Saturday, October 23, 2010

Astrophysics and Cosmology

Astrophysics is the study of physics of the stars and other stellar structures. This is a theoretical enterprise. science is about experimental observations. The observational input for astrophysics is provided by astronomy.
The latter is the science of measurement of the phenomena happening in the universe, in stars, galaxies and in between.

There is another related science. It is called cosmology. This is the study of the birth, evolution and fate of the universe. The word science has been italicized. Science is about experimental truth. The truth you ascertain by experimentation. Can you do experiments with the universe? Like saying, wind up and start again. Obviously not. Scientists know this. But still find some profound things to say about it.

To complete the scenario it can be noted that even astrophysics, based as it is on astronomy, is not experimental science. It is merely observations science. We do not have any control over the stars to manipulate them experimentally.

Apparently we are living in the golden age of astrophysics and cosmology. The peculiar thing about golden ages is that we do not realize that we are living in a golden age till it is passed. At least till now this was the case. And lo and behold we are in a golden age. Golden age of astronomy and cosmology.

This is because of around fourteen expensive observatories. You have heard of the names like Chandra Observatory, Hubble Telescope. These observatories are in the space. These are satellites and not the observatories on the ground. Then there are others.

How expensive are these? Lets us take a future observatory called JWST. James Webb Space telescope.
Its present cost is five billion dollars and it is rising. For comparison the cost of XIX Commonwealth Games (excluding infra structure development) was half of this cost.

(See here for more)