The opening of the speed of light is rightfully Danish astronomer Ole Roemer. Since 1671, he and his colleagues observed an eclipse of one of Jupiter’s moons – Io. At that time it was already well established that Io makes its full revolution around the planet Jupiter for 42.5 hours. But observations showed inconsistency: depending on the time of year because of Jupiter’s Io appeared then later, then before.
The merit of an astronomer is that he realized that this phenomenon is not related to the rotation of Io around Jupiter, and is associated with the rotation of the Earth around the Sun and Jupiter. It was found that the closer the Earth was close to Io, the sooner she appeared, and, conversely, the greater the distance between them, the greater the Io “late” because of the s
ound of Jupiter. Read the rest of this entry »