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Dark Matter

Dark Matter

Dark Matter Andrew Bilbrey Honors Physical Science Mr. Crupi 9/17/97 I'll be the first one to admit it. Dark mater is a boring subject. But until we can all grasp the meaning of quantum physics and what our universe is made of, we will never understand ourselves. This is what dark matter is all about; what scientists have been mystified about for the past few years. Many questions have come up in the study of this puzzling matter, but maybe we should start out with the basics. The Basics All throughout history, astronomers knew that there was matter that we couldn't see. The reason we cannot see it is because: 1. It doesn't emit any light, and 2. It doesn't emit any radio waves. The reason we know that there is matter we can't see is because of a few things. The one which we will be discussing at the moment is that the only thing that makes galaxies move is other galaxies gravitational pull. Scientists have noticed the galaxies inside of clusters over the years, and have perceived that to gain the speeds that the galaxies have been traveling, they would have to have much more, about 10 times more, mass to be moving at the speed they were moving. The more mass a galaxy has, the faster it will fling other galaxies, because of its gravity. In addition to the other facts, there is stronger evidence about mass in single galaxies, as opposed to clusters. This is called Rotation Curves. If you can find the rotation velocities of a galaxy, you can "weigh the galaxy". But how do you weigh the galaxy or the universe for that matter? We're about to find out. How Much Dark Matter You actually can weigh the universe with an actual measurement. A measurement that is almost inconceivable. This is called an "Omega". This might be a little confusing, but to explain an Omega you must think of infinity. A universe that is "closed", or so big that is eventually collapses into itself, has an Omega more than 1. On the other hand an "open" universe or a...

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