Telescope earliest existing record of a telescope was a 1608 patent submitted to the government in the Netherlands by Middelburg spectacle maker Hans Lippershey for a refracting telescope. The actual inventor is unknown but word of it spread through Europe. [[Galileo Galilei|Galileo]] heard about it and, in 1609, built his own version, and made his telescopic observations of celestial objects. The idea that the [[Objective (optics)|objective]], or light-gathering element, could be a mirror instead of a lens was being investigated soon after the invention of the refracting telescope. The potential advantages of using [[parabolic reflector|parabolic mirrors]]—reduction of [[spherical aberration]] and no
Jacob Metius Jacob Metius Jacob (Jacobus; sometimes James) Metius (after 1571–1624/1631) was a Dutch instrument-maker and a specialist in grinding lenses. He was born and died in Alkmaar and was the brother of Adriaan Adriaanszoon (simply called Metius). He is one of three people associated with the invention of the telescope, the other two being Hans Lippershey and Zacharias Janssen. Not much of him is known besides his 1608 patent application for the invention. He died in Alkmaar between 1624 and 1631. Metius may have made many inventions but kept them secret. Before his death he destroyed them all to prevent anyone