Beyond the observable universe
 

One of the great, unanswered questions of modern astronomy is the boundaries of observable space, basically the edge of the universe so-to-speak. There are a few theories and ideas as to what is beyond this big, black space of (presumably) nothingness, but nothing has been proven due to the nature of the subject. Some believe the universe wraps around like a piece of partially folded paper, so that reaching one end will make you pop out on the opposite side. Others think it's infinite, and that there is no ending.

Personally, I'm keen to believe in the wrap-around idea. It seems to be the idea with the least problems, at least in my mind. But it's still difficult for me to imagine something entirely without an edge. It just seems impossible to my mind.

However, I'm interested in hearing what everyone else is thinking. Infinite? Wrap around? Or some kind of invisible barrier?

Re: Beyond the observable universe
 

So the universe could be like a Pacman game? Crazy. I just assumed it was infinite. Humans can't really comprehend that though (at least I can't), sort of like how it's difficult to conceive of time having no beginning and no end. But we're evolved monkeys so it shouldn't be too surprising that we can't fully comprehend the reality of the universe.

Re: Beyond the observable universe
 

We can't comprehend infinite?

Try loading up a space simulator, that has no boundaries, and fly off of the grid, and see how long it takes for you to get tired. Then think about how long it could possible keep going. Think about what you would run into, outside of the grid of a game that measures everything in coordinates.

Until I get evidence to the contrary, I'm going to assume that our universe extends out four times the distance we can see, and then extends further into infinite blackness.

Current theories seem to say that the known universe will keep expanding, and will eventually die. Everything will be dead, for the rest of eternity. Life will have flashed by, gone in a blink, forgotten. There would be no rebirth, no destruction and recreation of the universe. No second chances. The known universe will continue to expand, filling up nothing, with whatever sparseness the known universe itself yet contained. The distance between a single particle would be exponentially greater than the size of the known universe itself, and still it would continue to expand. Will it ever stop expanding? Is the known universe's maximum size finite? Even then, the universe will be infinitely more vast and empty.

Re: Beyond the observable universe
 

The universe wrapping around makes no sense, as we can observe the galaxies we can see moving apart. If the galaxy wrapped around, they should all be crossing the "boundary", reappearing on the other side, and heading back towards the core of the universe. I'm included to believe it's infinite. Nothing I've seen or read gives me any reason to believe that universe just suddenly stops. It simply doesn't make sense. The wrapping around idea would make more sense than suddenly stopping, in my opinion.

Re: Beyond the observable universe
 

Here you go kiddos



No eeeeeedge

Re: Beyond the observable universe
 

Guys, come on...haven't you seen MIB, answer is right there:



It's just a giant marble :p


But really, I'm inclined to say it's infinite.

The wrap around concept is intriguing though. When you say wrap around, just to be sure, you mean that the "supposed" edges touch each other thus forming a kind of circle? If so I could see that as being a very plausible possibility. So would be like, if I flew to the north pole in the Western Hemisphere, going to the most northern point "the edge" and then going even farther north at which point I'd be entering the so called northern "edge" of the Eastern Hemisphere and would thus no longer be actually traveling north but south.

With that said though, the science fiction fan inside of me wants there to be a super stargate at the very edge to take you to funky town. ;)

Re: Beyond the observable universe
 

This would probably best fit my conclusion.

I believe one of two things;

1) The Universe is infinite and goes on forever (though as already stated, we can't truly comprehend what (or how far) infinite really is.

2) The Universe does have an edge, though if we are to believe this, then there has to be something on the other side of that edge, right?

This is where it gets confusing (from a human perspective at least). If the Universe has an Edge, then there should be something on the other side, yet, from our perception, there isn't actually anything on the other side of that edge. It's just nothingness. Our problem, as somewhat stated by SeinfeldisKindaOk is that we can't quite comprehend what nothing is. Such is beyond us.

Eventually, such simulator would probably crash. =p Besides, you say to fly off the grid and see how far you can go before you get tired. Who's saying the possible edge of the Universe is even penetrable?

Except that I don't think it's infinite. It the Universe is growing in size (which is speculated by many) then it has a size, else it wouldn't be growing. Something that goes on forever wouldn't be changing shape.

Excuse me. What is outside the marble? =p

A Super Gate will only take you to another Galaxy, not another Universe. And if you went to another Galaxy, you'd piss off some seriously messed up Religious folk who would bring their armies to our Galaxy and command that we convert to their religion.

Re: Beyond the observable universe
 

If the universe was finite and "wrapped-around" it wouldn't have any distinct edge that could be reached, any more than the surface of the earth does.

The boundary to the observable universe is just the limit on how much we can observe due to the time it takes for light and other signals to reach us.

Re: Beyond the observable universe
 

One of the problems with this sort of thing is that we're not really that well equipped to think about it. Nothing is infinite! What about space? Well space is nothing.

What about the range of natural numbers? Well, look, that's just something you've made up according to repetition of a finite pattern - there's not really an infinite number-line out there somewhere....

In which case talking about what space is bound by would be sort of meaningless. Space is all the area inside this sphere. Well what's on the other side of the sphere? Nothing! So - space then?

You know, we can talk about folding space as if it's a piece of fabric, and say that it curves around on itself and all that sort of stuff. But space isn't a piece of fabric. That's just a way of visualising gravitational fields. It's about as meaningful as saying space is an ocean. We just don't know enough to render a meaningful answer on this sort of question.

...

Consequently, I think we all know that wherever we've not yet looked is where the dragons and sea monsters are hiding. So, I'm voting for dragons. Even if I'm wrong, my guess is at least 80% cooler than the next closest alternative.

Re: Beyond the observable universe
 

There are several schools of thought on numbers, and the shape of space. We do actually know enough to make meaningful theories. The mathematics involved are just rather...intense, so to the general public it appears we don't.

Re: Beyond the observable universe
 

What's beyond the edge of the observable universe? More universe, in my completely uneducated opinion.

It's said that people can't imagine infinity. Humans have a beginning, and an end. Our species had a beginning, and people here are very keen to predict the end. Our entire planet had a beginning and will eventually have an end. We're linear, finite creatures, so it's understandable that we can't comprehend something that isn't finite.

Personally, I think that's bogus. I can't imagine a universe that isn't infinite. It's much easier for me to reconcile an endless universe that has always, and always will be here, than it is for me to imagine the possibilities that would present themselves if the universe did have a boundary, and if it didn't always exist. It's like trying to imagine being dead - you can't do it.

Re: Beyond the observable universe
 

I have the opposite problem. I can't imagine a space without a boundary. It would mean the universe would always have existed, and have no beginning. And if it does have a beginning, and not an end, how did it go from being finite to being infinite? But yeah, it might be that we're simply incapable of imagining something infinite. We can think about it, and consider it as a concept, but when it comes to imagining how it came to, and how it can exist? That's a whole different story. Maybe it is infinite. Or maybe it's a balloon inside an even greater universe.

Re: Beyond the observable universe
 

Define "Universe". My definition is this, the infinite blackness surrounding and including our known surroundings. Your definition appears to be that which is contained within that infinite blackness.

Is that blackness infinitely empty outside of the "known universe", or is there an infinite supply of matter and/or energy? It is difficult for me to imagine infinite matter and/or energy, but it is just as impossible for me to imagine that the there is some magical border to space.

I reconcile these two "impossibilities" by assuming that matter and energy end at some point. This is the finite end of the "knowable universe", but there is no barrier, no end, no wrap-around, it is simply a void. This void will be impossible to measure, it will be impossible to traverse.

In the end, our "knowable universe" is actually a matter/energy bubble that is smaller than a quantum particle in the grandness of the infinite blackness.

Matter can neither be created, nor destroyed, only converted to energy. The infinite blackness does not have a known beginning, neither has it a known end. It is not something that "exists", it is the absence of existence, and that which contains existence.

Our existence has a beginning, our solar system has a beginning, it is theorized that the "knowable" universe had a beginning, and its end will come with it freezes to death. Taking the Bing Bang theory, the Bing Bang does not have a beginning, nor an end, and is still happening.

That is how I understand it.

The greater universe being the non-existent blackness that surrounds the bubble. Like a bubble or balloon, filled with helium, then exposed to lower pressure, the "knowable universe" will expand. Only, not having a physical bubble, or balloon, there is nothing to pop. Having no counter-pressure, it will simply expand at an increasingly slower rate, to an infinite size.

Re: Beyond the observable universe
 

Y'all seem to have formed your picture of the universe from your own thoughts and feelings and supposition, rather than science and mathematics. Why is that?

Re: Beyond the observable universe
 

Believe it or not I've never really given much thought on the project. Occassionally I used to think of what was at the edge and beyond, but then I started waxing into why things exist and deep stuff that usually gets me in a bad mood.

That being said, I was always amused with Futurama's take on the "edge of the universe". I like what I've read in here though, makes me think without getting into an existentialist crisis.

Re: Beyond the observable universe
 

As I recall, the question there is whether the density of the universe is greater than a certain multiple of the square of the Hubble constant. The key point being whether, if I fire a photon off in a given direction, it will eventually come back to me.

But there are no boundaries involved there. To call it a shape is misleading. The Photon, at least under those assumptions, isn't coming back to you because it's run into the surface of the universe and bounced off it or anything – it was always on the 'surface' of the universe.

A sphere is the set of points that are all distance r from a given point. Here r seems undefined. You could stand at the apex of the photon's trajectory and fire another photon off and it would go on a ways before coming back to you – and you could do so an infinite number of times.

...

Maybe it works better with an example:
Say I tell you that space is spherical. Just enter it as an assumption. What can you tell me about what's beyond the observable universe that you couldn't tell me five minutes ago? Say I tell you space is flat - what can you tell me now that's different to what you could tell me if it was a sphere?

If your answer in both cases is the same, regardless of what that answer is - even if it's nothing, then you haven't actually expressed anything meaningful, the terms aren't supported by a framework of concepts that hooks onto reality.

Re: Beyond the observable universe
 

Why did you quote me? Your response didn't address my post at all.

EDIT: To clear things up for you, in the post you quoted I was referring to your preceding post. In it you claimed various things, such as one particular theory of numbers to be fact, and you also seemed set on one particular theory of the structure of the universe. You also claimed we're not well equipped to answer such questions, despite the plethora knowledge we do have, and the numerous valid workable theories.

tl;dr, your post was not structured well (in the sense that your point was a bit ranty) and lead me to believe you didn't know about current theories regarding the things you were talking about.

EDIT2: The answer to the cases is vastly different, actually.

Re: Beyond the observable universe
 

Because I thought that it did.

We're clearly dealing with too great an inferential distance here for the discussion to be worthwhile. Just don't pay it any mind.

Re: Beyond the observable universe
 

Heh, right.

Here's some light (no math knowledge required) reading on the subject, should you wish to be more educated in the matter

Curious About Astronomy: Why is the Universe flat and not spherical?

WMAP- Shape of the Universe

What Do You Mean, The Universe Is Flat?, Part 1 | Degrees of Freedom, Scientific American Blog Network

EDIT: If you're feeling up for it, there are several astronomy journals you can find through Google, though several are of course behind pay walls. :( They can explain current theories much more rigorously.

Re: Beyond the observable universe
 

Go figure, I actually remember reading the original article. It does, however, seem to cover primarily the observable universe, and not what is beyond the horizon. Since we can't see beyond it, we can't really do much other than guess and make estimates based on what little evidence is available. We can assume the rest of the universe, beyond the horizon, is also flat, but it could be curved as well. We probably won't ever know for certain.

... But I'm starting to think this would be better suited for someone with a university degree or something.

Re: Beyond the observable universe
 

Well, first, I don't intend to perform extensive calculations, and scientific experiments on this subjet, when I am not being paid to do so.

Second, what would it take for it to be "based on science and mathmatics"? Current science seems to indicate that the knowable universe is connected by some type of matter, I believe it was once called "dark matter".

Given that the universe is vastly larger than any means we have of exploring, we cannot know for sure what is beyond the "knowable universe".

There are certain facts that we know, "An object in motion, stays in motion". Air is expands to fill vacuum. If the known universe is showing evidence of expanding, then the we can postulate that the universe itself is not meeting with any resistance in its expansion, as air inside a balloon would not meet resistance in space. There is currently no reason to believe that the universe is accelerating, meaning that it is unlikely that there is a greater force at the edge of the universe, such as the universe itself (loop hypothesis).

We can look at planets, solar systems, and galaxies, and extrapolate from their what type of structure the "Knowable Universe" is likely to have. Likely the universe has the same shape as most solar systems, or galaxies, and is a flat circular rotating disc.

Now IF this entire universe is physically connected, that connection likely ends somewhere, beyond which there is likely no more matter, or existence. This would be the "edge" of the universe, but is likely not a magical end of space, just an end of matter, beyond which is blackness.

Otherwise matter and energy are infinite, and so is the "knowable universe". If the "knowable universe" is infinite, it could never be proven, but would indeed be beyond my ability to imagine it. Nothingness is much easier to imagine that something.

---------------------------------------------------------
I just came up with an interesting hypothesis.

The big bang was not just the beginning, but the end. For the universe that existed inside the "big bang" the universe was cold, dead, and incredibly vast. It was a universe that had reached its end, and that end would stretch out for an eternity for that universe, and continues to do so.

Yet, the universe is not dead as that universe perceives it, but is alive, and radiant. When our perception of the universe grows cold, another cycle will begin. This next cycle will consider our cold, dead, unmoving universe to be fluid, and a blazing inferno, a "big bang".

Given that the universe is infinite, and matter and energy are infinite, time itself has no meaning to the universe. What if the forces that created our worlds does not end when heat goes out of our universe? What if those forces have merely grown in size, like a child growing in size? What if this new cycle perceives time at a different rate that we do, thus they do not notice the slower than a glacial pace that their universe is moving at compared to ours.

There is no end, and no beginning, just an eternal cycle of death and rebirth. Like life itself here on Earth.

I do not believe that this is possible, but given infinite time, what is possible?

Re: Beyond the observable universe
 

That doesn't really clear anything up. I already know that in a curved space Euclidean geometry doesn't hold.

Where and how?

I'm weakly attached to any set of theories where distortions in the fabric of space time represent gravitational fields. This does not seem particularly controversial, even going faster makes you more massive.

I don't believe we're talking about the same question here so this is largely a point of procedure:

You come to the police with a load of evidence concerning a crime: the stolen goods you found in Bert's house, Bert's elaborate plans, Bert's confession given freely without any duress, videos of Bert doing the deed - and the police gives you a hundred theories about how Bert might have been framed by an unknown identical twin or something.

And then you're all like, "No! I wanted the exact OPPOSITE of this."

You can claim to be good at thinking if you have a large number of theories at a given level of generality and little evidence, or a lot of evidence and few theories. Not both.

Go on then.

Re: Beyond the observable universe
 

I seem to have gravely mistaken the purpose of this thread. My mistake. Clearly no one here has any interest in the actual state of the universe, instead preferring speculation and their own personal thoughts/feelings. That number of men made of straw (I'm looking at you, Nemmrle, as it seems be a habit of yours) are also getting annoying. I think I'll be going now.

Re: Beyond the observable universe
 

It's strange to think, with the vastness of space, there are still some people who believe we humans are the only intelligent species in the whole universe. :uhoh:

Re: Beyond the observable universe
 

I understood this thread to be about speculating about what lies beyond what we have seen of the universe.

Having a decent understanding of the state of the universe is necessary, but not the point of this thread.

I have shared my limited understanding of the universe. You have not pointed out the wholes in my argument, or on what points I am wrong. You merely posted a video, and a couple of articles, and failed to highlight any useful information. (I hate videos, especially of those with people just jabbering on, BTW).

In the video, and your links, it almost sounds as if the universe itself is unchanging. I.e, the universe is "expanding", but it is not expanding either. The "big bang" happened everywhere, but it is expanding? I cannot rationalize this. It happened "everywhere", but "everywhere" was smaller than what it is now, and thus "everywhere" had not expanded to where it even reached where "here" is now. And that video stated that the "knowable universe" has an edge (possibly).

How does that make any sense Obankonobi? How does that conflict with anything I posted? Okay, so meant "fabric" and not "Dark Matter", and I may be wrong about the universe not accelerating, but what else?

Let me go to Wikipedia,

It was dense, it expanded rapidly. If it is not expanding, then how is it expanding? Why are we measuring it, if it is not expanding? How could it be dense, and now not be dense, if it hadn't expanded?

Now, unless you can further explain the concept in the video, I don't see how it is relevant.


------------

Spherical space.
What Do You Mean, the Universe Is Flat?, Part 2: In Which We Actually Answer the Question | Degrees of Freedom, Scientific American Blog Network

You understand that current calculations are being made from a very limited range, with a limited knowledge of how the universe works right? I don't believe this is the most likely explanation, but didn't I mention planets in my post at the top of this page? I admit, it is possible, but it does not seem to contradict most of my post.

What this seems to be saying is that our "flat" universe sits on the surface of a sphere, a sphere that cannot be penetrated by light, because light itself flows along the surface of the sphere.

In short, the universe does indeed loop around from our perspective, even thought it does not loop around in reality, just that it looks that way. Just as a pilot who thought the world was flat, would be surprised to fly in one direction, and end up right back where he started.

If this is the case, then the edge of space is not left or right, but up. We would have to reach escape velocity to leave the "knowable universe", and reach the infinite blackness. At which point we return to the discussion of this thread.

Re: Beyond the observable universe
 

It's not a straw-man when someone goes 'Too much inferential distance,' and you go 'Heh, right. If you want to educate yourself...' and they answer along the lines of what they think you mean. Of course they don't understand you, they warned you of such.

Accusing someone of a straw-man isn't some trump card that beats any argument. If someone is doing it with malice, saying that they are won't help you any, and if they're not it will just insult them. At best it's a way of admitting to a breakdown in communications, most commonly it's just a way of spitting on the other person's character.

If you think I argue dishonestly, then please don't respond to any of my posts in future. And if you think I honestly try to understand you then... what is this? What is this I'm looking at you stuff meant to mean to me?

Re: Beyond the observable universe
 

To lighten the thread a little...

I'm curious, but are we talking about the universe, or are we talking about space? The Universe (in my eyes) is everything we can see. Space would be everything else. I can't remember who said it now, but someone up there said that the universe could be infinite? Okay, except aren't the respective galaxies and stars moving further and further apart? If this is the case, then wouldn't that point toward a growing universe rather than an infinite one? If its infinite, nothing would need to expand. :uhm:

Re: Beyond the observable universe
 

Everything we can see now? Or just whatever reflects or gives off light?

We are talking about whether or not there is an end to the universe, and what lies beyond that. Does space continue without the universe? What is the ultimate shape of space? Of the universe?

Re: Beyond the observable universe
 

If it's a balloon inside an even greater universe, then you have to consider whether that one is infinite or not.

We accept that matter and energy can't be created or destroyed, but then we try to come up with theories about how matter, energy and even time were created.

I like to think of our observable universe as a similar concept to galaxies. A galaxy is made up of stars. The universe is made up of galaxies. Maybe there is a similar collection of what we call universes, making up a super universe? And then there are super-mega universes made up of super universes. Etc.

In that line of thinking, maybe that would explain the big bang? Perhaps whatever we call the universe is actually the exploded remains of something far larger and older than anything we can comprehend? Much like when a star explodes; it's contents are sent shooting away, and coalesce into new things - like other stars, planets, or you and me.

But ultimately, it means that whatever space we inhabit has always been here and always will be, even if the contents weren't always arranged in the same way. In my mind, it's the only idea that works.

Even if we were to get into a religious debate, and say that God made everything, then we'd have to consider whether HE was always around, and whether or not whatever space he is contained in was always around.

In either school of thought, scientific or theological, SOMETHING has to be infinite.

Re: Beyond the observable universe
 

Well, to be honest I'm more into biology than astronomy. I'm not too familiar with these things- maybe you could give an overview of this rather than chastising us for not being as scientific as you would desire here?

Re: Beyond the observable universe
 

I wanted to post this but Obankobi already did.

NERDFIGHTERS!

Noooooo eeeeddgeeee

Re: Beyond the observable universe
 

Well, what I meant was that the *currently occupied* portion of the universe is expanding (this is fact, we can measure the speed at the which the objects in the universe are moving apart, relatively and approximately) and will continue to do so indefinitely as the universe is infinite (according to current calculations, the gravity of the known universe is insufficient to reverse the expansion. However, we know too little about the actual composition of "space", "empitness" and the universe to present this as fact)

Of course, if the universe is infinite, who is to say their is not another large cluster of galaxies elsewhere beyond our observable range, and our known "universe" is really just a cluster of galaxies among many, just as our galaxy is one of many. Of course, as intriguing as this possibility would be, our portion of the universe may as well be alone for the likelihood of it interacting with another cluster within any measurable length of time. After all, if we haven't even seen another cluster yet, it must so immeasurably far away that it would never be reachable. Perhaps some day our expanding cluster of galaxies will expand into another and 'restart' our long-dead cluster a few googol years from now.

[/ramblingoutofmyass]