Refracting telescopes

Through a curious set of circumstances, Newton failed to solve the problem of chromatic aberration, and so, he abandoned the attempt to construct a refracting telescope which should be achromatic, and instead designed a reflecting telescope, probably on the model of a small one that he had constructed in 1668. The form he used is known by his name today. 

The refracting telescope predated Galileo devices able "to bring far objects closer than they appear" were known well before his time, and their first origin... 

UV, X-ray and gamma-ray observatories are all space-borne because these wavelengths are blocked by the Earth s atmosphere. And what could be more natural than to place eyes in orbits But who sent them up there and why Astrophysicists are no longer naive when it comes to the relationship between the tools of military surveillance and those of astronomy. And this is not a recent invention. Galileo himself offered his refracting telescope to the delighted dignitaries of the Venetian senate in order to draw attention to its military potential. His salary was immediately doubled and he was appointed professor at the University of Padua ... 

Armed with a gamma telescope, to pick out this emissary of violence, the astronomer can show us the regenerating explosions that shake the cosmos. Each object has its eye, each eye its object. The refracting telescope reached out to the Moon, whilst the gamma telescope beholds the explosion of stars. 

Schlesinger used long-focus refracting telescopes to make observations, and, in 1935, he published the parallaxes of over 7,000 stars. 

The year 1877 promised to be an exciting timefor astronomers interested in the study of Mars. The Red Planet was to be in perihelic opposition, the closest position that exists between Mars and Earth. In the two decades since the last perihelic opposition, a new 26-in (66-cm) refracting telescope had been built at the U.S. Naval Observatory in Washington, D.C. The man in charge of the telescope, Asaph Hall, had decided to focus his efforts on finding out whether Mars had any satellites. 

Sir Isaac Newton was dissatisfied with the limitations of Galileo s refracting telescope, which operates like a spyglass, and he invented the reflecting telescope. 

CH4+H20 C0 + 3H2 occurs at about 900°C using a nickel catalyst, refracting telescope (refractor) See... 

Optical astronomical telescopes fall into two main classes refracting telescopes (or refractors), which use lenses to form the primary image, and reflecting telescopes (or reflectors), which use mirrors. 

The first set-up comprises two convex lenses L i and L2. Note that the forward focal point F of lens Li coincides with the rear focal point F2 of lens L2 see Figure 10.12 (top). This type of beam expander/ collimator is often called a Keplerian beam expander (its name is derived from the alleged inventor of the refracting telescope, which closely resembles the beam expander). The second method uses a combination of a concave lens Li followed by a convex lens... 

Some telescopes exist just to help other telescopes do their job. Astronomical transit instruments are small refracting telescopes that precisely determine the locations of specific stars and planets, enabling larger telescopes to focus directly on them. 

Refracting telescope (Hans Lippershey) Lippershey is one of several who can lay claim on developing the early telescope. 

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