and its source; so, our problem is this.Not quite.If I send a brief flash of light consisting of many photons through empty space, they all arrive at the same time.So there is no difference between timing a single photon (which is exceptionally difficult) and timing a group of photons.They all travel at the same speed anyway.
Well, I'm still thinking of doing the experiment. Driving a laser with a 10 MHz square wave isn't trivial.What do you think I will get if I do the experiment as I suggested.I will have with 2 sensors - one feeding each of the 2 channels on my 'scope. One sensor sampling the light before it's sent across the room and back (about 10 metres round trip) , and the other sampling it after it has made the trip. Do you agree that what I should expect to get is a pair of signals, one of which is delayed WRT the other by about 30nS?
In my opinion the distance must be 20 meters in accordance with the precision of ossiloscope.
The experiment was performed.