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Cougar
2012-Jan-15, 08:33 PM
I couldn't find the previous discussion on Hawking's and Mlodinow's recent (2010) book, The Grand Design, so I guess I'll start a new one. This just came in at my local library, so I picked it up and skimmed it to see just what the heck they were talking about.

You know, the book is probably entertaining enough. There is certainly an abundance of Stephen's sense of humor. And Mlodinow... oh, that's right, he wrote Feynman's Rainbow about his full-ride post-doc experience at Cal Tech, how he just kind of wandered around asking the other faculty what they thought he should do. Then apparently he ended up doing some screenwriting for Star Trek: The Next Generation and MacGyver. And now co-authoring a book with Stephen Hawking....

But I was looking to see if they were taking any liberties with the science. I seem to recall some pretty wild claims being attributed to this book. And indeed, Hawking seems to be pulling a Dawkins. He's claiming to discount the necessity for anything supernatural with respect to the existence of our Universe. While I basically share this viewpoint, I don't think Hawking presented anything new to support such viewpoint. I'm generally disappointed with his modelling, and even some of his accuracy.

First of all, it was kind of weird that the first page would state that "philosophy is dead," and then they would proceed to talk about philosophy for 10 or 20 pages.

But then, as is common, they exalt the Greeks as the ones who planted the seeds of science, so to speak. Remarkably, I had just finished reading Dick Teresi's book, Lost Discoveries: The Ancient Roots of Modern Science, which was most emphatic about how the Greeks were NOT the originators of non-trivial mathematics and modern science, but the breakthroughs in mathematics were known much earlier and later learned by the Greeks from... the Egyptians and Babylonians.

OK, but the science? The claims? I'm not sure what the claims are, or were, so I don't want to go after any straw men. But it appeared to me that Hawking took Feynman's quantum sum-over-histories approach to the evolution of our universe, blithely and literally concluding that this puts us in a multiverse, thus explaining the fine tuning problem. Of course, the multiverse solution to the fine-tuning problem is very popular these days, and has been for at least a decade. But I daresay that summing over histories is not going to get you there! Perhaps that's what all that philosophy was about. Hawking was qualifying that your model-dependent reality didn't necessarily have to be 'realistic.'

At any rate, the scientific highlight, perhaps, is Hawking's insight that the nature of time at t=0 is not going to be anything like our experience with time, pointing out that General Relativity makes the time dimension more "space-like" in such extreme circumstances. That has not typically been the explanation to the question of time in the vicinity of the big bang...

But beyond that, they seem to rely on, essentially, Guth's free lunch in order to state, "We don't need no..." uh, supernatural being, or even any external spark, since even from the beginning, the free lunch has been, well, free. There is a balance of energy in the observed universe.

But that was pointed out over 20 years ago....

I'd say the writing is a lot better than Stephen's Brief History, but there's not really any breakthrough announcements here, and the sum-over-histories argument seems awfully fantastical....

Selfsim
2012-Jan-15, 10:25 PM
Hi Cougar;

IMHO, I get the distinct feeling that in this book, Hawking seems to be 'handing over the reins' to his fellow leading edge theoretical researchers. In the process of doing this, he seems to have had to yield to all of those he has been seen to have tormented over the years (?) :)

I think overall, it may also be said that over the years, Hawking has mostly fallen towards the Classical approach on Cosmology, (and Astrophysics), and I find it amusing that in the final paragraphs, he has given his full endorsement to the M-Theory approach (?) :)

The multiverse concept, I think, is becoming the defacto in mainstream and it is difficult to envisage that either this, or M-theory, will disappear in the medium term. Perhaps if the LHC finds no evidence of supersymmetry, these ideas will have to rise up in their own defence, so perhaps we'll then see some kind of significant backlash and feel a major 'disturbance in the force' (?).

The mathematical concepts of the Infinite Universe also lead straight to the multiverse as well, so I guess even if the quantum sum-over-histories approach is contested, then there is still some fallback.

I also share your views on his/their seemingly unintended defense of philosophy following the 'philosophy is dead' comment. Although I have the impression that this was a dig at general navel-staring 'Philosophy', and that in this, he/they were attempting to distinguish the Scientific Philosophical principles of QM and Classical, which leads to what they see as far more productive outcomes (?)

Overall though, (IMO), it is certainly an interesting read, even if only for the spectacle of seeing how Hawking too, can re-orient his outlook, as research uncovers more persuasive arguments.

Thanks kindly for a great review .. much appreciated.

Regards

Cougar
2012-Jan-17, 02:40 AM
The multiverse concept, I think, is becoming the defacto in mainstream and it is difficult to envisage that either this, or M-theory, will disappear in the medium term.

Undoubtedly right, yet the multiverse concept is currently no better grounded than supernaturalism, with no prospects of changing that. M-theory could be onto something, but that's not yet known either. The six curled up dimensions are currently a 'leap of faith', but I'll know more after I've finished the OTHER book I checked out of the library: Shing-Tung Yau's 2010 book The Shape of Inner Space, String theory and the geometry of the universe's hidden dimensions. Yes, that's Yau of Calabi-Yau fame. Co-author Steve Nadis. My kinda book!


Perhaps if the LHC finds no evidence of supersymmetry....

AFAIK, string theory demands it. If they don't find it, they'll still say it's there, it's just really hard to see. Would be nice to find, to put it most understatedly.

Selfsim
2012-Jan-17, 03:31 AM
Undoubtedly right, yet the multiverse concept is currently no better grounded than supernaturalism, with no prospects of changing that.
I think the multiverse concept has a lot more physics behind it than the Supernatural.
In most of the legitimate versions of this I've seen, things which happen in each of the parallel universes, within the overall multiverse, are still determinable via the Laws of Physics. The Fine Tuning parameters may vary between them, so as to make them unrecognisable to us, but they still follow the same Laws we do.

Anyway, as far as I'm concerned, it is only a concept for extending thinking beyond our observable universe .. and there's plenty of that left for us to explore ! I think I'd have to classify the multiverse somewhere between pure belief and a hypothesis .. 'concept' seems like as good a term as any.


M-theory could be onto something, but that's not yet known either. The six curled up dimensions are currently a 'leap of faith', but I'll know more after I've finished the OTHER book I checked out of the library: Shing-Tung Yau's 2010 book The Shape of Inner Space, String theory and the geometry of the universe's hidden dimensions. Yes, that's Yau of Calabi-Yau fame. Co-author Steve Nadis. My kinda book!
That sounds interesting ! Love to see your review of that one ! :)


AFAIK, string theory demands it. If they don't find it, they'll still say it's there, it's just really hard to see. Well ... maybe... its another LHC outcome which will be interesting to watch out for. It'll also be fun to watch how the String guys handle a possible non-finding ... I know Brian Greene has said he would be 'thrilled' if they could rule out String Theory because he's not wedded to any 'particular theory'. He says he's still focused on observation/experimentation. I think many other String Theorists are of this view, also.

Would be nice to find, to put it most understatedly. A huge 'relief', eh ?
:)
Cheers