The National Bureau of Standards in Boulder Colorado used helium-neon lasers and meticulously accurate cesium clocks to measure the speed of light. The speed of light measured in the vacuum is a physical constant denoted by the letter c and has the value formula. By measuring the time elapsed between the first person uncovering their lantern and when that person sees the second lantern the speed of light could then be calculated by dividing twice the distance between them by the elapsed time.
If we were to catch an eclipse of Io in a certain position of our orbit then if we.
The National Bureau of Standards in Boulder Colorado used helium-neon lasers and meticulously accurate cesium clocks to measure the speed of light. To measure the speed of light would require an external definition of what a meter is and since about the 1970s we dont have one. To Einstein no one should ever measure a speed of light that is moving at 15 times the speed of light or at any other speed other than exactly the speed of light. Now we can measure the speed of light accurately with the help of laser beam.