Spread through Europe History of the telescope

19th-century painting depicting galileo galilei displaying telescope leonardo donato in 1609.

the italian polymath galileo galilei in venice in june 1609 , there heard of dutch perspective glass means of distant objects appeared nearer , larger. galileo states solved problem of construction of telescope first night after return padua venice , made first telescope next day fitting convex lens in 1 extremity of leaden tube , concave lens in other one. few days afterwards, having succeeded in making better telescope first, took venice communicated details of invention public , presented instrument doge leonardo donato, sitting in full council. senate in return settled him life in lectureship @ padua , doubled salary.

portrait of galileo galilei.

galileo spent time improving telescope, producing telescopes of increased power. first telescope had 3x magnification, made instruments magnified 8x , finally, 1 meter long 37mm objective (which stop down 16mm or 12mm) , 23x magnification. last instrument began series of astronomical observations in october or november 1609, discovering satellites of jupiter, hills , valleys on moon, phases of venus , observed spots on sun. galileo noted revolution of satellites of jupiter, phases of venus, rotation of sun , tilted path spots followed part of year pointed validity of sun centered copernican system on other earth centered systems such 1 proposed ptolemy. galileo s instrument first given name telescope . name invented greek poet/theologian giovanni demisiani @ banquet held on april 14, 1611 prince federico cesi make galileo galilei member of accademia dei lincei. word created greek tele = far , skopein = or see ; teleskopos = far-seeing .

these observations, galileo s improvement of instrument, led adoption of name of galilean telescope these forms of telescope employed negative lens.