$who invented refracting telescope$ $who invented refracting telescope$

'With a Concave lens you shall see small things afar off very clearly. In Italy, Giambattista della Porta also described a possible telescope as early as 1586 when he wrote in a letter, '.to make glasses that can recognize a man several miles away.' In his Natural Magic published in 1589 he wrote: 'But to leave these celestial causes and things done of antiquity long ago, my father by his continual painful practices, assisted with demonstrations Mathematical, was able, and sundry times hath by proportional Glasses duly situate in convenient angles, not only discovered things far off, read letters, numbered pieces of money with the very coin and superscription thereof, cast by some of his friends of purpose upon downs in open fields, but also seven miles off declared what hath been done at that instant in private places.'Īlthough Digges may have created a rudimentary instrument involving lenses and mirrors, the optical performance required to see the details of coins lying about in fields, or private activities seven miles away, was far beyond the technology of the time. Thomas Digges describes his father's device (In the preface to his 1591 Pantometria) as follows: They may have been experimental devices and were never widely reported or reproduced.

$who invented refracting telescope$

Writings by John Dee and Thomas Digges in England in 15, respectively ascribe the use of both reflecting and refracting telescopes to Thomas' father Leonard Digges. There is some documentary evidence, but no surviving designs or physical evidence, that the principles of telescopes were known in the late 16th century. 'This part of optics, when well understood, shows us how we may make things a very long distance off appear as if placed very close, and large near things appear very small, and how we may make small things placed at a distance appear any size we want, so that it may be possible for us to read the smallest letters at incredible distances.' Pre 17th Century Developments Thus, early knowledge of lenses and the availability of lenses for spectacles from the 13th century onwards through the 16th century means that it was possible for many individuals to discover the principles of a telescope using a combination of concave or concave and convex lenses in the 13th century, Robert Grosseteste wrote several scientific treatises between 12, including De Iride (Concerning the Rainbow), in which he said: It is generally considered that spectacles for correcting long sightedness with convex lenses were invented in Northern Italy in the late 13th to early 14th century, and the invention of the use of concave lenses to correct near-sightedness is ascribed to Nicholas of Cusa in 1451. It was approximately from the 12th century in Europe that 'reading stones' (magnifying lenses placed on the reading material) were well documented-as well as the use of lenses as burning glasses. He used the law of refraction to derive lens shapes that focus light with no geometric aberrations, known as anaclastic lenses. Ibn Sahl is credited with first discovering the law of refraction, usually called Snell's law.

$who invented refracting telescope$

Ptolemy (in his work Optics written in the 2nd century AD) wrote about the properties of light including reflection, refraction, and color.ĭuring the 10th century, Ibn Sahl, a Muslim mathematician of the Islamic Golden Age, in his treatise On Burning Mirrors and Lenses sets out his understanding of how curved mirrors and lenses bend and focus light. Simple lenses made from rock crystal and their properties were known well before the invention of the modern optical telescope. It was proposed that the lens was used by the ancient Assyrians as part of a telescope, and that this explains their knowledge of astronomy. It may have been used as a magnifying glass, or as a burning-glass to start fires by concentrating sunlight, or it may have been a piece of decorative inlay.

$who invented refracting telescope$

The Nimrud lens is a 3000-year-old piece of rock crystal, which was unearthed in 1850 by Austen Henry Layard at the Assyrian palace of Nimrud, in modern-day Iraq.

$who invented refracting telescope$

Who invented refracting telescope