View Full Version : Wall at the end of the universe?
If there is, and if we are to define the "end of the universe" then we should ask ourselves if the end consists of a physical wall where nothing can pass through and nothing can expand through. The theory of a wall begins to crumble when we attempt to define the wall. How thick is this shell? if it is infinitesimally thin, then it will not exist. If it is infinitly thick, then the universe itself is infinite containing "wall" matter. If the thickness is finite, then the outer surface must exist. An existing outer wall surface is definable by the space existing adjacent to it. The adjacent space, although it is an empty vacuum, is definable relative to the outer wall surface, and therefore part of the universe.
If space is infinite and has the potential to be filled, then every thing and every place and every time (and every ONE) must exist in parallel. In a an infinite universe, there are no probabilities - only certainties.
ElectricFetus
02-12-03, 10:33 PM
Some have said that if you reach the end of the universe you would end up back where you started! think of the universe as a sphere in 4D so that no matter what direction you go you will end up going arond in circles.
Beercules
02-13-03, 12:07 AM
Yes, our fetus friend is correct. Either the universe is a curved 3D surface, or infinite. In either case, there is no edge, so no wall.
Originally posted by WellCookedFetus
Some have said that if you reach the end of the universe you would end up back where you started! think of the universe as a sphere in 4D so that no matter what direction you go you will end up going arond in circles.
If this is the case, what is the maximum distance achievable before you start to approach the origin?
ElectricFetus
02-13-03, 01:53 PM
So far attempts to measure the "curve" of space have shown that the universe is very flat and if it does curve it would be trillions of light years round.
Originally posted by dsdsds
If this is the case, what is the maximum distance achievable before you start to approach the origin?
Well, what's the measured age of the universe - about (very roughly) 15 billlion years. So, assuming we're at the middle (or as much so as anyone else). It would be 15 billion light years. It's getting late here - is that right?
Cheers,
Ron.
Beercules
02-13-03, 06:50 PM
No, our visible region of the universe can be measured as such. But the rest of the universe is much bigger.
ElectricFetus
02-13-03, 07:02 PM
Exactly Beercules! Its already mind bogglingly big but dam it, it most likely much Bigger!!! I would put a guess a the trillions of light years round range! A genesis idea called something like “Multiple Big Bangs” would not make the universe round but give the 4D topography of space the shape of a bunch of soap bubbles, each bubble being a respective universe!
The size of the universe is irrelevant. What I'm concerned about is how the edge (if it exists) looks like. If the universe is curved and taking off in any direction will lead you back to the same point, then 2 objects 1mm apart should have their own space envelope. The universe would be like a giant 4D onion (or several 4D onions) – each object having their own shell defining their trajectory and never intersecting an adjacent shell. Onions or soap bubbles are defined by their shells or their LIMITS. And they are definable because their shells (LIMITS) exist inside a bigger shell which is the room we are in. The room we are in is defined by … --- and so on. An object can only exist if it is in a bigger object. – can someone debate this last statement?
ElectricFetus
02-14-03, 11:12 AM
Yes: what object does space existed in?
Beercules
02-14-03, 11:40 AM
Originally posted by dsdsds
An object can only exist if it is in a bigger object. – can someone debate this last statement?
How about you support that statement instead? I'm sure physicists and mathematicians would love to see the logical inconsistancy of a space-time that does not need to be embeded in a greater volume of space.
Wondering what an outside of the universe looks like is a problem of intuition, not geometry.
Sal-Man
02-22-03, 01:35 AM
:eek: ...I posted the same question (edge of universe...), if you would like to see the replys i got it's in the physics and math forum (i know, i think i screwed up on postage location...), couldn't find the though, sorry...:rolleyes:
Nova1021
02-25-03, 02:23 AM
There is no edge to the universe. The best analogy I've heard is this: Picture a balloon with dots drawn on it in marker. As you blow up the baloon, each dot gets farther from every other one because of the expansion. Now picture an little ant walking along the balloon's surface. He's so small he can't tell the balloon is curved, he think's he's going striaght. He can go and go on this "straight" path and never reach a boundary. We're the ant, the balloon is our universe. Except instead of expanding in 3 dimensions like the balloon, it is expanding in four dimensions (not including time). That's the way I understand it.
If this is the case, what is the maximum distance achievable before you start to approach the origin?
I don't think theres any known answer to that, but I'd say the likelihood of coming back right where you started is pretty low. Back to the ant, he could walk a long long way, many times around in his "straight" path before reaching the point at which he started.
An object can only exist if it is in a bigger object. – can someone debate this last statement?
The universe is not an object. But, to look at that statement anyways, it really depends on your definition of being "in" something. A hydrogen atom zipping along through interstellar space exists, and it's not in anything. It was once in a star, it will be in one again, most likey, but right now, it's just out there. Now you could say that it exists in the universe, but are we saying the universe is an object? It is expanding in four dimensions, plus time. I would say that it is not what you could classically call an object. Your statement would be more accurate if you said "An object can only exist is it is in a universe."
Weird discussion... Reminds me of some of the stuff by Plato we read a few weeks ago...but not as annoying as him. ;)
I can accept the fact that the universe is not an object if we describe the universe as emptiness or a vacuum. Space itself is not an object. It becomes an object when we try to define or describe it. If we define or locate point B RELATIVE to point A (which is where we are), then we are also defining the space around point B. The universe definitely becomes an object when you describe it as being curved like a balloon or bubbles or whatever .. – no matter how many dimensions we’re talking about.
If the universe is not infinite, it is an object. AND an object can only exist if it is in a bigger object.
Beercules
02-25-03, 12:51 PM
...AND an object can only exist if it is in a bigger object.
But you still haven't offered any support for that claim. Again, physicists and mathematicians would love to see how defining a volume of space without reference to external space is logically inconsistant.
Originally posted by Beercules
But you still haven't offered any support for that claim. Again, physicists and mathematicians would love to see how defining a volume of space without reference to external space is logically inconsistant.
I’m not a mathematician and I can only suggest this theory by intuition and by example. I couldn’t even phrase the question as elegantly as you have. How would we start attempting to prove that “defining a volume of space without reference to external space is logically inconsistent”? -- And if we are successful, what does this mean? -- that the universe is logically inconsistent? – does it leave no other option but to accept infinity?
Beercules, if you don’t mind I’ll start a thread in the math & physics forum on this (quoting your challenge)
ElectricFetus
02-25-03, 03:29 PM
I think it has to do with concepts: the idea that beyond the universe would be a void of nothing that nothing can exist in and even time its self is lacking is simply beyond some people.
Nova1021
02-25-03, 10:56 PM
If the universe is not infinite, it is an object. AND an object can only exist if it is in a bigger object
The universe is not in a bigger object. It IS space, as it expands, so does space. They are one and the same. The balloon example is helpful to visualize it, but it is flawed, as any example is. The balloon expands in some other space, the universe doesn't need that. It expands in the fourthe dimension just as the balloon expands in the third. The thing is, as I understand it, the fourth dimension is, itself, part of the universe. The universe is not some 3-d baloon expanding in a 4-d void. Unlike a normal object within the universe, it does not need a space in which to exist because it is, itself, space.
:bugeye:
Originally posted by Nova1021
The universe is not in a bigger object. It IS space, as it expands, so does space. They are one and the same. The balloon example is helpful to visualize it, but it is flawed, as any example is. The balloon expands in some other space, the universe doesn't need that. It expands in the fourthe dimension just as the balloon expands in the third. The thing is, as I understand it, the fourth dimension is, itself, part of the universe. The universe is not some 3-d baloon expanding in a 4-d void. Unlike a normal object within the universe, it does not need a space in which to exist because it is, itself, space.
:bugeye:
It makes sense but it's impossible to imagine something expanding without having space to expand in. I guess the only thing that makes sense is that the universe is all there is. And all there is, is everything including that which will be. Questioning infinity and/or edges or limits is suicidal! I made the mistake of posting this subject in the physics and math forum and I’m getting drilled on manifold and fractal geometry of an orange.
Originally posted by dsdsds
It makes sense but it's impossible to imagine something expanding without having space to expand in...<snip>...I made the mistake of posting this subject in the physics and math forum and I’m getting drilled on manifold and fractal geometry of an orange.
That's the whole point - both here and in P'n'M - that some spaces don't live within bigger spaces.
Cheers,
Ron.
vBulletin® v3.8.1, Copyright ©2000-2009, Jelsoft Enterprises Ltd.