Quote:
Originally Posted by TheGuru
But, its not opposite  |
Isn't it?? I give up. I'm not a scientist. Maybe not everything has an opposite. Ok I googled it.
Dark Matter Detailed
Scientists figure dark matter must exist because of the way galaxies rotate. In simple Newton's-first-law terms, moving things will remain moving in a straight line unless some force causes a change in direction. For the stars in a galaxy to remain in orbit around the galaxy's center, some force must be acting on them, and the only possible candidate, at such distances, is gravity.
But the gravity attributable to the stuff we can see is way too feeble to "glue" galaxies together.
It's dark matter -- or more exactly, the gravity it exerts -- that must supply the force holding galaxies together, and lots of dark matter is needed to do the job. The numbers seem to change each month, but roughly 80 percent of all matter in the universe is that unseeable flavor.