If the Big Bang created space itself how can there be a concept of the realm it's in?

julcab12

It's 'ugly' (to me). "Why is there infinity?". It is an idea where (1) equation can be insufficient or (2) unreachable/undefined depending on how you approached it (3)("How") Our limitation(technology) to put value(s)('steps' of larger value on bounds until it tends toward 0) to make sense out of it. BUT it'll end up infinite still. So it boils down to your 'liking' if you are willing to accept emergent(redundant ) infinity OR continue to find some new intuitive solutions to equation OR new model perhaps...

Whovian

Okay, imagine a one-dimensional Universe consisting of a circle. Not the interior of the circle, just the circular arc surrounding a circular region. This is clearly a finite Universe with no edge.

Now, there are definitely flaws in this analogy, most notably that an outside (the rest of the plane) exists. Try to imagine a circle with no plane to reside in. Nonsensical, but it works. Trying to define a point not on the circle would yield nonsense (Oh, hey! There's a point on this plane I said didn't exist!), and so asking what's outside this Universe would also yield nonsense.

Note that, as people said, trying to apply logic to cosmology can also yield nonsense.

Asking why things happen is, by the nature of science, outside the realm of science. Science is ugly in some ways (like this.) Such questions are probably in the realm of philosophy.

cdux

Ah, but what you haven't determined is if it's nonsense to reach undefined regions of understanding to begin with. Is it actually nonsense or a lack of a more complete model? In fact, some popular examples of new science concerning cosmology deal with a variation of this very concept, since cases of the appearance of a singularity are rarely accepted as the end of it.

At a basic level one could argue whenever our understanding yields nonsense instead of a clear answer given a certain input then it might mean the understanding might be incomplete. And I don't mean non sense in the sense of probabilistic results since those are a defined answer, even if of course there are ideas interpreting them as subsets of a more complete idea yet to be determined or accepted.

marcus

We both realize the same objective facts. Distances can increase without any change in the relative position of things----the angles of a triangle do not need to add up to 180, sometimes they don't and the presence of matter affects that. and so on.

I don't see a anything "illogical" or "ugly" about this. So we both are aware of the same realities but we simply adopt different attitudes towards them, which is normal for people to do.

The thing the OP fellow does not seem to grasp is, I would say, that geometry is something we experience and it is NOT something you imagine being viewed by some bizarre creature outside the universe.

We might for instance have the experience of living in a 3D space with a slight positive curvature. this means that with very large triangles we notice a pattern of them adding up to slightly more than 180.

And it means that 3D space is ANALOGOUS to the 2D surface of a ball (where that also happens with triangles.) But it does not mean that our 3D space is automatically the "surface" of some 4D "ball" and that there is something "inside" it and "outside" it. It does not mean that some 4D creature "outside" our 3D space can look at it and see something "round". that is a fantasy that carries the analogy way too far!

All we have then (if we measure a slight positive curvature) is the EXPERIENCE of living in a certain geometry and making measurements in that geometric context. We have no indication or need to imagine, or believe in, anything "outside" of the space we know.

My attitude is that this is not nonsense (your word). Instead it is commonsense---don't pretend to know what you have no evidence for. What we deal with in cosmology is the geometry of the space we live in and which our stars evolved in. We have no indication of any space "outside" of space. So we avoid overextended analogies and stay focused on what we see and know, which is a lot.

My perception of this is it's definitely not illogical, or ugly.

Maybe you were just being funny

Whovian

The point was that it's possible to design a reality which seems to conform to the known laws of physics with a finite Universe where "outside" the Universe is meaningless, not that it's te only case.

cepheid

I think this thread has run its course. The OP's question regarding whether the universe requires something to expand "into" has been addressed: it doesn't. Many other posters have emphasized the experimental nature of science and the fact that it, by necessity, deals only with what is observable and testable. Anything else is wild speculation and/or philosophy, and these things are not permitted in the Cosmology forum. Thread locked.