Ever heard of Hilbert’s hotel?
The hotel of Hilbert is infinitely large, it has an infinite number of rooms, and they are all occupied by an infinite number of guests.Yet someone is still offering to stay overnight. Is that going to be able? Yes: the guest of Room 1 moves to Room 2, which originates from 2 to 3 and so on. The guest of room “Infinity” moves to “infinity + 1”. And, as you recall from algebra: Infinity + 1 = infinity. An infinity can grow precisely because it is infinite.
Having said that, I do not believe that the universe is infinitely large. With George Ellis I believe that infinity is not realized in physical reality.
“Growing” is not the right term.Regardless of whether the universe is immeasurably large or infinite, the spreading of the universe means that the space between objects becomes larger and not that matter increases.
Although the space that encloses the “infinity” enlarges, the “infinity” itself does not increase, in other words: the distance between the boundaries of the universe is greater, but the content of the universe does not.
First you have to try to understand it nothing: suppose there was nothing, no stars no planets, no God (for those who happen to believe in it yet) no humans no animals no plants etc.
What would there be?
Maybe an infinitely large space with nothing in it?Well but which ones are the features of that space?
How many dimensions?What is the absolute minimum temperature? PLANCK constant?
That all makes no sense as there is just nothing.Nothing Is nothing!
Since the Big Bang, our cosmos expands with the speed of light.For instance, the properties of our cosmos are still being sent in the space VB our absolute minimum temperature of minus 273 Celsius or O degrees Kelvin.
Over an ever larger area These properties are distributed: unimaginable far but never infinite.
Now imagine that there is still somewhere else a big bang to the bullies with VB 20 degrees Celsius as absolute minimuntemperature and of course another triad other properties what is in the space between the 2 big bangs?
But the first bigbang that arrives right where takes the space he conquers and imposes his attributes on that space.
Because of the expansion, a big bang takes up more and more space but never infinity.
So We should not make the fallerror that there is an infinitely pre-existing space with all sorts of traits and that our big bang expands.No it is because of the expanding itself that more and more space is being found.
Ever more but never infinity…
Infinity is only an invented term to be able to make a representation of the concept.People are simply unable to create a visualization of something as gigantic as the universe. A billion or a trillion, it doesn’t matter to most people because it is an unimaginable large number.
The universe is (according to the most common theory) not infinitely large, but without boundaries (at least, in 3 dimensions).
Compare this to the surface falcon of a sphere: The Upper Falcon is limited (given the radius you can calculate it), but it has no boundary (in two dimensions).
So you have to pay attention to how you use the term ‘ infinity ‘: something cannot end, but still a finite size.