"Fundamental Properties of The Speed of Light"," Besides being the speed at which light propagates, it is also the universal speed limit - no matter or signal can exceed this speed.
Since the 17th century, scientists have devised more and more accurate means of measuring the speed of light.
His estimate was off by 26%, but it was still quite impressive in that it was the first experiment which showed that its value was finite.
The first terrestrial method came from a French physicist named Fizeau, who used a rotating toothed wheel and a distant beam of light to measure the speed.
By the late 20th century, lasers were used to measure the speed of light to better than one part in 10 billion.
Since light is an electromagnetic wave, the speed of light is also the speed of other electromagnetic waves, such as radio waves, X-rays, and gamma rays.