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The Road To Reality

  1. Nov 28, 2004 #1
    Hi, has any one read "The Road To Reality" by Roger Penrose? It looks quite complicated if you browse through it but I started reading the book and in the preface Penrose says that in the first 17 chapter he develops and explains all the mathematics necessary for the rest of the book. Is this really true? Is it easy or hard? I need some feedback. I was literally drooling over this book at the book store, a fairly mathematical treatment of loop quantum gravity in the last chapter! and the author claims that all needed mathematics will be explained! its like a dream!. Well any way, all feedback is welcome, tell me if its impossibly hard to understand or fairly easy or whatever.
  2. jcsd
  3. Dec 4, 2004 #2
    i have it. i had to ship it from the uk to hawaii = P. its a truly amazing book. definitly a must have. it is not meant for those that are weak at math though. he does explain what you need to know, but unless you have a pretty good math background, its really confusing. you could glance through it and give it a try. i love it.
  4. Mar 3, 2005 #3
    i saw this at the book store. I was tempted to buy it, but I saw the math and decided that i'd better not. I still want it though. heh
  5. Mar 3, 2005 #4

    James R

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    I have only browsed through it, but it looks like Penrose takes a fair amount of math for granted in the book. I think it would be heavy going for somebody with no background in math.

    My advice: if this is your first physics/math book, it is probably not a good place to start. You'll most likely get lost very quickly.
  6. Mar 12, 2005 #5
    The book gives this website for finding the solutions to the exercises:


    But, when you click on "solutions" there's just a note from Penrose saying he hasn't got around to posting them and they might be there in "November." What.. November 2012?

    Does anyone know if there's another place that has the solutions?
  7. Mar 15, 2005 #6
    I picked this up a week ago and I must say.. wow, GREAT book. I am only on page 90 right now, but it does a great job at starting from the beginning and covering most everything. Rather than just seing the "popular" belief, Penrose tries to give the reader many different opinions and ideas and he states each very nicely. This book is not one to read straight though like a novel, but if you have time and like to learn a thing or two, definitely check it out.
  8. Mar 17, 2005 #7

    James R

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    I couldn't help myself. I went out and bought the book, too, and am reading through it. So far, I'm only up to around Chapter 9.

    Penrose takes quite a bit for granted, and skips over a lot of things in his explanations. For example, he lost me with his discussion of Riemann surfaces, and this is something I'm supposed to know something about.

    The book is good for getting a taste of what's out there in terms of maths and physics, but in no way is it a textbook. You couldn't use it as the basis for teaching a beginner or intermediate course in maths or physics - at least not without bringing in a lot of supplementary material.

    It's always interesting to read a book which sets out the ideas of a deep thinker who has been working on stuff for years. This is a good book, but probably doesn't quite achieve its stated aim of being very accessible to the general public.

    For confirmation, just look at some of the "exercises", mentioned above. It would be very difficult for somebody who only had Penrose's book to complete many of the exercises (particularly the ones he classifies as intermediate or hard).
  9. Mar 17, 2005 #8
    it's definitely not for someone who has not had much mathematics. I was ok through chapter 7. I did not have much a clue on 8 and 9. I'm currently learning some calculus. I'm on calc II next chapter. I guess I have something to push me. I would like to understand as much as I can of this book. Penrose loves complex numbers. I never knew they were so cool.
  10. Mar 17, 2005 #9
    Well, you're not supposed to learn anything about physics until after Ch. 16, right? Aren't the first 16 chapters just mathematical context?

    And if anyone ever finds a web page for the solutions, please post it here. The site I mentioned above makes it look like Penrose just forgot.
  11. Mar 18, 2005 #10
    I have it. It is a great book, but fairly advanced. Do not be intimidated if you don't understand everything in the book - it is basically an informal discussion of graduate level math. As far as complex numbers go, the book he mentions, Visual Complex Analysis, written by one of his students, is absolutely fantastic - THE book on complex analysis.
  12. Apr 9, 2005 #11
    I have the book and I like it, but I wouldn't recommend it to a layperson. Perhaps the ideal readership would be math graduates who would like to understand some physics. Such graduates should have taken courses in com-plex analysis (and a bit of Riemann surface theory would not go amiss), differential geometry, general topology (a bit of algebraic topology would also be helpful), group theory, some representation theory, classical mechanics and classical electrodynamics. The Road to Reality is not a text, nor could it be within the scope of a mere 800 pages. It gives a heuristic overview that will only be comprehensible to those who already know the mathematics.

    I see the book has been favorably reviewed by the press, and I can't help wondering whether the journalists assigned to write the reviews understood the book at all.

    The book by Needham, titled, Visual Complex Analysis, is interesting, and on my shelves, but not one I'd recommend for a standard first course in the subject. Penrose wrote a favorable review for it perhaps because Needham refers to him obseqiously every few pages.

    In summary, if all you've taken are a couple of calculus courses, you might like to have the book for the purpose of inspiration, but don't think you'll understand what a connection is, or what Cartan's exterior calculus is.
  13. Apr 12, 2005 #12
    Needham quotes Penrose obseqiously in his book - he was one of his students.

    They didn't. I read the review in the New York Times, it was hilarious. There was one quote, I don't remember it exactly, but it was something like, "I must admit that I stuggled with the concept of a '(1,3) valent tensor'", or i.e. the reviewer didn't understand a word of what he read.
  14. Apr 15, 2005 #13
    I seem to agree with all the posts so far. I am currently reading my girlfriend's copy of this book and am thoroughly enjoying it, but I am not moving through it at other than a snail's pace (in my defence, I always take my sweet time getting throught the intro/review chapters, getting bored, but still plod through them in the event there is something I was not aware of). I have a great respect for Prof. Penrose. I just think he may be a bit (read, way the hell) too optimistic about either the knowledge level, intelligence, patience, or interest of the general public. His treatments of the mathematics are obviously and understandably not as in depth as a textbook, but imho, still a bit much for joe armchair-physicist out there. But, as I said, I am enjoying this book.
  15. Apr 30, 2005 #14
    I'm on chapter 26 now. I love Quantum Mechanics. Can't wait to read bout the other theories too. I'll probably never learn the math, especially not on my own, but at least I'll reconize terms now when browing the physics boards or when reading other physics books. Sometimes I had to push myself to read on in some of the math sections because I knew greater things were coming up. I can see how some of the math might be interesting though. I was glad one I got to the physics.
  16. May 1, 2005 #15
    So the book is worth than i take it...i keep glancing at it here and there when i visit chapters....apparently its been taken off shelf and a new one is coming out 2005-10 or 2005-11
  17. May 2, 2005 #16
    People keep mentioning how hard the maths is in the book, but what background of maths do they have?

    Could people tell me how good they are at maths so I can compare with me, see if I would be able to understand it. I obviously won't stand a chance if you are all undergraduates :)
  18. May 5, 2005 #17
    My background is only calculus I in college, a bit of Calc II from highschool and review lately, and I just learned a bit about vectors. Vectors are cool!
  19. May 5, 2005 #18

    James R

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    I am at PhD level in physics. There is maths in the book that is vaguely familiar to me, but not explained in enough detail for me to fully understand it without looking at other references.
  20. May 5, 2005 #19
    like cliffoard algebra?
  21. May 16, 2005 #20
    I see there is a new edition of the book coming out on October 25, 2005. Does anyone know if it'll include anything new? Like exercises with answers?

    I really want to buy it, but don't want to end up double dipping when/if an improved version is released.

    Also, for the people who have read it, how will an ignorant fool like myself only acquainted with math up to a little of differential equations and vector calculus fare with this mammoth?
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