Eternal Inflation and it's Philospohical implications

[heusdens]

Originally posted by Eh
It's only a proposal, but indeed avoids the problems of infinity. While inflation may make some predictions, it is not incompatible with the no boundary proposal. They both work.

But I'm not sure eternal inflation makes many predictions to stand out against the countless other inflation models. But I guess one prediction for an eternal inflationary universe is that space must be infinite. If WMAP finds conclusive evidence the universe is finite, that model will be dead. So in that sense, an infinitely old universe could be falsified within the year. Time will tell.

I would not know. I guess that in eternal inflation, time and space are infinite, but the spacetime bubble that comes out of a certain inflating region, is finite in size.
We can only know about the size of our own spacetime bubble.

 

[Eh]

The problem lies in the fact of the hyperbolic shape. A 3 dimensional hyperbolic closed space simply cannot be embeded by 3D space. You would need at least 4 spatial dimensions in order for there to be more universe outside our visible space-time. I don't know what changes would be required to work with an extra dimensional inflation model.

 

[Lifegazer]

Originally posted by wuliheron
One of the philosophical implications of an eternal inflationary universe is that it is paradoxical and infinity not being a number is one of the reasons why.

You're just semi-correct. An eternal inflationary-universe is not logically possible. There's no paradox about it (since it's not a mystery).
... If anything has been inflating for eternity, and there is still space outside of itself in order to maintain the inflation, then that thing has to be a finite entity. Therefore, its inflationary-time is definitely finite.
A finite object cannot inflate for an eternity - it needs an origin of time for the process to begin. And an infinite object has no rational meaning (therefore, as it does not exist, it cannot inflate).

 

[wuliheron]

You're just semi-correct. An eternal inflationary-universe is not logically possible. There's no paradox about it (since it's not a mystery).

Au Contre, it is infinitely mysteries. For example, because it has no beginning or end, for all I know every instant is somehow both a beginning and an end. Because it has no limit, for all I know eternity itself is also somehow finite. Logically and conceptually it makes no sense in these respects and is as magical an event as I can conceive of. No different from conceiving of the universe just suddenly appearing out of nowhere and nothing. Both inspire awe and it is perhaps this emotional connection above all that is our most accurate way of conceiving eternity.

 

[Lifegazer]

Originally posted by wuliheron
Au Contre, it is infinitely mysteries. For example, because it has no beginning or end, for all I know every instant is somehow both a beginning and an end.

I was trying to explain why an eternal inflationary-universe was not a viable possibility. I.e.; I was trying to show why time/change/motion has a beginning.

Because it has no limit, for all I know eternity itself is also somehow finite.

It is impossible that a finite entity should have no limits to its physical parameters of existence. That would make it an infinite physical-entity.

Logically and conceptually it makes no sense in these respects

If we are to apply reason to physical manifestation, then there are plenty of decisive conclusions to be gleaned. Like I said - in this respect, there is no mystery.

 

[heusdens]

Originally posted by Lifegazer
I was trying to explain why an eternal inflationary-universe was not a viable possibility. I.e.; I was trying to show why time/change/motion has a beginning.

Of course you can show that, but don't forget you can also and equally show that the opposite is true also: that time can't have a beginning. (see thread: https://www.physicsforums.com/showthread.php?s=&threadid=958").
Don't forget about that! i tried to bring that fact into your mind many times.

It is impossible that a finite entity should have no limits to its physical parameters of existence. That would make it an infinite physical-entity.

Not true. For instance the surface of the Earth has a finite size, but it is not limited. Nowhere you fall off the earth.

If we are to apply reason to physical manifestation, then there are plenty of decisive conclusions to be gleaned. Like I said - in this respect, there is no mystery.

Except for the mysteries you introduce yourself, when coming up with the concept of a "beginning of time, space, matter, motion", etc. which enables you to come up with this deity thing again..

 

[heusdens]

Originally posted by Lifegazer
You're just semi-correct. An eternal inflationary-universe is not logically possible. There's no paradox about it (since it's not a mystery).
... If anything has been inflating for eternity, and there is still space outside of itself in order to maintain the inflation, then that thing has to be a finite entity. Therefore, its inflationary-time is definitely finite.
A finite object cannot inflate for an eternity - it needs an origin of time for the process to begin. And an infinite object has no rational meaning (therefore, as it does not exist, it cannot inflate).

You're dead wrong here. The eternal inflation paradigm says that the current universe comes out of an inflated region of space which was finite in size, but which is part of a larger universe, that is infinite in size and has infinite history.
The finite object you refer to (the space-time bubble we call "our universe") has a definite begin, but that is not a begin of time as such. The eternal inflation paradigm states that the inflationary universe reproduces itself, so it came out of a previously inflating spacetime-bubble, and this process can go on in all eternity.

 

[wuliheron]

Originally posted by Lifegazer
I was trying to explain why an eternal inflationary-universe was not a viable possibility. I.e.; I was trying to show why time/change/motion has a beginning.

It is impossible that a finite entity should have no limits to its physical parameters of existence. That would make it an infinite physical-entity.

If we are to apply reason to physical manifestation, then there are plenty of decisive conclusions to be gleaned. Like I said - in this respect, there is no mystery.

This is paraconsistent logic which is also applicable to Quantum Mechanics and any number of paradoxes from which useful and decisive conclusions can be drawn. The difference is, Quantum Mechanics is an applied reality while this is pure speculation. I could literally (?) speculate endlessly about eternity and infinity without finding a single useful bit of information. Thus it has no advantage over any other possible answer.

 

[Lifegazer]

Originally posted by heusdens
Of course you can show that, but don't forget you can also and equally show that the opposite is true also: that time can't have a beginning. (see thread: https://www.physicsforums.com/showthread.php?s=&threadid=958").
Don't forget about that! i tried to bring that fact into your mind many times.

Yes; and now you have brought that to my attention, I find your reasoning to be corrupt (not in an immoral sense). I would also advise people to read that thread. They'll discover a few facts:-
1. You advocate that infinite-time is illogical. In fact, your first sentence here is an acknowledgment of this fact.
2. You have no reasonable disproof of a finite causality-chain. The reader should be aware that you (and Tom) just refuse to accept such a conclusion because you both realize that the conclusion infers the existence of 'God'.
3. Your decision to accept '1' is forced upon you by your absolute reluctance to accept the existence of 'God.
4. Your decision to accept '1' is a decision to accept an illogical premise.
5. Your refusal to accept a finite causality-chain is therefore a decision founded upon bias or incredulity. It is not a decision which reflects a reasoned analysis of the concepts involved.

 

[heusdens]

Originally posted by Lifegazer
Yes; and now you have brought that to my attention, I find your reasoning to be corrupt (not in an immoral sense). I would also advise people to read that thread. They'll discover a few facts:-
1. You advocate that infinite-time is illogical. In fact, your first sentence here is an acknowledgment of this fact.
2. You have no reasonable disproof of a finite causality-chain. The reader should be aware that you (and Tom) just refuse to accept such a conclusion because you both realize that the conclusion infers the existence of 'God'.
3. Your decision to accept '1' is forced upon you by your absolute reluctance to accept the existence of 'God.
4. Your decision to accept '1' is a decision to accept an illogical premise.
5. Your refusal to accept a finite causality-chain is therefore a decision founded upon bias or incredulity. It is not a decision which reflects a reasoned analysis of the concepts involved.

What is corrupt in my reasoning?

The reasoning is as follows. Both the finiteness (beginning) of time and the infiniteness of time are provable to be absurd, and refusing one, means to accept the other. Ultimately, however, the issue is contradictionary, and remeans so. Cause any attempt to remove the contradiction, creates even more absurd or profound contradictions.

Do you accept that?


Dialectical-materialism incorporates that in their central premises, and so the use of dialectical reasoning (dialectical reasoning is about contradictions) is a part of the very reasoning itself.

We can not escape from that situation.

The arbitrary introduction of a Deity does in total not remove the inherent contradiction, but creates an absurdity in it's own terms.
Because of that, such an artificial addition to reality, is refused.


Some coments:

1. I did not state that infinite time is illogical. I would state quite the opposite that it follows normal reasoning. The only thing that can be said about the infiniteness of time, is that the concept of inifinity isself is a contradictionary term in it's own. The attempt to remove this contradiction, is to remove infinity, which leaves us with the equal, or even more absurd proposition of having time 'started'. What was before that time? A mere nothingness? An unchanging-existence? Where did the first change come from?

2. The disproof of finite-causality, or better stated the proof that such can not be the case, is because it would require time, matter, motion and space to have begun at some 'time' (a time in which in fact, there was no time!). This is inacceptable. There is no physical evidence that such a thing can happen. On the other hand, there is plenty of evidence that matter can only exist in eternal, neverlasting motion, as this is seen to be the case.

3. The infinitness of time can be well understood and is based on theorems, which we base on material knowledge. Matter does not appear out of nothing. Matter only is in a constant and endless proces of transforming, changing, moving. This can not be said to have begun or end, and therefore the material world, the universe, is unfolding endlessly without begin or end.

4. We have no reason to assume that things in the past or the future work differently as they do now. If one assumes the past or the future the physical laws were different, it is up to that person assuming that to give us proof of that.

5. In part you already accepted the idea that there must be always something, and that at no point in time there can be 'nothing'. This is a reasonable proposition to conclude that therefore an existing material universe, in whatever material form or shape, must have been existing at all time, that is in all of eternity, endlesly.

6. Even when we are stubborn, and refuse the more obvious conclusions, which I have drawn here, and postulate the existence of some 'unknown/unknowable' Deity, what would it help? Is a Deity necessary to 'create' a universe? To create the universe in this manner of speaking would imply that before (before the universe existed, before time [whatever that can mean]) it (the unvierse)did not exist.
What existed before, or what was the state of the world before that? The mere nothing, or "notingness"? That can't be the case for logical reasons, and secondly, then also this Deity which was called for help, did not exist. So, that in fact means that a pre-existing Deity transforms into the world, and becomes the world. In fact it denotes a continuous transformation, not an act of 'creation' (as in 'creation ex nihilo'). But this ain't very helpfull, because instead of explaining the world, and where it comes from, it necessitates us to explain where this Deity came from. Same problems here as for the world itself.

7. So, this attempt doesn't work neither, for obvious reasons. What else might work then? Well, if neither the obvious (an endless, eternal and infinite existence) nor a pre-existing Deity might help, the only other option is that of a beginning of time, which started out of an absolute nothing. Before time, there was nothing. This implies us to believe that motion arises out of no motion, matter out of nothing, and time and space popup all by themselves. It implies us to accept that the "nothingness" is a real existing state of the world, which happens to have existed before the world started to exist. And that "out of nothing" (although it is a state which can not imply any form of change), all of a sudden everything pops out.

Excuse me, Mr Lifegazer, but such a thing I simply refuse to believe.

 

[Mentat]

Originally posted by wuliheron
I will challange such nonsense in the name of mathematics any time I please.

No you wont. There have been enough locked threads because of other members (not naming names) who keep trying to introduce their personal belief to all topics even remotely related to it. It doesn't matter that you think infinity is irrational. I think that Nietzsche's philosophy of all events (in the past) repeating themselves (in the future) is irrational and foolish. That doesn't mean that I'm allowed to insult/mock anyone who tries to make application of that philosophy. Philosophy allows for people to believe differently, and to speculate as to what would occur, if the premise were true.

As I already said Dorathy, if you want to stay in OZ that is your affair. This is a physics philosophy bulletin board, not the land of Oz where anything is possible. One of the philosophical implications of an eternal inflationary universe is that it is paradoxical and infinity not being a number is one of the reasons why.

Yes, this is a philosophy bulletin board. Not a bulletin board dedicated to sarcasm and arrogant patronization.

 

[Lifegazer]

Originally posted by heusdens
What is corrupt in my reasoning?

The reasoning is as follows. ~**Both** the finiteness (beginning) of time and the infiniteness of time are provable to be absurd~

That's the point: the finiteness of time is not absurd - until you then realize that 'God' is infered. And you reject 'God' because it just feels absurd.

1. I did not state that infinite time is illogical. I would state quite the opposite that it follows normal reasoning.

You've stated it on several occaisions. Most notably, in the first quote of this post. I've highlighted it, for effect.

 

[heusdens]

Originally posted by Lifegazer
That's the point: the finiteness of time is not absurd - until you then realize that 'God' is infered. And you reject 'God' because it just feels absurd.

You've stated it on several occaisions. Most notably, in the first quote of this post. I've highlighted it, for effect.

We have discussed this issue lenghty in the topic about Philosophy of Nature. Time and Space. It was about Kant's both argument pro- and contra- a finite time. Both were provable, which leads to the absurd situation of a contradiction, cause both can be proven.

Ok, so let us assume for a moment, that we have no way around this, and then we pretend to arbitrary adapt one of the conclusions, and go for finite time. Then time had a beginning, and the universe has an 'absolute' cause, namely God. But that would infer either:
1- That we add to the beginning finite causal chain another infinite causal chain, namely God.
2- Or we state that no cause can be given, and we have to believe that everything came from nothing literally!

It can be shown that case 1 is just the other choise we could have made (the infinity of time), and that 2 is an absolute absurdity, which therefore we refuse.

As explained in another thread the causality argument comes not in the picture when used in a proper way, and does not conflict with an infinite time. Only then namely causality is universally applied, and every event within the universe is based on cause-and-effect relationship. This however - and that is where the application of cuasuality goes wrong - is not applicable to the universe AS A WHOLE, as explained in the other thread. THAT would imply namely to KILL causality. If the universe AS A WHOLE would have had a cause, then causality can not be at the same time be established for every event IN the universe. Your reasoning goes wrong there in the same way as to imply that since all members of the football team have parents, therefore the football team must have a parent. For obvious reasons, that does not have to be the case.

The alternative of infinite time is therefore acceptable, and the only remaining contradiction is that of infinity itself. All attempts to remove the contradiction from infinity, remove in effect infinity itself, and thereby introducing new and more profound contradictions, and in fact, absurd contradictions.

 

[wuliheron]

Originally posted by Mentat
Yes, this is a philosophy bulletin board. Not a bulletin board dedicated to sarcasm and arrogant patronization. [/B]

The famous western philosopher of modern science, Descartes, was famous for his sarcasm. The land of Oz contains all types of strange characters, including such as yourself who endlessly ask the same questions over and over, demand proof that Santa doesn't exist, make personal slams, and then start calling the kettle black.

 

[Mentat]

Originally posted by wuliheron
The famous western philosopher of modern science, Descartes, was famous for his sarcasm. The land of Oz contains all types of strange characters, including such as yourself who endlessly ask the same questions over and over, demand proof that Santa doesn't exist, make personal slams, and then start calling the kettle black.

You can't even see how petty the above kind of posting is, can you?

Oh well, let's stop intruding on the thread. If you have something to say to me, personally, just PM me.

 

[Mentat]

Originally posted by heusdens
We have discussed this issue lenghty in the topic about Philosophy of Nature. Time and Space. It was about Kant's both argument pro- and contra- a finite time. Both were provable, which leads to the absurd situation of a contradiction, cause both can be proven.

Ok, so let us assume for a moment, that we have no way around this, and then we pretend to arbitrary adapt one of the conclusions, and go for finite time. Then time had a beginning, and the universe has an 'absolute' cause, namely God. But that would infer either:
1- That we add to the beginning finite causal chain another infinite causal chain, namely God.
2- Or we state that no cause can be given, and we have to believe that everything came from nothing literally!

It can be shown that case 1 is just the other choise we could have made (the infinity of time), and that 2 is an absolute absurdity, which therefore we refuse.

As explained in another thread the causality argument comes not in the picture when used in a proper way, and does not conflict with an infinite time. Only then namely causality is universally applied, and every event within the universe is based on cause-and-effect relationship. This however - and that is where the application of cuasuality goes wrong - is not applicable to the universe AS A WHOLE, as explained in the other thread. THAT would imply namely to KILL causality. If the universe AS A WHOLE would have had a cause, then causality can not be at the same time be established for every event IN the universe. Your reasoning goes wrong there in the same way as to imply that since all members of the football team have parents, therefore the football team must have a parent. For obvious reasons, that does not have to be the case.

The alternative of infinite time is therefore acceptable, and the only remaining contradiction is that of infinity itself. All attempts to remove the contradiction from infinity, remove in effect infinity itself, and thereby introducing new and more profound contradictions, and in fact, absurd contradictions.

Heusdens, you missed one possible explanation. Big Bang theory coupled with String theory. It's my favorite because it doesn't require the use of the word "nothingness", which I abhor, and which has no real meaning anyway.

 

[heusdens]

Originally posted by Mentat
Heusdens, you missed one possible explanation. Big Bang theory coupled with String theory. It's my favorite because it doesn't require the use of the word "nothingness", which I abhor, and which has no real meaning anyway.

Yeah, it is called "brane cosmology". I have heard about it, and read about it.

But in what way is that a "different" alternative?

All I know about the ekpyrotic model is that it states or assumes an infinite space and time frame.

Btw. I do not favour this model, nor the Turok-Hawking Instanton "pea", because of several reasons.
Brane and string cosmology have problems inthemselves, in that they are only theory, and are not yet established on empical evidence, and apart from that don't come with the right predictions on the universe we observe.

See for instante the critique of Andrei Linde on both these models.
Type "Andrei Linde" in Google search and find the link to a lecture about eternal / open inflation in which he talks in detail about that, and his own model).

 

[wuliheron]

You can't even see how petty the above kind of posting is, can you?

Oh well, let's stop intruding on the thread. If you have something to say to me, personally, just PM me.

Still being derogatory and attempting to tell me what to do. PM me yourself fool. Once again, stop handing out advice you aren't willing to take yourself. Get real, grow up.

 

[Eh]

Colliding branes produce the big bang: http://feynman.princeton.edu/~steinh/cyclintro/index.html

Time is infinite in that model, and each brane is infinite itself. It is still an infinite regress theory, and only the use of imaginary time gives us a real alternative.

 

[heusdens]

Originally posted by Eh
Colliding branes produce the big bang: http://feynman.princeton.edu/~steinh/cyclintro/index.html

Time is infinite in that model, and each brane is infinite itself. It is still an infinite regress theory, and only the use of imaginary time gives us a real alternative.

Lookup the link I provided in my earlier post (lecture of Andrei Linde) and you might be confronted that this theory still suffers from major deficits (for example brane stability, which requires all kinds of fine tuning in the branes relative positions, etc.)

It is not very appealing to me, with lack of physcial evidence, to go for 1o-D models of matter in forms of strings, that occur at the Planck level, which lacks any direct experimental evidence (we would need colliders the size of the solar system to produce the necessary energies required there).

 

[Eh]

Well I'm not going to get into the technical aspects of the theories, since it's over my head. But apparently inflation also has many fined tuned conditions, and has many feeling the theory is very ad hoc.

But I agree that extra dimensional branes are unappealing. It seems less intellectually satisfying to require all kinds of unseen extra dimensions to explain our world than using the 3 of common experience. I must admit I am not a big fan of string theory for this reason (and the fact it's the biggest reductionist theory ever created). However, once you accept curved space as an explanation for gravity, the comfort of our familiar Eucliean world is shattered. Maybe years from now, the idea of extra dimensions won't seem such a stretch. Experimental evidence would certainly help.

 

[wuliheron]

and the fact it's the biggest reductionist theory ever created

According to everything I've ever read about String theory it most definitely is not a reductionist theory, but a holistic one. It is essentially an extension of Relativity which incorporates the Indeterminacy of QM, both of which are holistic theories.

 

[Eh]

I've heard proponents of string theory call it holistic as well. But I don't see it. It reduces everything in nature into working parts (vibrating strings) and may eventually cut up the metric tensor into little stringy bits. It may one day elegantly unify QM with GR (which it does not yet do, being background dependent) but it still smells of reductionism.

 

[wuliheron]

Well, yeah. Relativity itself is a holistic extension of reductionist Newtonian Mechanics so the resemblance to reductionist theories is understandable. Basically, its the geometric aspect that lends it towards such a view as you point out. However, like Relativity it still does not break down the spacetime continuum itself into discrete parts and is still reliant upon shaky definitions of just what exactly a dimension is.

For example, M-theory postulates that size is relative. To the best of my knowledge the theory would be utterly useless without such holistic assumptions.

 

[Mentat]

Originally posted by Eh
I've heard proponents of string theory call it holistic as well. But I don't see it. It reduces everything in nature into working parts (vibrating strings) and may eventually cut up the metric tensor into little stringy bits. It may one day elegantly unify QM with GR (which it does not yet do, being background dependent) but it still smells of reductionism.

Well, actually, it's both reductionist and holistic, as Brian Greene points out in his book.

Also, it does unify QM and GR, because it doesn't allow anything to take place below the Planck length. Thus, it agrees with QM, that at such small sizes, "weirdness" would occur. But, it keeps space "smooth", as in GR, because nothing exists at the sizes required for such "weirdness". (This was an over-simplification, but it's basically the unification.)

 

[Eh]

Yes, Michio Kaku has made similar claims, but the justification is weak. The primary entity is the string, and the parts are the fundamental things in the universe. Contrast that to a theory like GR, where force=geometry. What is more holistic than a world of pure geometry? Supergravity for example, uses the super metric tensor to describe everything from quarks to the nuclear forces. No countless abritrary parts required.

And as I'm sure you've read before, since string theory is background dependent (the strings move in a background space-time) it cannot be a complete theory of quantum gravity.

 

[Mentat]

Originally posted by Eh
Yes, Michio Kaku has made similar claims, but the justification is weak. The primary entity is the string, and the parts are the fundamental things in the universe. Contrast that to a theory like GR, where force=geometry. What is more holistic than a world of pure geometry? Supergravity for example, uses the super metric tensor to describe everything from quarks to the nuclear forces. No countless abritrary parts required.

And as I'm sure you've read before, since string theory is background dependent (the strings move in a background space-time) it cannot be a complete theory of quantum gravity.

Are you sure of that? Doesn't string theory allow for the quantized weirdness, of a quantum theory of gravity, at levels below a Planck Length - and just get rid of them by saying that there is nothing below this size?

 

[wuliheron]

Originally posted by Mentat
Are you sure of that? Doesn't string theory allow for the quantized weirdness, of a quantum theory of gravity, at levels below a Planck Length - and just get rid of them by saying that there is nothing below this size?

No, that is not what string theory proposes at all. Below the Planck length everything emerges into a parallel universe or mirror world and it is this transition is what supposidly explains the action-at-distance of the forces. In fact, the theory proposes that distances and lengths are all relative.

What it most definitely does not eliminate is Indeterminacy, which is what Ed is really arguing about. He is claiming the theory is attempting to reduce Quantum Indeterminacy to a finite quantity. This is, of course, highly speculative. Exactly where the theory is leading even the most knowledgeable people on the subject are reluctant to speculate on and publically claim it most certainly will not resolve Quantum Indeterminacy.

Considering the consistent failures of people to resolve QM in the last century, I tend to take the side of experts when it comes to String theory.

 

[Eh]

Originally posted by Mentat
Are you sure of that? Doesn't string theory allow for the quantized weirdness, of a quantum theory of gravity, at levels below a Planck Length - and just get rid of them by saying that there is nothing below this size?

That's the gist of it. In string theory, there is nothing smaller than the Planck length, nor any parallel universes required to explain particle interactions. While quantum jitters still exist, the finite limit on the size prevents those jitters from making space-time a complete mess. But apparently when describing string interactions, it is done on a fixed backdrop of space-time. In other words, strings move about in a metric the same way a point particle would when describing other field interactions. String theorists know this, and it is hoped that a background free version of superstrings will emerge from M theory.

 

[Mentat]

Originally posted by wuliheron
No, that is not what string theory proposes at all. Below the Planck length everything emerges into a parallel universe or mirror world and it is this transition is what supposidly explains the action-at-distance of the forces. In fact, the theory proposes that distances and lengths are all relative.

What it most definitely does not eliminate is Indeterminacy, which is what Ed is really arguing about. He is claiming the theory is attempting to reduce Quantum Indeterminacy to a finite quantity. This is, of course, highly speculative. Exactly where the theory is leading even the most knowledgeable people on the subject are reluctant to speculate on and publically claim it most certainly will not resolve Quantum Indeterminacy.

Considering the consistent failures of people to resolve QM in the last century, I tend to take the side of experts when it comes to String theory.

When I said that it didn't allow for anything to be below a Plancks length, I meant that it things just started to get bigger (in the "mirror world") when they get that small. Doesn't that release physicists from the need to find out what happens below a Planck's length?