Is the amount of matter in the universe infinite?

[kmbop53]

I have heard the theory that there is an infinite amount of matter in space. Wouldn't that mean that there is zero volume? so I am trying to say i think that there is a limited amount of matter.

actually i think that i just answered my question with numbers but I will pose the question anyway to hear peoples opinions,

the explanation i just thought of is that there can be different amounts of infinity, such as there are an infinite amount of even numbers but paired with all of the odd numbers there is twice as much.

re-reading that last part i realized how badly worded it is and it probably just confused you more than anything.

 

[SpaceTiger]

There are several ways to approach this question. In astrophysics, we do not treat space as containing an infinite density of matter -- that is, a given volume has a finite amount of ordinary matter, dark matter, and dark energy. However, it is possible that the universe is infinite and that the total amount of matter in the universe is also infinite, despite everywhere having a finite density.

This is in contradiction with naive quantum field theories, which actually predict an infinite zero-point energy -- i.e. they say that the vacuum itself should have an infinite energy density. These infinities are almost certainly unphysical and the question of the zero-point energy is still an active area of research.

Finally, a naive Big Bang theory will produce an infinite density at the beginning of time (the "Big Bang Singularity"). This is probably also unphysical and hopefully will be resolved by theories of quantum gravity, which have been under discussion in several recent posts here.

 

[mathman]

the explanation i just thought of is that there can be different amounts of infinity, such as there are an infinite amount of even numbers but paired with all of the odd numbers there is twice as much.

It looks like you are confusing a methematical concept, which is what the quoted remark refers to, and the physical question of the finiteness of the universe, as discussed by SpaceTiger.