Question

what is matter?

Answer 1

Beats me.
It's mysterious.
All in all, we say matter has a mass, and thus experiences inertia, has momentum, and is attracted by gravity from other mass.

Matter also has a wave associated with it, which describes the probability of the matter to exist in a particular location.
It is sizable relative to the mass for small particles. It is extremely negligible relative to the mass for everyday objects.

Mass also has a energy associated with it, described by the famous Einstein with \(E=mc^2\).

I'm not a particle physicist, so I don't know a whole lot, but I plicked that up in a college course.

Answer 2

Seems pretty clear to me, matter is:\[m=\frac{E}{c^2}\]:)

Answer 3

Haha!