Clebrating 340th anniversary of the Determination of the speed of light using Google Doodle. The discvery was reported on 7th December 1976 by first scientific journal in Europe, the Journal des sçavans. The Journal is still operating, in a modern form known as Journal des Savants. What is the speed of light? The answer of this question was discovered 340 years ago, on December 7, 1676. Google marked the 340th anniversary of determination of the speed of light with fascinating Google Doodle today.
How was the speed of light determined and who found it, when? How close was the estimate of 186,000 mps to the ‘actual’ speed of light?
Asked by: Chuck Baker
How did Roemer measure the speed of light?
Roemer measured the speed of light by timing eclipses of Jupiter’s moon Io. In this figure, S is the Sun, E1 is the Earth when closest to Jupiter (J1) and E2 is the Earth about six months later, on the opposite side of the Sun from Jupiter (J2).
How fast is the speed of light?
The speed of light in a vacuum is 186,282 miles per second (299,792 kilometers per second), and in theory nothing can travel faster than light. In miles per hour, light speed is, well, a lot: about 670,616,629 mph. If you could travel at the speed of light, you could go around the Earth 7.5 times in one second.
How do you measure the speed of light?
Of Jupiter’s many moons, it has four large ones that you can actually see with a nice pair of binoculars. Even better is the fact that these moons have very regular and predictable orbits. In fact, you can use the motion of the moons of Jupiter to measure the speed of light. This is exactly what Ole Roemer did in 1676.
What is the formula for calculating the speed of light?
Formula: c = f where: c = the speed of light = 300,000 km/s or 3.0 x 108 m/s. = the wavelength of light, usually measured in meters or Ångströms (1 Å = 10–10 m) f = the frequency at which light waves pass by, measured in units of per seconds (1/s).