400 Years of Telescopes
400 years ago today Galileo demonstrated his telescope to a group of Venetian merchants.
A refinement of models first devised in the Netherlands, Galileo’s slim, brown stick was puny even by the standards of something one might buy in a hobby shop today. But his eight-powered telescope, and the more powerful models he soon produced, when pointed skywards led Galileo to a series of groundbreaking conclusions.The moon was not, as long believed, completely smooth. Another planet, Jupiter, also had moons. Meanwhile Venus showed a range of moon-like phases, something which could not happen if both it and the sun orbited the Earth.
This latter phenomenon had been predicted by Nicolaus Copernicus when, nearly a century before, he had proposed the notion of a planetary system with the sun at the centre, not the Earth.
HT to Google, whose main-page logo commemorates the event.Technorati Tags: Galilei Galileo, Telescope
I would like permission to reprint one of your articles. Would you please contact me?
Thank you
Ecolon