Telescopes

they do not need visivle light to obtain images

The only three syllable word that can be made out of some of the letters in telescope is "celeste"

The main disadvantage of a radio telescope is the poor resolution of the images they obtain. This isn't due to a flaw in the design, but in a limitation of the radio signals they observe. The longer the wavelength of light (radio waves are light!) the fuzzier the image you receive.

In order to combat this, a larger telescope is needed. Radio telescopes are thus the largest astronomical telescopes, measuring hundreds of meters across (e.g. Arecibo radio telescope) or composed of many smaller dishes in large arrays of dozens of radio dishes (e.g. VLBA, Very Long Baseline Array).

Another disadvantage is the amount of human generated noise can easily interfere with the telescopes, and is harder to isolate and shield than from light pollution, as it easily reaches beyond horizons and around terrain and obstacles. This can require remote observation sites.

They also have many advantages, but that isn't the purpose of this question.

Exactly the same way that an optical telescope gathers waves with wavelngths

shorter than radio waves:

Both the mirror of a reflecting telescope and the 'dish' of a radio telescope are

built to have the shape of a 'paraboloid' ... that's the solid shape you get when

you spin a parabola around its nose.

The paraboloid has the interesting geometric property that anything that comes

straight in, parallel to its axis ... whether it's bees, bullets, B-Bs, or electromagnetic

waves ... and bounces off the inside of the curve, all winds up at the same point,

called the "focus" of the paraboloid.

-- The focus is where the film, or the eyepiece, the CCD, or the spectrometer

of the reflecting telescope is placed. All the light that hits the whole mirror is

concentrated onto it.

-- The focus is where the radio receiver of the radio telescope is placed.

All the radio waves that hit the entire dish are concentrated onto it.

-- The focus is where the little LNB on the end of the arm that sticks out in front

of the TV dish on your neighbor's garage is placed. All the microwave waves

from the TV satellite that hit the entire dish are concentrated onto it.

It acts as a RADAR unit, sending radio waves and measuring the amount of time it takes for them to come back.

radio telescopes monitor radio signals from outer space. The signals are analysed and classified by type to determine the nature of the source and widen our knowledge of astrophysics and cosmology.

Optical telescopes use either lens' (refractory) or mirrors (reflective) to magnify light. Radio telescopes use dishes to pick up radio waves. sensors on the dishes collect the waves and turn them into a picture

Galileo Galilei put together his telescope in 24 hours in Padua after while he had about a Hans, a Dutch spectacle-maker, having invented a 3x spyglass which made objects seem near while on holiday in Venice. Galileo worked on things that had been said about this spyglass (which had been kept secret) and instinct. A few days later he produced an improved 8x version. He presented it in Venice it in early 1609, just months after Lipperchey's invention. Galileo's invention was named telescope by Giovanni Demisiani a Greek poet/theologian at a banquet of the Accademia dei Lincei in Aril 1609 form the Greek tele (far) and skopein (to see). Galileo continued to perfect his telescope until he produced a 33x model.

The Yerkes observatory (named after the Chicago Industrialist and street-car empire builder Charles Yerkes, who financed it) is the home of the world's largest telescope that uses a lens as the main light-gathering instrument. More recent large telescopes have used mirrors to gather the light, since large mirrors are far easier to make.

* The telescope helps us understand space and the stars and other planets.

He invented the reflecting telescope. Galileo was the first to use the telescope for studies of the heavens.

Ptolemy never saw a telescope. The first telescopes were invented about 1500 years after Ptolemy died.

Telescopes, were essentially discovered in 1609. Galileo and later Keppler were the first astronomers to use them. They caught on rapidly as observing instruments and for look out purposes., it took the optician's a while to correct the inverted view on some of them, but once done, they took off.

A Barlow lens is an accessory used in telescopes to increase the focal length, resulting in magnification of the image. It allows the telescope to achieve higher magnification without needing to switch to a higher power eyepiece. By inserting the Barlow lens between the telescope and eyepiece, it effectively doubles or triples the focal length of the telescope.

Galileo is the first recorded instance of the use of a telescope, though it is well known that he developed the idea for it from a toy that arrived from a traveling merchant.

An optical telescope cannot be used during cloudy days. Of course, this assumes that the telescope is located somewhere on the Earth's surface and therefore subject to weather. Since clouds obscure the sky - and any heavenly object otherwise visible - the optical telescope will be unable to see anything. A radio telescope, however, can see through clouds, simply because clouds do not block or cause significant interference to radiowaves reaching the Earth's surface from space.

The Yerkes Telescope is the worlds largest telescope that's founded by the University of Chicago.

Reflectors - the main two types being Newtonian and Cassegrainian.

A Galilean Telescope is also an Astronomical Telescope so it is just a subset of Astronomical Telescopes.

One end of a reflecting telescope is the big hole pointed at the star. The other end of the reflecting telescope has a lens called an eyepiece.

Because the Hubble Space Telescope was designed for periodic servicing, the items to be replaced are easily accessible. Ranging in size from a shoebox to a telephone booth, most of these items can be removed or installed using special wrenches and power tools.