Given we know roughly where the center of the universe is ( from the reviser direction of traveling objects)
Then would it be fair to say there is an " edge"
By my presumuption the universere is expanding/expanded Like a bubble … but is it creating new “space” as it expands our has it finished expanding.
Given that the above is correct ( just for arguements sake) would that mean there there IS an edge to the universe and if so - what do you surpose would be on the other side ?
We don’t (and cannot) know where the centre is; space itself is expanding; wherever you are, everything is moving away from you and it looks like you are in the centre.
Sorry - i should have added i have dismissed the curved space theroy.
But … ok ok … so we can nto determain where the center is … but there is a center.
And what are we expanding into ?
If the answer is NOTHING … yet we are still moving away from all object … could it be the matter is shrinking ?
OK, but if you’re going to arbitrarily dismiss theories then we might just as well be asking whether the giant turtle underneath the earth is male or female.
By what reasoning do you dismiss the curved space theory?
And no, the idea of a centre point may be meaningless; where is the centre point of the earth’s surface?
There is no precise answer your question. Its all conjecture and theory.
You say you have dimissed “curved theory”, on what basis do you dismiss it? Astrophysics is probably one of the most difficult disciplines in science to understand and comprehend.
The current theory states that EVERY point in the universe, is in fact, the centre.
For a good overview, I suggest reading Stephen Hawkings A Brief History of Time, and recall that asking “What’s outside the universe?” is akin to asking “Is there a God?”
It is a malformed question, along the lines of what is north of the north pole?
Various Lovecraftian Horrors, along with a big tag that reads “Do Not Remove Under Penalty of Law”.
I am happy to be educated.
Explain why space Must be curved
If the big bang came from a single point - it must have expanded from that point at equal speeds - would this not suggest that there a center and there is a end or are we saying that the big bang created a solid state ?
Ofcause there is a center to the universe. And “…we are on the planet furthest from it…”
You appear to be assuming that the big bang occurred at a point in space or in the universe, like an object exploding or something; this would not be correct; the big bang is space.
It doesn’t have to be. Its just a theory. Explanations for these theories can’t be summed up in a sentence, they involve alot of complex mathematics, hard thinking and even a little faith. Seriously, read Hawking’s book, its the best primer for the layman about the construct of the universe.
For instance, we still can’t be sure whether the universe will a: expand forever b: slow to a halt or c: collapse at some point… It all has to do with calculating the amount of mass in the universe and things like dark matter etc.
Length is a matter of definition. By the current definition of meter, we are forced to say that space is expanding and that gravity causes space to curve. You could say that space is not expanding and that matter is getting smaller, but you would have to use another definition of length. You could also deny that space can be curved, but you would have to allow universal forces. A universal force is a force that affects everything and cannot be blocked. We usually define length so that all universal forces are zero. This allows us to use ideal rigid rods to mark off length. Allowing non-zero universal forces is the only way I can think of that would let you dismiss curved space. If space is not curved, then rigid rods change lengths and don’t remain straight.
So basically you can dismiss curved space and have a universe that is not expanding. The price is that you cannot use rigid rods to measure length (because of non-zero universal forces). Nor can you use the distance light travels in a particular time, because this gives the same result as rigid rods. While it is theoretically possible to set up an alternative definition of length, I don’t see how you would do so. And I don’t see any benefit.
The Big Bang was not an explosion that flung matter out into space. It is the expansion of space itself. The expanding space carries matter with it. There is no center of expansion. Space is expanding everywhere.
And the Big Bang created space and time, there is nothing outside, nor is there an edge, there was no before.
That’s probably not true. While there’s no before for our universe, none of the theories have said anything about an “outside.”
Probably higher dimensions.
#1) It’s not space, per se, that’s curved, but rather spacetime. There is a difference. Space time curves in a very predictable fashion giving us locally flat places in the universe that actually define geodescics (that is, the shortest distance between two points) that are not straight lines. These geodescics themselves are not straight because spacetime is curved by a thing called the stress-energy tensor (basically a substitute for mass in general relativity). To see one of these in action, hold a ball out at arms length and let go. It follows a straight line in spacetime which would look like in flat space simply a ball that stays put and travels one second per secon into the future. Instead, that “staying put” looks to be that the ball accelerates toward the ground (or the ground toward the ball, they are equivalent). You look at this in 4-d spacetime and you find that this path looks curved to an outside observer. Now, we can extend this theory to the entire universe. Suddenly we have that the stress-energy tensor of the universe is curving the spacetime of the universe. There are many different ways to view the problem, but all of them take into account the curving of spacetime.
#2) The big bang is not only expanding at the same velocity from the “initial point”, it is also expanding at the same velocity from all other points as well. If we keep in mind that all points are rushing away from any given point in the universe in the same way (related to the distance between the two points), we find that a “center” is not readily apparent. The only center we can appeal to is the center defined by the Hubble Horizon, that is, at the point where the observer is standing she can look out and back in time (since the speed of light defines the time of the observations) and can only go back in time to the point when the Big Bang first started to occur. Anything beyond that is unobservable. Right now, that distance is about 3000 megaparsecs or so. Going by this definition, we are the center of the universe. It doesn’t make us special though, because every observer anywhere in the universe also has a horizon defined for them by the age of the universe and sees themselves as the center.
trader, the standard balloon analogy might help here. If you’re standing on the surface of an expanding balloon, where on that surface did the expansion start?
Trouble is with the balloon analogy is that for it to work properly, you have to remember that the surface of the balloon is the whole universe; effectively a two-dimensional rubber sheet that is warped back on itself to form a sphere, but that warping is undetectable to the inhabitants of said rubber sheet (it looks flat to them).
Otherwise it just reinforces the idea that there is something ‘outside’ (and sometimes inside) the balloon.
I know I’m probably taking the balloon analogy too far, but I don’t understand how space can be two-dimensional. Does it have a “thickness”? Does that mean that everything we observe is “straight-ahead,” “behind,” and to the “left” and “right” of us? And there is nothing “below” and “above” us? Take pity on my swirled noggin.
This very question was argued recently in Great Debates. It’s not really a debate, except for those who flatly refused to entertain consideration of astrophysicists’ more outré conclusions. Anyway, those who are confused about a nonbounded, curved-space cosmos that expands everywhere at once should read What is containing the universe?