What Is Beyond The Observable Universe?

Silverbackman

Is it just black space extending forever? Or perhaps black space for a finite distance until another universe?

I find it hard to believe our universe is just the only universe. I don't see how it wouldn't extend for eternity instead. What is so special about our universe and the space we are in?

What do you think?

Chronos

By logical necessity, there is literally 'nothing' beyond the observable universe. It is impossible to apply falsifiable predictions to something that is inherently unobservable.

Silverbackman

In other words it is more in the realms of philosophy right now. But don't you think in the future we may be able to see beyond what is now considered the observable universe and find other universes? What do you think?

It just doesn't make any sense how this universe could be the only one. I always thought of the universe/multiverse/omniverse as infinite.

If there is 'nothing' outside the observable universe it would be just black space for eternity, right? Unless the universe is round (which all current evidence points to it being flat) then you can't arrive back in the universe in the other side. Plus most likelly space, like "time" is infinite.

mathman

According to the inflation model, the universe is much bigger than the observable universe. On the other hand, the total universe is is still finite, but there is no such thing as outside. The simplest analogy is what is outside the surface of a sphere (ingnoring the third dimension).

Silverbackman

But most evidence points to the universe being flat. In that case a what would happen if you reach the end of the universe? If it were a spherical universe then we would just reach the other side. But what would happen if you reach the end of the universe? Would their be like a giant hard barrier that you can hit but not explode? Sounds to mythical to me. The universe seems to complex for it to be just finite.

The universe isn't infinitely big and infinitely small?

Chronos

The 'edge' of our observable universe is receeding faster than the speed of light: which means you can't get there from here.

Silverbackman

Well yea of course we can't really see it. However is that proof there is nothing beyond there? What proof is there that 'nothing' exists at the edge of the observable universe? We just can't see it from our place in the cosmos. Perhaps if we were on another planet across the universe we may be able to observe more into what we cannot currently see, right?

kant

What do you mean by "logical necessity"?

I think there is something that cannot be explain 'outside' space-time of own universe, but that is a different assertion of "nothing"?

Chronos

Let's focus on the definition of a 'universe'. It necessarily includes all things possible to observe. This allows the possibility we have not yet observed all things possible to observe. In that sense, anything that is truly external to our observable universe is literally 'nothing'. It is, and will forever be undefinable.

Silverbackman

Our guess the space and time in our universe is finite. However it is just hard to believe there was no time before the big bang and no content beyond our observable universe. It doesn't make sense how things can by finite. I mean what happened before the big bang and why are there boundaries at the ends of our universe?

By studying the universe and the physical world one can truly see things aren't orderly per se. They far beyond the realms of organized imagination and can only be understood with observation and empiricism. Limits on the universe would truly make things beyond confusing.

BTW, what do scientists think happened before the big bang. Since the universe is expanding according to most of the evidence today, the cyclical big crunch is unlikely. What do scientists think are the likely choices?

kant

You define 'everything' to be the observable universe( U ), and anything that is not U is nothing. Am i talking to a robot, or am i talking to a human being?

Chronos

Just dealing with the logical inconsistencies. 'U' includes the set of events possible to observe in this universe. 'Not U' includes the set of events impossible to observe. 'Not U', hence, is not causal in the chain of events that occur in this universe. 'Not U', therefore, is irrelevant [i.e., does not exist].

kant

So if an 'event' occur outside of our spacetime; its effect is incapabe of reaching us. In your opinion, it does not exist?

Why should existence need an observer?

selfAdjoint

Listen to yourself! Do events we can never know about exist or not? How the hell can you or I or anyone ever know? It's just a fantasy!

kant

What is your point? Your last three sentence seems to be in agreement with me.

SpaceTiger

The generic flat universe (with a trivial topology) is actually infinite in extent. Other topologies allow for a finite universe, in which one could (in theory) loop around it, given enough time.

SpaceTiger

The only boundaries are those set by the finite age of the universe (also known as "horizons"). For example, the "particle horizon" is the distance of the largest object whose light could have reached us since the beginning of time.


In the standard cosmological model, there is no "before" the Big Bang. Realistically, though, we can't say much of anything about the universe pre-inflation, so the best answer is that we don't know.