Is Infinity Plausible in the Universe?

[Lightning-Rod]

Hello. The word "infinity" often comes up in physics, but observational evidence seems to preclude any form of infinity whatsoever: either everything must be infinite, or nothing can be infinite.

My line of thought comes from the fact that the density of our universe is not infinite. Therefore, the mass of our universe cannot be infinite either. Then, the size of the universe cannot be infinite either, since it's been growing ever since the beginning of time and you can't grow from "infinite" to "more-than-infinite", can you?

Indeed, even numbers themselves would be finite: if you made each and every elementary particle in the universe represent one bit of information, there would still be an upper limit to the numbers that could be represented by such a computing system. Since no higher numbers could possibly exist in the universe, it effectively makes numbers finite.

Is my reasoning correct or flawed?

 

[pergradus]

Why does it follow that if the universe doesn't have infinite density that it doesn't have infinite mass?

If the universe is infinite in spatial extent and contains infinite mass that says nothing about what the density should be.

 

[Lightning-Rod]

Why does it follow that if the universe doesn't have infinite density that it doesn't have infinite mass?

Because if mass were infinite, you would have enough of it to fill every nook and cranny of the universe, no matter how big the universe was. Otherwise, it would mean that mass is "less infinite" than space.

 

[ZapperZ]

Could you describe the density of states in conventional superconductivity, please? And try to do that without invoking any "infinity" at the superconducting gap edge.

If you can't do that, move on to the van Hove singularity that's present in the phonon density of states of the common materials that you use in your modern electronics.

Zz.

 

[pergradus]

Because if mass were infinite, you would have enough of it to fill every nook and cranny of the universe, no matter how big the universe was. Otherwise, it would mean that mass is "less infinite" than space.

and the same argument can go the other way - if the universe were infinite in size, you could always spread the mass around thinner and thinner no matter how much mass there was.

See why infinities usually don't make any sense?