Domination

Cosmology, like a woman, inspires you to take on the most adventurous of tasks at one moment, then it kicks your confidence out from under you the next. Sunday I declared my victory over the devious dealings of this callous science, and to day I lie in the rubble of my own self-proclaimed greatness. The theories of a radiation dominated universe crushed those of us with little grasp on methods of mathematical manipulation. It's difficult enough trying to solve equations pertaining to the visually observable world, but when one studies cosmology, 90% of the work has to do with that which is invisible to everyone except those who can see the matrix (I'll take the red pill please).

For those of you who don't quite understand what I am leading you to believe, let me explain. The universe can either be:

a) Dominated by matter

b) Dominated by radiation

c) Dominated by unknown particles

d) Dominated by me

In case a) we are most concerned about measuring the effect of gravity on our universe since that is the force which is trying to bring all masses closer together. In a radiation dominated universe, it's not nuclear radiation that concerns us the most (though my roommate Dave will tell you that we are concerned. See What Dave Wants, Dave Getz). To physicists radiation refers to any wave emitted from a source including any of the waves in the electromagnetic spectrum i.e. visible light, x-rays, or microwaves. If we inhabit this universe, then the pressure effects of these waves effect our everyday life the most. It is possible case c) is true, but at this time there is nothing known about the effects of the unknown. If d) is true I demand tithings!

As I was saying before, the class mathematically derived the effects of a radiation dominated universe. To the untrained student (me) there is not much of a difference between matter and radiation equations: Radiation domination implies density varies with 1/a^4 and matter domination it changes according to 1/a^3. To a cosmologist this is the difference between reality and reality television. Imagine the early universe. When you jump, gravity isn't doing most of the work to keep you down. Instead, you are at the mercy of the pressure from a densely packed front of electromagnetic waves which push you around in random directions.

Welcome to the real world.