Google Doodle marks 340th anniversary of Ole Rømer's determination of the speed of light
340 years ago, on December 7, 1676, Danish astronomer called Ole Romer determined the speed of light by observing the planet Jupiter eclipsing its moon Io 140 times.
New Delhi: Internet search giant Google on Wednesday celebrated the 340th anniversary of Ole Rømer's 'determination of the speed of light' with a beautiful animated doodle.
340 years ago, on December 7, 1676, Danish astronomer called Ole Rømer determined the speed of light by observing the planet Jupiter eclipsing its moon Io 140 times. Io is the innermost of the four moons of Jupiter discovered by Galileo in January 1610.
Rømer estimated that light would take about 22 minutes to travel a distance equal to the diameter of Earth's orbit around the Sun. This means that light at about 200,000,000 metres per second, which is around 26 per cent lower than the true value.
To honour Rømer and his discovery of the speed of light, Google came up with an animated doodle on its homepage which shows a thoughtful Rømer repeatedly pacing back and forth after viewing his telescope.
Today's Google illustration also depicts how much detail and thoughtfulness Google applies to its doodles.
Rømer's theory was controversial at the time he announced it, and the director of the Royal Observatory, Giovanni Domenico Cassini, wasn't convinced. However, it was finally confirmed nearly two decades after Rømer's death, with the explanation in 1729 of stellar aberration by the English astronomer James Bradley.