The Universe opened up more questions than it answered.

Last night I watched History Channel’s The Universe: Beyond the Big Bang. I found it utterly fascinating and informative. This first sentence should explain exactly how much I actually understand about the science and mathematics of astronomy, namely a History Channel understanding, so please, please keep this in mind when replying. I’d be ever so grateful.

There are a gazillion questions this program raised with me but there are 3 which that I desperately need answers to before I can try to wrap my head around all this Universe stuff. Heck, I’m having a problem even forming the questions that I’d like answered. I’ll give it the old college try.

  1. What is ‘the known universe’?
    The show tossed around this phrase as if it was quite clear what the hell ‘the known universe’ is. Is it all that we can observe? And if it is, wouldn’t that make our idea of the known universe a couple of tens of thousands to millions of years out of date? Is it what scientists and mathematicians theoretically “know”? So that when astrologist say ‘the known universe’ they mean about as far as they can extrapolate from their equations?

  2. The age of the Universe.
    I can see why Einstein didn’t want to take that leap into an expanding universe and why Hoyle clung so desperately to Solid State. Our current understand of The Big Bang puts our universe at just shy of 14 billion years old. This number is waaaaay to small for me. I can get behind a finite universe if, say, the number of years involved is some number so huge that I can’t comprehend it. Like say a google to the tenth power. See that number there-- even though it is finite-- may as well be an eternity as for as I can tell.

But 14 billion years? That means that if the United States paid a dollar for every year that the universe and everything–I mean everything, even energy itself-- has existed, we’d never get close to paying off our national debt. There have got to be theories that make the universe much, much older than almost 14 billion years. Can anyone tell me what they could be?

  1. The edge of the universe.
    I can totally wrap my mind around a universe with no center. All of the galaxies and stuff out there are rushing away from each other faster and faster, stretching time as it does so making things further away from us even further away than they are. Yeah, I can get behind that even though it doesn’t seem to make sense.

What I’m having a hard time reconciling is the edge. If there is no center, how can there be an edge? If there is an edge, what is it expanding into?

Without the answer to the questions, me and my feeble brain have come up with a theory that helps me try to grab on to these wispy concepts. I’d be glad when smarter people than I tell me what’s wrong with it.

You know that singularity that our universe started as? That thing was so heavy it folded space/time around itself and this universe is caught inside this wrapped space/time thingamabob. So, if you ever get to the edge of the universe, you’re at the folded space/time-- which puts you at the beginning, the center.

Why should there be? This example says more about the small size of a dollar than anything else. A dollar a year is next to nothing.

Not necessarily anything - it’s just getting bigger by making more of itself. Any analogy we tried to offer would necessarily be embedded in a containing space, so it would mislead the listener into thinking that it implied some kind of meta-space outside of the universe.

As I understand it ( as a layman ), there is no edge; it’s either a higher dimensional version of a sphere, or flat and infinite, or this infinite negative curvature that’s also infinite ( the latter seeming most likely at the moment; I’m not sure how to describe it ). Now, there is such a thing as the edge of the observable universe; that’s the farthest distance we can possibly see, given the speed of light. But that’s not the edge of the actual universe.

It’s making more of itself, as said.

Ah but the “making more of itself” was Hoyle’s theory which has been abandoned for the expanding universe/big bang theory. According to this theory, the universe will expand itself into nothingness, ripping itself into smaller and smaller peices until there is nothing left.

The known Universe is simply a way of acknowledging that every thing we have perceived, plus all that we have inferred from those observations may not be the sum total of the Universe. A century ago the “known Universe” was pretty much all in the Milky Way. We know now that that is a pitifully small part of the universe. It might be that the fourteen billion light year region we can see now represents a similar proportion. In fact, the four dimensions in which we perceive it might be a similar small aspect of it. All that is is the Universe. Kind of inherent in the definition of the word. All we can really talk about is All that we know about, and it becomes reliably demonstrable over time that what we know about is smaller than what we don’t know about.

The age of the universe is either very old, or simply meaningless. (And, by the way, fourteen billion years is very old.) The idea that the universe has a particular nature, and remains the same requires that it always has had that nature. The steady state hypothesis has a lot of simplicity, aside from the conservation of matter being troublesome. Any progression in any characteristic that is not reversible over the entire universe implies a beginning, or an end. Einstein, and many others found that possibility esthetically troubling, and the philosophic consequences were difficult to describe without ending up with religious sounding pronouncements.

The edge of the universe is a tough geometry problem. There isn’t one. If there was one, almost everything would have to be there, and we are not, and cannot see one. There isn’t a center either, unless you can wrap your head around everywhere being the center. I can’t. The concept is called curvature for some odd reason, although it isn’t curving in any way that you or I would recognize as a curve. It’s the reason that things fourteen billion light years “that a way” are not 28 billion light years away from things fourteen billion years “the other way.” There simply is no other way, on that scale.

Tris

“It should be possible to explain the laws of physics to a barmaid.” ~ Albert Einstein ~
“You should see the place where Einstein used to drink!” ~ Triskadecamus ~

No, Hoyle was speaking of matter; the supposed spontaneous appearance of hydrogen, not spacetime. The universe isn’t making more matter; it’s making more spacetime.

Empty space is not the same as ‘nothing’.

It’s nothing if everything there is-- isn’t. There will be no matter, no energy. No nothing. It is the absence of everything. What is ‘empty space’ if not ‘nothing’?

Spacetime.

I think you can only quantify space if you have something else to compare it to and make an observation or take a measurement relative to other things. Space wouldn’t exist if there wasn’t other matter around.
There will always be energy in that empty space as long as there are two objects to attract each other. And the distance between them is only relative to the observer doing the measuring. For all we know the whole universe could be a bubble on a doorknob.

Now I’m really confused. Space/time is a relative term. It is the stuff inside space/time that defines space/time. Without the stuff, there is no space/time.
On preview, what Uncommon said.

Did the program claim there was an “edge”? This is not part of standard descriptions of the universe.

The common analogy is to imagine a 2-dimensional universe as the surface of a balloon that’s slowly inflating. All points on the balloon are growing further from all other points. But you can wander all over the balloon and never get to the “edge” of its surface. Nor is there any point on the surface that can be said to be its center.

Nope, they actually showed a picture (taken with a deep space whoziwatsit that took a snapshot of the echo of the BB) that was the universe 380 some odd thousand years old. It showed the edges of the ‘known universe’ and spoke about what was going on there.

I wish I could grasp that balloon analogy. It makes more sense and fits into my ‘captured in space/time’ theory but. . . if you are walking around this balloon, you are walking around the edge of the universe and the reason you never reach an edge is because you are already there.

Man, next time I’m going to skip The Universe and watch American Idol. This stuff actually made me lose sleep trying to wrap my head around it.

The thing with the balloon analogy, is you have to ignore the air and space surrounding it, ignore the air it contains, and picture yourself as a two-dimensional Flatlander, constrained to its surface, and unable to know about anything else outside of that space.

To you, the balloon’s surface is the whole universe - when we inflate the balloon, your universe gets bigger - everything in it gets further apart, but nothing new appears in it. There’s no edge to the surface in which you live, and there’s no centre either. If you travel a long distance in a straight line, you end up back where you started.

I think most descriptions would say there isn’t an edge. But it could perhaps be equally true that whatever edge there is is present everywhere - no place in the universe is closer to or further from the “edge” than any other.

Ah— yes! I think I get it now.

And yet. . . my space/time folding singularity works just as well, no? I say we combine the two and teach it in schools.

Just a side clarification: The observable universe appears to have a diameter of 92.94 billion light-years, right? ( http://en.wikipedia.org/wiki/Observable_universe ) Does anyone have a guess as to the size of the entire universe? Or is it just a shrug-unknowable?

I don’t like to nitpick, but I thought this shouldn’t pass without remark:

Emphasis added. Astrology and Astronomy are, these days, two totally different disciplines. Astronomers are practicing a science. Astrologists are not.

Imagine a very long ruler made of rubber. It’s stretching everywhere along its length at the same rate – say it doubles in length every second.

You’re standing at the 0 mark. The one-foot mark is moving away from you at 1 foot per second; one second from now it will be two feet away from you. The 1 mile mark is moving away from you at 1 mile per second. And the 1000 mile mark is moving away from you at 1000 miles per second.

The 186,500 mile mark? You can’t see it. Because it’s moving away from you faster than the speed of light. Your “known ruler” ends somewhere around the 186,282 mile mark. There’s plenty of ruler out beyond it, but you can never observe it because it’s moving away too fast.

That’s how the infinite universe can have an edge. The universe is expanding. This doesn’t mean that all the stars and galaxies are flying apart. The fabric of space itself is expanding. The farther you go from Earth, the faster this expansion is relative to us. If you aim your telescope in the right direction eventually you’ll see a galaxy that’s moving away from us almost at the speed of light. That’s the edge of the known universe. There’s more universe beyond it, but we’ll never ever be able to see it.