Thread: What is beyond the universe?

When I think about space, I think about what is beyond our known universe. It confuses me. If it is infinite, then by definition can anything be beyond it? Maybe in other dimensions that are not part of our known universe???

Or if its limited but curved does our universe limit itself by rolling back into itself?

Also what is it expanding into?

Most likely outside of space-time there is no space-time, but something we cannot ever imagine or understand, since we live in space-time. We can, of course try to figure it out, but there is probably no way to test our theory, since whatever is outside of space-time isn't space-time. There are two theories that have been offered since the beginning of physics - there is nothing, and there is God, and of course there are those who say they don't know and don't care. I believe that the athiestic "nothing" and "God" ideas are both unprovable, but a universe that just happened for no reason is an absurdity for me. The problem with the God thesis, is that it must be based on faith, but has evolved into belief systems that have no evidence. This leads to fighting and misery when the belief systems differ and this is rediculous. When we die, and that will be too soon for most of us, we will find out whether or not there is a God, what God is, if he exists and what is outside of space-time. So discussing ideas and theories about it is always useful, but fighting over it is pointless since we will all find out eventually what the story is.
IMHO, of course.

46dodge...so true. It is so pointless to be intolerant of other beliefs, and especially, to fight when we encounter a group with differing faith. Recently saw one of those cable TV science shows (sorry, at the age where I have an impaired short term memory) in which one scientist stated that the human brain might not be configured to successfully investigate 'The Ether'. I feel knowledge builds and accumulates and eventually humans grasp concepts there-to-fore unrealized. My fear is that we won't survive our technological adolescence. Human intelligence seems to be on track as an evolutionary dead-end.

I believe Dobson said that we all, you and me, have just as good a chance of coming up with a theory of everything, as the astrophysicist does. Some people believe god was a good influence on early man and helped him develop his mind. And some people believe god clamped our brains so that we use only 10% of our minds. It all boils down to it's going to be a long trek to figure out the nature of the Universe.

i like to think that our known visible universe is tucked away in a quiet corner of space.space does not have to end at the boundry of the universe.if the doppler red shift is from accelerated expansion,then we must be expanding into something.if all that exists is the universe and it was created with the big bang,then woulnt there be continious bangs as the universe enters nothingness.i like to imagine universe clusters,much like galaxy clusters.or that our universe is a stellar clump of matter spacially extended to form "our nieghborhood" in space.

Take a look at all the bodies in space, they always form spheres. Planets, moons and stars. Why not the universe? It's a sphere that keeps growing, but beyond the boundry doesn't exist because it hasn't been formed yet. The physical is being formed as the universe grows. Over and over again we see how recycling is a constant, dependable activity that is fundamental to making the universe run. Old things die so new things can replace them, therefore they take up the space of the old thing but at the same time moving outward along with the expansion. So why all this space? If a human was to live eternally, what would he do? Just sit on the Earth forever or get out there and enjoy the wonders of the universe. Why can our brains even entertain the idea of future? Eternity exists in our minds to give us reason to look towards the future. Why then do we fear death if not for the reason that we were meant to live forever. So the universe will ultimately be our grand playground, endless discovery because our brains, when "unlocked", will never fill up.

According to GR, our universe might be either finite or infinite--we just don't know. If it's infinite, then there is no "beyond it", of course--unless you're talking about other dimensions, which is another story (that we know even less about). If it's finite, then, yes, it does curve back on itself, forming a closed hypersurface (probably approximating a hypersphere). But this is intrinsic curvature; there's no need to assume this curved space is embedded in a higher-dimensional space. So, again, there is no "beyond". It's like asking, what's north of the north pole? Also, it doesn't need anything to expand "into". Everything is just getting farther from (almost) everything else.

Similarly, *as far as we know*, the whole of physical reality began at the Big Bang--including time itself. If that's true, then there was no "before the Big Bang".

Of course, we don't know if this is the whole story. Maybe other dimensions do exist. Maybe there ~was~ something before the Big Bang. It may be impossible for us to ever know--in fact, that seems rather likely. In which case, it's arguable that there is no correct answer, that the question is meaningless.

Personally, I prefer the simplest theory/model, with no beyond, before, or after, until a more compelling theory comes along. And I'm comfortable with the uncertainty.

Hi. I'm a newcomer to the forum. I found you topic particularly interesting because I've often asked it myself. I minds are so limited in that we think in terms of what we can sense. With math and the computational tools we have available, we're at the infancy of our ability to "see" things in higher-order geometries-beyond three dimensions. I often think of the analogy of a dot that lives on a "2D" sheet of paper. What will that dot make of a pencil sticking straight through it's paper universe? The dot would try to explain it in terms of what it can percieve as "real." And so when we think of how the universe is shaped, we imagine perhaps some sort of essentially 3-D construct. Something with a surface or edges or boundaries of some sort. But what if the universe doesn't really have an edge, or what if it's "edges" are actually entire space-time regions through which other universes or dimensions are peeking through? The same what that when two 3-d closed surfaces intersect, they create curves? Of course, even my analogies are filled with familiar geometric terminology, but am I making sense?

Originally Posted by tom

When I think about space, I think about what is beyond our known universe. It confuses me. If it is infinite, then by definition can anything be beyond it? Maybe in other dimensions that are not part of our known universe???

Or if its limited but curved does our universe limit itself by rolling back into itself?

Also what is it expanding into?

a very good explanation of this is the book the fourth dimension. the story of A Sqaure in flatland by i belive edward abbot abbot(get it, a squared) uses this theory,A Square is 2D and meets A Sphere who is 3D and appears godlike to A Square.

My imagination does not have any basis for any kind of conception of the "potentially" infinite universe outside of spacetime. But I am fascinated by the possibility of the space time which probably exists beyond the red limit. Some astronomers have suggested that the actual dimensions of spacetime is 50-75 Billion light years in diameter, with our 27.4 Billion light year diameter "observable universe" (the sphere inside the Red Limit) inside of it. What I find interesting about this idea is that the relative motion beyond the red limit, by definition, exceeds the speed of light, from our vantage point. I think "time" must be like "temperature" in this context. You cannot go past Absolute Zero, and time cannot go backward. So what happens out there?