The physical universe does have an end. Somewhere around 93,000,000,000 light years across. However beyond that is empty space. And empty space does not have to end because it's just that. Empty. Nothing.

by Anonymous 12 years ago

But I mean it can't just go on forever, that's impossible.

by Anonymous 12 years ago

It's not a physical thing so yes it can. Look at numbers. Numbers don't actually exist so they can in fact go on forever. The emptiness of space is no different.

by Anonymous 12 years ago

But numbers are just something we made up, it's completely different. Space IS a physical object, we can see it and you can go in it so we know it's real. It has to end somewhere.

by Anonymous 12 years ago

The space between stars and galaxies in our universe is a physical thing that acts under the laws of physics. The nothingness beyond our universe is, as far as we know, infinite.

by Anonymous 12 years ago

Space isn't really an object, and we can't see it. The alternative to space going forever is a physical barrier stopping it at a certain distance which also goes on forever (otherwise there would be space behind it which goes on forever). Either way there can and must be an infinite amount of something.

by Anonymous 12 years ago

Space is not an object but Space-Time is. It can be bent and warped by gravity. Space is just a name we give to children so they don't ask questions that involve math.

by Anonymous 12 years ago

And if you want to get technical with it, our Universe is only one of an infinite number of Universes.

by Anonymous 12 years ago

I thought an object had to be something tangible. Also, has it actually been proven that there are infinite universes?

by Anonymous 12 years ago

It's been proven the way "all things fall at the same speed" was proven 100's of years ago. We had the math to support it but it couldn't be tested until Apollo 15 dropped a hammer and a feather on the moon and they hit the ground at the same time. There's math to prove infinite universes and I don't think you'll find many Physicist who would say that there aren't. But no, it has not "technically" been proven.

by Anonymous 12 years ago

And I'm not sure what you mean by tangible. Radio waves and light waves are not "tangible" but they definitely exist.

by Anonymous 12 years ago

Master J is referring to this. http://io9.com/5811706/if-you-keep-going-around-the-universe-will-you-end-up-where-you-started However this does not conflict with infinite universes.

by Anonymous 12 years ago

Of course space-time exists, but I wouldn't think of it as an object. I always defined an object as a solid piece of matter (tangible means able to be felt). I have no idea how you can prove infinite universes, but I'll take your word for it and it sounds cool.

by Anonymous 12 years ago

Master J is right. There are multiple theories (and this is where we meet up with modern day physics) There were 5 different theories to explain multiple universe. All a different version of string theory. All with 10 dimensions. All with some sort of problem. Then they actually combined them together in to what is now Super-String theory or M-Theory which suggest 11 dimensions. Unfortunately science has not progressed enough yet to fully confirm even the math of M-Theory. For example we don't even know why gravity works!

by Anonymous 12 years ago

Also for anyone who just ignored that link. Quit being lazy and read it. It'll be the most interesting thing you've read all month. I promise.

by Anonymous 12 years ago

Also you said earlier "I watch too much of the science channel, really." Not. Possible.

by Anonymous 12 years ago

The Multiverse theory is not proven in any sense. Quit saying it is when it's not. The mathematics suggest something like it, but it's not the same as math suggesting all things fall at the same speed. There are a couple of problems in our current theories of physics that can be remedied by adding a multiverse to the equation, but that doesn't count as evidence. Multiverse theory can't be proven at this time. Also, in this universe, there's really no such thing as "empty space". Even if you take out all the lingering gas particles floating around, there's tons of activity going on. Google "quantum foam" if you're interested. The expansion of the universe isn't just an expansion of stuff you can see. It's an expansion of space-time as well. Beyond the universe, not only is there nothing in the most absolute sense, there is no space and no time.

by Anonymous 12 years ago

"Unfortunately science has not progressed enough yet to fully confirm even the math of M-Theory." I quite literally said that.

by Anonymous 12 years ago

Damn, the "Also for anyone who just ignored that link. Quit being lazy and read it. It'll be the most interesting thing you've read all month. I promise." actually got me. It was worth it. I don't think humans will ever be able to truly figure it out. By the time we create machinery to catch up with our minds to test all of our insane theories, we'll either be extinct or we'll run through the tests with our spaceships that can go 9,000,000,000,000,000 lightyears only to find that the universe is many times bigger. There are some things we'll never find out, and unfortunately I think this is one of them.

by Anonymous 12 years ago

To be honest. Scientists say that our universe came from another universe. That's why we have black holes. Imagine two pieces of paper. Each paper represents a universe. Now, stick a pin in both of them. That point where the pin is a black hole. That hole helped make our universe. There is an idea that a white hole helped create it as well. A white hole is nothing more than a reverse black hole. The stuff that went through the black hole came out of a white hole. Since nothing can enter a white hole, that is how our universe was made. An interesting concept if I say so myself.

by Anonymous 12 years ago

If I think about this kind of stuff for too long my head starts to spin.

by Anonymous 12 years ago

The category?

by Anonymous 12 years ago

Just a little bit of fun for you guys (:

by Anonymous 12 years ago

I like the loop theory, or that's what I call it. Imagine space is in the shape of a bagel, it has no edge, but it's not a sphere either. Space is supposedly like that. But, there's little evidence for it.

by Anonymous 12 years ago

Like a möbius strip?

by Anonymous 12 years ago

So kind of like earth? That actually makes sense...

by Anonymous 12 years ago

Not like the Earth. If the universe was the surface of the Earth, then what's on the inside or if the Universe is a ball, what's on the outside?

by Anonymous 12 years ago

Also i got my question wrong, I meant is it like a klein bottle. The whole no edge not a sphere thing, sorta same principle just different shape

by Anonymous 12 years ago

Your "loop theory" is talked about in my link above. Assuming you're talking about what I think you're talking about.

by Anonymous 12 years ago

Yeah, it's the same principle. If you kept going in one direction of the Universe you'd end up somewhere else in the Universe. If this is true those it does raise the question, what if we're just one of many Universes in a Omniverse?

by Anonymous 12 years ago

I think it goes on forever. For humans, on earth, everything ends eventually, and that's why we can't understand the concept of forever.

by Anonymous 12 years ago

i feel like my brain is going to explode just thinking about this

by Anonymous 12 years ago

NO EDGE http://www.youtube.com/watch?v=Z0o6hQLcSRc

by Anonymous 12 years ago

Grr, I wanted to be the first to say that! Oh well. NO EDGE!!!

by Anonymous 12 years ago

Mindfuck to infinity and beyond

by Anonymous 12 years ago

Well they say the universe is ever expanding so there could be an edge, it's just always getting farther away. If the universe is some kind of self contained area and there is an outside to it, my guess would be either pure nothingness that can extend forever, or the super trippy idea of our Universe being in something even larger we can't comprehend. Like how the Earth is in our universe, our universe could be like a "planet" in some kind of larger outside multi-verse. That'd be super crazy, if there was an even bigger area outside the universe, that was filled with thousands or millions of other universes.

by Anonymous 12 years ago