1. Dark Matter: Introduction
1. Dark Matter Introduction
Pictures courtesy of UC Berkeley
Dark matter. What is it? Why is it important? How do we find it? These are all very good and relevant questions.
If you look at the pictures above, the one on the left depicts dark matter, while the one on the right is obviously not dark matter, but visible matter. In fact, it is showing you a galaxy.
Dark matter is matter in the universe that we cannot see directly because it does not emit light. However, we know dark matter exists because of how its gravity affects other universal bodies, like stars and galaxies.
Dark matter can be found everywhere in the universe; it is not confined to one galaxy cluster or to certain types of stars. The universe consists of approximately 95% dark matter- that is a lot space to take up. But think about it: when you look up into the night sky, you see stars and planets, but these luminous bodies are surrounded by tons and tons of black: of dark matter.
But that is just a simple answer to a much more complicated question. For the whole deal on dark matter, browse around. Find out about (1) the history of dark matter theories or why dark matter is important,(2) clusters or what exactly dark matter is, (3)galaxy rotation curves and mass accounting, just big words for the effects of dark matter on other things and how we observe it, and (4) nonbaryonic candidates or how we look at the universe for what dark matter is.
So read on! Don’t stay in the dark about this matter.
Posted by bsalmon on March 26, 2005 at 7:55 PM