Date: 25/04/2026 13:22:56
From: Spiny Norman
ID: 2384500
Subject: re: Spiny's thread of occasional interest
In 1849, Hippolyte Fizeau became the first person to measure the speed of light on Earth using a rotating toothed wheel and a distant mirror.
A beam of light passed through the gaps in the spinning wheel, traveled several kilometers to the mirror, and reflected back. By changing the wheel’s speed, Fizeau found the point where the returning light was blocked by the next tooth. This allowed him to calculate the speed of light with remarkable accuracy.
His experiment was one of the earliest demonstrations that light travels at a finite speed and became a major milestone in the history of physics.