Where Does Space End? It Must End Somewhere!

[Sorcerer]

Actually the probability of a particle being in any one place is proportionate to its last measured location, this means that there still is an infintesimal chance of a particle being an infinite distance away, meaning the universe would be infinite. However this needs to somehow be resolved with relativity, since things cannot travel faster than the speed of light we can draw a radius of probability which expands at the speed of light as time progresses. Thus, unless space itself has expanded faster than the speed of light (which it has, so it kinda throws this out the window), all matter/energy in the universe has a radius of probability of ~14 billion light years.

 

 

 

The universe is everything. If the universe ended and something else began then the original thing you called the universe wouldn't truly be the universe.

 

LOL bump from 5 years ago

[RyanJ]

there is a theory that we are likely connected to loads of othere universes and even multiverses but our universe only contains life because that our universe was just cool enough to support life and in millions even billions and trillions of years time our universe will be to cold...[sNIP]

 

You refer to the multiverse theory, it is fair to warn you that it hasn't been proven at the time of writing. There are some ideas about how it could be shown to be correct but none have yet been tested as I recall.

 

You make one fatal assumption in your post however - you assume that we can define exactly what life is and what limits it can endure. Neither are true. In face every time we try to set a limit on what we believe life can endure, we usually find an extremophile that can live there.

 

As to the original question of this thread - it doesn't necessarily have to end somewhere... not even if the universe were finite in volume!

[purintjp]

The Big Bang is AFAIK not thought to be the beginning of the Universe, and we already have mathematical models, although still in early stages and very speculative, that reaches back in time beyond the ignition of BB event.

 

"The Big Bang is the cosmological model of the initial conditions and subsequent development of the Universe that is supported by the most comprehensive and accurate explanations from current scientific evidence and observation."

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

 

"One of the main problems with the Big Bang theory is that at the moment of the Big Bang, there is a singularity of zero volume and infinite energy. This is normally interpreted as the end of the physics as we know it; in this case, of the theory of general relativity. This is why one expects quantum effects to become important and avoid the singularity.

 

However, research in loop quantum cosmology purported to show that a previously existing universe collapsed, not to the point of singularity, but to a point before that where the quantum effects of gravity become so strongly repulsive that the universe rebounds back out, forming a new branch. Throughout this collapse and bounce, the evolution is unitary."

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

 

I was thinking about this and I was wondering if it were

possible that the universe were cyclic and that it had

collapsed to the point that BBT theorists posit had

occured around 380,000 LYrs just before light is able to

escape and then big-banged into existance. I don't have

the math experience to calculate what the density would

have been at that point but I would be curious if anybody

has ever calculated that based on what the believed

density is today at 13.7 BLYrs to see if it might make

sense. (Assuming a spherical universe).

I wonder if there would be any correlation to

the density required to create a black hole and the

calculated pre-BB density. It is interesting that at those

points light could escape neither of those. Maybe all the

basic building blocks of matter have always been here

and were not created by the expansion of a point singularity

as a big bang from nothing.

[Spyman]

I was thinking about this and I was wondering if it were

possible that the universe were cyclic and that it had

collapsed to the point that BBT theorists posit had

occured...

Well, if the Big Bounce turns out to be correct then we know that at least there was one excisting universe before ours and that it did collapsed before our Big Bang occured. But all knowledge, information and observation we have today indicates that our universe will continue to expand forever and eventually cause a Big Freeze.

(Although we still don't fully understand Dark Matter nor Dark Energy so the universe might still cough up a few surprises for us.)

 

... I don't have

the math experience to calculate what the density would

have been at that point but I would be curious if anybody

has ever calculated that based on what the believed

density is today at 13.7 BLYrs to see if it might make

sense...

Loop Quantum Gravity has models where they calculate the density of the universe as it goes through an collapse, to then "bounce" into a big bang and finally ends up with the universe we have today.

 

...I wonder if there would be any correlation to

the density required to create a black hole and the

calculated pre-BB density...

If the LQG models with repulsive gravity close to the point of a singularity is correct, then that state should excist inside a black hole too.

 

 

Some other parts of your post confuses me a little, so I want to clarify a few things:

- The Universe is NOT thought to be a spherical thing in a big emptyness in the Big Bang model, the Big Bang was not like an explosion of matter in space, the Big Bang is about expansion of space, which never halted and is still going on.

- Light can never escape from the universe, the universe is by definition everything, wherever the light would go, would therefor also be included as a part of the universe.

- The universe was not holding back light like a black hole before the time of ~377,000 years, instead it was so dense that the light that was inside it, could not traverse through it. Think of it more lika a room so filled with smoke that you can't shine through it with a flashlight, after the recombination the smoke cleared up and the universe became transparent.

[purintjp]

Some other parts of your post confuses me a little, so I want to clarify a few things:

- The Universe is NOT thought to be a spherical thing in a big emptyness in the Big Bang model, the Big Bang was not like an explosion of matter in space, the Big Bang is about expansion of space, which never halted and is still going on.

- Light can never escape from the universe, the universe is by definition everything, wherever the light would go, would therefor also be included as a part of the universe.

- The universe was not holding back light like a black hole before the time of ~377,000 years, instead it was so dense that the light that was inside it, could not traverse through it. Think of it more lika a room so filled with smoke that you can't shine through it with a flashlight, after the recombination the smoke cleared up and the universe became transparent.

 

I was only positing a spherical model for ease of calculation.

Without some sort of explosive impetus why would space expand ?

I wasn't referring to light escaping the universe, I was referring to the

release of light from the singularity into space as it began to expand.

 

As far as light being held back by dense matter, it would seem to me if

I were able to stand outside that singularity I would be able to see

something that hot and dense unless it had black hole charactistics.

Is that what you are claiming ?

 

If not;

What about light at the extreme edge of this singularity, what would be

holding it back ?

 

I'm assuming that the universe never got smaller than 377,000 LYrs.

[Airbrush]

"...What about light at the extreme edge of this singularity, what would be

holding it back ?"

 

Because of cosmic inflation, maybe there is no extreme "edge". Or that is long gone, beyond our visual horizon. This kind of stuff is very strange and hard to imagine.

[Zolar V]

wow this is an interesting concept, honestly iv never really thought about it. that is that space is finite or that there may be multiple BB's.

in my opinion if there were multiple bb's then there would have to be some sort of new governing force behind all of the forces inside a bb and after the event.

but what of time? if there were multiple bb's then is it possible that instead of spacetime there could be a seperate entity that is similar to time but is unbound by the forces inside a bb?

what about outside of a bb? what types of "matter" are outside of a bb? would there be a nothingness outside of the singularity or would it be similar to a universe with lots of matter, antimatter, Electromagnetic waves, and forces yet unknown?

 

 

as for finite space, i always thought of it as a sphere except inverted where instead of the defined Edge on the outer side of the sphere. you would have some point in the center that is an edge of some sort.

 

ma bad.. wrong account to post with

[Spyman]

I was only positing a spherical model for ease of calculation.

Without some sort of explosive impetus why would space expand ?

I wasn't referring to light escaping the universe, I was referring to the

release of light from the singularity into space as it began to expand.

You don't seem to understand the Big Bang theory, the Universe was not thought to be a singularity surrounded with space that suddenly exploded. The BB theory has developed a lot since the "hypothesis of the primeval atom" that, at least in my very old physic book from ground school, claims that universe started out as a very dense clump of matter that exploded. Today General Relativity is used in how spacetime behaves and cosmological models.

 

"FLRW metric

General relativity describes spacetime by a metric, which determines the distances that separate nearby points. The points, which can be galaxies, stars, or other objects, themselves are specified using a coordinate chart or "grid" that is laid down over all spacetime. The cosmological principle implies that the metric should be homogeneous and isotropic on large scales, which uniquely singles out the Friedmann–Lemaître–Robertson–Walker metric (FLRW metric). This metric contains a scale factor, which describes how the size of the Universe changes with time. This enables a convenient choice of a coordinate system to be made, called comoving coordinates. In this coordinate system, the grid expands along with the Universe, and objects that are moving only due to the expansion of the Universe remain at fixed points on the grid. While their coordinate distance (comoving distance) remains constant, the physical distance between two such comoving points expands proportionally with the scale factor of the Universe.

 

The Big Bang is not an explosion of matter moving outward to fill an empty universe. Instead, space itself expands with time everywhere and increases the physical distance between two comoving points. Because the FLRW metric assumes a uniform distribution of mass and energy, it applies to our Universe only on large scales—local concentrations of matter such as our galaxy are gravitationally bound and as such do not experience the large-scale expansion of space."

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

 

<Snip>Is that what you are claiming ?<Snip>

I tried to explain why light couldn't travel INSIDE the Universe before the time of ~377,000 years, since I thought you where confused about the Recombination era, which coincides with the year of 380 000 you spoke about.

 

"Recombination: ca 377,000 years

WMAP data shows the microwave background radiation variations throughout the Universe from our perspective, though the actual variations are much smoother than the diagram suggestsHydrogen and helium atoms begin to form and the density of the universe falls. This is thought to have occurred about 377,000 years after the Big Bang. Hydrogen and helium are at the beginning ionized, i. e., no electrons are bounded to the nuclei, which are therefore electrically charged (+1 and +2 respectively). As the universe cools down, the electrons get captured by the ions, making them neutral. This process is relatively fast (actually faster for the helium than for the hydrogen) and is known as recombination. At the end of recombination, most of the atoms in the universe are neutral, therefore the photons can now travel freely: the universe has become transparent. The photons emitted right after the recombination can now travel undisturbed and are those that we see in the cosmic microwave background (CMB) radiation. Therefore the CMB is a picture of the universe at the end of this epoch.

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

 

As far as light being held back by dense matter, it would seem to me if

I were able to stand outside that singularity I would be able to see

something that hot and dense unless it had black hole charactistics.

<Snip>

If not;

What about light at the extreme edge of this singularity, what would be

holding it back ?

As have been stated and explained in this thread several times, the Universe or spacetime has no edge, if we go back in time to very early stages, the Universe was very dense and compact but it was not a singularity and it had no edge nor outside.

 

"As used by cosmologists, the term Big Bang generally refers to the idea that the Universe has expanded from a primordial hot and dense initial condition at some finite time in the past (currently estimated to have been approximately 13.7 billion years ago), and continues to expand to this day."

 

"Without any evidence associated with the earliest instant of the expansion, the Big Bang theory cannot and does not provide any explanation for such an initial condition; rather, it describes and explains the general evolution of the Universe since that instant."

 

"Extrapolation of the expansion of the Universe backwards in time using general relativity yields an infinite density and temperature at a finite time in the past. This singularity signals the breakdown of general relativity. How closely we can extrapolate towards the singularity is debated—certainly not earlier than the Planck epoch."

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

 

I'm assuming that the universe never got smaller than 377,000 LYrs.

You are free to assume whatever you want, but that is not what mainstream scientists or what the Big Bang theory assumes.

Edited November 6, 2009 by Spyman
Spelling

[laluskiie]

The more i hear about space, the more it confuses me.

My fiance' explained it to me as filling a balloon with air and having it continuously expand.

My question was, where is it expanding to. I know its huge and there are billions of galaxies, but it has to end somewhere... or does it? If it is expanding, where to? and what is in that area before the universe? I am truly confused....

[Martin]

Laluskiie,

Think about the balloon surface example. It is a toy 2D version. The real 3D picture is analogous but harder to imagine.

 

Think about all existence concentrated on that 2D sphere surface. Only 2D creatures can live there. Flat amoebas with no thickness sliding around in the 2D surface.

 

No rubber. The balloon does not exist, only it's surface. No inside space, no air inside. No outside space, no room for the balloon to sit in. Only the pure 2D surface, and all existence is concentrated in that surface. flat galaxies, flat stars, flat planets flat amoeba people. Nobody can point in any direction that is not in the 2D surface.

 

Google "wright balloon model" and get the animation and watch it a few times.

Concentrate on thinking that no surrounding space exists, the only space is the pure 2D surface. You will see galaxies getting farther apart and the ittle wiggly things are photons of light going from one galaxy to another.

 

We can study geometry internally. We can learn the shape of space without there being an outside. To discover the curvature of space all you have to do is measure the angles of various size triangles. If they add up to more than 180 degrees then it's curved. The 2D people on the 2D sphere can do that too.

 

We know our 3D space is curved but we don't know that there is any space outside it. We know distances between clusters of galaxies are increasing but we don't know that there is any "outside" space to expand into. doesn't need to be. To keep things as honest and as simple as possible we have to not make up unnecessary baggage. We assume no outside. Most cosmologists don't anyway. A few fantasize about higher dimensional surroundings and stuff like that, but it's not useful. doesn't help model the U or fit the data.

[michael nelson]

we are only aware of what we can see-just as a fish in a bowl can see out and see what it see's-in his room his fish bowl is in-perhaps at some point out there something differant is going on but we cannot see that far-so we can only guess alot as the fish in the bowl could only guess within its limited scope only from what it could see-same is with us-and how much can we know?,our brains are not unlimited-our abilities to understand are limited-and so it is- we are limited we are not but what we are-wish for the rest-Mike

[Sayonara]

we are only aware of what we can see-just as a fish in a bowl can see out and see what it see's-in his room his fish bowl is in-perhaps at some point out there something differant is going on but we cannot see that far-so we can only guess alot as the fish in the bowl could only guess within its limited scope only from what it could see-same is with us-and how much can we know?,our brains are not unlimited-our abilities to understand are limited-and so it is- we are limited we are not but what we are-wish for the rest-Mike

 

Well no, because the fish can't devise ways to experimentally demonstrate things that it suspects but cannot see.

[williamthegreat]

It depends on our understanding of space - what is space? Something must be outside of our view of space, whether it just be more space, or something altogether different we cannot yet observe

[crownedconquern]

Space ends where it begins...."Common Sense":doh:

[Akhenaten2]

Unfortunately, cosmologists are about as divided as everyone else on this subject. You have 2 choices - If you believe our universe started from nothing then it is still finite with nothing outside. If you believe there must have been something in which it could start then logically this must have been an infinitely large space in which our universe is a tiny bubble. Almost certainly not the only one.

[StrontiDog]

[Pip Threlfall]

It seems to me that if we are to have a meaningful discussion on "Where does space end? It must end somewhere!" it is necessary to first define what space is. I would be interested in hearing others definition of space.

[toastywombel]

It seems to me that if we are to have a meaningful discussion on "Where does space end? It must end somewhere!" it is necessary to first define what space is. I would be interested in hearing others definition of space.

 

Space in physics can be referred to as the fabric of our universe.

 

 

More appropriately it can even be referred to as Spacetime.

 

In physics, spacetime (or space–time; or space/time) is any mathematical model that combines space and time into a single continuum. Spacetime is usually interpreted with space being three-dimensional and time playing the role of a fourth dimension that is of a different sort from the spatial dimensions.

 

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

[Airbrush]

It seems to me that if we are to have a meaningful discussion on "Where does space end? It must end somewhere!" it is necessary to first define what space is. I would be interested in hearing others definition of space.

 

"Space" is not what we are familiar with. We only know about space-time. Without the time dimension, there is only eternal space, far beyond the confines of a local Big Bang. Suppose Big Bangs are localized events separated by unfathomable distances, like a Googleplex light years between Big Bangs.

[toastywombel]

"Space" is not what we are familiar with. We only know about space-time. Without the time dimension, there is only eternal space, far beyond the confines of a local Big Bang. Suppose Big Bangs are localized events separated by unfathomable distances, like a Googleplex light years between Big Bangs.

 

Space expanded with the Big Bang, it was not there before the big bang.

[Pip Threlfall]

It seems to me that there are two types of space. What I would call real space and imaginary space. For ‘real’ space to exist it needs dimension points, and is therefore finite. ‘Imaginary’ space does not need dimension points so it can be as vast as the mind that is conceiving it.

 

When we look up to the stars we are aware of real space because the stars define it. Once we think there must be something beyond the stars we have changed from real space to imaginary space.

 

The same thing is happening with time. There is real time, which is the moment of now, and all other time is in the mind, both past and future.

 

Space-time I don’t understand, but from the diagram it would appear to involve gravity, which I understand cannot exist without mass, which has a direct relationship to energy. These four, matter, energy, space and time, are the basic building blocks of the physical universe, so perhaps what appears to be the physical universe isn’t actually true.

[Airbrush]

Space expanded with the Big Bang, it was not there before the big bang.

 

Space-time expanded with the Big Bang. "Space" was the pre-existing condition before the BB. Time depends upon matter to exist. Before time, before matter, there was only space, not space-time.

[Spyman]

"Scientists have come to some agreement on descriptions of events that happened 10⁻³⁵ seconds after the Big Bang, but generally agree that descriptions about what happened before one Planck time (5 × 10⁻⁴⁴ seconds) after the Big Bang will likely remain pure speculation."

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

(Mine emphasis)

[Pip Threlfall]

For space to exist there needs to be dimension point and a viewpoint to view the dimension points. If no matter existed before the big bang then no space could have existed. “Space” before the big bang was not space but nothing.

 

So I am ok for there to have been nothing before the big bang, but there would have had to be awareness of awareness preceding the big bang, to be aware of the nothing. That that is aware of nothing is a NO-THING. It is the concept of NO-THING that is missing in the big bang theory. See http://www.buddhanet.net/bt_52.htm

[StringJunky]

For space to exist there needs to be dimension point and a viewpoint to view the dimension points. If no matter existed before the big bang then no space could have existed. “Space” before the big bang was not space but nothing.

 

So I am ok for there to have been nothing before the big bang, but there would have had to be awareness of awareness preceding the big bang, to be aware of the nothing. That that is aware of nothing is a NO-THING. It is the concept of NO-THING that is missing in the big bang theory. See http://www.buddhanet.net/bt_52.htm

 

In the beginning there was nothing....then it exploded.

 

There must have been preconditions that initiated the BB but are not known as yet. It's best to leave its initial state as 'unknown' until scientists have some evidence or tangible clues I think.