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
Zacharias Janssen likely dates of birth would have made him 2-5 years old at the time) grandfather Hans Martens must have invented it. Other claims have come forward over the years. Physicist Jean Henri van Swinden's 1822-23 investigation reached the conclusion supporting Janssen and in 1841 a collector named Zacharias Snijder came forward with 4 iron tubes with lenses in them purported to be Janssen original telescopes. In historian Cornelis de Waard's 1906 book on the history of the telescope he recounted his discovery of note written in 1634 by the Dutch philosopher Isaac Beeckman in which Beeckman mentioned that Johannes Zachariassen