why hasn't destiny reached the edge of the universe yet?

[KEK]

I was referring to the scientific definition of course. I'm not saying that it isn't a well established theory, because it is, and very supported for that matter. And unproven was probably the wrong word to use. I was just trying to point out that we cannot observe it.

We can observe it, just not in complex organisms.

[thekillman]

It most definitely exists. However, you can't possibly expect to find every kind of animal that ever existed, nicely preserved. Nature simply doesn't work that way, and we are lucky we found skeletons and fossils like we did.

[Snowman37]

Hello? Did anyone see my post?

Space is the absence of matter, so wouldn't space be infinite by default? I think of the universe as that which exists within space, whether it be known to humanity or completely beyond our comprehension. If something is out there, that would be part of the universe. Think of the universe like a cloud. The further out you get, the thinner it gets. There's no defining edge like on a sheet of paper. I think the universe, the collective whole of all existence, is finite. However, I think the empty space in which the universe resides is infinite. How can the absence of existence have limitations? If space were finite, would that not necessitate the universe to be infinite?

[KEK]

The universe is everything, not just matter and energy, it's space-time too. You might think of the universe as just the stuff that's in it like stars and galaxies, but that's not the totality of what it is. If the universe is finite, then either space has an edge, or it's simply curved. The general thinking is that it's the latter.

[thekillman]

Hello? Did anyone see my post?

Space is not the absence of matter. Space is the 4 known dimensions along which everything moves. Consider it the railway, and the particles the trains. Except that there's 3 tracks, one for each dimension of space, and 1 track for time.
Also, these particles can't derail.

Now, Space is basically the playing field in which everything we know exists. And it expands, so it's not infinite.

If we go by the classic definition of Universe, then it is infinite, since Universe means "all that exists". The more modern definition is that it's basically the entire "space-time bubble" in which we exist, plus all matter and energy in it. So it's not infinite then.

Furthermore, Space does not get thinner, or the presence of matter does not get thinner, the further out you go. Space, at every point in time, has matter more or less equally distributed throughout it. Sure, gravity creates clumps, but on the larger whole it's quite smooth. Since every point of space expands in every direction at the same accelleration, Matter stays equally distributed throughout it. So the "density" of matter globally decreases, but locally increases through gravity. That means that wherever you go, you'll observe galaxies, and stars and such, and there's not gonna be a place where it all suddenly gets a lot thinner, and eventually you're in completely empty space.

If you were to go to the edge, if it existed, it would just "stop" there, you'd observe a sky quite similar to ours, except suddenly it's empty (in the direction of the "edge"). Space is quite homogenous on the large scales, so you will never find it thinning out suddenly.



Again, the problem with these "edge" theories and the very idea of an edge, is that it's unproveable. We can never go there. It's practically impossible in real life.

[metaboretz]

Well yes there is no center of the Universe since it is expanding apart equally in all directions. But my understanding of Destiny's mission was that they were attempting to locate the area of space where the signal was strongest or where they could gather more information about it. Even though there is no center, couldn't you theoretically locate the area of space where the big bang occurred? Who knows what would be there, but it seemed to me that the Ancients believed something was there.

[thekillman]

Well yes there is no center of the Universe since it is expanding apart equally in all directions. But my understanding of Destiny's mission was that they were attempting to locate the area of space where the signal was strongest or where they could gather more information about it. Even though there is no center, couldn't you theoretically locate the area of space where the big bang occurred? Who knows what would be there, but it seemed to me that the Ancients believed something was there.

no.

However, since the background radiation varies in SG, they're basically moving around, measuring the signal and seeing if it changes, getting data about the universe and so apparently trying to piece the puzzle together

[KEK]

Well yes there is no center of the Universe since it is expanding apart equally in all directions. But my understanding of Destiny's mission was that they were attempting to locate the area of space where the signal was strongest or where they could gather more information about it. Even though there is no center, couldn't you theoretically locate the area of space where the big bang occurred? Who knows what would be there, but it seemed to me that the Ancients believed something was there.

The big bang occurred everywhere. The universe is not expanding from a single point, it's expanding in it's entirety.

[Jack O´neill]

It´s really simple! Many theories suggest the universe is expanding!

[thekillman]

that has nothing to do with it

[jojojo70]

I loved SGU, but I was always puzzled by Destiny's path. To stay on topic, I'll state that I lean towards the infinite flat model theory which began wtih a singularity. I'm interested in atrophysics, but I don't think we have the answers. (ex -- the accretion disk that seems to have disappeared recently --NASA scientists don't understand it and neither do I.

Here's the big question that is bothering me. I assume many of you know the answer. Where is Destiny going? I assume it was not trying to reach the edge of the universe. Aside from the rapid acceleration, the trip would have literally been an infinitely long one. So, I assume they were trying to reach a point closer to the singularity that started it all.

So again, where was the ship going? Wouldn't staying on the ship force them farther away from Earth? Once the crew had control of the ship, why didn't they turn around? I don't understand what the crew (except Rush) had in mind. Did I miss an episode? Were they trying to get home?

[QuantumIguana]

The theory of gravity is an explanation for the phenomenon of gravity. The theory gets adjusted as new evidence is discovered, but gravity is a fact. Likewise the theory of evolution is an explanation for the phenomenon of evolution. Just as we know that things fall due to gravity, we know that organisms have evolved. Just like the theory of gravity, we don't know everything about it, but we know that it exists. If the theory is shown to have faults, then the theory will need to be improved. But that doesn't mean that the phenomena doesn't exist.

[Ser Scot A Ellison]

Snowman,

Space is the absence of matter, so wouldn't space be infinite by default? I think of the universe as that which exists within space, whether it be known to humanity or completely beyond our comprehension. If something is out there, that would be part of the universe. Think of the universe like a cloud. The further out you get, the thinner it gets. There's no defining edge like on a sheet of paper. I think the universe, the collective whole of all existence, is finite. However, I think the empty space in which the universe resides is infinite. How can the absence of existence have limitations? If space were finite, would that not necessitate the universe to be infinite?

No, because everywhere is the center of the Universe. The mistake is thinking of galaxies flying away from each other in space. What's happening is space is expanding therefore the space between galaxies is getting larger. Think of dots on the surface of a balloon as the balloon expands. The dots get further and further apart. That's what the expansion of the Universe is analogus to. Therefore, the Destiny will never hit the edge of the Universe.

You should watch "Fabric of the Cosmos" on NOVA. The first two episodes are on PBS right now.

[psl1]

I just suffered through several Nova specials on 'Life the Universe and everything'. In order to include string theory, Dark Matter , Dark energy, Big Bang, and all that makes up Quantum Mechanics....They seem to be push theories that say something different.

A there is no one universe , but a multiverse?

The 'Big Bag' is ongoing from one universe to another?

The rate of Time and space expansion is accelerating?

There was more but I forget at this moment.

[Dr. D.]

An interesting video on this website:

http://www.speed-light.info/video_universe_size.htm

Scroll down to the lower half of that page to view the video.

Here is an interesting excerpt:

"...the whole universe would have grown to some 10 billion trillion times the size of the observable universe. That's 10 followed by 24 zeros. Put another way, the complete universe is to the observable universe, as the observable universe is to an atom."

[Brian]

Probably, but it would likely mean you start finding galaxies you've already encountered, rather than any sort of edge.

Mind. Blown.

We can't look at the edge of the universe because when we do look in it's direction, we also look back in time. We eventually see nothing but a big cloud of super-hot plasma, and we can't look past that.

That notion has always had me puzzled. If we're looking back in time when we look at galaxy A, then if we spin 180 degrees and look at galaxy B facing the other way it's weird that we'd still be looking back in time, rather than forward.

Also I remember reading something Stephen Hawking said a while ago about the universe is probably still expanding at faster than the speed of light...which in turn implies that there would be an edge. But, and this has boggled my mind like literally nothing else and given me headaches...what is outside of the universe? This whole subject of the universe, where things came from, why things happened, what was there before the big bang, what's going to happen after, everything... the whole idea of it BOGGLES MY MIND! These things as bother fascinating and terrifying at the same time.

Just to add to the videos here, I saw this on TED a good while back and thought it was pretty incredible.
http://www.ted.com/talks/lang/en/geo..._universe.html

[jeri]

BOGGLES MY MIND!

I agree!

[Flyboy]

That notion has always had me puzzled. If we're looking back in time when we look at galaxy A, then if we spin 180 degrees and look at galaxy B facing the other way it's weird that we'd still be looking back in time, rather than forward.

Because it's not about direction. What you physically see, regardless of direction, is an image of something from billions of years ago. Because it took the light THAT long to reach you. No matter which direction you look in, you're always looking into the past - from OUR perspective.

[Quetzocoetl]

Mind. Blown.




That notion has always had me puzzled. If we're looking back in time when we look at galaxy A, then if we spin 180 degrees and look at galaxy B facing the other way it's weird that we'd still be looking back in time, rather than forward.

As already stated, direction is meaningless. The light itself just took so damn long to reach you, the image you are seeing is the light from so long ago. If galaxies A and B are 2 billion light years away from each other, than from either galaxy, you are seeing the light from the opposing galaxy from 2 billion years ago.

Also I remember reading something Stephen Hawking said a while ago about the universe is probably still expanding at faster than the speed of light...which in turn implies that there would be an edge. But, and this has boggled my mind like literally nothing else and given me headaches...what is outside of the universe? This whole subject of the universe, where things came from, why things happened, what was there before the big bang, what's going to happen after, everything... the whole idea of it BOGGLES MY MIND! These things as bother fascinating and terrifying at the same time.

The fact that it's expanding doesn't imply there is an edge anymore than the fact a balloon is expanding implies there is an edge to it's surface. We are on the surface of this "balloon", no matter how far you travel, you aren't going to find the edge.

[Quadhelix]

Where is Destiny going?

Short answer? Everywhere. The Destiny's mission is to travel to various parts of the universe and compile information on variations in the Cosmic Microwave Background. The CMB, or the "light of the Big Bang" comes from every direction because the Big Bang happened everywhere.

So, I assume they were trying to reach a point closer to the singularity that started it all.

That doesn't make since because the "singularity" that started it all was everywhere. No matter what direction you travel, you get neither closer nor farther.

So again, where was the ship going? Wouldn't staying on the ship force them farther away from Earth? Once the crew had control of the ship, why didn't they turn around? I don't understand what the crew (except Rush) had in mind. Did I miss an episode? Were they trying to get home?

Destiny has been traveling away from Earth for all of human history - perhaps since around the time of the extinction of the dinosaurs. Turning around now won't accomplish anything because it will take thousands of year or more for the Destiny to make a return trip.

That notion has always had me puzzled. If we're looking back in time when we look at galaxy A, then if we spin 180 degrees and look at galaxy B facing the other way it's weird that we'd still be looking back in time, rather than forward.

This has been well addressed, but to make sure that it's clear, I'll provide a simple analogy:

If you live in, for example, New York, you might get a letter from a friend in London a few days after he or she sent it. If another friend in San Fransisco sent you a letter, you wouldn't expect to get the letter a few days before he or she sent it.

However, since the background radiation varies in SG, they're basically moving around, measuring the signal and seeing if it changes, getting data about the universe and so apparently trying to piece the puzzle together

Fun fact: the CMB in real life has small variations in it, generally on the order of 0.1% or less. Because the CMB is believed to be the thermal radiation of the early universe, "hot" spots are believed to be areas of slightly higher density that eventually formed galaxy clusters and superclusters.