?? English instruction:
Plane mirrors and double and triple-sided corner reflectors are mounted on a rotating wheel.
Turn the winch. What happens to your reflection?
- How many reflections can you see?
- Count the rotations of the mirrors, then count the rotations of your reflections.
- In what position must the two sided corner reflector stand in order for your reflection to be upside down?
In the 19th century, the French physicist Jean Bernard Léon Foucault (1819-1868) developed a method to measure the speed of light. Rays of light where reflected between a rotating mirror and a stationary mirror. Focault determined the speed of light by measuring the displacement between the starting point of the rays of light and their subsequent reflection. He measured the speed of light to be 298.000 km/s, rather close to the speed of light in vacuum, 299.792,458 km/s.