Fizeau

Hippolyte Fizeau was a 19th-century French physicist best known for his work on the speed of light. In 1849, he conducted a groundbreaking experiment using a rotating toothed wheel to measure how quickly light travels. By sending light through the wheel's openings and reflecting it back, he could calculate its speed, which he found to be approximately 313,000 kilometers per second. Fizeau's method was significant because it provided one of the first precise measurements of light's speed and laid important groundwork for future developments in physics, especially in understanding the nature of light and electromagnetic waves.