This year is the International Year of Astronomy, so to help all of us armchair astronomers celebrate, New Scientist has a nifty gallery of the most important telescopes in history (from Eyes on the Skies: 400 Years of Telescopic Discovery by Govert Schilling and Lars Lindberg Christensen).
This one to the left is the Galileo Refractor (c. 1609):
This one to the left is the Galileo Refractor (c. 1609):
Though he didn't invent the telescope, Galileo improved on its design - gradually increasing its magnification power. And he was the first to realise that it could be used to study the heavens rather than just to magnify objects on Earth.
Here you can see Galileo demonstrating one of his telescopes to the ruler of Venice in August 1609 (Galileo is standing to the right of the telescope). In the years to come, Galileo's observations - including the discovery of four large moons orbiting Jupiter - would lend credence to the sun-centred worldview of Nicolaus Copernicus, who removed the Earth from its central position in the universe.
From the Upcoming ueue, submitted by JKirchartz.