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

Good evidence comes from galaxy cluster collisions.

We can see huge amounts of matter (gas) that has collided and forms big shock cone structures, and we can also see where the mass is due to gravitational lensing.

We’d expect the mass to be in the same place as the matter, but instead most of the mass seems to have just carried on going and just passed through each other as if they were ghosts.

[Hence the idea for dark matter](https://www.youtube.com/watch?v=6itfq4CzxZ8) as some form of matter that has mass but doesn’t interact with normal matter or itself except by gravity.