Question: What is dark matter and is it different from anti matter?

Kerrianne Harrington answered on 6 Nov 2017:

They are different, because we’re not sure what dark matter is. We just know it’s there!

Dark matter has never been observed directly, is hypothetical (a very good idea) and is different from ordinary matter because it is not made from the same fundamental building blocks. It was sort of made to explain some weird astronomical observations. It’s called dark matter because it is literally dark – it doesn’t give off any light with which we can see it with. We’re not sure what it is.

Antimatter is like a pair to ordinary matter (which outnumbers it!). Antimatter is made from similar fundamental building blocks that normal matter is, where these building blocks “partner” to each other. A big question at the moment is why most of the observable universe is ordinary matter and not equally antimatter, but unlike dark matter we know what antimatter is.