Space Explosion Is Farthest Thing Ever Seen

[photon]

Originally Posted by Cowperson

To me, the first and second paragraphs contradict the third . . . . . or, at the very least, go beyond the definition of the third.

The first and second don't contradict the third because they're talking about different things. The last part is talking about the diameter of the observable universe which is different than the whole universe.

The observable universe is the portion of the universe which we can ever hope to see due to the speed of light. The actual universe appears to be larger, though how much larger who knows.

Originally Posted by Cowperson

In the first and second paragraphs, the "universe" is a concept, which could include the argument I've made, that there could be something beyond a boundary.

Current models (or at least the ones I'm aware of) don't have any kind of boundary. The surface of a sphere doesn't have a boundary, and neither does an infinite plane, when thinking about the geometry of our universe think of that kind of thing.

Originally Posted by Cowperson

The third paragraph seems to make Photon's argument. That there are defined limits, both observed and not observed, to the universe, the universe originating from the single Big Bang we know about. A starting point and a point where it ends, although still expanding.

The defined limit on the observable universe is just based on how far we can see based on the speed of light and the amount of time that has passed since the universe started.

As for a limit on the universe itself, a point where it ends, again it's not really necessary or indicated.



If the universe is curved like a sphere, then there's no end point because the surface of a sphere has no end point (remember that for the sphere the surface of the sphere represents all of reality).

In the other two solutions, the universe is infinite spatially.. if you go in one direction you can go in that direction forever and never stop, even if you could travel much faster than the expansion of the universe and faster than the speed of light. So there's still no end point.

Originally Posted by Cowperson

The first two paragraphs do leave open the theoretical question of something beyond the results of the Big Bang we know and love.

I think.

Cowperson

There's always the possibility, and when talking about the origin of the universe or other universes or the structure of reality there are no really good theories (theory in the scientific sense), but BBT itself and the Lambda-CDM model are extremely well supported by the observations.

[Cowperson]

The observable universe is the portion of the universe which we can ever hope to see due to the speed of light. The actual universe appears to be larger, though how much larger who knows.

To break this down into simpler terms, the paragraph above tells me you view this conversation as centering around everything related to the Big Bang. The Big Bang and the results of that event IS the Universe, seen or unobservable.

I might see the Universe as this particular Big Bang and all other potential Big Bangs, with the knowledge I can only study this one Big Bang . . . . . but all of them within one dimension. In your definition, I might say "What lies beyond this universe?"

That is why I see a contradition in paragraphs 1/2 versus 3 in the earlier post while you see those paragraphs as compatable.

Is my imagination too big for my britches?

Cowperson

[photon]

Originally Posted by Cowperson

The observable universe is the portion of the universe which we can ever hope to see due to the speed of light. The actual universe appears to be larger, though how much larger who knows.

To break this down into simpler terms, the paragraph above tells me you view this conversation as centering around everything related to the Big Bang. The Big Bang and the results of that event IS the Universe, seen or unobservable.

Yes, and this is how cosmologists use the term I think as well.

Originally Posted by Cowperson

I might see the Universe as this particular Big Bang and all other potential Big Bangs, with the knowledge I can only study this one Big Bang . . . . . but all of them within one dimension. In your definition, I might say "What lies beyond this universe?"

That is why I see a contradition in paragraphs 1/2 versus 3 in the earlier post while you see those paragraphs as compatable.

Ah ok I see where you are going. In that case I would totally agree with you, although I wouldn't use the term universe to refer to the results of our big bang and other big bangs, terms like the multiverse or the manifold are usually used to refer to those kinds of things (though those terms usually have their own definitions as well).

Our universe may not be expanding "into" anything, but it may very well be spawning child universes, or there might be an infinite # of universes if you like the many worlds interpretation of quantum mechanics.

Originally Posted by Cowperson

Is my imagination too big for my britches?

Cowperson

Not at all, the famous quote is something like, the universe is not only stranger than we imagine, it's stranger than we can imagine.

Another fun link with more speculation on the topic:

http://blogs.discovermagazine.com/co...niverse-start/

[LChoy]

Originally Posted by troutman

I think so, but perhaps it is impossible or meaningless to know of anything outside our own universe.

Is the world outside my aquarium of any relevance to my fish?

Yes, but only if they jumped out of the tank

[troutman]

Originally Posted by Lchoy

Yes, but only if they jumped out of the tank

Perhaps they worship me as a God?

[LChoy]

Someone needs to post of that Simpsons intro where it zooms out of Homer->Springfield->US-> World->...........all the way back to Homer
That was a good intro

[photon]

[BlackNRed1237]

all this science mumbo jumbo is confusing me.

[Cowperson]

I was reading Poul Anderson's "To Outlive Eternity" last night and was thinking of this thread as a result, the boundaries of the universe.

If you find this topic interesting and get a chance, at Chapter's right now is a compendium of short stories titled "To Outlive Eternity And Other Stories," by Poul Anderson, with the story in question written in 1967.

A summary here:

a starship hurtling through the cosmos at a speed so close to that of light—and unable to slow down—that relativistic effects make millennia fly by for each tick of the clock onboard

http://www.dailylit.com/books/to-out...-other-stories

It seems a rather simplistic take initially then keeps going to places that are startling in terms of concept. Probably about $10 in paperback for some light reading on the deck.

Cowperson

[Gozer]

Originally Posted by Cowperson

a starship hurtling through the cosmos at a speed so close to that of light—and unable to slow down—that relativistic effects make millennia fly by for each tick of the clock onboard
...some light reading on the deck.

You grossly overestimate CP's collective IQ my friend.