Telescopes
The History of Telescopes
Telescopes alone have created the history of astronomy, but what about their own? In 1609, an Italian scientists, inventor and mathematician by the name of Galileo Galilei invented the first telescope, a refracting telescope, which means that you could look straight through the lens of the telescope at the desired object or image. As people soon discovered, refracting telescopes worked best if the lens were further apart, bringing people to build bigger and bigger telescopes in order to achieve the clearest image possible. The race was on to see who had the best telescope. Then, in 1680, world renowned physicist and mathematician Isaac Newton created an entirely new telescope, known as the reflecting telescope. This telescope had a mirror inserted inside the telescope, so that the light would reflect into what is now known as a focal point, making the image much clearer and sharper in detail. Since then, telescopes have grown and developed with technology, leading people to build bigger, better telescopes. As these telescopes have developed, so has our knowledge of what the Universe is, and has answered many of mankind's questions as to what is really out there. Nowadays, many categories and subdivisions of telescopes exist, with radio telescopes, x-ray telescopes, infrared telescopes, gamma ray telescopes and ultraviolet telescopes leading the charge in mankind's quest for knowledge.
Telescopes alone have created the history of astronomy, but what about their own? In 1609, an Italian scientists, inventor and mathematician by the name of Galileo Galilei invented the first telescope, a refracting telescope, which means that you could look straight through the lens of the telescope at the desired object or image. As people soon discovered, refracting telescopes worked best if the lens were further apart, bringing people to build bigger and bigger telescopes in order to achieve the clearest image possible. The race was on to see who had the best telescope. Then, in 1680, world renowned physicist and mathematician Isaac Newton created an entirely new telescope, known as the reflecting telescope. This telescope had a mirror inserted inside the telescope, so that the light would reflect into what is now known as a focal point, making the image much clearer and sharper in detail. Since then, telescopes have grown and developed with technology, leading people to build bigger, better telescopes. As these telescopes have developed, so has our knowledge of what the Universe is, and has answered many of mankind's questions as to what is really out there. Nowadays, many categories and subdivisions of telescopes exist, with radio telescopes, x-ray telescopes, infrared telescopes, gamma ray telescopes and ultraviolet telescopes leading the charge in mankind's quest for knowledge.
Reflecting Telescope
As previously mentioned above, the reflecting telescope was created in 1680 by Isaac Newton to combat the problems that plagued the refracting telescope, an earlier design. The telescope uses a curved, metal mirror (primary mirror) rather than a lens to collect light and direct it towards a focal point. Mirrors, unlike lens, do not suffer from chromatic aberration, meaning that the light is distorted making the image blurry. Good examples of reflecting telescopes are the Hale Telescope, a 5-meter diameter (200 inch) telescope situated at Palomar Observatory and the 10 meter (diameter) Keck Telescope at the W.M. Keck Observatory.
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Some advantages that Reflecting Telescopes have over other telescopes are:
Negative
Some disadvantage that Reflecting Telescopes have compared to other telescopes are:
As previously mentioned above, the reflecting telescope was created in 1680 by Isaac Newton to combat the problems that plagued the refracting telescope, an earlier design. The telescope uses a curved, metal mirror (primary mirror) rather than a lens to collect light and direct it towards a focal point. Mirrors, unlike lens, do not suffer from chromatic aberration, meaning that the light is distorted making the image blurry. Good examples of reflecting telescopes are the Hale Telescope, a 5-meter diameter (200 inch) telescope situated at Palomar Observatory and the 10 meter (diameter) Keck Telescope at the W.M. Keck Observatory.
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Some advantages that Reflecting Telescopes have over other telescopes are:
- Due to the fact that mirrors are much easier to construct than lens, reflecting telescopes can be made larger and enduring when compared to their refracting counterparts.
- Another advantage that reflecting telescopes have is that they are more cost effective, due to that mirrors are cheaper to produce compared to lens made out of optical glass.
- As reflecting telescopes have only one reflective surface they are easier to construct and less time consuming than other types of telescopes.
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Some disadvantage that Reflecting Telescopes have compared to other telescopes are:
- They are generally require more maintenance when compared to other telescopes, due to the mirrors accumulating a certain amount of dust or other particles periodically. Whenever cleaned, reflecting telescopes must also be realigned which can become very expensive over time.
- The single reflective surface that is incorporated in a reflecting telescopes design allows it to be large in size and diameter, but leaves it open to other particles and substances, namely air. This leads to a reflecting telescopes mirrors tarnishing easily and must be regularly polished and cleaned to achieve the clearest image possible, adding to maintenance costs.
Radio Telescope
Radio telescopes are used by scientists to detect radio wavelengths produced by objects in space. These 'telescopes' are usually found in arrays, as shown to the left, and are able to produce images and information from celestial objects they are listening to deep in space. The idea of the radio telescope was first pioneered and developed by American radio engineer Karl Gothe Jansky in 1932, where he detected radio waves coming from an unknown source, which turned out to be the central region of the Milky Way galaxy. An example of a radio telescope would be famous Parkes Radio Telescope, which is 64 metres in diameter and is situated in New South Wales outside the central-west New South Wales town of Parkes.
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Some advantages that Radio Telescopes have over other telescopes are:
Negative
Some disadvantages that Radio Telescopes have when compared to other telescopes are:
Radio telescopes are used by scientists to detect radio wavelengths produced by objects in space. These 'telescopes' are usually found in arrays, as shown to the left, and are able to produce images and information from celestial objects they are listening to deep in space. The idea of the radio telescope was first pioneered and developed by American radio engineer Karl Gothe Jansky in 1932, where he detected radio waves coming from an unknown source, which turned out to be the central region of the Milky Way galaxy. An example of a radio telescope would be famous Parkes Radio Telescope, which is 64 metres in diameter and is situated in New South Wales outside the central-west New South Wales town of Parkes.
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Some advantages that Radio Telescopes have over other telescopes are:
- They can detect parts of the electromagnetic spectrum which optical telescopes cannot, for example, radio waves.
- They are capable of working 24/7, which is something that optical telescopes cannot do due to light pollution.
- They can see and penetrate matter which absorbs light, which allows them to see further and more than optical telescopes.
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Some disadvantages that Radio Telescopes have when compared to other telescopes are:
- They are expensive to build and maintain when compared to other telescopes.
- They produce images which are much lower in resolution and detail when compared to their optical counterparts.
Refracting Telescope
Reflecting Telescopes are an early form of telescope, first invented by Galileo Galilei in 1609. Reflecting telescopes are a type of optical telescope that uses lens to magnify objects or images, namely the objective lens, which gathers light and bends it into the focus, or focal point, which is where the light rays combine into what is called a 'bright' image. This bright image is then interpreted by the eyepiece and magnifies it to the desired magnification. Examples of a refracting telescope is the well-known Johannes Hevelius telescope which had a focal length of 158 feet (48m).
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Some advantages that Refracting Telescopes have over other telescopes are:
Some disadvantages that Refracting Telescopes have when compared to other telescopes are:
Reflecting Telescopes are an early form of telescope, first invented by Galileo Galilei in 1609. Reflecting telescopes are a type of optical telescope that uses lens to magnify objects or images, namely the objective lens, which gathers light and bends it into the focus, or focal point, which is where the light rays combine into what is called a 'bright' image. This bright image is then interpreted by the eyepiece and magnifies it to the desired magnification. Examples of a refracting telescope is the well-known Johannes Hevelius telescope which had a focal length of 158 feet (48m).
Positive
Some advantages that Refracting Telescopes have over other telescopes are:
- They require little maintenance when compared to other telescopes due to their sturdy design and construction.
- Another advantage refracting telescopes have compared to their reflecting rivals is that the lens are fixed in place, which negates the need to constantly readjust the optical components, subsequently lowering maintenance costs.
Some disadvantages that Refracting Telescopes have when compared to other telescopes are:
- Chromatic Aberration is a problem which plagues refracting telescopes, which, in other words means that the lens used distort the light rather than focus it, making the image blurry and discoloured due to imperfections in the lenses.
- They are approximately 5x more expensive to produce and manufacture than reflecting telescopes, due to the fact that refracting telescopes require more time and skill to craft than their reflecting counterparts.
The Future of Telescopes
As mankind's quest for knowledge continues, so will the evolution and design of telescopes. In the not-so-distant future, new telescopes, with all new designs and purposes will start to observe and examine not only the night sky, but will reveal the birthplace of galaxies, delve into the deepest regions of space and attempt to locate other habitable worlds like our own. Telescopes such as the European Extremely Large telescope and the James Webb Space telescope will allow scientists to answer questions never thought to be answerable and observe the Universe like never before. I for one, can't wait.
As mankind's quest for knowledge continues, so will the evolution and design of telescopes. In the not-so-distant future, new telescopes, with all new designs and purposes will start to observe and examine not only the night sky, but will reveal the birthplace of galaxies, delve into the deepest regions of space and attempt to locate other habitable worlds like our own. Telescopes such as the European Extremely Large telescope and the James Webb Space telescope will allow scientists to answer questions never thought to be answerable and observe the Universe like never before. I for one, can't wait.