In the history of the evolution of science and the ability of the human being to observe the phenomena around him/her, one of the most important innovations is the telescope. From the days of Galilei Galileo and beyond, the telescope has evolved from its rudimentary forms to its present state that can vividly observe stars and even planets in other solar systems. The evolution has been mostly due to the advances in science that have predicted better technologies in the making of the modern telescopes. This essay seeks to explore the history of the telegraph from its rudimentary beginnings to its present form.


Background of Astronomy

One trace can the need for a telescope can back to the Renaissance period in Europe. According to Lattis, for a long time, the official projection of the universe had been geocentric, a position that was held by the then powerful Church. Ptolemy is the oldest known documented proponent of this outlook of the issue other than religious manuscripts. Aristotle also believed in this thrower. Moreover, he believed the stars were a perfect sphere but the world was not. This view was to hold sway for over a thousand years after the death of Aristotle, with no scientist seriously threatening it partly due to the need to avoid the wrath of the Catholic Church. However, Nicolas Copernicus was to contradict this with his theory that the solar system was heliocentric and not a geocentric one. To do this, Copernicus used calculation methods that had been traditional in the study of astronomical issues. These included watching the movement of the planets to back out what he believed was true. Galileo Galilei picked up Copernicus's work and would further develop it through observations of terrestrial objects with the optical telescope which revolutionized astronomy. This started the evolution of the modern astronomy and telescope.

Early Development: Lipperhey, Metius, Jansen and Galilei

Magnifying qualities of the mirror has been apparent for ages. After the establishment of glassmaking centers in Italy as early as 1400 set the ingredients for making the telescope. People might have observed the telescopic effect by combining the convex and the concave lens. However, the earliest known references to the manufacture of the telescope. Due to the easy way in which the making of the telescope was easily duplicable, the Netherland's government denied both the applicants the patent. Another Dutchman, Sacharias Jansen also seems to have made a similar instrument around the same time as the other two but did not apply for a patent. 

These initial telescopes were made up of both a concave and convex lens. The purpose of using the two lenses was such that the inversions of the image would not occur. However, these telescopes also had very low magnification, of only 3. The Dutch telescopes soon spread all over Europe. 

Upon getting a description of the telescope, Galileo build one without ever seeing a telescope in 1609. Galileo was to spend a considerable time improving the functional capacities of the telescopes. In few years he was able to build instruments that would magnify thirty-three times. The higher magnification enabled him to be the first person to notice that Saturn has satellites and the sun spots and the depressions on the moon. In respect to the pivotal role Galilei performed concerning the telescope, these early telescopes were to be referred to as Galilean telescope. 

Refracting Telescopes

Refracting telescopes formed first paradigm shift the technology of making telescopes. While Kepler was to be the first person to theorize on the effects and possible advantages of a telescope made up of only a pair of convex lens; Christophe Scheiner was the first person actually to construct it. William Gascoigne followed this up by further refining the refracting telescope by inventing the micrometer. This telescope's chief benefit was that it had a much wider field of view than the Galilean telescope.  A further development in the refracting telescopes was the powerful telescopes that Christian Huygens made. Huygens’s telescope was powerful enough to view Titan and give a clear description of Saturn’s ring. 

To deal with the challenge of the poor image due to chromatic aberrations, Giovanni Cassini invented the long focal length refractors. However, these needed support structures such as scaffolds to hold them, and they would shake even a small breeze thus reducing their impact. However, some of the telescope makers chose to do ways with the tube joining the lenses. The observer would fix one of the lenses on a tree or another tall support structure. Then the eyepiece would be handheld. Because of their structure, these telescopes were hard to use. Regardless, Cassini was to discover the third and fourth satellites of Saturn using such telescopes. 

Reflecting Telescopes

The technology changing business was to change even more in the years that followed. These used a curved mirror in place if the glasses in the 1600s. Newton was to develop further these telescopes basing them on his theory of the qualities of light, particularly refraction. The model developed by Newton was to be the standard telescope for many years, and many would subsequently name it the Newtonian telescope. Laurent Cassegrain was to make the Cassegrain telescope. This type used a convert hyperboloidal mirror to reflex light through the main mirror. The main disadvantage of these types of telescopes was that they would limit the amount of light that reached the eyepiece. Mikhail Lomonosov came up with a telescope that tried to solve this problem by using an eyepiece that one could mount on the front part of the telescope that would avoid the blockage of the light. William Herschel also had a similar design, and eventually, these telescopes would be known as the Herschelian telescopes. William Parsons would build one telescope based on this principle 

Achromatic Refracting Telescopes

The making of telescopes continued to evolve leading to the telescope that was supposed to do way with the chromatic errors. Chester Moore Hall would succeed in doing so, but a court would declare John Dollont, the originator of the achromatic telescope. The telescope would be made using two lenses which were compound in nature and had different dispersing capacities. The achromatic refracting telescopes reduced the need for very long focal-length telescopes in a bid to correct the chromatic effect on them.

Large-scale Reflecting Telescopes

With the advent of the methods through which physicists could deposit silver on glass telescope mirrors, the silver-on-glass large reflecting telescopes started being made. Among the first was the Hale telescope in 1908 and the Hooker telescope both mounted on Mt. Wilson Observatory. Their main advantages were that they allowed the removing of their mirrors, and the resilvering without destroying the telescopes or the mirrors. The BTA-6 in Russia was to be the largest of these kinds of telescopes, but the Hale was the most technologically advanced and had features such as the hydrostat bearings to reduce gravity and the mirrors made of Pyrex low expansion glass. Thus, in a period of less than century, the telescope had evolved significantly both in terms of its functionality, scope and size.         

Active and Adoptive Optics

Better technology from the 1980s meant that the telescopes could produce. These telescopes used computers to correct the distortions in the atmosphere that would affect the image. The active optics would correct the image at a few times per minute, but the frequency of the adaptive optics was several hundred times a minute. The manufacturers of the New Technology Telescope employed this technology in the 1980s. The Keck Telescopes and the Gemini telescope in the 1990s bettered the New Technology Telescope. A further development of active and adaptive optics will improve the images transmitted to the observer.  

Giant Paradigm Shift: Telescopes on other Wavelengths other than Visible Light

The most fundamental change in the construction of telescopes was the construction of telescopes that relied on other parts of the electromagnetic sphere. These started developing after the Second World War and would enable the scientists to perceive aspects of astrophysics that visible light could not. These range from the radio telescopes, infrared telescopes, ultraviolet telescopes and x-ray telescopes and Gamma-ray telescopes. These new types of telescopes have danced the study of astronomy to fields and distances that the optical telescope could not have done itself. 


This paper sought to describe the history of the telescope from its rudimentary form to the present advanced forms of optical and non-optical telescopes. As it was apparent, many of the world’s earliest scientists believed in that the solar system revolved around the earth but strain with Copernicus, this idea was displaced. The ingestion of the telescope was necessary to prove that the solar system was not geocentric, but heliocentric. Since its invention in Netherlands, and its refining by Galileo, it has evolved with technology. The refracting telescope followed and then reflecting and the achromatic refracting telescopes. Better technology led to the development of large reflecting telescopes. The advent of computers led to the development of active and adaptive optics. Lastly, other types of telescopes that do not rely on optical light have also developed in twentieth and twenty-first centuries. 

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