The Elegant Universe

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I've just finished (belatedly) reading The Elegant Universe, and I was wondering if any of the very intelligent people here had any comments about it.

I was a bit disappointed that the subject matter doesn't lend itself more to an intuitive understanding the way relativity does; I suppose that's inevitable, given that intuition seems to have gone out the window with quantum mechanics. With all the glowing reviews, I was hoping it would give a clearer picture of string theory. I don't feel that I understand the subject any more than when I started. There again, that's probably inevitable without a thorough grounding in the math involved.

What's the current state of string theory? Has it advanced any further since the book was published? Are these advances completely opaque to the educated layman or can someone make them clear?
 
I am afraid I cannot answer any of your questions, but I have the book and have read about a third of it so far. I have found it very interesting and do think the discussion at the beginning of the book relating to "vibrating strings" gave me a good intuitive base for understanding string theory. Now, I dont think I will ever understand quite what all those dimensions are, but I think that is inherent in them, and not the book (ie, if you live in 2 dimensions 3d is pretty hard to comprehend spatially)
 
I was fine too with the first third of the book. Keep reading. ;)
 
Regarding the Elegant Universe by Brian Greene!

I am on page 350 in this book. It is hard to grasp its 10 space dimensions, and 1 time dimension. They doesn't know if the theory is correct or not, maybe experimental findings in the future will vindicate the theory, so for the moment I am skeptic about that they are on the right way! The problem with physics today is to reconcile quantum mechanics with gravity, because the geometry in Einstein's general theory of relativity is too smooth in order to describe the jerky nature of quantum phenomena, and quantum theory cannot describe gravity! The closest reconciliation I know about was made by Paul Dirac in the early 1930s, it was between special relativity, and quantum mechanics, but special relativity deals not with gravity, only relativity phenomena!

The moment has no objective time according to Einstein's special relativity theory 1905! Before, now and after, or simultaneity have no universal meaning! For instance, suppose that I am traveling in a space rocket at 90% of light speed, and I light a candle, the photons will reach my back wall and my front wall simultaneously, and my rocket's weigh is let's say 10 tones, because the rocket is at rest according to my vantage point, but it probably weighing over 20 tones, and the light's photons reaches my back wall first, because my rocket traveling forward according to your vantage point on earth! Hence what the rocket weigh, and at which moment in time photons reaches the front wall, or the back wall, have no universal meaning! The observer has a unique position in both quantum physics, and special relativity!

The physicists have also problems to reconcile relativity phenomena and quantum phenomena with a realistic universe as defined as "the universe exists independently of any observer"! Most physicists reject faster than light signals as explanation to Alain Aspects experiments, but instead explain the phenomenon as, faster than light mathematical objects, or polarization switcher A, influence photon counter B, without this influence traveling between! Except John Bell, he prefer faster than light signaling in the aether, with Einstein's faster than light speed limits rejected, according to an interview with him in Paul Davies's book, The Ghost in the Atom!

Take the Bohr atom as illustration, the more we know about an electron's momentum the less we know about its position, and vise versa! An electron orbiting the atom in a standing wave of probability distribution of Eigenstates, when this electron emits energy of quanta, and thus jumping down to a lower energy level, the electron doesn't exists between these two orbits, or levels, hence we know about its two positions, the higher and the lower energy levels, or orbits, but we doesn't know about its momentum between these levels, because the electron doesn't exist there! It is a discontinuous transfer of energy. Experiments later than Aspects' has been made in order to pin down the electron's momentum and position in a closed box, but the electron begins to bounces like crazy more, and more as the space decreases. That confirms that Heisenberg 's uncertainty principle is intrinsic in the quantum world!

The Elegant Universe by Brian Greene Chap 4: Microscopic Weirdness
If an electron is confined to a space of decreasing size, its motion (momentum) increases wildly due to "quantum claustrophobia"
http://www.mcgoodwin.net/pages/elegantuniverse.html

Quotations by Werner Heisenberg: Thus, the more precisely the position is determined, the less precisely the momentum is known, and conversely. The "path" comes into existence only when we observe it. I think that modern physics has definitely decided in favor of Plato. In fact the smallest units of matter are not physical objects in the ordinary sense; they are forms, ideas which can be expressed unambiguously only in mathematical language.
http://www-groups.dcs.st-and.ac.uk/~history/Quotations/Heisenberg.html

Werner Heisenberg 's home side!
http://www.aip.org/history/heisenberg/p08c.htm
 
Many people on the forum have read the book. I have seen mostly positive comments. I bought it about six months ago after LukeT praised it highly.

My experience is less favourable. I find something in the style unattractive, which doesn't help with the difficulty of the material. (This is personal taste of course and scarcely a valid criticism).

My biggest difficulty is with the n-dimensional visualisation and with the concept of a 1 dimensional entity to start with. Nor do I get any clear grasp of how vibration of a string would translate into physical properties like mass.

Still, it would be hopelessly naive to expect a deep comprehension of this material after one reading of any book. I often find that ideas take a while to sink in , so that next time I re-read a text, I understand more. I will persevere with the book. Certainly it's as "readable"as any text on the subject is likely to be.
 
I decided to whip out the May 31, 2003 of Scientific American. Page 12, "The Theory Formerly Known As Strings". I've read the entire article and I am mystified. I dont have the faintest idea what Cosmic Strings are some way to fine an ubertheory to link quantum mechanics and Einstiens General Relativity. Funny pictures though.
 
Yahweh said:
I decided to whip out the May 31, 2003 of Scientific American. Page 12, "The Theory Formerly Known As Strings". I've read the entire article and I am mystified. I dont have the faintest idea what Cosmic Strings are some way to fine an ubertheory to link quantum mechanics and Einstiens General Relativity. Funny pictures though.
Click to expand...

That's it in a nutshell. The book makes a great deal clear; there's just a lot that's opaque to me yet.
 
Yes, the string theory can describe General relativity and quantum phenomena, a string is a sub-quark, but the problem is that a sting has never been found!
 
Peter Soderqvist said:
Yes, the string theory can describe relativity and quantum phenomena, a string is a sub-quark, but the problem is that a sting has never been found!
Click to expand...

Hmm, my reading of it is that a quark IS a string vibrating in a certain way. Yes, living way down there in the Planck-length range, it will be a while before we observe any directly, unless as he says, one of the primordial strings fly past in the sky some night. ;)
 
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