Telescope is an instrument used to observe minute objects. It has the capability of collecting and analyzing radiations from objects that are at a distance. It has an electromagnetic spectrum that helps to magnify the size of an image when taking a photograph.
Information is also collected/ gathered through image sensor. There are various types of telescopes that are operational but the most common one is called optical telescope (Dupre 2008, p. 250).
This category of telescope has mirrors / lens that are used to magnify objects that are at distance or help to increase the brightness of objects that are faint.
Furthermore, optical telescopes are classified under three categories. One of them is called refractors. This kind of telescopes use lenses to magnify objects also called dioptics.
The second is called reflectors and use mirrors for magnification also called catoptrics. The third category is known as catadioptric. This uses both mirrors and lenses to magnify objects.
The history of telescope dates back from 1608 when the first refracting optical telescope was invented. The telescope recorded for the first time in Netherlands. The invention is credited to Lippershey Hans and Janseen Zacharias in Middelburg, who used to make spectacles.
Another important contributor who was also a manufacturer of instruments as well as optician was Metius Jacob came from Alkmaar. Later on, Galileo improved these inventions. He was later accredited as the first person to use his telescope in astronomy. In his telescope, he adopted the designs that were used by Hans.
Hans’ design had used a concave eye lens and convex objective lens, which he adopted. His new telescope therefore was an improvement to that of Hans and it was popularly known as the Galilean telescope. This was not to be end of the journey in terms of improvement of the telescope.
Kepler Johannes came with a proposal that sort to improve on the Galileo telescope. His new design was to be made using convex eyepiece. The telescope was also named after the founder – Keplerian telescope.
The invention of achromatic during 18th century brought about great development as refractors were used in the telescopes (Consolmagno & Dun 1989).
This kind of telescope solved the problem of chromatic aberration that was witnessed in the Keplerian telescopes. The new telescopes had the potential of functioning in shorter instruments that had large objectives.
However, this was not to be the end of the road as new ideas cropped up among scientists. Important figures such as Giovanin Sagredo, Isaac Newton and James Gregory worked on various studies to improve on the telescopes.
Improvements in reflecting telescopes saw the parabolic mirror improved in 18th century, and then silver-coated glass mirrors were adopted in 19th century. The invention reached its peak in 20th century when the mirrors were coated with aluminum that could last long.
By the middle of 20th century, cataddioptric telescopes were invented, which provided satisfactory services. One of the popular models of this kind of telescope is Schmidt camera. This camera used both mirrors and lens to magnify objects that are at distance and to make faint objects appear brighter (Mark, Maureen & Ahmed 2001).
It could also be used in imaging without using spherical aberration. By late 20th century, more sophisticated/advanced telescopes such as space telescope and adaptive optics had been invented to be used by an astronologist in viewing distance objects and carrying out their researches.
Currently, more sophisticated and advanced telescopes are being invented that provide fine imaging. The history of telescope is therefore very long. Development of these instruments has faced a lot of challenges but scientists are succeeding in their inventions.
Development of telescope to the largest
The advancement /development of the telescope has kept on improving as the years went on. From the Catadioptric telescopes, which operated at between 300nm-1100nm, came infrared, radio and millimeter wave, x-rays, ultraviolet and gamma rays that were used in larger areas due to their advanced capability.
Infrared telescopes operate at a wider range. They are used in examining emissions that come from the gas clouds. When they are used, they are usually located in areas of high altitude because water vapor in the atmosphere absorbs some of the radiations that are transmitted.
This kind of telescope was used by the NASA in 1983. It was able to survey the sky opening new avenues for the astronomers on various issues in the sky leading to discoveries.
The infrared telescopes were further improved leading to invention of other new kinds of infrared telescopes like infrared optimized telescope. This telescope has a diameter of 8m facility and was used at Mauna Kea in the city of Hawaii (Coward 2001, p. 1922).
Radio astronomy is yet another kind of telescope that was invented during the World War II. This telescope has the capability of examining radio emissions that are coming from the sky.
Radio telescopes, which were developed in early 20th century, were simple compared to the current ones. Their antenna was made from wires. The dish was introduced in 1950 and gained popularity as most astronomers used it in their studies.
Large telescope were built in the mid-20th century during the Second World War. Their development can be summarized into six major categories since the Second World War.
The latest largest telescope was called the Hale telescopes. Its core founder was Geoffrey Hale who succumbed to death in 1938. The telescope was completed under the management and direction of Max Mason, who was the president of Rockefeller foundation and died in 1961(Antoni 2011, P. 34).
Under the diminishing returns/ new tools, was oschin Schmidt telescope. This was also large and during that time, the telescope could not be made larger any more because of some limitations: thermal stability required thinner and small mirrors, the atmospheric pressure had some problems and fabricating big mirror was a challenge.
The third category was the MMT and Keck telescopes. These telescopes solved/addressed the problems that were experienced in the diminishing returns era. An example of such telescope was Mount Hopkins multiple mirror telescope (Gehrz 2010, P. 1004).
The fourth generation was adaptive optics and modern optical interfrometry, which were very thin with a size of around 20 centimeters in thickness. The fifth generation was called very large telescope/ large binocular telescope. They had four telescopes that could function separately.
They have a unitary mirror measuring 8.2 meters in its diameter (Ali, Eftekhar, Adibi & Farid 2012, p. 46). Other new telescopes include US overwhelmingly large telescope OWL. They were extra larger and were found not to function properly.
The telescopes have revolutionized and the modern telescopes are known as computer revolution. These kinds of telescopes are installed with electrical systems that help in production of digital data instead of the usual photographic images. The adaptive mirror and the alt azimuth mountings function as control system.
Examples of these telescopes include Telescope, Technologies Ltd, vista telescope and Sloan digital sky survey SDSS. These telescopes have a wider diameter compared to other versions (Huiyun, Zhenhai & Jinbao 2012, p. 25).
Since the early 20th century, many more innovations and developments have been invented. Advanced telescopes that were applicable to different situations became a reality. They also could be used to view very wide distances into the sky compared to the earlier ones.
Plans for the future
As time goes by and technology advances, various institutions dealing with research are also working hard to ensure that they develop telescopes that will be used in future to assist in their studies. As time elapses, the environmental changes require change of telescopes that will be able to provide sufficient information or discovery for planning.
Therefore, to ensure that the future is well guaranteed, various research organizations have teamed up to develop advanced telescopes for the same purpose (Tucker & Tucker 1986).
For instance, Aryabhatta Research Institute of Observational Science [ARIES], a research institute functioning under the department of science and technology together with the India government have teamed up to develop an optical telescope 1.3 m and 3.6 m at the Devasthal in Nainital.
Other institutes that are also contributing to the development of a 3.6 m telescope include Bangalore, Tata institute of fundamental to research and India institute of Astrophysics (Sagar 2011, p. 1020). They are working from Mumbai.
Belgium and Russia are also participating in the project under the bilateral arrangements that require cooperation in issues to do with science and technology in India.
Plans are also underway to set up two more survey telescope that are meant for specific purposes. One of the telescopes is 0.5-m wide field, which is equivalent to 25 square degrees. This telescope is called Schmidt and is being carried out at the Manora peak.
The telescope is being designed behind the scenes. A baker Numm satellite, which is a tracking camera, is the telescope that is being changed or converted to the Schmidt telescope. The second telescope is called liquid mirror telescope and has 4-m. it is planed to be set at Devasthal (Sagar 2011, p. 1020).
The new and modern telescope 3.6 m that is expected to be set is designed to provide high spectral resolution. Therefore, this telescope will have the capability of seeing limited images that are not visible and those that are near infrared.
Furthermore, the telescope is expected to be used in follow up studies of some of the issues/sources that were identified in the sky using radio region such as UV/X ray (Sagar 2011, p. 1020).
New technologies used to meet the need of large increasing telescopes
The larger telescopes are very heavy and therefore require invention of new technologies that are able to support them. For instance, some of the telescopes are made using trusses as opposed to tubes. The idea behind this is to ensure that the telescopes are well supported even during windy climate.
Tubes cannot support the weight of the telescopes because they are weak and vulnerable to wind. Therefore, many of the large professional telescopes are trusses. Some of the larger telescopes are made using carbon tubes. These are athermalized compared to truss telescopes.
This therefore makes them have high stability because they are not 100 percent made out of aluminum. They are further protected from the strays of light, which are useful in imaging during the way.
Extra larger telescopes are designed with special infrastructure that supports them. Most of the big telescopes are placed on a special designed surface for their support.
Others are built in-house and afterwards taken to strategic positions that are well prepared to support them while they are being used by the researchers to carry out their investigations.
Therefore, as the telescopes development has advanced, appropriate technologies are improvised to ensure that they are well taken care of to ensure that the purpose for which they were invented is achieved.
It is apparent from the discussion that the history of telescope has come from far. The journey was cozy and full of challenges. However, with the determination and dedication of researchers, they have managed to develop and come up with innovations that have proved successful.
Even though more large and sophisticated telescopes have been invented, the quest is still on and researchers are carrying their studies on how they can improve these instruments.
The future is unknown but scientists are putting in more efforts to come up with more advanced telescopes that can be counted on in terms of discovering new things in the sky.
List of References
Ali, H, Eftekhar, A, Adibi, A, & Farid, A. 2011. ‘A Kalman filter based synchronization scheme for telescope array receivers in deep-space optical communication links’, In Optics Communications, vol. 4 no. 4, pp. 5-62.
Antoni, R 2011, ‘Review: Progress in focal plane array technologies’, In Progress in Quantum Electronics, vol. 5 no. 3, pp. 34-50.
Consolmagno, G & Dun, M 1989, Turn Left at Orion, Cambridge University Press, Cambridge, UK.
Coward, D 2011, ‘The Zadko telescope: A resource for science education enrichment’, In Advances in Space Research, vol. 47 no. 11, pp. 1922-1930.
Dupre, S 2008, ‘Renaissance Vision from Spectacles to Telescopes’, Renaissance Quarterly, vol. 61 no. 1, pp. 250-252.
Gehrz, R 2010, ‘Status of the Stratospheric Observatory for Infrared Astronomy (SOFIA)’, In Advances in Space Research, vol. 48 no. 6, pp. 1004-1016.
Huiyun, W, Zhenhai, S, & Jinbao, C. 2012. ‘Optimizations’, In Optics and Laser Technology, vol. 2 no. 2, pp. 25-30.
Mark, H, Maureen, S, & Ahmed, Y. 2001. Encyclopedia of Space Science & Technology, John Wiley & Sons, New York.
Sagar, R 2011, ‘The new 130-cm optical telescope at Devasthal, Nainital’, Current Science (00113891), vol. 101 no. 8, pp. 1020-1023.
Tucker, W & Tucker, K 1986, The Cosmic Inquirers, Harvard University Press, Cambridge.