The reason people build larger Telescopes is because smaller telescopes have a smaller power to them, which results in less detail the farther they look. Larger telescopes use much larger lenses to see much farther and with much more clarity.
Basically, the larger the mirror (in reflectors) and the larger the lens (in refractors), the greater the light gathering capacity. Therefore you can see fainter stars.
But there is a limit for refractors because the glass gets too heavy and starts to sag. The biggest refractor is 40" Yerkes Telescope and that is about the limit for refractors.
But reflectors are supported behind or beneath so they can be huge.
Radio telescopes and optical telescopes work on exactly the same principles.
But . . .
Their performance depends on their size ... measured in wavelengths of the signal.
Just for an example . . .
The wavelength of the hydrogen spin transition radio telescopes often observe is
roughly 352 thousand times the wavelength of yellow light that the optical jobs
often observe.
And that's why you need a bigger collector for radio waves.
Two advantages.* A larger diameter increases the resolving power - how close apart two points can be, while still being able to distinguish them.
* A larger surface area makes it possible to watch dimmer (less bright) objects.
It's difficult to understand the question, but WikiAnswers doesn't do well with multiple choice questions. In general, refracting telescopes are smaller than reflecting telescopes; a refractor has the light going straight through the tube, and structural considerations force limits on its size. In a reflecting telescope, the light path is folded back on itself, and reflecting mirrors reflect more light than thick lenses can pass through. But the largest current reflecting telescope is perhaps 300 inches in diameter, although larger ones are planned. By contrast, the Very Large Array of radio telescopes is ACRES in total size, and there is no theoretical limit in how large "it" could be - because "it" is actually "they". Dozens, potentially hundreds of radio telescopes can add their size together to develop a more sensitive and more precise instrument.
The two types are refractor and reflector. In a refracting telescope, the light comes in THROUGH a magnifying LENS where it is REFRACTED (bent) to focus the light into an objective lens. In a reflecting telescope, the light BOUNCES OFF a curved magnifying MIRROR , and then reflected again on a secondary mirror to direct the light into an objective lens. Among the advantages of a reflecting telescope are that in a refracting lens, the thickness of the lens can absorb some of the light, while a mirror reflects all of the light. Additionally, a reflecting telescope can "fold" the telescope into a much more compact instrument, which is essential with especially large devices. A large refracting telescope would be enormously heavy and cumbersome.
Not exactly. A light telescope is a telescope that catches and shows visible light. The main light-gathering piece may either be a lens, in which case you would have a refracting telescope. Or - much more common with the larger telescopes - the main light-gathering piece is a parabolic mirror. In this case, it is a reflecting telescope. The largest refracting telescope is about 1.2 meters in diameter; all larger telescopes - currently up to about 8 meters - are parabolic mirrors.
In principle, there's no reason why it couldn't be. But it would be prohibitively expensive, harder to operate mechanically, and tough to match the optical performance of an equal-sized reflector. That's why, bowing to pragmatism and practicality, there hasn't been a larger refractor built since the 40-incher at the Yerkes Observatory was completed in 1895.
Larger telescopes are often used to focus on one specific star or distant formations. Smaller telescopes view broader areas of stars or larger formations.
A reflecting telescope uses mirrors while refracting telescopes uses lens. The refracting telescope also had chromatic aberration and bad resolution while the reflecting telescope had none of these.
A reflecting telescope is much easier to build than a refracting telescope and consequently is much less expensive. A reflecting telescope uses a concave mirror to collect and concentrate starlight and send it to your eye, whereas a refracting telescope uses a series of lenses to do the same thing. Optical quality lenses are much more expensive (and heavier) than a well-made mirror. For a given amount of money, much larger reflecting telescope can be built than a refracting. For very large telescopes, the lenses needed would be enormous and next to impossible to make optically perfect. Consequently, most telescopes are reflecting.
Ground-based telescopes, and space telescopes. Or: refracting telescopes (main collector is a lens), and reflecting telescopes (main collector is a mirror). Or: Home telescopes (small ones), and professional ones (larger and more expensive).
They are refracting telescopes(:Large refracting telescopes are no longer built because there were too many problems with them. There was color distortion, light pollution, and when the object hits the focal point it turns upside down. Then you don't see the object for what it really is, you see it upside down and weird-ed out. They are to complicated and scientists believed they should just stick with the simple, small, original refracting telescopes!!!!-Meghan Betts (8th grader)
The three major types are the optical, the infrared, and the radio telescopes. There are other specialized instruments for observing gamma rays, or x-rays, or for doing processes such as interferometry. Among the optical telescopes are the refracting (lens), reflecting (mirror) and compound telescopes (computer-assisted combinations of several smaller telescopes to simulate a much larger one).
It's difficult to understand the question, but WikiAnswers doesn't do well with multiple choice questions. In general, refracting telescopes are smaller than reflecting telescopes; a refractor has the light going straight through the tube, and structural considerations force limits on its size. In a reflecting telescope, the light path is folded back on itself, and reflecting mirrors reflect more light than thick lenses can pass through. But the largest current reflecting telescope is perhaps 300 inches in diameter, although larger ones are planned. By contrast, the Very Large Array of radio telescopes is ACRES in total size, and there is no theoretical limit in how large "it" could be - because "it" is actually "they". Dozens, potentially hundreds of radio telescopes can add their size together to develop a more sensitive and more precise instrument.
The two types are refractor and reflector. In a refracting telescope, the light comes in THROUGH a magnifying LENS where it is REFRACTED (bent) to focus the light into an objective lens. In a reflecting telescope, the light BOUNCES OFF a curved magnifying MIRROR , and then reflected again on a secondary mirror to direct the light into an objective lens. Among the advantages of a reflecting telescope are that in a refracting lens, the thickness of the lens can absorb some of the light, while a mirror reflects all of the light. Additionally, a reflecting telescope can "fold" the telescope into a much more compact instrument, which is essential with especially large devices. A large refracting telescope would be enormously heavy and cumbersome.
In principle, there's no reason why it couldn't be. But it would be prohibitively expensive, harder to operate mechanically, and tough to match the optical performance of an equal-sized reflector. That's why, bowing to pragmatism and practicality, there hasn't been a larger refractor built since the 40-incher at the Yerkes Observatory was completed in 1895.
Refracting
Not exactly. A light telescope is a telescope that catches and shows visible light. The main light-gathering piece may either be a lens, in which case you would have a refracting telescope. Or - much more common with the larger telescopes - the main light-gathering piece is a parabolic mirror. In this case, it is a reflecting telescope. The largest refracting telescope is about 1.2 meters in diameter; all larger telescopes - currently up to about 8 meters - are parabolic mirrors.
In principle, there's no reason why it couldn't be. But it would be prohibitively expensive, harder to operate mechanically, and tough to match the optical performance of an equal-sized reflector. That's why, bowing to pragmatism and practicality, there hasn't been a larger refractor built since the 40-incher at the Yerkes Observatory was completed in 1895.
refracting telescopes use lenses instead of mirrors. 1. chromatic aberration: when light passes through a lens it is focused at different points. Blue focuses closer to lens and red farther creating a smeared image. 2. Some light is absorbed by lenses. 3. Lenses are heavy and can only be supported by the edge. 4. Lenses must have to optically acceptable surfaces whereas a mirror only needs one.