Is there any evidence for dark matter?

Question

I have always heard about dark matter, but I do not know what it means, what its uses are, and does it really exist?

In: Chemistry

Answer 1

Galaxies spin faster than they should, according to our understanding of gravity. This means either we don’t properly understand gravity on that large scale, or there is more mass making up galaxies than we can see. That extra mass is what we call dark matter.

We have not made any direct observations of dark matter, but we do know that galaxies are spinning as if they have more mass than there appears to be.