isaac newton built the first practical telescope and developed a theory of colour.
isaac newton built the first practical telescope and developed a theory of colour.
who built the first practical telescope and developed a theory of colour?
isaac newton
gregorian telescope









































the gregorian telescope is a type of reflecting telescope designed by scottish mathematician and astronomer james gregory in the 17th century, and first built in 1673 by robert hooke. james gregory was a contemporary of isaac newton, both often worked simultaneously on similar projects. gregory's design was published in 1663 and pre-dates the first practical reflecting telescope, the newtonian telescope, built by sir isaac newton in 1668. however, gregory's design was only a theoretical description and he never actually constructed the telescope. it was not successfully built until five years after newton's first reflecting telescope.









































section::::history.
gregorian telescope
based only on uncertain descriptions of the first practical telescope which hans lippershey tried to patent in the netherlands in 1608, galileo, in the following year, made a telescope with about 3x magnification. he later made improved versions with up to about 30x magnification. with a galilean telescope, the observer could see magnified, upright images on the earth—it was what is commonly known as a terrestrial telescope or a spyglass. he could also use it to observe the sky; for a time he was one of those who could construct telescopes good enough for that purpose. on 25 august 1609, he demonstrated one of his early telescopes, with a magnification of about 8 or 9, to venetian lawmakers. his telescopes were also a profitable sideline for galileo, who sold them to merchants who found them useful both at sea and as items of trade. he published his initial telescopic astronomical observations in march 1610 in a brief treatise entitled "sidereus nuncius" ("starry messenger").
galileo galilei