August 21, 1609 (, Jiyou July 22), the first telescope in the world on display.


in 1609, the Italian scientist Galileo exhibited human history a telescope manufactured in accordance with the scientific principles. the
first discovered the the telescope secret not Galileo, but a man named Li Bose Netherlands glasses businessman. Make lenses, a convex lens and a concave lens together out to see distant things closer. on this
Galileo discovered very interested, he calculated mathematical study what kind of lenses, how to combine better. Finally, Galileo two tubes, one end of a tube put the convex lens, another tube at one end put a concave lens: which is a slightly thin, just can trap another tube inside slide freely. Observed when you can back and forth adjustment, select the appropriate distance. In this way, after the repeated development and testing, and finally in 1609 invented the world's first one 32 times magnification telescope.
Galileo used this tool for astronomical observation, the first to discover the lunar surface is neither smooth nor pure, and crater cracks; Secondly found next to Jupiter has four satellites operation in around Jupiter. Galileo his astronomical discoveries the compiled "astral informed immediately reported to the world, caused the shock of the intelligentsia. Orders to buy Galileo telescope flow freely, but he does not count any reward, this invention is dedicated to the Duke of Venice. Duke ordered a hiring him as for Pa Duoya tenured professor. Soon, he was invited to Florence as a palace professor of mathematics.