I was trying to guess what Hawking's new book will be about. The only recent papers with his name on them I can find seem to be to do with further work on the no-boundary wavefunction. If this is the case there won't be any significant new stuff in the book, and the whole "Hawking has changed his mind about god" is completely spurious.

klazmon wrote: Lambda is the cosmological constant. An arbitrary scalar in the Einstein field equations. Einstein initially thought it must be zero but then astronomers told him the universe was static. A static universe is impossible if Lambda is zero

and why is this? Sorry if it's a dumb question but I have never even heard the term before now. Is it because a positive value means that pressure is being exerted that overcomes gravity thus meaning it doesn't collapse like a star?

,

klazmon wrote:so Einstein decided it must have a positive value sufficient to stop the universe from collapsing. Then Edwin Hubble said hang on, I can see that the universe appears to be expanding. Einstein said whoops, Lambda is zero after all.

so wait, if there is no vacuum pressure being asserted that means that dark energy is pushing the universe apart by expanding or does it mean there is no resistance and the initial expansion is still going on or have I completely butchered the concept and provoking some to bang their heads against a wall about how off base I can be?

I have to admit much of the physics here is going over my head. However, I have problems with the way Hawking's view is being portrayed by the media (and I am assuming that Hawking himself is not to blame for this.)

First of all, the impression being given is that he at one point thought God was a plausible explanation and has now changed his mind. AFAIK, he has never considered God to be a plausible scientific mechanism for the existence of the universe.

Secondly, the entire line of argument is flawed, in that it seems to state that heretofore we had no scientific explanation for the existence of the universe, therefore until this time it was intellectually acceptable to propose God as that explanation. This confers legitimacy onto the "God of the gaps" argument that it does not deserve. If Hawking is right, it doesn't mean that he has disproven an argument that was legitimate before he made his finding. It just shows how that argument was a stupid one to begin with.

Still, so long as this makes religious apologists squirm in discomfort and forces them to think of new obscurantist nonsense to salvage their pathetic arguments (I'm looking at you, William Lane Craig), I can't really complain.

klazmon wrote:

robinhood wrote:

klazmon wrote: Lambda is the cosmological constant. An arbitrary scalar in the Einstein field equations. Einstein initially thought it must be zero but then astronomers told him the universe was static. A static universe is impossible if Lambda is zero

and why is this? Sorry if it's a dumb question but I have never even heard the term before now. Is it because a positive value means that pressure is being exerted that overcomes gravity thus meaning it doesn't collapse like a star?

Think of it like a ball balancing on the point of a pin. A static universe described by the Einstein Field equations which has lambda = zero is unstable. Expansion or contraction is no problem with lambda = 0. What happens in that case depends on a density parameter called Omega. See here.......

klazmon wrote:so Einstein decided it must have a positive value sufficient to stop the universe from collapsing. Then Edwin Hubble said hang on, I can see that the universe appears to be expanding. Einstein said whoops, Lambda is zero after all.

so wait, if there is no vacuum pressure being asserted that means that dark energy is pushing the universe apart by expanding or does it mean there is no resistance and the initial expansion is still going on or have I completely butchered the concept and provoking some to bang their heads against a wall about how off base I can be?

Dark Energy is a version of the cosmological constant.

You might find this article useful:


http://super.colorado.edu/~michaele/Lambda/lambda.html

Or this if you want to get into a lot more technical detail:

http://nedwww.ipac.caltech.edu/level5/Sept02/Padmanabhan/Pad_contents.html

o.k, thanks for the links. I'll have to see if that makes anything clearer.

robinhood wrote:

Mr P wrote:Of course he's not saying anything new, Victor Stenger promotes the same idea (and goes one step further in the case of the Abrahamic god) that the universe can get along fine without a creator. Also a number of physicists are pushing the idea of a cyclic model with subsequent big bangs happening in succession i.e. Steinhardt and Turok, Lee Smolin and Roger Penrose. Penrose is about to release his new book Cycles Of Time later this month with his own take on the idea.

All of these rest on the theory that the (inherently) chaotic conditions present during the Planck era are unstable due to quantum fluctuations and it's this chaotic system that Stenger defines as nothingness. This arises from the fact that no meaningful information can be extracted from a system such as this and so rendering enquirey obsolete. This is opposed to the semantic skullduggery usually employed when people try to define nothingness.

o.k, so let me double check

Your pretty much saying that the layman's version of the term "nothing" is inaccurate in the context it's being used. In the context of the very first few moments when the universe was only a few plank units old (I hope I am using his correct measurement of time) everything was so unpredictable due to the uncertainty principle that no useful data could be attained from this because everything was constantly shifting in an unpredictable manner. So, the term "nothing" is really referring to the extreme chaos in the early universe which (might as well be) considered nothing meaningful seeing as no reliable laws can yet be applied to it. Is this correct?

That's pretty much my understanding of the situation (Disclaimer: I'm no professional scientist so these views are open to review )

The semantic argument the Stenger makes reference to is in attempting to define an "absolute" nothingness and the many linguistic pitfalls that can trap the unwary; this wiki page gives a good run-down of the philosophical and semantic problems in volved. With respect to the ideas of physicists the page goes on to state:

In physics, the word nothing is not used in any technical sense either. A region of space is called a vacuum if it does not contain any matter, though it can contain physical fields. In fact, it is practically impossible to construct a region of space that contains no matter or fields, since gravity cannot be blocked and all objects at a non-zero temperature radiate electromagnetically. However, even if such a region existed, it could still not be referred to as "nothing", since it has properties and a measurable existence as part of the quantum-mechanical vacuum.

Essentially the "something from nothing" argument rests on the definition of nothing from within the context of the reality we percieve. Philosophical arguments are all well and good if we want to tie ourselves in semantic knots but to obtain any meaningful answers then adopting a chaotic system as defining nothingness gives us a starting point and allows us to postulate a first event (for example a cosmic expansion initiated by the prior instability of this chaotic system).

...but...
Don't take my word for it as I'm still picking up a lot of new information and ideas are open to revision. Stengers thoughts on this subject are laid out in his book Quantum Gods also The Void by Frank Close gives the subject of nothing a fair hearing.

Excellent post.

BlackRogueDreams wrote:Without having read the book I can't say much but the gist of it is that he has sufficient evidence to conclude that natural processes were enough to create the universe and thus god is once again unnecessary and superfluous to requirements.

Natural processes cannot have created the natural (physical) world as a whole, since all of them are part of it.

Mr P wrote:
All of these rest on the theory that the (inherently) chaotic conditions present during the Planck era are unstable due to quantum fluctuations and it's this chaotic system that Stenger defines as nothingness.

Why do so many physicists misleadingly use the words "nothing" or "nothingness" when what they mean is actually something?!

robinhood wrote:This is the main portion of the article that bugged me. How did he draw that conclusion? I notice he says "laws SUCH AS" gravity and not gravity itself as I have origninaly misinterpreted.

Strictly speaking, there is a difference between gravity as a force and the law of gravity as a proposition describing the nature of this force.

robinhood wrote:
…So, the term "nothing" is really referring to the extreme chaos in the early universe which (might as well be) considered nothing meaningful seeing as no reliable laws can yet be applied to it. Is this correct?

A nothing is nothing, not even a chaos; for if there is a chaos, there exists something chaotic.

hackenslash wrote:Excellent post. Placeholder for an Orson.

Praise indeed.

Another point I'd like to raise is with regards to the nature of time within a chaotic system. IIRC time is an inherent part of the fabric of reality as detailed first by Herman Minkowski and then adopted by Einstein in their theories concering spacetime, however the flow of time from past to future is as a result of that pesky second law of thermodynamics. This is usually illustrated by the example of a cup falling from the edge of a table and smashing on the floor.

The reasoning goes like this; in falling from the table and smashing the cup has gone from a high energy to a low energy state, this is the second law in its most simplistic terms, heat flows from a hot area to a cooler area until eqiulibrium is reached. The problem is that all other fundamental laws of physics are symetrical with respect to time, they're the same if run in reverse, if that's the case then why do we never witness the cup re-assembling itself and regaining its former glory on the table top?

Thanks to the studies of Ludwig Bolztmann (among many others... the history of thermodynamics could be a field of study in its own right) we know that thermodynamics describes the interaction of countless molecules together with the flow of energy that these interactions convey. The second law deals with the loss of availble energy from this system of interacting molecules and is usually referred to as its entropy, with the conclusion being that entropy will always increase with time.

So here's the thing, does the flow of time depend on the second law or is it the reverse?

I gave a hint earlier when I said that all other fundamental laws of physics are symetrical with respect to time, the second law describes the actions of certain elements within spacetime and as such doesn't describe any properties of the underlying structure... you could say the second law is secondary Therefore the study of entropy is a statistical pursuit that ultimately can only deal in probabilities, i.e. the temperature of a body of gas is really a measure of the average motion of all the molecules within that gas.

So there are no prohibitions on all those gas molecules assembling themseves (via their random motion) into a state where one side of this cloud is 100 degrees hotter than the other, it's simply vanishingly improbable. The same holds with the cup now smashed on the floor, theoretically all the molecules within this system could be re-arranged (again by random motions) so that the cup sits back on the table, in one piece and re-filled with its original contents. The reason this has never been (reliably) witnessed is due to the fact that the probabilty of this time-reversal event is insignificantly small. So small in fact that an event like this would never occur in the lifetime of this universe, anywhere in this universe (or cosmic expansion, cosmic bubble, D-brane... take your pick ).

So here's the point I'm labouring; within a chaotic system the second law of thermodynamics wouldn't apply and so time has no intrinsic flow... could this be that void from which we spontaneously sprang?

Teuton wrote:

BlackRogueDreams wrote:Without having read the book I can't say much but the gist of it is that he has sufficient evidence to conclude that natural processes were enough to create the universe and thus god is once again unnecessary and superfluous to requirements.

Natural processes cannot have created the natural (physical) world as a whole, since all of them are part of it.

Could Teuton please demonstrate to me 1 un-natural process and without using these intertubez?

newolder wrote:

Teuton wrote:
Natural processes cannot have created the natural (physical) world as a whole, since all of them are part of it.

Could Teuton please demonstrate to me 1 un-natural process and without using these intertubez?

My point is simply a logical one: natural processes are by definition part of, i.e. immanent in, nature, and so you cannot consistently explain the existence of nature as a whole in terms of them.

Teuton wrote:

robinhood wrote:
…So, the term "nothing" is really referring to the extreme chaos in the early universe which (might as well be) considered nothing meaningful seeing as no reliable laws can yet be applied to it. Is this correct?

A nothing is nothing, not even a chaos; for if there is a chaos, there exists something chaotic.

This is the semantic problem I was describing earlier, using "nothing" as an indefinite pronoun means you're using the word to both describe a concept and the absence of a concept. The contradiction is the fallacy of four terms as detailed in the link I provided above.

For all practical considerations a chaotic system is nothingness, we can never extract any information from such a system while it remains in this state which renders it both inherently meaningless and unstable.

Mr P wrote:This is the semantic problem I was describing earlier, using "nothing" as an indefinite pronoun means you're using the word to both describe a concept and the absence of a concept. The contradiction is the fallacy of four terms as detailed in the link I provided above.

Yes, the absence of being is not the same as the presence of nonbeing.
I am well aware of the logico-grammatical distinction between "nothing" as an indefinite pronoun and "nothing" as a noun.
There cannot possibly be any nothings, since speaking of an existing nothing is a contradiction in terms. Nothings are necessarily nonentities, nonbeings: they do not and cannot exist. Nothings do not exist and they do not have any properties.
So much for using "nothing" as a noun.
It is doubtless impossible that a nothing exists, but this doesn't mean per se that it is impossible that nothing exists.
Here, "nothing" is used as an indefinite pronoun, and in this sense "Nothing exists" doesn't self-contradictorily mean "There is something that is a nothing" but merely "It is not the case that something exists". And whether it is really possible for there be nothing (not a nothing!) is an intricate onto-logical question that has no generally accepted answer yet.

Mr P wrote:
For all practical considerations a chaotic system is nothingness, we can never extract any information from such a system while it remains in this state which renders it both inherently meaningless and unstable.

It is still confusing and misleading to nominally equate an existing something, i.e. an entity, with nothingness, i.e. a nonentity.

Teuton wrote:

BlackRogueDreams wrote:Without having read the book I can't say much but the gist of it is that he has sufficient evidence to conclude that natural processes were enough to create the universe and thus god is once again unnecessary and superfluous to requirements.

Natural processes cannot have created the natural (physical) world as a whole, since all of them are part of it.

You assume that the physical world was created. Your statement is tautological.

"The physical world was created and didn't create itself so it was created."

Sityl wrote:
You assume that the physical world was created.

That's not my assumption. Actually, my conjecture is that nature as a whole is eternal and thus uncreated.
In my opinion, the big bang was the beginning of something but not the beginning of everything.

Teuton wrote:
Yes, the absence of being is not the same as the presence of nonbeing.

The problem is that we cannot explain being in terms of nonbeing, since nonbeing has no causal powers.
And to say that being began to be "just so", i.e. without any cause whatsoever, is no explanation at all.

"If the explanation cannot begin with some entity, then it is hard to see how any explanation is feasible. Some philosophers conclude ‘Why is there something rather than nothing?’ is unanswerable. They think the question stumps us by imposing an impossible explanatory demand, namely, Deduce the existence of something without using any existential premises. Logicians should feel no more ashamed of their inability to perform this deduction than geometers should feel ashamed at being unable to square the circle."

(http://plato.stanford.edu/entries/nothingness)

Teuton wrote:...It is doubtless impossible that a nothing exists, but this doesn't mean per se that it is impossible that nothing exists.
Here, "nothing" is used as an indefinite pronoun, and in this sense "Nothing exists" doesn't self-contradictorily mean "There is something that is a nothing" but merely "It is not the case that something exists". And whether it is really possible for there be nothing (not a nothing!) is an intricate onto-logical question that has no generally accepted answer yet.

The potential to do work when a force is applied can neither be created nor dstroyed, I believe (based on available evidence) that the absence of all things is an impossibility. When talking about this absence we are framing our comments in a temporal framework, we talk about a prior state of unbeing somehow giving rise to the reality we percieve around us and it's this temporal frame that renders the philosphical interpretation of non-being as irrelevant. The closest we have come to taming the void is by defining a chaotic system as the absence of organised structure (and by extension information). My post regarding the 2nd law touches on the possibly timeless nature of this system but one problem I've found is how do we discuss the properties of a system where the flow of time can't be guaranteed?

Teuton wrote:

Mr P wrote:
For all practical considerations a chaotic system is nothingness, we can never extract any information from such a system while it remains in this state which renders it both inherently meaningless and unstable.

It is still confusing and misleading to nominally equate an existing something, i.e. an entity, with nothingness, i.e. a nonentity.

Personally I think the error lies in trying to establish the concept of the absence of all things.

Edited to fix tags.