Michelson - speed of light measured using Foucault's method
Michelson was an instructor in physics. He had to do a lecture demonstration of how Foucault measured the speed of light.
It was years since Foucault made his measurements.
When Michelson was setting up his demonstration, he saw how it could be improved to give a much more accurate measurement.
The distance between the wheel that Foucault used and his mirror was 60 feet.
Michelson put the very high quality (expensive) mirror 2 000 feet from the toothed wheel. He also had very high quality lenses to focus the beam onto the mirror.
His final measurement was 186,355 miles per second. This measurement had a possible error of around 30 miles per second.
Foucaults speed of light with an accuracy of about 1,000 miles per second.
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