# Thread: Ok, here is PROOF that the universe IS finite!

1. Here is MY proof that the universe is in fact NOT infinite BUT finite.

Now, space (and time, although time is not necessary for my proof) starts with a tiny dot and it expands. So, even if the universe is expanding at the C, still there has to be an edge, because the big bang happened 14 Billion years ago. So, the SIZE of the universe is at maximum, is a bubble whose diameter is 14 * 2 billion = 28 billion light years.

Universe has to have an edge (and hence finite) because it started with a finite space (a dot, a very small thing). Since the universe started with a finite space, or something small (not infinite), it HAS to have a finite space even now, even if the edge of the universe is expanding at C.

Sure, we won't be able to travel to the edge of the universe cos we cannot travel faster than C, BUT, hypothetically, suppose we built a warp-drive type ship that can travel very much faster than C, we should be able to reach the end of the universe in finite time.

Am a genius or am I missing something very big here???

2.

3. The Universe expanded not into empty space at the speed of light, but it expanded itself. One cannot just look at the Universe as something moving away from a point at a certain speed. It's not that simple. Like finding "the center of the Universe" is also not that simple.

You should search up the simple "surface of a balloon" explanation and see if that will help you grasp it.

4. Now, space (and time, although time is not necessary for my proof) starts with a tiny dot and it expands. So, even if the universe is expanding at the C, still there has to be an edge
The universe does not have an edge according to GR. It can't have an edge, because what can be on the other side of the edge, but more space? Think of the surface (only the surface!) of an expanding balloon. It has no edge and no centre, yet can be imagined to expand from a small point to any size.

Since the universe started with a finite space, or something small (not infinite), it HAS to have a finite space even now, even if the edge of the universe is expanding at C.
That does make the most intuitive sense and is indeed the most favoured current idea, i.e. that the universe is finite, but it is not required to be so. If the universe is infinite, then it was infinite in space the moment of the bang, or it might be a finite bubble in an infinite expanse. We just can't give any definitive answers right now.

Sure, we won't be able to travel to the edge of the universe cos we cannot travel faster than C, BUT, hypothetically, suppose we built a warp-drive type ship that can travel very much faster than C, we should be able to reach the end of the universe in finite time.
If you could travel at warp speed (and we were in a spherical universe), you would simply eventually end up back where you started, having never reached an edge, just like if you went on a journey on the earth.

Am a genius or
Realistically, your idea was wrong in one way and very basic in another. No offence.

5. Originally Posted by rohandesilva
Now, space (and time, although time is not necessary for my proof) starts with a tiny dot and it expands. So, even if the universe is expanding at the C, still there has to be an edge, because the big bang happened 14 Billion years ago.
1. We don't know what geometrical & topological structure the universe had in its earliest stages; there is no requirement for it to have been a "dot", in fact it is exceedingly unlikely if one considers quantum effects
2. There does not need to be an edge simply because the universe expanded from a point outwards, and is finite. The surface of an expanding baloon is also finite, but does not have an edge.

Universe has to have an edge (and hence finite) because it started with a finite space (a dot, a very small thing).
No, this is a logical fallacy. There is no requirement for an edge ( boundary ) to exist, see above.

Since the universe started with a finite space, or something small (not infinite), it HAS to have a finite space even now, even if the edge of the universe is expanding at C.
1. We don't know whether the universe started as a finite space or not
2. Even if it did start as a finite space, there is no requirement for this still to be the case - it could have started off with spherical geometry, and then opened up ( like a flower ) to a flat manifold, and is thus now infinite.

Sure, we won't be able to travel to the edge of the universe cos we cannot travel faster than C, BUT, hypothetically, suppose we built a warp-drive type ship that can travel very much faster than C, we should be able to reach the end of the universe in finite time.
Like I said, it is highly unlikely for any boundary to exist in the universe.

6. You are correct in a sense, that the universe is finite, why?

Because the universe is expanding, take infinity and try expanding it what do you get? Infinity, it's still the same size.
However that said, what the universe is expanding into 'may' be infinite. But that is impossible to measure infinity thus anything physical, i.e with dimensions cannot be infinite.

7. Originally Posted by Chrisgorlitz
But that is impossible to measure infinity thus anything physical, i.e with dimensions cannot be infinite.
Are you sure ? Look at my avatar - it is called a Menger Cube. It is a geometrical construct with infinite surface area enclosing zero volume, but well defined external measurements.

Besides, space-time is not "physical" in the usual sense.

8. Well Markus, I was sure until your post, though I freely accept you are a great deal more knowlegdeable in such matters I'm having a really hard time getting my head round the concept. This is why, for the way I understand it in order to be able to measure something you need to be able to have something to measure it against and with inifinity no matter what you measure it against it always comes out the same. This would also be true for any part of infinity.

So if your Menger Cube does indeed have infinite surface area and could exist what is to stop me from having two or three menger cubes, which whould logically then have two or three times the surface area?

9. Originally Posted by Chrisgorlitz
So if your Menger Cube does indeed have infinite surface area and could exist what is to stop me from having two or three menger cubes, which whould logically then have two or three times the surface area?
Ha ha, you found the crux of the matter...can it exist in real space ?? The great beauty of the Menger cube is that whether or not it can exist depends on the structure of space-time itself...if space-time is continuous and smooth ( i.e. can be subdivided ad infinitum ), then yes, my avatar can exist ( even though there is no conceivable way to actually construct such a thing ). If space-time on its most fundamental level is discreet, then the Menger Cube is a physical impossibility.
Right at this moment no one really knows the answer - which is why I chose this as my avatar

10. Ok well since I don't understand that, well I'll state again for the benefit of others that I have faith in the fact you know what you are talking about, and remain unconvinced personally due 'only' to the fact I don't understand it.

11. As far as I understand it, it is perfectly logical for an infinity to exist that has local structure. Consider an infinity of 1's vs an infinity of 9's or an infinite succession of random numbers. Or an infinite line with loops and twists along the way. Similarly, our universe could be infinite, yet at the same time have local curvature, energy concentrations, etc.

12. Originally Posted by KALSTER
As far as I understand it, it is perfectly logical for an infinity to exist that has local structure. Consider an infinity of 1's vs an infinity of 9's or an infinite succession of random numbers. Or an infinite line with loops and twists along the way. Similarly, our universe could be infinite, yet at the same time have local curvature, energy concentrations, etc.
Infinity couldn't have loops that related to us as we exist in three dimensions, it could theorectically have extra dimension appendages such as loops and remain infinite in our spacial dimensions but we wouldn't notice.

It is only this level of at a least three dimensional infinity that could dictate our universe though I still believe this to be impossible. The only way you could expand a 3 dimensional infinity is into other dimension, and yet our universe is expanding, expanding in our 3 spacial dimensions, so I don't think it can be infinite.

13. The 1D analogy of loops and twists can be expanded to 3 physical dimensions. I just don't understand your objection to what we see around us possibly existing into infinity, that the visible universe threshold might simply be due to the recession speed exceeding C.

The only way you could expand a 3 dimensional infinity is into other dimension, and yet our universe is expanding, expanding in our 3 spacial dimensions, so I don't think it can be infinite.
Are you familiar with the balloon analogy to illustrate curvature? If not, have a look HERE. Now imagine the balloon not expanding, except for a bubble forming at a weak spot. There you have a local expansion with the total universe not expanding. The same can be envisioned with a bubble forming on a balloon of infinite size (which works out to having zero total curvature mathematically, if I am not mistaken).

14. Thank for the link Kal, it is quite interesting and a good example, you could just draw your coordinates on the balloon imagine they're points in space and watch as they all expand away from each other at the same rate.

As for the twists and loops I'm obviously missing something, my logic was something like this in order for space to be infinite in 3D it has to be like a cube and extend to infinity equally across all 3 dimensions. The reason I'm thinking this is infinity is always equal to infinity so the length of each dimension has to remain the same. Now if you take a cube an place any other shape inside it, other than a cube, there will be bits of that shape that don't reach the edge of cube, since we're talking infinity here the cube will always be expanded to the same rate as any other shape. Thus any other shape could not be infinite in all 3 dimensions.

15. Hi, this is interesting stuff, most of which I cannot fathom.

My biggest problem is this. I can understand the balloon surface example. Problem is, you will never find an edge if you were in a balloon surface only if you had only 2 dimensions. But we have 3 dimensions. We can go up, side and down.

Here is my idea of the universe, I created just now.

Because, according to the big bang, say after 1 second, the universe had to be a 3d sphere, right???

Why do you say that you cannot "One cannot just look at the Universe as something moving away from a point at a certain speed. " when Wikipedia says that after few minutes helium nuclear formed. So at that time, shouldn't the universe be a huge 3D sphere.

Say we take a spaceship and travel straight. Then how can we come to the same place. The earth scenario I understand. But again, arn't you assuming that the there are only 2 dimensions. If we take a rocket then we can go out of the earth and we will go past the edge of the earth and move to space.

Are you saying that there is a THING called space-time??? Is space-time curved mean actually like a curve (steering wheel in a car) like??

My biggest problem is that to me, since we live in a 3d world, I always visualize this as a 3D sphere. But, how else can we visualize it.

How can we say that the universe is like the surface of a balloon when clearly we can move in 3d space and and feel it.

So, if the universe is like the surface of a balloon, where are the galaxies??? On the surface??? But then that is 2D scenario?? Moment you add the extra 3rd dimension you can move any way you want.

Also, I have read that we really don't know what happened during the Planck epoch, where current science cannot describe the universe.

BUT, we do know what happened after few minutes of the big bang. So, can't we tell the shape of the universe after few minutes or few days after the big bang. Isn't it natural to think the universe as a big 3d Sphere???

Ok, we don't know what is beyond the sphere. But we don't have to assume it is more space. It could be something else. So, can there be a edge as the edge of the 3d sphere, to the universe. Beyond the edge we don't know what is there, just like we don't know what happened during the singularity. Why can't we assume this???

Why do we have to assume that there is more space beyond the edge?? Why can't we assume that there is actually something else which we do not know??

Markus, how can you say that "We don't know whether the universe started as a finite space or not"??? After few minutes of the big bang, after inflation, shouldn't the universe be like a giant 3d sphere??

Also Markus, how can something FINITE, turn to INFINITY in FINITE TIME???? Is it pure speculation?? Are there any evidence for this???

How can something started off with spherical geometry, and then opened up ( like a flower ) to a flat manifold, and is thus now infinite, when you need INFINITE TIME TO do this???

Your Menger sponge example also needs to do the construction process of the cube to infinite iterations, in order to get infinte surface area in zero volume??? So it's practically never possible, right???

16. no bubble - bubbles !

17. Originally Posted by Water Nosfim
no bubble - bubbles !
If no bubbles, then if you were asked to draw a 3D map of the universe with all the galaxies, what would you draw???

If you asked to create a 3D exhibit of the universe, you know, like a wireframe diagram, where you can see the inside also, what would you construct???

18. Because, according to the big bang, say after 1 second, the universe had to be a 3d sphere, right???
No, the universe is 4-dimensional, not 3D. It is possible that its "shape" could be spherical, but there is no requirement for it to be so. There are other possibilities, like a torus, or a hyperbola, all in 4 dimensions.

My biggest problem is that to me, since we live in a 3d world, I always visualize this as a 3D sphere. But, how else can we visualize it.
We live in a 4-dimensional world, therefore you cannot visualise it directly.

How can we say that the universe is like the surface of a balloon when clearly we can move in 3d space and and feel it
The baloon surface is only an analogue, not an accurate depiction of the universe.

BUT, we do know what happened after few minutes of the big bang. So, can't we tell the shape of the universe after few minutes or few days after the big bang. Isn't it natural to think the universe as a big 3d Sphere???
That is only one possibility. We know the possibilities, but we do not know which one is the correct one.

Ok, we don't know what is beyond the sphere.
The term "beyond" is meaningless in this context, because there is no boundary.

Markus, how can you say that "We don't know whether the universe started as a finite space or not"??? After few minutes of the big bang, after inflation, shouldn't the universe be like a giant 3d sphere??
Not necessarily, like I said, there are other possibilities, and there is also no requirement for it to have started as a finite space. I know that is hard to visualise, but the possibility nonetheless exists.

Also Markus, how can something FINITE, turn to INFINITY in FINITE TIME???? Is it pure speculation?? Are there any evidence for this???
There is no empirical evidence for or against any of these possibilities, except for the observational fact that our universe appears flat as far out as we can see.

How can something started off with spherical geometry, and then opened up ( like a flower ) to a flat manifold, and is thus now infinite, when you need INFINITE TIME TO do this???
Why do you assume this would take infinite time ? All physical process within space-time are of necessity restricted to the speed of light, however, space-time itself is not subject to that restriction, at least not as far as we can tell.

Your Menger sponge example also needs to do the construction process of the cube to infinite iterations, in order to get infinte surface area in zero volume??? So it's practically never possible, right???
If you mean practical as in "man-made", then no, definitely not. But in a natural process like the creation of a space-time manifold then we cannot exclude the possibilty. We know too little about the small-scale structure of space-time to be able to tell for sure.

19. Markus, thanks for your answers. What you mean when we say the universe is FLAT?? I have read quite a number of web-pages on this, but I still don't get it.

Does flat refer to 2D flat, or what????

Does flat means that all the galaxies are in one plane like in a giant table????

20. Originally Posted by rohandesilva
Markus, thanks for your answers. What you mean when we say the universe is FLAT?? I have read quite a number of web-pages on this, but I still don't get it.

Does flat refer to 2D flat, or what????

Does flat means that all the galaxies are in one plane like in a giant table????
Flat in this context means that there is no intrinsic curvature, in terms of geometry; this is quite difficult to explain in plain English - a sheet of paper is flat. A cylinder is also flat, because one can unroll it into a flat sheet. The surface of a sphere is not flat, because no amount of folding will ever turn it into a flat sheet.
More technically, in a flat space the sum of angles of any arbitrarily big triangle is always 180 degrees, not more and not less.

As for the universe, the same principle applies, but we are now in 4 dimensions, so this is no longer visualisable.

21.

22. Yup, that's the projection of a tesseract...very pretty

23. Originally Posted by Markus Hanke
Yup, that's the projection of a tesseract...very pretty
Would be prettier still if I could borrow some of your brain cells to to get my head around this 3 to 4D aspect!!!

24. Originally Posted by KALSTER
f not, have a look HERE. Now imagine the ba.
Great article. Thanks. Wow, I was MISSING a lot. Only now I am beginning to understand this. So, this big bang was NOT like a normal explosion of a bomb at all. It was an explosion of space. Awesome.

I just have one more question. If it is space that is expanding then, why aren't we expanding also, like an elastic???

Or expanding means, new space is created???

Of course this could be a real dumb question, but what is SPACE???? Do we have a proper definition of this??? I know for sure it does not mean a vacuum now?? It has to be a THING, right??? Do we KNOW what it is???

25. Originally Posted by Markus Hanke
Originally Posted by rohandesilva
Markus, thanks for your answers. What you mean when we say the universe is FLAT?? I have read quite a number of web-pages on this, but I still don't get it.

Does flat refer to 2D flat, or what????

Does flat means that all the galaxies are in one plane like in a giant table????
Flat in this context means that there is no intrinsic curvature, in terms of geometry; this is quite difficult to explain in plain English - a sheet of paper is flat. A cylinder is also flat, because one can unroll it into a flat sheet. The surface of a sphere is not flat, because no amount of folding will ever turn it into a flat sheet.
More technically, in a flat space the sum of angles of any arbitrarily big triangle is always 180 degrees, not more and not less.

As for the universe, the same principle applies, but we are now in 4 dimensions, so this is no longer visualisable.
Well, I understand little bit, but since I cannot visualize, I am stumped.

Is there SOME THING called SPACE-TIME??? Like you know, height, width etc. Or is time just one more dimension???
Do we KNOW what TIME is???

26. Originally Posted by rohandesilva
Originally Posted by KALSTER
f not, have a look HERE. Now imagine the ba.
Great article. Thanks. Wow, I was MISSING a lot. Only now I am beginning to understand this. So, this big bang was NOT like a normal explosion of a bomb at all. It was an explosion of space. Awesome.

I just have one more question. If it is space that is expanding then, why aren't we expanding also, like an elastic???

Or expanding means, new space is created???

Of course this could be a real dumb question, but what is SPACE???? Do we have a proper definition of this??? I know for sure it does not mean a vacuum now?? It has to be a THING, right??? Do we KNOW what it is???
Expansion happens everywhere, more or less. It does not happen where gravity dominates, like our solar system, galaxy, etc all the way to galactic superclusters, where expansion starts to have an effect.

Space, in terms of metric expansion, is simply the distance between two points, i.e. a "place'. Like the seventh side of a standard die does not exist, there is no "there" there to worry about "outside" of the universe. It is that presence of space that is expanding, which is different than things moving "through" space. With expansion there is simply more space with time.

27. I just have one more question. If it is space that is expanding then, why aren't we expanding also, like an elastic???
To put it very simply - because we are held together by gravity and the other fundamental forces. In other words - only empty space on large scales actually expands.

Or expanding means, new space is created???
Not really, it is more a case of existing space "stretching". Be careful here, because space-time is not like any material object.

It has to be a THING, right???
That depends how you define "thing". It is a not a material object or substance, but it does have certain properties, like curvature.

28. Is there SOME THING called SPACE-TIME??? Like you know, height, width etc. Or is time just one more dimension???
Yes, our universe is space-time, not just space. Time is just an additional dimension ( that is why our universe is 4-dimensional ); however, temporal and spatial dimensions behave a little differently mathematically, and are not interchangeable.

29. Just for the record, do we know for SURE that the universe is Infinite??? Or we don't KNOW about that??

I have been reading about Alan Guth who discovered inflation, but he also does not give a clear answer.

30. Originally Posted by rohandesilva
Just for the record, do we know for SURE that the universe is Infinite??? Or we don't KNOW about that??

I have been reading about Alan Guth who discovered inflation, but he also does not give a clear answer.
I think Kal answered that in post #3.

Originally Posted by KALSTER

That does make the most intuitive sense and is indeed the most favoured current idea, i.e. that the universe is finite, but it is not required to be so. If the universe is infinite, then it was infinite in space the moment of the bang, or it might be a finite bubble in an infinite expanse. We just can't give any definitive answers right now.

31. Originally Posted by rohandesilva
Just for the record, do we know for SURE that the universe is Infinite??? Or we don't KNOW about that??
We don't know, we only know which possibilities are there ( according to physics as we currently understand it ), but not which one correctly describes the universe.

32. have you learn M-Theory or Brane worlds? i think universe is infinite based on that theory

33. Originally Posted by saizokano
have you learn M-Theory or Brane worlds? i think universe is infinite based on that theory
I have heard of M Theory but I don't know that it is.

Is it a proven theory, like GR, or is it still just a hypothesis, like "String Theory".

Another question I like to ask is, why is it called "String Theory" when it is still not proved. Shouldn't it be called "String Hypothesis", since only proved hypothesis is called a theory?

34. To end this, space is unlimited, the universe is just a word we use to define all matter within the endless space. We are not going to continue spreading out into endless space however, as we are bound by gravity, read my Universal Inevitability post to understand the simple truth.

35. Originally Posted by Bud
To end this, space is unlimited, the universe is just a word we use to define all matter within the endless space. We are not going to continue spreading out into endless space however, as we are bound by gravity, read my Universal Inevitability post to understand the simple truth.
Surely the more the expansion takes place the less the effect of gravity to slow it dow or stop it, doesn't the effect of gravity get weaker at a proportional rate to increased distance?

36. Originally Posted by Chrisgorlitz
Surely the more the expansion takes place the less the effect of gravity to slow it dow or stop it, doesn't the effect of gravity get weaker at a proportional rate to increased distance?
Yes, gravity gets weaker with increasing distance. That's the same for all fundamental forces, with the exception of the strong force.

We are not going to continue spreading out into endless space
It's a distinct possibility that we are. Not pretty, but very much a possibility.

37. Originally Posted by rohandesilva
Originally Posted by saizokano
have you learn M-Theory or Brane worlds? i think universe is infinite based on that theory
I have heard of M Theory but I don't know that it is. Is it a proven theory, like GR, or is it still just a hypothesis, like "String Theory".Another question I like to ask is, why is it called "String Theory" when it is still not proved. Shouldn't it be called "String Hypothesis", since only proved hypothesis is called a theory?
theory and hypothesis is different Theory was supported by fact or proof even though its not always true Please forgive my bad english skills

38. Originally Posted by Bud
To end this, space is unlimited, the universe is just a word we use to define all matter within the endless space. We are not going to continue spreading out into endless space however, as we are bound by gravity, read my Universal Inevitability post to understand the simple truth.
If you can't even understand the basic principle of escape velocity, even after having it explained to you, there is no hope for you. Then concepts like curvature must be just way above your level of comprehension.

39. I am just curious. How do you guys know so much about these stuffs??? Are you professional physicists???
Or are you SW engineers, lawyers (highly unlikely), doctors etc who just happen to read physics books?

But, I have also tried reading physics books (like this one by Lawrence Krauss) but I just can't grasp most of it. Biggest problem is space, time things. I just can't understand something I cannot visualize in my brain. Is it normal to not understand something you cannot visualize or something I am lacking???

I also read this book by Lee Smolin. Lots of it was non-technical stuff which I understand. BUT, the technical stuff I just don't get it.

What is the easiest way to understand, visualize this space-time thing???

Cos to read any book on physics, u need to know that concept of space-time, like, I want to buy this one, but I am afraid I will spend about 50 USD for it and end up not understanding anything in it.

40. Originally Posted by Markus Hanke
Like I said, it is highly unlikely for any boundary to exist in the universe.
Well, on the case where matter behaves differently at certain parts of space. It is comprehensible that several regions in space can not be inhabited by matter. This would be a boundary to matter. At that point i can also see a point where molecules would cease, atoms, quarks, etc etc. Would be unable to keep their form, and even up to an area where only strings would exist... Or (if sting theory actually is bollux), you would end up with energy. An absolute boundary would be the point where all the energy in the universe would be required to propel a part of energy, or a string to a specific point in space. This would make it the absolute limit, and thus boundary..

I am just curious. How do you guys know so much about these stuffs??? Are you professional physicists???
Or are you SW engineers, lawyers (highly unlikely), doctors etc who just happen to read physics books?
My guess would be, most people here would be analists, retired scientists, physicists, or nerds who like to keep their basic knowledge up. And i say nerd in the most positive way possible .

But, I have also tried reading physics books (like this one by Lawrence Krauss) but I just can't grasp most of it. Biggest problem is space, time things. I just can't understand something I cannot visualize in my brain. Is it normal to not understand something you cannot visualize or something I am lacking???
I don't like reading myself.. But i usually come over articles that just spark my interest. Or parts on the physics section that just seems incredible.

What is the easiest way to understand, visualize this space-time thing???
My opinion, stay open to others, and whatever their arguments are. Think them over. If it seems logical, try to play with it a little, then test your knowledge against an actual professor, or doctor (in physics), and see if they can correct your. In a way philosophy and math got a baby, and it's physics :-)

Time is the rotation of atoms, electrons, the vibration of parts in the atom, time is the limitation of the universe, but time is not a constant. Space, is the distance between, and around things, space is not a constant value, and it is currently unknown what it is that is space, is it nothing, is it essential? we don't know..

Try to look around the equations, as they are to clarify, not to totally explain. Only if you understand a text, you could possibly understand the equation representing it. See them as summaries for advanced mathmaticians..

41. Originally Posted by Zwolver

Time is the rotation of atoms, electrons, the vibration of parts in the atom, time is the limitation of the universe, but time is not a constant. Space, is the distance between, and around things, space is not a constant value, and it is currently unknown what it is that is space, is it nothing, is it essential? we don't know..

Try to look around the equations, as they are to clarify, not to totally explain. Only if you understand a text, you could possibly understand the equation representing it. See them as summaries for advanced mathmaticians..
I don't understand. I don't need any rotating atoms to know that time is passing. So, how can you say time is rotation???

Why can't we think of time BEFORE the Big Bang??? Is it because there was NOTHING??

Is it wrong to think of time before the big bang?? I mean, has anybody proved that time does not exist before the big bang or is it just speculation???

42. Originally Posted by rohandesilva
I don't understand. I don't need any rotating atoms to know that time is passing. So, how can you say time is rotation???

Why can't we think of time BEFORE the Big Bang??? Is it because there was NOTHING??

Is it wrong to think of time before the big bang?? I mean, has anybody proved that time does not exist before the big bang or is it just speculation???
Well, time isn't rotation, but the speed of time is relative to the speed of an object compared to the speed of it's own motion, which is the rotation/vibration of particles inside the atom.

We can not say anything from before the big bang, because the big bang destroyed all the evidence. And on it's turn, the big bang itself planted an increddible amount of evidence of it's own existence.

Everything happened before the big bang is merely speculation, as no-one can prove that nothing happened before it.

43. Everything happened before the big bang is merely speculation, as no-one can prove that nothing happened before it.
The term "before the Big Bang" is meaningless; the situation here is one of geometry, and is analoguous to the question : What is north of the north pole ?

44. Originally Posted by rohandesilva
I am just curious. How do you guys know so much about these stuffs??? Are you professional physicists???
Or are you SW engineers, lawyers (highly unlikely), doctors etc who just happen to read physics books?

But, I have also tried reading physics books (like this one by Lawrence Krauss) but I just can't grasp most of it. Biggest problem is space, time things. I just can't understand something I cannot visualize in my brain. Is it normal to not understand something you cannot visualize or something I am lacking???

I also read this book by Lee Smolin. Lots of it was non-technical stuff which I understand. BUT, the technical stuff I just don't get it.

What is the easiest way to understand, visualize this space-time thing???

Cos to read any book on physics, u need to know that concept of space-time, like, I want to buy this one, but I am afraid I will spend about 50 USD for it and end up not understanding anything in it.
Guth's The Inflationary Universe is a very readable book, with a minimum of technical terms and math. I'd highly advise getting it.

45. Originally Posted by rohandesilva
Why can't we think of time BEFORE the Big Bang??? Is it because there was NOTHING??
There's nothing to prevent you from thinking about "before" the BB. However, science currently has no answers for you.

It's very important to keep in mind what cosmological theories are: They are a set of equations that describe the universe in a way that is consistent with observation. Now, we run these equations backward in time to infer what the past looked like and thus see how we got here. However we find that we can't go all the way back to t = 0 without going outside the regimes of validity for that set of equations. That means we can't get (continuously) to times less than zero. Science is therefore currently silent on the question you ask. That hasn't stopped speculation, but nothing testable has yet emerged. There's no guarantee that science will ever be able to offer an answer.

Another way of summarizing our state of affairs is that BB cosmology is a theory of evolution, not origin (no matter what popularized science documentaries often say). In that sense, it is really a close cousin of Darwin's theory of evolution. Both are silent on the question of beginnings.

Is it wrong to think of time before the big bang?? I mean, has anybody proved that time does not exist before the big bang or is it just speculation???
No proof of any kind currently exists, and is highly unlikely ever to (just as science cannot prove the non-existence of Santa Claus). Our models simply break down before we get to t = 0.

46. Originally Posted by tk421

It's very important to keep in mind what cosmological theories are: They are a set of equations that describe the universe in a way that is consistent with observation. Now, we run these equations backward in time to infer what the past looked like and thus see how we got here. However we find that we can't go all the way back to t = 0 without going outside the regimes of validity for that set of equations. That means we can't get (continuously) to times less than zero. Science is therefore currently silent on the question you ask. That hasn't stopped speculation, but nothing testable has yet emerged. There's no guarantee that science will ever be able to offer an answer.
And even those equations would break if we didn't arbitrarily change the expansion rate at certain points. Which implies that even what picture we have of that time is not a perfect extrapolation.

Deductive logic tells us that once all other possibilities have been ruled out, whatever possibility remains, however improbable it may be, must be the truth.

Inductive logic tells us to be skeptical of deductive logic whenever it throws that argument at us. I prefer inductive logic, so you can see where I stand on these issues.

Another way of summarizing our state of affairs is that BB cosmology is a theory of evolution, not origin (no matter what popularized science documentaries often say). In that sense, it is really a close cousin of Darwin's theory of evolution. Both are silent on the question of beginnings.
That's a good way of putting it. Whatever logical contortions it may undergo when applied to the past, it is incredibly successful when applied to the present.

47. Originally Posted by rohandesilva
Here is MY proof that the universe is in fact NOT infinite BUT finite.

Now, space (and time, although time is not necessary for my proof) starts with a tiny dot and it expands. So, even if the universe is expanding at the C, still there has to be an edge, because the big bang happened 14 Billion years ago. So, the SIZE of the universe is at maximum, is a bubble whose diameter is 14 * 2 billion = 28 billion light years.

Universe has to have an edge (and hence finite) because it started with a finite space (a dot, a very small thing). Since the universe started with a finite space, or something small (not infinite), it HAS to have a finite space even now, even if the edge of the universe is expanding at C.

Sure, we won't be able to travel to the edge of the universe cos we cannot travel faster than C, BUT, hypothetically, suppose we built a warp-drive type ship that can travel very much faster than C, we should be able to reach the end of the universe in finite time.

Am a genius or am I missing something very big here???
If you believe in the Big Bang model (BB) you need to be aware of the Inflation hypothesis. According to the present BB model the beginning universe expanded at many times the speed of light accordingly becoming of unknowable size before it finally slowed down. Not only is the size not accordingly known but neither is the universe's configuration. The prevailing BB idea is that the universe curves around upon itself having no center or edges. This is accordingly due to the mathematical geometry of the BB model which is General Relativity (GR). GR is based upon a non-linear type of geometry whereby parallel lines can eventually meet or diverge from each other which accordingly can create non-spherical configurations.

48. Originally Posted by Markus Hanke
The term "before the Big Bang" is meaningless; the situation here is one of geometry, and is analoguous to the question : What is north of the north pole ?
But, isn't it meaningful in a multi-verse scenario where our universe is only one of an infinite universes popping up and then dying and repeating the same cycle endlessly. In that scenario even time before the big bang and and edge to the universe, i.e. our universe, is also kind of meaningful???

What bout this Tegmark classification of a multiverse?? He has proved it they say.

49. But, isn't it meaningful in a multi-verse scenario where our universe is only one of an infinite universes popping up and then dying and repeating the same cycle endlessly.
No, it still is not meaningful. To stay with the example of the north pole - just because there are other planets in our solar system still does not mean that the question "what is north of the north pole" has any meaning. Likewise with the BB - even if we do live in a multiverse ( which cannot be ruled out ), the term "before the BB" is still without meaning.

50. Here is my understanding of the Beginning.
Before the BB there was no spatial dimenson of any kind and therefore no time. Thus the beginning was the Beginning (of this universe).

However, as per the cosmic constant of Cause and Effect, the causality was a zero state singularity of pure Potential (the Implicate) which expressed itself in a single mega quanum event, the BB (the Explicate) where everything happened all at once in the same place. An instant of total chaos.

IMO, this view is consistent with the current M theory which proposes that Nothing is not nothing, but an ocean of virtual strings, which each have a specific harmonic. As the sum total of these virtual harmonics cancels itself a zero state of nothingness exists. However this does not mean Nothingness is static (in perfect balance). On the contrary these harmonics are dynamic in nature and when some of these harmonics reinforce each other, virtual particles may be created.
The Official String Theory Web Site

IMO, when we visualize near infinite potential (dynamic harmonics) compressed into a singularity, it is not a large step to visualize a single mega quantum event, when this potential became expressed as physical reality.
I suggest reading David Bohm's papers on the Implicate and the Explicate.
Implicate and explicate order according to David Bohm - Wikipedia, the free encyclopedia

As this initial expansion was not yet bound by gravity or other physical limitations such as C, this singularity expanded at a rate much greater than C. The Inflationary epoch. At this time spatial dimensions were created during this process and the known laws of physics slowed this inflation (and internal actions) down to the current limitations, i.e. C, meanwhile creating condtions for the basic elements to form from the energetic chaos.
During this time of expanding spatial dimensions, Time was also created as an inherent byproduct of spatial dimensions. This why science today speak of "spacetime", as an integrated wholeness. The two are intrinsically interwoven into a single multi dimensional constuct.
NOVA | The Elegant Universe: Series ...

51. Originally Posted by Markus Hanke
But, isn't it meaningful in a multi-verse scenario where our universe is only one of an infinite universes popping up and then dying and repeating the same cycle endlessly.
No, it still is not meaningful. To stay with the example of the north pole - just because there are other planets in our solar system still does not mean that the question "what is north of the north pole" has any meaning. Likewise with the BB - even if we do live in a multiverse ( which cannot be ruled out ), the term "before the BB" is still without meaning.
But, if there are other universes, that means that when the big bang occurred, there were living beings in other universes experiencing time and reality. They could be still present. So, that means time was there before big bang, only thing is we were not still ''born'' then. Like there is no time for a fetus before conception in the womb. But there WAS/IS a world already existing.

Other universes could be sprouting (with big bangs of their own) in other places in the multiverse right NOW. So, that means there is time and space and stuff for real although you did not exist previously.

52. But, if there are other universes, that means that when the big bang occurred, there were living beings in other universes experiencing time and reality. They could be still present.
Careful here - if there are multiple universes, then those would be completely isolated from one another. There may be space and time in each of them, but there would not be any way to relate them to one another. So once again, the expression "before the BB" remains meaningless, even in such a scenario. Each universe would experience its own BB event, and hence exist in its own reality, entirely independent of all other universes. There would be no space and time outside of the multiverse, so concepts such as "between universes" or "before our BB" are undefined and without meaning.
This is an altogether very complicated scenario, for which there does not exist any visualizable analogue.

53. Originally Posted by Markus Hanke
But, if there are other universes, that means that when the big bang occurred, there were living beings in other universes experiencing time and reality. They could be still present.
Careful here - if there are multiple universes, then those would be completely isolated from one another. There may be space and time in each of them, but there would not be any way to relate them to one another. So once again, the expression "before the BB" remains meaningless, even in such a scenario. Each universe would experience its own BB event, and hence exist in its own reality, entirely independent of all other universes. There would be no space and time outside of the multiverse, so concepts such as "between universes" or "before our BB" are undefined and without meaning.
This is an altogether very complicated scenario, for which there does not exist any visualizable analogue.
The notion of an infinite number of universes seems a little extreme, and IMO may well be in conflict with current science. Extra dimensions (11 in string theory) or branes on which this universe functions is as far as I can conceptualize. An infinite number of other different universes seems extravagantly complicated.

54. There is a difference between dimensions, (geometric), and dimensions (realities, or planes of existence). On one side, i agree, infinite universes seems complicated. But it is not. divide 1 by infinite, and you will reach 0, divide 1 by 100000000000 then you get... well 0,00000000001 or something. I like infinite, it's a nice round number... We can not prove anything, we can rationalise, and explain our concepts and thoughts. If it takes infinity, i'd rather take that then 114 dimensions, much rather. Then where is the border in having an easy calculation and a rational number.... Well, that would be 11, then string theory is half infinite if speaking in dimensions with their 11. i'd even say it's (X^11!) or something like that. Btw, this was filosofical. not factual..

55. Originally Posted by Zwolver
There is a difference between dimensions, (geometric), and dimensions (realities, or planes of existence). On one side, i agree, infinite universes seems complicated. But it is not. divide 1 by infinite, and you will reach 0, divide 1 by 100000000000 then you get... well 0,00000000001 or something. I like infinite, it's a nice round number... We can not prove anything, we can rationalise, and explain our concepts and thoughts. If it takes infinity, i'd rather take that then 114 dimensions, much rather. Then where is the border in having an easy calculation and a rational number.... Well, that would be 11, then string theory is half infinite if speaking in dimensions with their 11. i'd even say it's (X^11!) or something like that. Btw, this was filosofical. not factual..
As i understand superstring theory,
wki,
Superstring theory - Wikipedia, the free encyclopedia

56. Hi all
I have been reading through all the threads on this topic and have a question.

If space time is curved then wouldn't that not mean that no mater what speed we traveled at we would just keep going and going never finding any end thus giving us the illustration that space is infinite or would this just mean that we could just not leave our own universe. ( like going around and around the surface of a ball. )

This could mean that there could be other universe beyond the one we know and if other universes do exist that would mean that there would be a infinite amount of universes and there would be a good chance that there would be some universe with the same amount of dimensions as our universe and other dimensions we still don't know about would this also mean that their would be a possibly that one or universe could collide or pass through with another universes (who to say this has not already happened ) just as Galaxy's do all the time this could mean that universe dose have an end to it but is dose not mean that space is not infinite just that we confined to this universe.??

Andy

57. Yea but something surely can't expand into nothing. Surely there has to be space there for it to expand into. Thus no matter how big the universe is, there has to be space beyond it, if it is to expand further. Surely matter cannot expand into nothing. Surely it requires space.

58. Originally Posted by HeyIts007
Yea but something cant expand into nothing. There has to be space there for it to expand into. Thus no matter how big the universe is there has to be space beyond it, if it is to expand further.
our universe started from nothing?

59. Our definitions of nothing may will be allot different from what universe definitions of nothing is. Where and how did the string theory come into being who is to say their is not strings floating around in nothing waiting to bump into each-other to create something from nothing.

60. Originally Posted by ANDY T
our universe started from nothing?
?????????????????????????????????????????????????? ?????????????????

61. Originally Posted by HeyIts007
Yea but something surely can't expand into nothing. Surely there has to be space there for it to expand into. Thus no matter how big the universe is, there has to be space beyond it, if it is to expand further. Surely matter cannot expand into nothing. Surely it requires space.
Nope. Space is created between things as the universe expands. It does not require anything to expand into.

62. Originally Posted by SpeedFreek
Originally Posted by HeyIts007
Yea but something surely can't expand into nothing. Surely there has to be space there for it to expand into. Thus no matter how big the universe is, there has to be space beyond it, if it is to expand further. Surely matter cannot expand into nothing. Surely it requires space.
Nope. Space is created between things as the universe expands. It does not require anything to expand into.
Between what things ?

63. Originally Posted by SpeedFreek
Nope. Space is created between things as the universe expands. It does not require anything to expand into.

Between what things ? What things are these so called things you are referring to ?

64. Between the clusters of galaxies. Or more formally, between the worldlines of objects that are themselves at rest in relation to the expansion.

The gaps between comoving reference points.

65. The only certainty is that even the experts can't agree on topics like this, becuase they don't even know the full picture themselves. If the universe is expanding, then everything in it must be expanding, yet I dont see my PC screen getting any wider, so looks like I will have to go buy one.

66. Originally Posted by HeyIts007
The only certainty is that even the experts can't agree on topics like this, becuase they don't even know the full picture themselves. If the universe is expanding, then everything in it must be expanding, yet I dont see my PC screen getting any wider, so looks like I will have to go buy one.
You don't seem to know much about this topic, but still find it ok to laugh about it? Lol indeed. You have no idea what the experts actually know or not. Also, there is nothing wrong with not knowing the full picture already. That is the nature of science. No idea why you think it warrants making fun of.

There is indeed very good reasons why your PC screen doesn't fly apart, most obvious of which is that gravity completely overwhelms expansion. Only at scales of stellar super-clusters do the expansion start to make an impression. Much more technical is the effects of relativity which effectively gets rid of the apparent need for gravity to do work in order to keep matter at smaller scales in tact.

67. Have a read of this explanation, it covers all the points recently raised:

Curious About Astronomy: What is the universe expanding into?

68. Ultimately we are talking about using language to define so many things that form the basis of explanation and the interpretation of every word we use can be subjective, even though the words themselves might hold more explicit meaning. That in itself is a major hurdle.

It seems the universe is simply everything that we are aware of and offers no explanation for things we are not aware of. That might seem irrelevant, however really considering that such entities as ourselves, form such a infinitesimal part of the universe that we know of, let alone that which we don't know of, really begs the question of what do we really know ? We know our realities are defined and limited to our sensory abilities. Beyond such abilities and as much as we as humans do know, we don't know a great deal.

Whether in relation to the original question, the "universe is in fact NOT infinite BUT finite", one holds one view or another will be influened by one's subjectiveness.

69. Originally Posted by HeyIts007
Ultimately we are talking about using language to define so many things that form the basis of explanation and the interpretation of every word we use can be subjective, even though the words themselves might hold more explicit meaning. That in itself is a major hurdle.

It seems the universe is simply everything that we are aware of and offers no explanation for things we are not aware of. That might seem irrelevant, however really considering that such entities as ourselves, form such a infinitesimal part of the universe that we know of, let alone that which we don't know of, really begs the question of what do we really know ? We know our realities are defined and limited to our sensory abilities. Beyond such abilities and as much as we as humans do know, we don't know a great deal.

Whether in relation to the original question, the "universe is in fact NOT infinite BUT finite", one holds one view or another will be influened by one's subjectiveness.
Subjectivity is indeed a problem, but science does all it can to remove it from the equation. There are a large number of confirmed scientific principles now that do not conform to "common sense". Basically the whole field of quantum mechanics is an example of that. There is also a concerted effort in science to have precisely defined terms. Scientists are acutely aware of these problems you mention. The best anyone can do is to try and determine which models best describe what we see and at the moment evidence seems to point very strongly towards a finite universe.

70. Originally Posted by SpeedFreek
Have a read of this explanation, it covers all the points recently raised:

Curious About Astronomy: What is the universe expanding into?
Just saw that link. Thanks. Slightly enligtening. Don't buy his explanation of expanding Vs stretching. This is part of my point. It seems each have their different handle on what words they choose to describe things. This inconsistency in language and terminology presents a problem in itself, let alone all the other issues.

71. Originally Posted by HeyIts007
Originally Posted by SpeedFreek
Have a read of this explanation, it covers all the points recently raised:

Curious About Astronomy: What is the universe expanding into?
Just saw that link. Thanks. Slightly enligtening. Don't buy his explanation of expanding Vs stretching. This is part of my point. It seems each have their different handle on what words they choose to describe things. This inconsistency in language and terminology presents a problem in itself, let alone all the other issues.
That problem occurs when a scientist tries to explain very technical principles in layman's terms. Don't equate different approaches in presenting science to the layman with a similar confusion among experts.

72. It doesn't really matter what words you use, when you are using them to describe the same mathematical principles.

Perhaps this is the time for me to introduce the following paper:
[0707.0380] Expanding Space: the Root of all Evil?

"While it remains the staple of virtually all cosmological teaching, the concept of expanding space in explaining the increasing separation of galaxies has recently come under fire as a dangerous idea whose application leads to the development of confusion and the establishment of misconceptions. In this paper, we develop a notion of expanding space that is completely valid as a framework for the description of the evolution of the universe and whose application allows an intuitive understanding of the influence of universal expansion. We also demonstrate how arguments against the concept in general have failed thus far, as they imbue expanding space with physical properties not consistent with the expectations of general relativity."

And while we are at it, more in line with the OP, we have this:
[astro-ph/0604616] Extending the WMAP Bound on the Size of the Universe

"While it is certainly possible that the Universe extends inﬁnitely in each spatial direction, many physicists and philosophers are uncomfortable with the notion of a universe that is inﬁnite in extent. It is possible instead that our three dimensional Universe has a ﬁnite volume without having an edge, just as the two dimensional surface of the Earth is ﬁnite but has no edge. In such a universe, it is possible that a straight path in one direction could eventually lead back to where it started. For a short enough closed path, we expect to be able to detect an observational signature revealing the speciﬁc topology of our Universe."

73. I think that is the question. Is the universe finite or infinite.
If we look around the universe at what we do know like a planet size is finite before becoming a Sun. A sun has a finite size becoming as black hole at its extremism, is a black hole finite before collapsing on its self again or dose it enter yet another stage we don't know.
But what we do know is that most thing do have a finite size limit and a finite time and an finite speed.
So could the universe have finite time and a finite size this is a question that may never be answered as we will probably never be able see to beyond our own universe to answer it.

74. Andy, no offence, but PLEASE try and apply some punctuation to your posts. As it stands it is little more than a jumble of letters.

75. "Although the galaxies haven't moved through space at all, they get
farther away from each other as time goes on because the space in between them
has been stretched. " ???

Surely if physical objects are increasing in relative distance within space, they have moved in space.

" It is possible instead that our three dimensional Universe has a ﬁnite volume without having an edge, just as the two dimensional surface of the Earth is ﬁnite but has no edge." ???

Surely the surface of the earth is the edge.

76. Originally Posted by KALSTER
Andy, no offence, but PLEASE try and apply some punctuation to your posts. As it stands it is little more than a jumble of letters.
Hi
Grammar is not my best skill as i have disleksia so please for give it but i do have a keen mind, what did you not understand.

77. Originally Posted by HeyIts007
"Although the galaxies haven't moved through space at all, they get
farther away from each other as time goes on because the space in between them
has been stretched. " ???

Surely if physical objects are increasing in relative distance within space, they have moved in space.
There is a difference between moving through space and moving with space. With the former there is a maximum speed possible, which is the speed of light. With the latter there is no limit to the apparent recession speed. There are indeed objects that are receding from us at apparent speeds exceeding that of light.

As an analogy, consider an object in water. It can either move through the water or with it.

Surely the surface of the earth is the edge.
It is the edge in 3 dimensions, but the analogy is about the 2 dimensional surface of the earth. There is no boundary in the 2 dimensional surface and in case you were wondering, curvature is possible mathematically in 2D, as well as 3D without extra dimensions needed.

78. Andy I have always seen most things as infinite, but we as living entities have a natural tendency to see
them as finite, due to our physical sensory limitations, governed by the law of evolution.

79. Originally Posted by ANDY T
If we look around the universe at what we do know like a planet size is infinite before becoming a Sun.
No, the size of a planet is always finite.

Originally Posted by ANDY T
A sun has a infinite size becoming as black hole at its extremism, is a black hole infinite before collapsing on its self again or dose it enter yet another stage we don't know.
The size of a Sun is always finite. The size of a black hole is always finite.

Originally Posted by ANDY T
But what we do know is that most thing do have a infinite size limit and a infinite time and an infinite speed.

No, what we do know is that most things have a finite size, a finite time and a finite speed.

Originally Posted by ANDY T
So could the universe have finite time and a finite size this is a question that may never be answered as we will probably never be able see to beyond our own universe to answer it.
The universe as we know it has a finite size (the observable universe) and a finite time (the time back to the Big-Bang). The whole universe that took part in the Big-Bang might be either finite or infinite in size, but it is finite in time.

80. Originally Posted by KALSTER
As an analogy, consider an object in water. It can either move through the water or with it.
But they talk about more than 1 object. They talk of galaxies moving apart getting further away from each other. The water analogy might explain 1 object moving in water or with water, but not two objects in water increasing in distance, without them moving through, in, or with water. For objects to increase in relative distance, surely be it water, space or whatever medium, they have to move through that medium.

81. Originally Posted by HeyIts007
Originally Posted by KALSTER
As an analogy, consider an object in water. It can either move through the water or with it.
But they talk about more than 1 object. They talk of galaxies moving apart getting further away from each other. The water analogy might explain 1 object moving in water or with water, but not two objects in water increasing in distance, without them moving through, in, or with water. For objects to increase in relative distance, surely be it water, space or whatever medium, they have to move through that medium.
No, imagine the medium is expanding, like dough.

82. Yea I see the dough explanation. Odd thing is that if the universe represents everything we are aware of and it's expanding, then it then becomes more than what we were aware of in physical terms, which seems to contradict the finite explanation of the universe in terms of its definition, which implies finality. i.e. the universe commonly defined as the "totality of existence"

Anyway as far as finite Vs. infinite, I will leave this for others to contemplate. When you get the newly confirmed answer, I'm all ears and eyes. Nonetheless it's been an interesting insight.

83. Originally Posted by SpeedFreek
Originally Posted by ANDY T
If we look around the universe at what we do know like a planet size is infinite before becoming a Sun.
No, the size of a planet is always finite.

Originally Posted by ANDY T
A sun has a infinite size becoming as black hole at its extremism, is a black hole infinite before collapsing on its self again or dose it enter yet another stage we don't know.
The size of a Sun is always finite. The size of a black hole is always finite.

Originally Posted by ANDY T
But what we do know is that most thing do have a infinite size limit and a infinite time and an infinite speed.

No, what we do know is that most things have a finite size, a finite time and a finite speed.

Originally Posted by ANDY T
So could the universe have finite time and a finite size this is a question that may never be answered as we will probably never be able see to beyond our own universe to answer it.
The universe as we know it has a finite size (the observable universe) and a finite time (the time back to the Big-Bang). The whole universe that took part in the Big-Bang might be either finite or infinite in size, but it is finite in time.
Sorry got my finite/infinite the wrong way round but you know what i meant.

84. Originally Posted by ANDY T
Sorry got my finite/infinite the wrong way round but you know what i meant.
Well I know what you meant, now.

85. Happy New Year's eve and New Year 2013 to all!

Pretty good running commentary today on this thread

ANDY T,

I have been reading through all the threads on this topic and have a question.

If space time is curved then wouldn't that not mean that no mater what speed we traveled at we would just keep going and going never finding any end thus giving us the illustration that space is infinite or would this just mean that we could just not leave our own universe. ( like going around and around the surface of a ball. )
If space is curved, then curving around upon itself would be the expected state or condition. But If GR is wrong then space may not curve at all.

This could mean that there could be other universe beyond the one we know.......
yes, there could be.

......and if other universes do exist that would mean that there would be a infinite amount of universes
This does not follow logically. If there were other universes, the quantity of them would simply be hypothetical. An infinite number of them would be just one of the possibilities.

....and there would be a good chance that there would be some universe with the same amount of dimensions as our universe and other dimensions we still don't know about........would this also mean that their would be a possibly that one or universe could collide or pass through with another universes (who to say this has not already happened ) just as Galaxy's do all the time this could mean that universe dose have an end to it but is dose not mean that space is not infinite just that we confined to this universe.??
Yes, these are hypothetical or speculative possibilities. A more well known hypothesis, however, is that any other possible universe(s) would exist in a dimensional state(s) whereby it/they could not interact with our own universe.

I agree with the OP conclusion that the universe is finite and believe it is the only universe. If the universe is finite, but not curved, this may require "space" to be solely defined as the distance between and within matter, and the volume that matter and field occupies. There accordingly would be no existence of any kind, by this definition, beyond its boundaries (not even space).

86. Originally Posted by Ascended

This is going to be on my desktop...to freak out visitors!

87. Originally Posted by rohandesilva
Here is MY proof that the universe is in fact NOT infinite BUT finite.

Now, space (and time, although time is not necessary for my proof) starts with a tiny dot and it expands. So, even if the universe is expanding at the C, still there has to be an edge, because the big bang happened 14 Billion years ago. So, the SIZE of the universe is at maximum, is a bubble whose diameter is 14 * 2 billion = 28 billion light years.

Universe has to have an edge (and hence finite) because it started with a finite space (a dot, a very small thing). Since the universe started with a finite space, or something small (not infinite), it HAS to have a finite space even now, even if the edge of the universe is expanding at C.

Sure, we won't be able to travel to the edge of the universe cos we cannot travel faster than C, BUT, hypothetically, suppose we built a warp-drive type ship that can travel very much faster than C, we should be able to reach the end of the universe in finite time.

Am a genius or am I missing something very big here???
The devil is in the details. We dont know what points really are, since we cant observe them.

Were we to observe them we could observe only their outsides.
Thats to say the intersection of two lines. If the universe once was inside a point then how do you know that the point expanded outwards to occupy territory not previously inside the point? What if "the space" inside (Well? mustnt it be some "space" within the point if our space really IS inside it?) is expanding (...er ...maybe "contracting" really is a better term) ... in an inside direction.

The edge you are imagining is the radius of the universe. Its difficult to define otherwise than as half the diameter of the universe (since every point...or no point... is the center of the universe) and the diameter then? Well its a longest straight line connecting points.(When we look at the bubblemodel below we see that only the endpoints of the diameter is inside the universe) It is expanding all the time since the whole universe is expanding and you are probably correct in that it expands faster then you can approach any of its "endpoints" which might be your front and backside (if the universe is bent into itself with the diameter inside the universe so theres no outside to the universe). A situation I vaguely think would be the case if the universe remains packed into a point. Think of the pearls in a necklace: Doubling the amount of pearls means that the pearls should brake the string connecting the pearls in the necklace...Right? Not necessarily! If you simultaneously half the size of all pearls as you double their amount ...you can double as many times as you like.

Scientists do not really claim that the universe ever had a diameter of zero (The requirement to be IN a point surely?) They think of such a point as a "singularity" and is satisfied with the view that the diameter of our universe once was approximately zero but NOT identical to zero... meaning there always was some space inside it. The geometry of universes (and points) IS confusing to think and speak about. Lets simplify:

Think of blowing bubbles. They leave their membrane of origin. (think of the membrane as just another bubble ... sit inside it and kiss the wall...notice your not IN the membrane which is supposed to be the analogue of our space) There is no membrane matter between bubbles... its air! So if our SPACE is analogue to a bubble then whats outside it (possibly containing more bubbles) is something analogue to air. Maybe that air is just a bubble of another kind...who can tell?

You now think you are God creating universes dont you? But this is not necessary!
Bubbles can be separated from its membran of origin by some force inside the membran.

Well then: Earhly bubbles are twodimensional membrans bent into themselves in a third dimension... IF this model holds in the details then our fourdimensional #bubble# is surrounded by fivedimensional *air*

88. Originally Posted by HeyIts007
"Although the galaxies haven't moved through space at all, they get
farther away from each other as time goes on because the space in between them
has been stretched. " ???

Surely if physical objects are increasing in relative distance within space, they have moved in space.
Paint two dots on a balloon and measure the distance between the dots (ON the fabric of the balloon). Then blow it up and again measure the distance. Its now longer than before but the dots have not moved IN THE FABRIC OF THE BALLOON!

89. Originally Posted by sigurdV
Originally Posted by HeyIts007
"Although the galaxies haven't moved through space at all, they get
farther away from each other as time goes on because the space in between them
has been stretched. " ???

Surely if physical objects are increasing in relative distance within space, they have moved in space.
Paint two dots on a balloon and measure the distance between the dots (ON the fabric of the balloon). Then blow it up and again measure the distance. Its now longer than before but the dots have not moved IN THE FABRIC OF THE BALLOON!
How do you account for the movements and joining of Galaxies if every thing moves apart from each other, gravity must also play a part in speed of individual object within the balloon.

90. Originally Posted by Ascended
... in order to be able to measure something you need to be able to have something to measure it against?
You dont carry around pebbles to use as "measuring pebbles"... Counting coins by placing one pebble each on every coin and then seeing either how many pebbles are left in the sack or counting the pebbles on the coins...but hey if you can count you dont need the pebbles you count the coins directly using a mental yardstick consisting of infinitely many natural numbers.

1,2,3,... and so on forever... resulting in an infinite total.
Suppose somebody stole your first number would you now not have as many numbers as before?
To make it worse suppose what you have left is the even numbers:
2,4,6,... Surely you lost half your amount of numbers?

NO! Infinity is not found within the series: 1,2,3,... It does not have the same properties as any number in the series!

There is as many (natural) numbers as there are even numbers. To see that you PAIR them

One with two (1,2) two with four (2,4) three with six(3,6) and so on...no number is left out of the pairing!

Now: Suppose there is a sack of coins with a finite outside and an infinite inside containing an infinite amount of coins...

How do we prove that it is really so? Can we count the coins?

91. Originally Posted by ANDY T
Originally Posted by sigurdV
Originally Posted by HeyIts007
"Although the galaxies haven't moved through space at all, they get
farther away from each other as time goes on because the space in between them
has been stretched. " ???

Surely if physical objects are increasing in relative distance within space, they have moved in space.
Paint two dots on a balloon and measure the distance between the dots (ON the fabric of the balloon). Then blow it up and again measure the distance. Its now longer than before but the dots have not moved IN THE FABRIC OF THE BALLOON!
How do you account for the movements and joining of Galaxies if every thing moves apart from each other, gravity must also play a part in speed of individual object within the balloon.
I think it does not matter if you blow ballons in Space or on Earth...
The distance between the dots on the balloon surface depends on the amount of air within the ballon.
(the pressure outside the balloon not considered)

The gravity in space holds the galaxies themselves together (at least up to now)!
RESISTING the force behind the universal expansion.
But if the force gets continually stronger it will tear everything apart eventually. (The Big Rip.)

Our Universe is funny: Earlier it was supposed to kill us by contracting back into a point.
Or transforming all available energy into heat. (The Heat Death.)
And now its the big rip... I wonder what will come next?

92. sigurdV,

........Our Universe is funny: Earlier it was supposed to kill us by contracting back into a point.
Or transforming all available energy into heat. (The Heat Death.)
And now its the big rip... I wonder what will come next?

As you mentioned the big rip/ big freeze are the current favorites. What will be next, I believe, is that we will finally have good evidence that the universe is not expanding at all, no dark energy or dark matter, and that the universe is in a steady state condition. I think then such theories will again become mainstream, or mainstream alternatives, about 2022, about 4 years after the James Webb has been up. This will happen, I believe, when they begin to realize that the most of the distant galaxies, using the James Webb scope, appear to be just like the Milky Way and other galaxies in our local group.

Then, I think, many will again be proposing an infinite universe. Others, like myself, will be discussing arguments in favor of a finite universe, greatly older than the Big Bang model, but still finite in its age, matter, and extension. New Year's and all, this is my prediction concerning the question of "what will be next?"

93. Originally Posted by rohandesilva
Here is MY proof that the universe is in fact NOT infinite BUT finite.

Now, space (and time, although time is not necessary for my proof) starts with a tiny dot and it expands. So, even if the universe is expanding at the C, still there has to be an edge, because the big bang happened 14 Billion years ago. So, the SIZE of the universe is at maximum, is a bubble whose diameter is 14 * 2 billion = 28 billion light years.

Universe has to have an edge (and hence finite) because it started with a finite space (a dot, a very small thing). Since the universe started with a finite space, or something small (not infinite), it HAS to have a finite space even now, even if the edge of the universe is expanding at C.

Sure, we won't be able to travel to the edge of the universe cos we cannot travel faster than C, BUT, hypothetically, suppose we built a warp-drive type ship that can travel very much faster than C, we should be able to reach the end of the universe in finite time.

Am a genius or am I missing something very big here???

good theory however with the recent (final) proof of the higgs field interacting with particles and giving mass mass from the beginning on the universe, we are however still unaware if the higgs field gave relative mass to the photon or not ;therefore the speed of light in the early universe cannot be confirmed to be the speed it is now, if it's not constant then well the equation doesn't work I'm afraid.
however your theory is valid for a good approximation I think , assuming our perception of time is constant as well :}

94. Noble Forrest!
Originally Posted by forrest noble
sigurdV,

........Our Universe is funny: Earlier it was supposed to kill us by contracting back into a point.
Or transforming all available energy into heat. (The Heat Death.)
And now its the big rip... I wonder what will come next?

As you mentioned the big rip/ big freeze are the current favorites. What will be next, I believe, is that we will finally have good evidence that the universe is not expanding at all, no dark energy or dark matter, and that the universe is in a steady state condition. I think then such theories will again become a mainstream alternatives about 2022, about 4 years after the James Webb has been up. This will happen, I believe, when they begin to realize that the most of the distant galaxies, using the James Webb scope, appear to be just like the Milky Way and other galaxies in our local group.

Then, I think, many will again be proposing an infinite universe. Others, like myself, will be discussing arguments in favor of a finite universe, greatly older than the Big Bang model, but still finite in its age, matter, and extension. This is my prediction of "what will be next."
You aint afraid of sticking out your neck. I admire that! I will not enter into polemic mode.
My personal opinion is that your prediction will fail...heres my prediction:
We will be extinguished either soon, by local dangers like incoming comets, or later by Alien "Visitors"

95. sigurdV,

.....My personal opinion is that your prediction will fail...heres my prediction:
We will be extinguished either soon, by local dangers like incoming comets, or later by Alien "Visitors"
Yeah, this might be humanities fate someday, but I hope not I hope by then that humans will have become a multi-planetary species, as well as having many large traveling space colonies, traveling arks so to speak.

96. Now, space (and time, although time is not necessary for my proof) starts with a tiny dot and it expands. So, even if the universe is expanding at the C, still there has to be an edge, because the big bang happened 14 Billion years ago. So, the SIZE of the universe is at maximum, is a bubble whose diameter is 14 * 2 billion = 28 billion light years.
You are making an elementary mistake here - you are imagining the universe like a bubble being blown up, and equate it with the inside of that bubble. That is not correct though - the analogy holds only for the surface of the bubble. That being said, it may still start off as a single point, however, as the bubble expands there is neither an edge/boundary nor a "radius" to this surface, and all points on that surface move away from one another over time as it expands.

So no, the universe does not need to have an edge, and if it did it then that would create all manner of problems which we will hopefully never have to consider.

97. Originally Posted by ANDY T
How do you account for the movements and joining of Galaxies if every thing moves apart from each other, gravity must also play a part in speed of individual object within the balloon.
Yes indeed. When galaxies formed, if they were close enough to each other to be gravitationally bound, they would cluster together against the expansion, whereas if there was enough distance between them for the rate of expansion to beat the gravitational attraction between them, they are drawn apart by the expansion.

So we end up with galaxies forming into groups or clusters, whilst the universe expands between those groups or clusters.

98. How do you account for the movements and joining of Galaxies if every thing moves apart from each other, gravity must also play a part in speed of individual object within the balloon.
Be careful that you get the analogy right - they are not within the balloon, they are on the balloon's surface. The difference is a crucial one, and the source of much confusion and misunderstanding.

99. Originally Posted by forrest noble
sigurdV,

.....My personal opinion is that your prediction will fail...heres my prediction:
We will be extinguished either soon, by local dangers like incoming comets, or later by Alien "Visitors"
Yeah, this might be humanities fate someday, but I hope not I hope by then that humans will have become a multi-planetary species, as well as having many large traveling space colonies, traveling arks so to speak.
I would like you to tell me more about it. But we should not clutter up this thread. Please visit me at:
http://www.thescienceforum.com/pseudoscience/32261-how-selfsupported-space-station-constructed-new-post.html

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