There now exists a variety of combinations of telescopes which range from very large telescopes to some extremely small ones (Moore 1996, p. 97). These telescopes are predominantly scattered in the northern hemisphere, but recent projects have also resulted in the creation of different telescopes in South America. The reasons behind include ambient light pollution (that comes from cities), the weather (including humidity, visibility) and the geographical location (including elevation, height and relative position on the planet).
As a result of this, several different approaches have been taken and as a result, innovative telescopes have been invented. These telescopes have utilised different aspects of the behaviour of light waves and topics (Moore 1996, p. 71).
