Sure this is going to come off stupid and ignorant, but

Sure this is going to come off stupid and ignorant, but...

Isn't the fact that gravity pulls on us in all directions proof that the universe is infinite?

Assuming infinity mass in all directions, the force should be equal in all directions, right? Otherwise, everything would be slightly moving in one direction, the center of mass of the universe?

Or if there's infinite mass in all directions, does that mean we would be ripped apart, proving that the universe is indeed not infinite? And we are moving toward the center of mass (or perhaps orbiting it), just moving so slowly that we don't know the difference, or because relatively we don't even notice it, because it's happening on such a huge scale?

Ponderings of a layman.

There is no 'center of the universe' or 'center of mass of the universe'.

Right? Because it's infinite? Doesn't that prove that it's infinite? Or is this even in question?

Sorry, newfag here

Can you define infinite here, exactly?

By 'infinite', I'm meaning the distance in all directions is infinite, never ending. Not sure if that's the proper use

No, it doesn't have to be infinite in order for there to be no center. Consider the surface of a sphere. It has finite area, but there's no 'center'.

Are you considering the universe to have always been infinite? Or it took time to reach that infinite size?

I'm just meaning right now, I'm not making any implications about previous states

Is this possible with a 3 dimensional object with volume?

I guess that's fine. But consider this a problem for later. For the Universe to be infinite in size it must not have a definite beginning. For the Universe to reach an infinite size from the big bang would require an infinite amount of time to elapse. An infinite amount of time elapsing would mean you wouldn't have existed, since before your existence, it took an infinite amount of time to get there. Make sense?

Yes, that's definitely an interesting consideration. I'm not really very familiar with the big bang or the theories behind it though. I would describe my knowledge of astrophysics extremely limited at best

It's more of a philosophical explanation than one of physics. But don't feel bad about your idea being bullet proof. Asking these sort of questions is a good thing, you're thinking about what you've learned beyond what was explicitly taught.

Consider two spheres, one inside the other. The space between them would have three dimensions and volume, but no center.
The three dimensional surface of a four dimensional hypersphere would also have no center.

Ok, maybe I'm not understanding, but wouldn't the center of mass between them be the center of the sphere? Even though that space isn't occupied by the volume. Like, assuming the graphs of the spheres were f(x,y) = x^2 + y^2 and f2(x,y) = 2x^2 + 2y^2, wouldn't the center of mass be the point (0,0)?

It all started when Hubble observed that galaxies are all moving away from one another. Reversing this in time means that at some point the universe must have been all in one microscopic place. Calculations, observations, and computer models put that at about 13.7 billion years ago.

Well, in this case we're only considering the space between the two spheres, not the entire volume of a sphere. For our purposes, thats the whole 'universe' and forces can't propagate outside of it.

>infinite mass therefore we should be torn apart
you dont seem to understand how gravity works

The easiest way to think of the big bang, the expansion of the universe, and the space between galaxies growing, without there being a center is this:
Imagine a very small spherical balloon. You mark it with dots. Then you start blowing the balloon up. The surface grows larger, the dots get further apart, but no one dot is the center.
The surface of the balloon represents space, the dots represent galaxies. But you have to think abstractly of the surface being a three dimensional space that curves back and becomes continuous in all directions. Unfortunately, human brains don't have the capability to visualize that.

So, does that mean, and this might be a stupid question, but if you "walk" to the end of the universe in one direction, you would eventually wind back up where you started, kind of like pacman going through the side of his universe?

That's a plausible possibility, but no one really knows. And the balloon model is a simplification. So far all the measurements taken seem to indicate that space is flat. But that could be because space is so vast that the local curvature isn't measurable with current technology.

To help answer part of your original question, like light, gravity propagates at the speed of light.We are not affected by infinite gravity all around us for the same reason we're not blinded by the infinite amount of stars out there. The observable Universe is a real thing. Anything outside the boundary of the observable Universe has no effect on us and never will.

Interestingly enough, one could say that the true "center" of the Universe would be the point you're measuring from, and you wouldn't be entirely wrong. At least it would seem so from your frame of reference.

Just to clarify a bit, the entire Universe is not visible to us due to the expansion of the Universe. Because this expansion is accelerating the observable Universe is shrinking.

We don't drift towards a gravitational center because empty space is mysteriously pushing everything apart.