Is the universe truly infinite?

...

How do we know the universe's full size?

No.

That is not a question that can be easily answered.

I wouldn't waste my time pondering it.

Quite easy: no body knows

We can't know because we can't observe it.

>Is the universe truly infinite?

Of course. Because everything outside any boarder is also inside the universe.

The universe can be self contained without having a defined border, user.

But what's outside that self containment?

The universe is simply a 3d torus. The directions wrap around.

ur mum an 3d torus

Yes, but you need to meditate a lot and be on psychedelics to really see that for yourself. Aka you have to be enlightened.

Maybe im just a pleb, but I don't really understand the "infinite universe" thing. Here is what I understand it to mean, please correct me if im wrong .

There is a finite amount of matter in the universe, correct? (I suppose Energy can also be considered matter but whatever).

So there is this X amount of matter, in the form of planets/solar systems / galaxies/ etc, and it is all moving through three dimensional space with the speed given to it by the big bang.

So we have celestial bodies quickly moving away from each other in all directions, steadily increasing the "boundaries" of the universe as they push back the frontier.

But then what is 'space'? What are we moving through? How can there possibly be an infinitely large area to contain the entirety of our universe?

>There is a finite amount of matter in the universe, correct?
Maybe

Space an time are concepts of thought we use to understand, explain and predict our reality. Not mediums in wich we exist.

>Expecting people to explain cosmology to you in layman's terms

Fuck off

i'm sorry to have offended you.
Can you point me in the direction of some solid scientific background then? This is a topic I am eager to learn more about

The word "universe" means everything.

Nah, you got it wrong. Most theories predict either an infinite universe with infinite matter or a finite universe, but unbounded, so geometry in higher dimensions and stuff.

Only numbers are infinite. To actually consider that space is infinite is mind-numbingly retarded

We can measure qualities of spacetime that might be useful in answering the question though.
>3-D torus
uhhh no.
>There is a finite amount of matter in the universe, correct?
If the Universe is infinite, homogeneous, and isotropic, then yes. Data suggests this is true, but only really gives a lower bound for how smooth the distribution of matter is.
>with the speed given to it by the big bang
Incorrect. The kinetic energy of celestial bodies came from the gravitational potential energy of the once mostly uniform early Universe. Slight variations in the density created regions for matter to fall towards.
>So we have celestial bodies quickly moving away from each other in all directions
Only on very large scales does the inflation of spacetime overpower gravitational attraction of nearby matter. Our galaxy will never be pulled apart by inflation.
>the rest of your post
Read an introductory cosmology book.

Right. The reality is known as "spacetime."

>Most theories predict
Most theories leave this particular question open and explain the dynamics in any case. For example, General Relativity.

Why is that? Spacetime doesn't have to fit into a box. Why should it need to be finite?

We have no way of telling if the universe is infinite, as we simply don't have the time to find out.