2006-12-24 10:06:03 · 4 answers · asked by jonester 2 in Science & Mathematics ➔ Physics
It is measured directly by dividing the distance traveled the time of flight. Modern clocks and light detectors are accurate and fast enough to determine it to many decimal places over laboratory distances. The first successful measurement used the distance to predictable orbital events of Jupiter's moons. Even the clocks of the day (1600's, calibrated by sundials) where up to the task of measuring the time of flight delay vs. predicted time over such a distance
2006-12-24 10:32:46 · answer #1 · answered by Dr. R 7 · 1⤊ 0⤋
The speed of light was estimated long long before the Michelson Morley Experiment. Scientist Ole Romer was observing the motion of Io, a moon of Jupiter, in the 1600's. He noticed that at some points during the year it looked like the moon was ahead of schedule in its orbit and at other times it was behind. He used his knowledge of the moon's orbit and the distance to Jupiter to determine the speed of light.
2006-12-24 18:24:26 · answer #2 · answered by Zach T 2 · 0⤊ 0⤋
They use michaelson-morley interferometer, which splits coherent light and sends its over different paths and you can tell by the change in interference patterns how light moves.
2006-12-24 18:10:17 · answer #3 · answered by Chido 36 2 · 0⤊ 0⤋
Simple: the frequency of the light wave multiplied by the wavelength -
2006-12-24 18:08:43 · answer #4 · answered by Upon this rock 3 · 0⤊ 0⤋