# Anything actually physically infinite within the universe?

camilus
Hi guys,
I'm a mathematician from Miami Florida working in paraquaternionic and symplectic differential geometry, but I come from a very extensive physics background, pretty much well-versed in all modern physics. But my favorite of all is probably the philosophy of mathematics and science as well.

So I'm a mathematician, and infinity is one of the most intriguing ideas that there exists to me. With some of my colleagues, mathematicians and physicists alike, I have an ongoing wager, currently at \$200, for anybody who could point out anything to me that is actually physically infinite inside the universe. I guess I must be specific, and it cannot be something like ideas that exist inside the human mind, like infinity itself and set theory (the natural numbers).

To this day no one has been up to the challenge, so I thought maybe I would ask this question within this community and see if anybody here could come up with a counter-example, because I believe the answer is negative.

I'm sure most of you know that the universe is discrete, even the approximate number of atoms within the universe, something like 10^80, is nowhere near infinity by any sense of the definition (obviously).. So could anybody come up with one example, or just I would love to hear your thoughts on this particular (philosophical/mathematical/physical) question.
Camilo

## Answers and Replies

Gold Member
Stupidity. Every single day I am more convinced that there is no end to stupidity. If you doubt me, watch Springer or Fox News sometime.

Oh, never mind. I guess that counts as non-physical...

Vagn
irk
Pointing out anything infinite in the universe? It would be very hard to prove it in reality. For example in quantum theory e.g. the charge of 'naked' electron is considered infinite. How this is possible when we see a very small charge? Explanation is that electron is in vacuum and vacuum is not 'nothing', it has to be taken into account when considering the actual charge we see. The effect is described in such a way that the naked charge polarizes vacuum creating in a charged screen, what we see is the residual effect of this.

camilus
No, I'm willing to bet those things are by definition to make the mathematics work, the electron doesn't have physically infinite charge. Period.

Mentor
Unless you're willing to accept Danger's counterexample :) you are not going to be able to settle your bet here.

It's easy to find infinities in mathematical models of physical systems (for example, treat an electron as a point particle and use Coulomb's law to calculate the field strength at ##r=0##) but these infinities are never observed in real experiments. When they appear in a mathematical model, we generally take them as evidence that the mathematical model is no longer accurately describing the physical system and that some (possibly as yet undiscovered - as with the singularity that appears at ##r=0## in the Schwarzschild solution) new theory is needed.

Does this mean that there are no "real" infinities? Who knows? All we can say is that you won't get a helpful answer from empirical science and therefore that this topic is outside the scope of this forum.

This thread is closed. As always, you can PM me if there's something more to be said on this subject, but we aren't going to throw it open for an unlimited descent into the rathole non-empirical discussion.