Astronomic Telescopes Chapter Summary The fifth chapter discusses radiation and provides overview of main types of telescopes used in modern astronomy . In astronomy telescopes are used for gathering light , seeing the tiny details and magnifying the necessary image . Refracting and radio telescopes are two common types used in astronomy . Refracting telescopes were used earlier and nowadays astronomers tend to use radio telescopes because they are able to detect cool hydrogen in the space . Radio telescopes allow seeing through the dusk and to analyze invisible processes . Refracting telescopes are equipped with a lens that bends the light focusing it on the necessary image . Actually , reflecting telescopes are equipped with mirror that focuses the light . Refracting telescopes are less expensive than radio telescopes .Further , it is necessary to admit that the author provides definition of what light and electromagnetic spectrum are . Light is defined as visible form of electromagnetic radiation . It is magnetic and electric disturbance which is known to transport energy at the light speed . X rays , gamma rays , visible light , ultraviolet radiation , radio waves and infrared radiation are included in electromagnetic spectrum . A photon is a particle of the light . Photon is defined as a bundle of waves that may act as a particle and as a wave . It is known that the length of the wave may range from 400nm to 700nm and depending on the wavelengths photons are classified as infrared , ultraviolet and so on . Infrared and radio photons have longer wavelength , whereas ultraviolet and x rays have shorter wavelengths and carry , therefore , more energy . PAGE PAGE 1…