Physics Van 3-site Navigational Menu

Physics Van Navigational Menu

Q & A: ancient history

Learn more physics!

Most recent answer: 10/22/2007
Q:
I understand that all objects and substances are made up of matter. The evolution of mankind has been ponderd upon my many people. Before the earth there were billions of stars and other objects in space, but what came before those objects and how were they created?
- Adam (age 13)
Massachusetts
A:
Earlier in the universe, things were very hot and very uniform. We can directly see light left over from that era in the Cosmic Microwave Background.

The galaxies and stars formed by gradual clumping of material around spots that by accident had a little more than their share of stuff. (We can even see those tiny irregularities in the Cosmic Microwave Background.) Gravity would pull other matter into those spots, and friction allowed that matter to dump its energy and stick in clumps.

Tracing things back even earlier means tracking the cosmology back toward a Big Bang, in which all the parts of the universe which we now see were compressed down to a point, or whatever is the closest thing to a point in nature. We don't really understand anything about nature on that tiny a scale yet.
In between the time scale which we don't understand and the time scale of the microwave background, there were a series of very dramatic events, but they form too long a story for one of our little answers. There are some great articles in the Scientific American magazine (your library probably has a large stack of them) on the history of the aftermath of the Big Bang, and we recommend you look at those. If you have further questions, please come back.

Mike W.

(published on 10/22/2007)

Follow-up on this answer.