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Philosophy of Quantum Gravity

  1. Feb 7, 2007 #1
    has someone taken a look to this book?
    The Structural Foundations of Quantum Gravity

    contents

    Quantum Gravity Meets Structuralism: Interweaving Relations in the Fundation of Physics
    by Dean Rickles and Steven French

    Structural Realism and Quantum Gravity by Tian Yu Cao
    (I also remember his book Conceptual Developments Of 20th Century Field Theories)

    Structure, Individuality and Quantum Gravity by John Stachel

    Points, Particles, and Structural Realism by Oliver Pooley

    Holism and Structuralism in Classical and quantum General Relativity by Mauro Dorato and Massimo Pauri
    The first is a philosopher who knows well Carlo Rovelli, the latter is an old good man of italian physics with interest in epistemology.

    Time and Structure in Canonical Gravity by Dean Rickles

    The Case for Background Indipendence by Lee Smolin

    Quantum Quandaries: a Category-Theoretic Perspective by John Baez


    the book is just published, so it's quite expensive yet...
    I put it in my wish list, saved for later :frown:
    but it would be interesting, don't you think?
     
    Last edited: Feb 7, 2007
  2. jcsd
  3. Feb 7, 2007 #2

    marcus

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    Francesca, I think you may already know this, but I will say anyway---these two chapters of the book (by Smolin and by Baez) may very possibly already be available on the arxiv. Or at least earlier drafts.

    Both of them are very interesting papers:

    http://arxiv.org/abs/hep-th/0507235
    The case for background independence
    Lee Smolin
    46 pages

    http://arxiv.org/abs/quant-ph/0404040
    Quantum Quandaries: a Category-Theoretic Perspective
    John C. Baez
    21 pages, 2 figures

    Also this has appeared at arxiv. I haven't read it but the abstract is interesting.
    http://arxiv.org/abs/gr-qc/0507078
    Structure, Individuality and Quantum Gravity
    John Stachel
    39 pages, to appear in "Structural Foundations of Quantum Gravity," edited by D.P. Rickles, S.R.D. French and J. Saatsi Oxford University Press

    "After reviewing various interpretations of structural realism, I adopt here a definition that allows both relations between things that are already individuated (which I call 'relations between things'') and relations that individuate previously un-individuated entities ('things between relations'). Since both space-time points in general relativity and elementary particles in quantum theory fall into the latter category, I propose a principle of maximal permutability as a criterion for the fundamental entities of any future theory of 'quantum gravity'; i.e., a theory yielding both general relativity and quantum field theory in appropriate limits. Then I review of a number of current candidates for such a theory. First I look at the effective field theory and asymptotic quantization approaches to general relativity, and then at string theory. Then a discussion of some issues common to all approaches to quantum gravity based on the full general theory of relativity argues that processes, rather than states should be taken as fundamental in any such theory. A brief discussion of the canonical approach is followed by a survey of causal set theory, and a new approach to the question of which space-time structures should be quantized ends the paper."
     
    Last edited: Feb 7, 2007
  4. Feb 8, 2007 #3
    Thank you Marcus! I find also these:

    http://fds.oup.com/www.oup.co.uk/pdf/0-19-926969-6.pdf
    Quantum Gravity Meets Structuralism: Interweaving Relations in the Fundation of Physics
    by Dean Rickles and Steven French

    http://philsci-archive.pitt.edu/archive/00001606/
    Holism and Structuralism in Classical and Quantum General Relativity
    Dorato, Mauro and Pauri, Massimo (2004)

    http://philsci-archive.pitt.edu/archive/00001845/
    Time and Structure in Canonical Gravity
    Rickles, Dean (2004)

    http://philsci-archive.pitt.edu/archive/00002939/
    Points, particles, and structural realism
    Pooley, Oliver (2005)

    http://philsci-archive.pitt.edu/archive/00001845/
    Time and Structure in Canonical Gravity
    Rickles, Dean (2004)
     
    Last edited: Feb 8, 2007
  5. Feb 24, 2007 #4

    john baez

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    Yeah, I have.

    I'll talk about in my next Week's Finds - week246. (Don't click on the link until, oh, maybe February 25th or so.)
     
  6. Mar 5, 2007 #5

    john baez

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    Sorry, I changed my mind. Since I wound up talking about Peter Woit and Lee Smolin's rather controversial books, I decided not to get this book involved in the ensuing fistfight. Saying physics is stuck is bad enough; saying that philosophy might help is even more outrageous. :rolleyes:

    I'll mention it later...
     
  7. Mar 6, 2007 #6

    Chronos

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    Agendas are hard on the spirit. Both Woit and Smolin are brilliant, and gifted wordsmiths, but appear to enjoy being embroiled in controversy for no obvious reasons. Perhaps it is merely a subtle political maneuver. I truly admire Smolin, but, I don't think physics is stuck - merely that we have entered the age of impatience. The advances in physics have been breathtaking over the past decade IMO.
     
  8. Mar 6, 2007 #7

    marcus

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    blowing the whistle is a moral choice, I think in large part.
    It may not benefit the whistleblower---there's an opportunity cost: spending time and energy differently might have been individually more rewarding.

    Smolin's book put the top institutions on notice to show some non-string QG research.

    It looks like Martin Bojowald has a parttime appointment at KITP now. Looks like, I don't know anything for sure about it.
    Derek Wise has a job at UCDavis.
    Last year people like him were going to Utrecht.

    It is hard to imagine history different and say "what if?" what if Smolin/Woit hadn't written their books?

    As of last year there was only ONE PLACE in the US that had a nonstring QG group that is more than one faculty. Normally you don't get postdoc money if you dont have a group. Solo faculty don't get postdocs.
    I think it was clear something had to be done, even if it was just light a stick of dynamite.
    Only ONE GROUP in the whole United States is not right.

    I don't think Smolin is temperamentally disposed to fights. I just think he has a moral streak, like some kind of quaker. sometimes they are the only ones who will stand up.

    About woit's motivation, i wouldn't speculate. But I'm glad both did what they did. There is a lot more interesting discussion going on now than back in 2004, say. something opened up. something cleared the air of some mugginess. Anyway that's my two cents:smile:
     
  9. Mar 6, 2007 #8
    honesty of thought...

    I feel the same when I have to talk with people without science background.
    There are not so many people interested in science...
    I want to interest them and go beyond the very stereotypes, so I'm often divided between the vision of science as the best way to knowledge and my deep feeling about science in my will... Even if I love science I want to see it changing! first we have to be honest about what we know in Nature and about our methods, and this raise of consciousness would be easier if we deal with philosophy since it's a long time that philosophers have to do with honesty of thought...

    -----------------------------------------------------------------------------
    "You should be the change that you want to see in the world." Mahatma Gandhi
     
  10. Mar 6, 2007 #9
    This is, by far, the most important quality we must have as scientists.

    Christine
     
  11. Mar 6, 2007 #10

    marcus

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    shhhhh. the fundamental zeroth order approximation: the more true, the more it upsets people to be told :biggrin:
    this is why God made the "rolleyes" smilie
     
  12. Mar 7, 2007 #11

    Chronos

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    Honesty does not emerge without a price - and the price is humility. Falsifiability is the token offering to the gods of science. Faith is not an issue in science, well reasoned objective conclusions are the only issues that interest me.
     
  13. Mar 7, 2007 #12
    But faith is a part of our way of reasoning... many scientists started from Faith to gain their great discoveries! The problem arises when you are not honest in showing what you state and what is experimentally given. For example I can only have faith that gravity like everything in Nature have to be quantize! I must have faith in quantization itself because I can't be sure that it is a fact of Nature rather than a issue in epistemology.

    ps: there is a lot of literature about science and faith...
    first time I enjoyed this question was with this book
    Pythagoras' Trousers: God, Physics and the Gender Wars by Margaret Wertheim
     
  14. Mar 8, 2007 #13

    Chronos

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    In that case, we are kindred spirits . . . not that it matters. I could care less about who is right or wrong, I just want to know. I am not attached to any theory of anything. I have no preconceived notions - at least none that I am aware of - I enjoy the input from people like Christine, who know what they are talking about. Nearest thing to a religious experience to me. And kudos to John Baez. He is my personal hero. He finds the time to make science understandable to morons like me. To all I say, please keep up the good work. Some of us pay attention and care about teaching our children the right way to conduct the business of science.
     
  15. Mar 8, 2007 #14

    john baez

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    There's no one "like him" (words of a proud thesis advisor)... but anyway, here's the story:

    He got an offer at Utrecht, and it was darn tempting, but his wife would not have been able to get a work permit. Also, the Utrecht job would be at a physics department, which might lessen his chances for a good math job further down the road. Since his Ph.D. will be in math, and he seems to enjoy the slower more contemplative existence of a mathematician, a math postdoc seemed a bit more suitable. U.C. Davis is also very attractive: Steve Carlip is there doing quantum gravity, there's an excellent group in the math department studying hyperbolic 3-manifolds (= 3d Riemannian gravity with cosmological constant), and there's Greg Kuperberg, who is an expert in quantum topology.
     
    Last edited: Mar 8, 2007
  16. Mar 8, 2007 #15

    marcus

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    I'll take responsibility for stating what may or may not be an accurate paraphrase:

    Saying physics is stuck is true enough; saying that philosophy might help is even more true.

    Chris Isham just posted four hefty papers on arxiv yesterday (this is not news to JB, I expect, but might be to some others reading this thread).


    A Topos Foundation for Theories of Physics

    http://arxiv.org/abs/quant-ph/0703060
    http://arxiv.org/abs/quant-ph/0703062
    http://arxiv.org/abs/quant-ph/0703064
    http://arxiv.org/abs/quant-ph/0703066
     
    Last edited: Mar 8, 2007
  17. Mar 8, 2007 #16

    marcus

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    As his advisor you naturally look at it from his point of view and explain the choice in terms of D.W. career pros and cons but as a California QG watcher and sportsfan I simply relish our good fortune to have Derek Wise on the West Coast at least for a while.

    There is a chance of a West Coast QG axis developing.

    And yes UC Davis looks attractive. it looks to me like more is happening there than at UC Berkeley! And has been (with Carlip) for some time.
    The only sign of life I could see from Berkeley lately was that Dah-Wei Chiou who had been doing string, got out of there and went to Penn State to work in Ashtekar's group.

    It is great that they are doing 3D hyperbolic manifold geometry at UC Davis.

    Without predicting anything so optimistic, I can at least contemplate the possibliity of increased traffic and collaboration up and down the coast between Davis and SantaBarbara. It is a little like in a Go game where some black stones appear and begin to suggest a pattern in a place where there weren't any before.
    Pardon the effusion of happiness.:smile:
     
    Last edited: Mar 8, 2007
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