Expert: Steve Nelson - 11/23/2011

Question
Hi Steve,

I am just wondering; do we know whether the ratio between matter and dark matter is constant? Does one galaxy of a 100 billion solar masses have the same amount of dark matter as another galaxy of the same size, or does it vary? I cannot find anything about such a ratio on Wikipedia.

If there were a set ratio between matter and dark matter, wouldn't that seem to indicate that dark matter might be an unknown but specific property of matter (or vice versa)?

Thanks,
- Tue Sorensen, Denmark

Answer
I'll say it this way:  1)  People in physics are ABSOLUTELY obsessed with dark matter and come up with theories about it that are outside of the normal theories of physics.  2)  There's currently no evidence that there's a different amount of dark matter being unevenly distributed, and that is EXACTLY the kind of thing physicists in that field would be looking for.