![]() ![]() Good enough to be used in telescopes would not be available for another This is an alloy of copper (2 parts) and tin (1 part). spherical, paraboloid).Įarly reflecting telescopes were made from these designs using the speculum metal then usedįor regular mirrors. ![]() Several configurations ofĬonvex mirrors ,concave mirrors and lenses were proposed, some of which are still in use today.ĭifferent shapes were suggested for the mirrors (e.g. The reflecting telescope did not have these problems. ![]() This could result in fuzzy edges to objects. The problem is that glass refracts theĭifferent wavelengths of light differently, resulting in different focus Light rays at the objective to a single focus point. Interest were some very serious problems with early refracting telescopes. The Jesuit priest, Niccolo Zucchi,Įven built a crude reflecting telescope as early as 1616. Shortly after the invention of refracting telescopes. Interest in the idea of building telescopes using mirrors instead lenses began To the work that preceded them and that was being done by contemporaries. Understanding the contributions of Mersenne, or for that matter Newton, requires some attention Marin Mersenne presented workable designs for reflecting telescopes that are still used today.īut he was not the first to toy with the idea of using mirrors in place of the lenses of the telescope. By coincidence, all three were Roman Catholic priests. TheĮarly proponents of reflecting designs (Marin Mersenne, Bonaventura Cavalieri,LaurentĬassegrain) deserve a closer look. Histories of the reflecting telescope typically skip over theirĬontributions to start with Isaac Newton (1668) or James Gregory (1663). The earliest champions of this design published their designs 30 yearsīefore the debut of Newton's telescope. Over the last 120 years, almost all of the largest optical telescopes were reflecting telescopes The role of the lenses is to concentrate light rays into a single point – the focal point – so as to obtain a sharper magnified image.The Early Reflecting Telescope:Cassegrain and Mersenne The larger of the two is the objective, or primary lens, and the second is the ocular. The first refracting telescopes consisted of two lenses separated by some distance within a closed tube. His book revolutionized our concept of the Universe. Galilei, however, was the first to have published his observations in a book entitled “The Starry Messenger” (translated from Latin). The English mathematician Thomas Harriot was the first to study the Moon in detail using an astronomical telescope in 1609, and it is known with certainty that this occurred several months before Galileo Galilei, the famous Italian physicist, did the same. Lippershey applied for a patent for what he claimed was his own invention, but was refused on the grounds that the device was already in existence. The instrument did not become widely known to the public until 1608 when Hans Lippershey (or Lipperhey), a Dutch optician of German origin, began to make and sell telescopes. Leonard Digges – or perhaps his son, the English astronomer Thomas Digges – was also the first to turn a refractor towards the sky to study celestial objects. The first person to do so with certainty, and thus the person to be credited with its invention, was the English mathematician Leonard Digges who constructed a refracting telescope sometime between 15 to assist with his topographic surveys. It is difficult to determine when a refracting telescope was first assembled using lenses. ![]() Other historical evidence reveals that the Arabs were using lenses by the year 600 AD, as were the Vikings around the year 900. The crystal was cut and polished into the shape of a lens, however it is not entirely certain that it was used as a magnifying lens and not as jewellery or for some other purpose.Įvidence that lenses were in use during the first century BC can be found in the records of the Roman authors Pliny and Senecio who reported that an engraver at Pompeii used a lens to help him in his work. The evidence is a rock crystal discovered by the English archaeologist John Layard in 1850 during the excavation of the ancient city of Nimrud. The Assyrians (people who lived in a region that is known today as Iraq) were perhaps the first to have used lenses to magnify objects, possibly around 1,500 BC. ![]()
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