Where Does Space End? It Must End Somewhere!

[SplitInfinity]

That is not necessarily so. Whether or not a Big Crunch begins must take into account the velocity of the expansion and the amount of mass in the universe. The universe could theoretically expand forever even without the effect of Dark Energy.

 

Perhaps...but one thing is for certain...Universal Expansion would not be accelerating.

 

Split Infinity

[zapatos]

No 'perhaps' about it.

An important parameter in fate of the universe theory is the Density parameter, Omega (Ω), defined as the average matter density of the universe divided by a critical value of that density.

 

f Ω < 1, the geometry of space is open, i.e., negatively curved like the surface of a saddle. The angles of a triangle sum to less than 180 degrees, and lines that do not meet are never equidistant; they have a point of least distance and otherwise grow apart. The geometry of such a universe is hyperbolic.

 

Even without dark energy, a negatively curved universe expands forever, with gravity barely slowing the rate of expansion.

http://en.wikipedia.org/wiki/Ultimate_fate_of_the_universe

[SplitInfinity]

No 'perhaps' about it.http://en.wikipedia.org/wiki/Ultimate_fate_of_the_universe

The ability of your statement to hold water depends upon whether the Geometric Model and equasion specific to such geometry giving allowances for endless expansion.

 

Not only is there not enough of a knowledge base to make this assumption...but by it's very nature it is in conflict with Energy Concervation.

 

There is NO WAY...that any model that details endless Universal Expansion without detail of Universal Contraction...be it reversal of both effect and specific directional travel or Universal Contraction specific to a Geometricaly Closed System of Return...is going to be a proven reality or a logical or mathematically sound Natural Law of our Universal Reality.

 

It is logical to assume that for every WHITE HOLE...AKA...The Big Bang...there will be a Black Hole associated to it. It is NOT LOGICAL TO ASSUME...that Universal Space/Time Dimensionality will exist or retain the same dimensionality that it has when Galactic Existence and position is in it's current state as opposed to when Dark Energy accelerates it so great in distance from both the point of origin as well as the distance from other Galaxies.

 

Split Infinity

[Delta1212]

It is logical to assume that for every WHITE HOLE...AKA...The Big Bang...there will be a Black Hole associated to it.

What?

[Iggy]

What?

 

A white hole model that fits cosmological observations would have to be the time reverse of a star collapsing to form a black hole. To a good approximation, we could ignore pressure and treat it like a spherical cloud of dust with no internal forces other than gravity. Stellar collapse has been intensively studied since the seminal work of Snyder and Oppenheimer in 1939 and this simple case is well understood. It is possible to construct an exact model of stellar collapse in the absence of pressure by gluing together any FRW solution inside the spherical star and a Schwarzschild solution outside. Spacetime within the star remains homogeneous and isotropic during the collapse.

 

It follows that the time reversal of this model for a collapsing sphere of dust is indistinguishable from the FRW models if the dust sphere is larger than the observable universe. In other words, we cannot rule out the possibility that the universe is a very large white hole. Only by waiting many billions of years until the edge of the sphere comes into view could we know.

 

Is the big bang a black hole? -- Physics FAQ

 

That faq was written in '97 before the discovery of the acceleration of expansion

[liver]

Could you learned folks please express yourself, if you care, on this idea? post 708 made reference to the model of the universe as a spherical object and on post 50 wqs posited the thought that the void outside the universe would "repel" matter on an escape track.

using these simple analogies, my questions are:

 

1)The ratio between the diameter and the circumference of a circle, disk/sphere,- d x 3.14= c - is linear. so would not the modest expansion, stretching of the universe/space "outer border/edge," by a mere 6 meters give enough added interior room everywhere to stick the arm out of the imaginary universe without having to go into the "void"? what does that show for the rate of expansion versus size/time elapsing?

 

2) since all entities including the universe have zero gravity at the center. and Maximum Gravity is at the surface (not just outside the surface), would it not be the repelling by the void (post50), but the gravity of all the matter this side of the void make for a strongly defined edge? then;

if it can be imagined that every point is at the edge of the universe, would not any motion in space generate the centrifugal force that counteracts gravity and maintains the ever slowing expansion that 2r x 3.14--= c suggests? if we consider r the direction of movement through the 4st dimension? would not such centrifugal force diminish as the universe got "flatter" and "flatter" (flattering thought)?

simple questions from a simple mind

[SomethingToPonder]

I remember thinking this when i was a kid, When does space end, Or where does it end? I mean surely there has to be something else, Somewhere. It cant just go on forever and be infinite, It dosen't make sense to me. Of course you would drift in and out of atmospheres and into different galaxies. Do you think it's possible we are some kind of bacteria and eventually you would get to a point in space if you just kept going straight where we were in another world, almost like We are so miniscule, And we are imagining things on too large a scale. Hard to explain but i hope you get my point.

it is probably a question we will be unable to answer for thousands of years, if that..

[EWyatt]

I wish, for once, with an authoritative source, someone would define the difference between "space" and our "universe." To me, most bloggers seem to think that our universe is the volume of "space." They say that "space expanded" after the Big Bang..... etc, etc. Oh yeah, where did it expand into? More "space?" Until we humans determine, or define, what "space" really means, we're just all spinning our wheels.

[Delta1212]

Why would it need to expand into anything? It doesn't grow "at the edges" so to speak. It's expanding at every point. The total distance between any two points increases, but space isn't filling up some kind of space container as it expands.

[yaboybillnye]

I have my own theory where space does not have an ending or a beginning and it would be infinite. This has to do with a kind of bagel or donut theory where the universe expands in a circle until it loops around upon itself and where light photons bend around the circular universe creating a 3D projection of the universe we think we know however time actually lapses on itself and matter is held within this "donut" by the vacuum of space. what is outside of this donut I have no idea perhaps a vast matter less vacuum of inter-universal space.(not proven just another theory!!)

[hypervalent_iodine]

I have my own theory where space does not have an ending or a beginning and it would be infinite. This has to do with a kind of bagel or donut theory where the universe expands in a circle until it loops around upon itself and where light photons bend around the circular universe creating a 3D projection of the universe we think we know however time actually lapses on itself and matter is held within this "donut" by the vacuum of space. what is outside of this donut I have no idea perhaps a vast matter less vacuum of inter-universal space.(not proven just another theory!!)

 

 

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Moderator Note

Please keep your own speculations out of other threads. If you wish to discuss it, you are welcome to do so in your own thread in the Speculations forum.

[petrushka.googol]

My personal opinion is that is very difficult to hypothesize where exactly space "ends".

If you look at it differently it is very difficult to hypothesize where exactly space "begins".

You are considering a frame of reference familiar to yourself (from a vantage point) which is not absolute.

Is there mass at the extremities of the universe? We consider yes.

Time is a vital component of the space time continuum and there is no evidence to suggest that the "ticking" of time did not start before the "big bang".

if that is the case, the time component of space time projected itself beyond the corresponding limits of physical dimensions.

Where then does space-time "end"?

This is matter of debate.

[Airbrush]

Time is a vital component of the space time continuum and there is no evidence to suggest that the "ticking" of time did not start before the "big bang".

if that is the case, the time component of space time projected itself beyond the corresponding limits of physical dimensions.

Where then does space-time "end"?

This is matter of debate.

 

There is no debate about when space-time ends. Either it ends in a bang or a whimper, either expansion stops and reverses (very unlikely from what we see) or it continues expanding until all the black holes and black dwarf stars evaporate, or when a big rip occurs. When there is no way of detecting any change to the universe, then OUR space-time ends. There could have been OTHER space-times before ours appeared about 13.7 Billion years ago or other space-times beyond our visual horizon.

Edited October 22, 2013 by Airbrush

[ed2992]

Well since space has no mass or dimensions its a non question because we are asking a question about something that isn't there. Like the area we occupy at any giving time was always there and will always be there like the gap between your fingers etc. So I think space never starts or finishes because we are talking about nothingness absolute zero well that's my simplistic approach to it sometimes I have other views.

[hoola]

I think space has an end, and that is based upon several ideas developed with an informational description of reality as a basis. If a finite quantity of information is responsible for creating and sustaining this finite universe, by simple logic, it should have some boundary limit. In more specific reasoning, space itself is a product of information, with the dark energy expressions held within the vessel of the dimensions, Even the dimensions themselves are built from this same well of information developed from within the original singularity. With only so much information to go around in a finite universe, there should be an end of space itself, with a "hair cut" boundary, of virtual particles, or dark energy at this edge. At the edge, virtual particles behave as near a black hole horizon, but instead of one partner falling into the hole, one partner crosses the boundary where there is no space. There is no space as the dimensions are not there to support physical reality, so they disappear forever from our universe. With the loss of the partner, the universe is evaporating all along it's outer boundary...so this is information loss that continues for the length of the universe's lifespan. But it does seem a minor loss, and shouldn't have any bearing on life expectancy of the universe...so what is "out there"? Nothing observable past an invisible line of demarcation of weak energy flux from the remaining virtual particle partner, hence, the hairy boundary..... beyond that boundary a true void. The boundary should be in continual expansion as the universe expands, as the boundary area increases, so does the energy loss, but in a smaller relation to the overall increase of informational content of the universe....and getting smaller as a proportion as the universe expands. The expansion is at the speed of light, so no going out there to throw a rock across the boundary to see it disappear...If there is any thing that could be considered "infinite" that is this void. This is in keeping with my "just say no to infinities" policy, even in regards to mathematics in our universe. That rule may not apply to a possibly infinite void....edd

[WebbMi11734]

If a universe can be infinitely small than space could most likely be infinitely large

[jaffamooooo]

Ever since I was a young boy, I have wrestled with trying to understand space. In particular, I have never really understood how space is supposed to never end. I really don't see how that's possible. Everything ends somewhere. Where one thing ends the next begins.

 

Can people please provide thoughts on this?

I recon like a bit of chalk on the floor you can keep on deviding it so space then must be like this where you can keep going and going

[mking67]

not if it folds into it's self

it is not space and time. it is space time there is really no time.. there is only eternity. all things are happening at once the past present and future.

[TJ McCaustland]

Space is quite indeed infinite, just as time is, one point of evidence it that if you take a piece of tracing paper put dots on it, and then take another piece of tracing paper and put dots in similar places but farther away to represent expansion, and you move one point over another point, that point becomes the center of reference, so in all reality if this is applied to the universe all points are the center, which is a clear statement of infinity.

 

 

 

 

 

 

Do Not think of time as a straight line, it is a wibbly wobbly ball of interconnecting strings that is infinite. The 12th Doctor (Dr. Who)

Edited October 10, 2014 by TJ McCaustland

[Strange]

Space is quite indeed infinite, just as time is, one point of evidence it that if you take a piece of tracing paper put dots on it, and then take another piece of tracing paper and put dots in similar places but farther away to represent expansion, and you move one point over another point, that point becomes the center of reference, so in all reality if this is applied to the universe all points are the center, which is a clear statement of infinity.

 

This does not imply that space is infinite. Instead of a sheet of paper, do the same thing on the surface of a sphere. As the surface expands all the dots move apart in the same way, but the surface is finite.

[TJ McCaustland]

That was what I was trying to convey but a sphere is much harder to work with IRL

[James Dixon]

I read the other day that a gigantic super black hole had been found and was roughly 3 billion times the mass of our sun, something that large is totally incomprehensible to the human brain and imagination and therefore I don't believe it.

[Strange]

I read the other day that a gigantic super black hole had been found and was roughly 3 billion times the mass of our sun, something that large is totally incomprehensible to the human brain and imagination and therefore I don't believe it.

 

You might want to consider whether you are really suited to a career in science ...

[Greg H.]

I read the other day that a gigantic super black hole had been found and was roughly 3 billion times the mass of our sun, something that large is totally incomprehensible to the human brain and imagination and therefore I don't believe it.

The milky way is about 500 billion times the mass of our sun - two orders of magnitude larger. Do you not believe in the milky way too?

 

What you believe is inconsequential - nature is not constrained by your beliefs.

[alexandraericks]

half a quark

actually, that's the point of a quark. there's no known way to divide a quark, since it's literally the smallest known (well, not actually known, just theorized) constituent of matter. however, we used to think that atoms were the smallest particles, so you might just be ahead of the times. stick to your truth, buddy. it might just be proven right someday

actually, the beautiful thing about the mysterious nature of the universe is that its edges might be the inside of a rubber ball sitting on a child's desk. or they might not exist, or they might still be becoming. it's also why trying to understand it could either be the most beautiful riddle or the most terrible truth