What Is Outside The Universe

Great Debates
1

A question that has puzzled both scientists and civilians for many many years is what exists outside the universe. Many people have differing ideas about what is outside the universe. But I would like to propose my own idea, not really a solution but an idea.

For humans to try and work something out we use what we already know to piece things together. When we look at the universe we imagine it as a shape, a ball, a cube etc. A shape that has defiant edges. This is completely natural as we imagine the universe as a box, a box filled with galaxies etc. So logically we would wonder what exists outside the box.

What I would like to propose is that what if the box has no boundaries, what if there are no barriers, not saying the universe goes on forever, but what if there is no edge of the universe what if everything that has existed, is existing and will exist is inside the universe, there is nothing to be outside the universe. This is obviously a mind-boggling concept as we base all our decisions on the knowledge we have, and this goes against what we have been taught, that everything three dimensional has a boundary, separating it from one thing and another.

What do you think?

(btw i am 15)

2

It’s not a bad answer given that it’s pretty much what I was going to write based on you thread title.

Now go read “The Elegant Universe”, you’ll love it.

3

I think you’re pretty close to being right. What you describe is what cosmologists are saying; there is no “outside” of the universe. It doesn’t have “edges”. Some have suggested that space curves back on itself. If you imagine an ant walking on the surface of a balloon, he can keep walking infinitely and never reach an edge, but eventually will end up back where he started. You just have to imagine that the 2-dimensions of the balloon surface are the 3-dimensions of the universe. It’s not something you can picture intuitively, because we only think in 3-dimensions, but supposedly the math works out. There’s no “before” or “after” the universe, either. If you haven’t read “A Brief History of Time” by Stephen Hawking, I highly recommend it. I think you’d like it a lot.

Something to consider, though: Saying there’s nothing “outside” the universe doesn’t mean there can’t be other universes. Our universe might not be all there is. But these other universes would be temporally disconnected from ours, if they exist.

4

By definition, the universe is everything that exists. What’s outside the universe? Nothing.

As for what’s outside our little subspace of it…we can’t know. Could be quantum foam, could be more subspaces, could be all those socks you can’t find. All of these possibilities are equally plausible.

5

I agree that you aren’t too far off from what physicists would say. Just wanted to point out how difficult it is to describe the problem, as can be seen in your quote, above. If there’s no outside, how can there be an inside? :slight_smile:

But also note that even though the human mind cannot actually comprehend the concept of infinity, we still can use it as concept in mathematics.

6

You should take a look at this thread started by SentientMeat. He does a great job (IMHO) discussing the ideas you’ve brought up.

7

I like to start by thinking small.

Imagine if you were just a simple cell in a human body, your universe would be the body you were in. It would be beyond your comprehension that there could be another body out there with other cells, let along billions of bodies, and billions of bodies that have since died and billions more yet to be born.

So, in our limited scope, as far as our primitive eyeballs and Hubel telescopes can determine, the universe seems to go on forever, or at least out of our range of view and concept.

Stepping back for the big picture, I tend to think that the universe is probably one of billions of universes, some long since dead and others yet to be born. And perhaps it is the combination of these billions of universes that create a single cell in something even bigger than our feeble minds could ever comprehend.

8

If you want to define “universe” as literally all that “is”, both observable and unobservable, then there is no “outside” the universe. It’s a meaningless question, like, giving an example Stephen Hawking provides, “What’s north of the North Pole?”

Now, if you take our “universe” to be the observable region of a larger structure, then there could be almost anything “outside”. Some people call this structure the “multiverse”, which I think most who work with the concept posit is of infinite extent in at least one dimension (time, probably), and is constantly growing. Maybe it’s just an infinite, topologically flat expanse (according to the topologists, it’s possible for the universe to have any “shape” in any number of dimensions and still have no “outside”…my mind completely boggles, but I defer to their greater intellect), and we are each roughly at the center of an expanding bubble (in 2+1 dimensions, this bubble is called a “light cone”) that demarks the cosmic boundary of what we can ever know. Now, if the “multiverse” is just more of the same 3+1D space with all the matter and forces that we see in our visible region, forever and ever into infinity (and remember, this is the most prosaic possible multiverse imaginable), what is outside of our universe, among the infinite other possibilites that are not precluded absolutely by the laws of physics as we know them, is an exact, perfect, indistiguishable copy of ourselves and our world. Don’t believe it? Check out this article:

Not only that, I expect there is a universe with purple people eaters in it. Somewhere Forest Gump is a real-live human being. Dinosaurs are kept as pets by two cavemen named Fred Flintstone and Barney Rubble. And why not? Is it not possible that matter couldn’t be arranged thusly? Certainly it can! There is nothing in the laws of physics that preclude such a thing. Hence, if the universe is infinite and flat, like some believe, Fred and Barney are mandatory! Wilma and Betty really do giggle in that annoying 50’s sitcom kinda way. Barney Googles with goo-goo-googly eyes and wives three times their size abound. An infinite number, in fact.

What’s outside? Maybe everything!

9

I like Magicmans theory. It’s like the image of the serpent eating it’s own tail (Ouroboros). It seems like a more practical way of running a universe also.

10

Hi,
I would like to give my view of the problem, but must say it is based on my belief that God created the universe (not trying to start any religious arguments).
Lets say that God creates the universe in which we humans are put to live. He makes the universe big enough that we will never reach it’s “end” or “edge,” but it definitely is a finite space with a very real “edge.”
If you’re a gamer you might understand this example better: Imagine a 3D game world, in this case Grand Theft Auto: Vice City ( I use this example because the game world’s “edge” can be reached). Now, in this game you can fly a helicopter, and the first thing I wanted to do when I got in was see how far away from the city and over the ocean I could fly. Anyone who has done this has found that after you get so far out over the ocean the game locks up, and must be restarted. This is because the programmers couldn’t make the game world an infinite amount of space; it would require an infinite amount of storage space. Other games have an invisible wall that you run into once you go so far out of the main playing area, such as Everquest. The point is, these game worlds, or “universes” are not infinite, they have a definite end to their size, yet truly nothing exists outside of their boundaries. I believe the same to be true of our universe, though it is not a game.
I understand it is hard to grasp this concept. It is like asking “How long has God existed, no matter how long, something had to exist before Him.”. We think this way because the concept of “time” is such a fundamental part of our existance; there must be a past, present, and future. It’s hard to believe that there is no such thing as “time”, or the length of God’s existance, time is just made up for us and for our universe. The same is true of the size of our universe; there doesn’t have to be anything “on the other side,” and it can still be finite, we just have to look outside the scope of our understanding of what “existance” is to see it.
Thanks for hearing my view, and sorry if I rambled on or got off topic (also sorry if anyone was offended by any religious talk, this is just my view of the subject, and hopefully gives another way for people to think about the question, among the many other possibilities mentioned).

11

I don’t know what God thinks or wants, and I make no assumptions about what the universe “ought” to look like. What I do know is that current observations of the cosmic background radiation (CMB) support, to some extent, the hypothesis that the universe is infinite and flat, with the caveat that structures of arbitrarily large size are not seen in the CMB, suggesting it’s possible the universe (at least the bubble of the multiverse we inhabit) could be finite .

If the latter is the case, rather than being like a video game with walls, we’d be in a space more like the old arcade standard “Asteroids”: You fly to edge of the screen, you pop up on the opposite side; and if you keep flying, you’ll wind up back where you started. In that case the universe is topologically similar in 3D of space to what a sphere is like in 2D of space, and if one could move fast enough (not possible, but lets just pretend you have a warp drive that, like the Starship Enterprise, allows you to go very, very, VERY fast without experiencing the relativistic effects of high speed travel), you could literally fly off in one direction, never alter your trajectory, and end up where you started again in space.

The thing is, with a finite sort of wraparound universe, when you look at a picture of the CMB, you should be able to see the same pattern repeated in different parts of the sky, kind of like a “house of mirrors” effect, where you can look in one direction and see the back of your head, repeated endlessly. This is not what is observed. In fact, there’s no evidence that anyone can find yet of anything but a flat, infinite universe in the way the temperature fluctuations in the CMB are arragned. So, you’ve got the CMB pattern size data, which shows an upper limit in magnitude, suggesting a finite universe, but no arrangement of cooler and hotter regions of the sky that would suggest anything but infinite and flat. This is perhaps the most important conundrum in cosmology, presently, and needs to be resolved. It has great relevance to the “what is outside” question.

Them’s the facts right now. I prefer those to metaphysical assumptions.

12

it was only after i made this post that the thought that there may be more universes out there occured to me.

there are billions of stars. billions of galaxies etc. Stars and plantets are part of a galaxy, galaxies are part of the universe, amongst other things.

So it is entirely possible that the universe is part of something bigger, or that there is in fact more that one universe.

If there was another Universe everything could be completley different. Differant elements etc. It is impossible to imagine what life could be like in another universe.

13

Basically, the idea of many universes, perhaps best articulated first by Andrei Linde, comes to us rather as a possible solution to a problem than by using the enormity of the current universe as an analogy for what lies beyond. The problem is this: The universe we inhabit is extremely fine-tuned for the existence of intelligent life. The masses of the elementary particles, the strengths of the fundamental forces, the cosmological constant…if any of these were even slightly different, the universe as we know it would not exist. It might collapse on itself in microseconds after the Big Bang, or it might expand so quickly that even atoms would be ripped apart. Or maybe electrons would fall into atomic nuclei, or stars could not coalesce, or an infinite other inhospitable possibilities.

It was believed or hoped not long ago that built into the laws of physics would be some inevitable explanation for why the universe is the way it is, and no other way. Unfortunately, that hasn’t panned out. Our best candidates for a Theory of Everything (TOE) can’t tell us why the masses and forces we observe take the values they do. Even worse, these theories can be formulated in essentially an infinite number of ways that are self-consistent, even though they bear no resemblance to our universe. So, what the physics seems to be telling us is that maybe the strengths of the forces and the masses we see are “free parameters” that can (and maybe do) take any value. But why, then, do they take the value they do? Is it just chance?

The answer might be “yes”. If it is yes, we seem to be awfully, perhaps impossibly, lucky. The universe seems to be designed to produce intelligent beings like us, and you pretty much have to evoke the existence of God to explain it all. But there’s a potential alternative: Allow these “free parameters” to take any value, at once. Then it’s not so amazing we get the values we do; if there’s an infinite number of possibilities, one of the permutations will be the perfect fit for the universe we inhabit. But what about all the other possibilities? Well, they exist, but “outside” of our own universe, as part of a larger structure, dubbed the multiverse. Because our universe is one of a short list of universes in this multiverse that can support the evolution of intelligent beings like us (ones who can ask “Why is the universe the way it is?”), it’s no longer a such mystery why we happen to be in it: I couldn’t be any other way.

14

“Flat & infinite” seems almost like an oxymoron. Doesn’t “flat” suggest restrictions?

15

(Sorry, haven’t read the replies. I expect if I do I will just get very confused)

The way I see it the answer to the question What is outside the universe is - More universe.

16

No, flat means flat. It means if you go off in one direction, one of two things will happen: You will hit (or fall off, I suppose) the edge, or you’ll just keep going forever, always straight away from where you started. Infinite and flat covers the latter possibility.

17

But flat defines a border, which is contrary to the term “infinite”. If something was truely infinite, couldn’t I travel endlessly in any direction I so choose?

18

Surely a flat thing (two dimensional) can be infinite in either or both of the two dimensions.

19

It does? My, all the topologists and differential geometers have been doing it wrong all this time.

20

The way we usually use the word, ‘flat’ does imply a limitation. It means that the thing being discussed is two-dimensional- it could have infinite length and width, but has no depth. So it’s limited in the third dimension.

‘Flat’ with regard to the universe is just an analogy - it’s meant to explain something you can’t actually visualize. The universe is infinite in all directions, so you could travel in any direction you chose. Flat in this case is an alternative to other models of the universe.