is space infinate?

[Fearzone]

Zero x infinity = zero.

That's not necessarily true.

Would be interesting to hear the logic in situations where it is not.

Very simple.
Take the limit(x -> 0) x/(x^2) as x tends to 0.
The algebra of limits tells us this is equal to (limit(x -> 0) x)*(limit(x -> 0) 1/(x^2)).

(limit(x -> 0) x) = 0
(limit(x -> 0) 1/(x^2)) = infinity

So
(limit(x -> 0) x)*(limit(x -> 0) 1/(x^2)) = limit(x -> 0) x/(x^2)
Therefore, in the context of the functions x and 1/x^2 as they tend to 0,
0*infinity = infinity

Fair enough.

But this step here:

limit(x -> 0) x/(x^2) = infinity

Feels like a hyperbolic function, where it trends toward infinity as x goes to zero, but at zero, it's undefined.

Yes, it is a hyperbolic function, because if x passes zero slightly into the negative range, suddenly we are at negative infinity.

 

[Maze1125]

Zero x infinity = zero.

That's not necessarily true.

Would be interesting to hear the logic in situations where it is not.

Very simple.
Take the limit(x -> 0) x/(x^2) as x tends to 0.
The algebra of limits tells us this is equal to (limit(x -> 0) x)*(limit(x -> 0) 1/(x^2)).

(limit(x -> 0) x) = 0
(limit(x -> 0) 1/(x^2)) = infinity

So
(limit(x -> 0) x)*(limit(x -> 0) 1/(x^2)) = limit(x -> 0) x/(x^2)
Therefore, in the context of the functions x and 1/x^2 as they tend to 0,
0*infinity = infinity

Fair enough.

But this step here:

limit(x -> 0) x/(x^2) = infinity

Feels like a hyperbolic function, where it trends toward infinity as x goes to zero, but at zero, it's undefined.

That's why I spoke about the limit of the function, not the function itself.

 

[Mira Star]

Well, for it to not be infinite, there has to be an end, but what would be on the other side of the end? Its just physically impossible for it NOT to be infinite....unless the universe is like the waters of Morrowind >.>

 

[Fearzone]

That's why I spoke about the limit of the function, not the function itself.

Okay, but a little bit of something, even an infinitesimal amount, is still something, which is apples and oranges to zero.

 

[Ryuk2]

It is infinite, but there is probably only one ''big bang'' and after these galaxies there's just whole infinite space of emptiness.

 

[ben117]

To put a long story short. It is fucking immense, mindboggling huge. If you were to compare a human cell to the continent of Africa you would still be thinking on a too small scale. Now the closest star to sol is alpha centuari is over 4.3 light years away now put in to mind that the speed of light is over 300km per second/1,079 million miles per hour it would take 4.3 years travelling at that speed just to get to the nearest star. To get to the next galaxy would take over 2 million years at light speed. Its just fucking huge. Now the theory of universal expansion is that as the universe expands (still moving away from the centre of the big bang) it actually creates time and space so theoretically the universe is intimate. However Another theory suggests that this expansion would slow down(even though there is no solid matter to slow down the expansion) it would soon go back towards the centre meaning that the universe would eventually reach a set size.

 

[phoenix352]

a better question would be what lies inside a black hole or if its an actual wormhole like some speculate whats on the other side now thats something we can actually get an answer to ..

since you know we actually have a black hole in our little solar system .

 

[Maze1125]

That's why I spoke about the limit of the function, not the function itself.

Okay, but a little bit of something, even an infinitesimal amount, is still something, which is apples and oranges to zero.

The function x/x^2 is undefined at 0.
But the limit of x/x^2 as x tends to 0 is equal to infinity.

It's true that a small positive amount, no matter how small, is completely different to zero, but that doesn't change any of my claims.

 

[Voodoomancer]

Nope. It's not.

But it's expanding at such a rate that you'll never reach it's edge, so it might as well be...

 

[Zaksav91]

Even if we did discover some alien species far off in space. The governments would most likely act idiotic and take the aliens and do these weird experiments on them. This would in turn piss them off and soon we'll have a nice invasion fleet shoved up our global anus.

 

[Martymer]

Maze, how do you explain the distribution of matter in a universe of infinite size? Shouldn't it be infinitely sparse? To me, it would seem like anything else would require an infinite amount of matter, and thus infinite energy, and since you appear to know your physics, I don't need to keep rambling about that, now do I?

Not necessarily.
It's quite possible that the matter would collect around the point where the original singularity was. Which would allow an infinite universe to have finite matter and positive matter density.

Also, there's no problem with the universe having infinite matter or energy, because in any given bubble of observability the total energy would still be finite.

The original singularity was everywhere. By collecting around "where the singularity was", matter spreads out throughout the universe, fairly evenly. This leads to three possibilities (as far as I can tell):

1) The universe has positive matter density and finite matter, and is finite.

2) The universe has positive matter density and infinite matter, and is infinite.

3) The universe has zero (or infinitessimal) matter density and finite matter, and is infinite. We can strike this one off the list, as... well, as we are here to do so, which we wouldn't be if this were the correct one.

Also, I'm very skeptical about #2. Infinite matter and energy would mean infinite gravity, which would not just cause the expansion of the universe to slow down and reverse, but this should have happened within fractions of a second into its history. We see in fact, that the rate of expansion is increasing instead. To me, only #1 makes much sense.

Another thing I have to ask is, what arguments are there to support the statement that the universe is infinite? You've defended your standpoint by attempting to dismiss my arguments (and you're doing a pretty good job, btw ), but I've yet to see any attempt to support your claim. What is it that suggests the universe is actually infinite?

 

[Martymer]

a better question would be what lies inside a black hole or if its an actual wormhole like some speculate whats on the other side now thats something we can actually get an answer to ..

since you know we actually have a black hole in our little solar system .

Black hole =/= wormhole. A black hole is not really a hole, like a tunnel. It's a point with zero size and non-zero mass (typically multiple times the mass of our sun, in some cases millions of times that). This means there's a volume of space around it, the boundry of which is called the event horizon, from which nothing, not even light, can escape its gravitational pull. Going in means you're stuck. Of course, before you get inside the event horizon, you'll be torn to shreds by tidal forces, so you're not going to live to see what's inside. Oh, and if you somehow did, you'd find that inside, time stands still, which means that you wouldn't perceive anything. Your brain would be frozen in time.

 

[DevilSShadoW]

By our terms, anything that we don't know the end of is "infinite" but just because we don't know doesn't make it true. Personally i don't think it's infinite. It's just very large.

 

[BehattedWanderer]

Infinite like a sphere, sure. The start is the end, and both are middle points for a different direction. That which is infinite is only infinite possibility, very little reality. It's more a blank page, though, on which a child draws--when he runs out of usable room, he flips the page, and starts anew.

Hopefully he doesn't flip soon, eh?

 

[Fbuh]

Scientists theorize that the universe is currently something around 15 billion light years from the center to the outer edge. As to what exists outside of that, it's quite possible that it is simply other universes, all pushing into each other and vying for space.

 

[titanium turtle]

well.... the 2 theories- it is expanding into endless nothing
or there is a giant wall at some point
which sounds more realistic?

 

[LiftYourSkinnyFists]

Red shift / blue shift

The universe is expanding and yes space is infinite!

As for the post above me, you're an idiot and your logic is flawed... Light travels both as particles and waves. they dissipate over time and space, not to mention the dust other particles in space that would hinder your theory even more so.

Sorry but if you believe the Big Bang your the idiot; finite starting point+ finite expanding speed+ finite time to expand, doesn't equal infinity.

Sorry, but what do you believe? that we're all just little bacterium in a high tech Petri dish? Or are you one of them religious ignoramus'?

 

[caz105]

Huh? The number line is infinite even without gaps between natural numbers.

No it isn't.
If the distance from 0 to 1 is zero and the distance from 1 to 2 is zero, then the distance from 0 to 2 is zero.
If the distance between every number is zero then can conclude the distance between 0 and an arbitrarily large number is zero and therefore all the numbers would be on a single point.

Ok didn't really understand what you meant before. The problem with your theory is your increasing it by an infinite amount therefore it can be infinite from a single point.


Edit:

*snip*

Sorry, but what do you believe? that we're all just little bacterium in a high tech Petri dish? Or are you one of them religious ignoramus'?

So there's only three possible options then? I cant just believe the universe is expanding?

 

[Kuchinawa212]

It doesn't blow my mind. I just never think of what could be beyond....

Once you do you get into trouble

Once again, Futurama has solved this question already.

We are outside the box, but also in it.

D:

ha ha ha...wait...hang on if I understand this correctly

*brain explodes*