There are two main designs of telescopes

uranology bear be defined as the sight of all electromagnetic radiation from outer space. This definition encom payes the nature of the field, that the objects actually under study the planets, stars, galaxies, et. al are quite unreachable and frequently(prenominal), information and knowledge we suffer of them stems not from direct experimentation except from thoughtfulness of their emitted radiation.For most of astronomys history, that radiation was in the form of ethereal and the primary rotating shaft for gathering and observing that frail was the human eye. Without any aids, early astronomers such as Tycho Brahe, the Mayans and the Egyptians were able to develop a very detailed reasonableness of the stars and their motions.Ever since Galileo pointed his setting towards the heavens, astronomy has been revolutionized. Far from being a study of gossamer motions, astronomy evolved to the study of the actual celestial objects. The telescope allowed for direct observati on of these specks of enlighten traveling in the velvet sky.Moreover, the telescope allowed us to mold what is impossible to perceive with the naked eye. Even the most basic telescope available today can reveal craters on the moon, or the moons of Jupiter and the peal of Saturn.There are two chief(prenominal) designs of telescopes reflecting and refracting. A telescopes main function is to do one thing gather light and focalize it to one point. Refractor telescopes do this using lenses curved pieces of glass which light passes through. The suit of lens used by refractor telescopes are convex lenses which make tally rays of light (emanating from the astronomical object) converge to a single point.The path of the light gets bent as it passes through the lens resulting in all the light rays being focused to a single point. In the case of reflecting telescopes, light is focused through the use of curved mirrors. Light being reflected by the mirror is directed to a single point . The shape of mirrors used in reflector telescopes can include parabolas, hyperbolic and elliptical curves depending on the precise design of the reflector telescope.Today, the largest telescopes are all reflector telescopes. This is because to some indispensable advantages in reflector telescopes. First, we pick up to realize that a telescope is a very precise opthalmic device. With a reflector telescope, we only need to exhaust one very precisely make side the mirror side of the glass reflector. Compare this to a lens where light has to pass through.A lens would have two surfaces which need to be perfectly polished, resulting in twice the amount of effort. Couple this with the fact that most contemporary refractor designs bank on multiple lenses to correct for optical aberrations. Secondly, reflector telescopes are more than structurally sound at large sizes. Since light does not have to pass through the mirror, a support structure can be placed directly underneath the mir ror.The support structure would be much harder to create for a refractor telescope. Firstly, the shape of the convex lenses fashion that it is heaviest at the center. Secondly, level if it is heaviest at the center, the support structure can only be made at the edges receivable to the need for light to pass through the lens.As we tell earlier, the primary purpose of a telescope is to gather light. A greenness misconception is that telescopes are used to simply make far away things scene nearer, that is a telescope is supposed to magnify the view of objects. The outburst of a telescope is not a function of a telescope itself but a function of the telescopes focal length and the focal length of the eyepiece used in viewing.The magnification is equal to the focal length of the telescope divided by the focal length of the eyepiece. This means that a single telescope can have many divergent magnifications depending on the eyepiece used. One might be tempted to think that telescop es can have infinite magnification simply by using eyepieces with shorter focal length.In reality, the highest magnification for a telescope is around 50 x the aperture (the diameter of the telescopes objective optical element) in inches. This limitation is due to several factors. First, high magnifications will result in a dark image. Secondly, aberrations in the atmosphere and optical train become more unadorned with high magnifications.Secondly, there is a limit to magnification as optical limitations would place a threshold on the available response produced by the telescope. Any magnification beyond this threshold only produces empty magnification as not additional detail can be resolved.The cleverness of the telescope to resolve details is inversely proportional to its aperture. This is set by the Rayleigh, Dawes and Sparrows limit which all say that the limiting resolution of an optical system is some factor divided by the diameter of the optic. Simply put, the larger the telescope, the higher its resolving power.