Thursday, February 27, 2014

Telescopes a window to the universe

A telescope is an instrument made up of lens or mirror to observe the far away objects. A telescope magnifies and brings object much closer. Thus making the study of far away object much easier. The first telescope was invented in Netherlands in 17th century. Soon after that Galileo made similar telescope and used it to study the sky.
Observation of moon by Galileo and the picture he made from the observation.


http://www.nasa.gov/audience/forstudents/9-12/features/telescope_feature_912.html
Above link gives us brief history of the telescopes.
http://science.howstuffworks.com/telescope1.htm
The above image illustrates a very simplistic view of how a telescope work. Initially telescopes were made using lenses, later the use of mirror was introduced. There are various types of telescopes in use now.
It can be divided based on what range of electromagnetic waves we are looking at. The light we see is also a collection of a range of electromagnetic (EM) wave.  EM waves can be divided into various categories based on their wavelength. There is very limited range of wavelengths that a human eye can perceive.
Electromagnetic wave spectrum
Brief classification of telescopes on the basis of wavelength
a) Optical telescope
b) Radio telescope
c) X-ray telescope
d) Gamma ray telescope
e) Infrared telescope etc.


These different types of telescopes are used for different proposes. For example
the image here shows the galactic centre but
they are observed by different types of telescopes (i.e. in different wavelengths).
So depending on what they are trying to understand, scientists use different types of telescopes. Even though the older telescopes were ground based (i.e. they were used from the earth for observations) there are many telescopes now which are space based. Some of them are Hubble, Sptizer, Chandra etc. There are lot of beautiful images taken by these telescopes which you can find very easily in the internet.

Also the sizes and weight of telescopes varies a lot. There are telescopes weighing few pounds to thousands of pounds.
I encourage everyone to look through the telescope whenever you can. Most schools with observatories have open house. You can see many wonderful celestial objects through these telescopes if you go to an open house. Here at University of Denver, there is one open house at old Chamberlin observatory every month for the public. If you are in Denver area you should definitely make use of it. Click here to get more informations regarding the open house. http://mysite.du.edu/~rstencel/Chamberlin/

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