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| 5/25 |
| 2003/12/4 [Science/Physics, Computer/Theory] UID:11308 Activity:nil |
12/3 Did anybody catch the Nova series on PBS a month or so ago on
String Theory? What do you think of it? Is this Witten guy really
that smart? He looks a bit phony.
\_ Dunno about string theory, but string practice: ~john/ringback.jpg
\_ Hot. Who's she?
\_ why the fuck do people keep talking about this goddamn show?
If you want to know about string theory, for some godforsaken
reason, read a fucking book.
\_ somepeople want a lay person's explanation to be done in
an hour. Books take much longer than that.
\_ How about http://staff.science.uva.nl/~rhd/string_theory.html
\_ I'll sum it up in two lines on the motd:
If a theory is unrelated to experiment, it's not
physics, it's philosophy.
for more information type "dict wank."
\_ Apparently you're a wank wannabe scientist who's never
read Kuhn. --williamc
\_ I heard there may be experiments with the potential
to falsify string theory coming after the CERN accelerator
comes online in 2006. -- ilyas
\_ right, and when they do, the theory will either
be falsified or just unverified. wake me when
they can calculate the mass on the electron from
frist principles or predict a new particle
acurately, or do *anything* predictive. <snore>
\_ We will eventually run out of things to predict.
A theory isn't good only if it predicts something new
(although that's really nice). A theory is good
if it doesn't contradict any data and is as small
as possible. Personally I know next to nothing
about string theory, and lack the background to
learn more. I don't know how well it fits, and
I don't know how small it is (or why there's so
\_ How about http://staff.science.uva.nl/~rhd/string_theory.html
much hype). -- ilyas
\_ wow, this is the first time i heard this show mentioned. i must
be out of it. anyway, go read Brian Greene's "The Elegant
Universe." it gets pretty dense as you get into it, but given
enough dedication, you can follow what he's writing.
\- the Witten/Schwartz/MGreen(not BGreene) is a pretty standard
serious work on string theory: http://csua.org/u/557
witten solved a problem a bunch of other people were
stuck on [i think this is descrived in vague terms in
the show, but i saw it a only in part and a while ago]
annd he's not doubt a bright guy ... but personally i
find s. weinberg more impressive and certainly more
articulate. "dreams of a final theory" is a more accessible
but still interesting book. it's also cheeper than the
GSW book ... which is a $50 "paperback" and fairly tough
going if you dont have say 2yrs of grad math. --psb
\_ did anyone in this thread express interest in
a "standard serious work?"
\- dear mr. too short: "phony physicists rarely write
standard serious works". --psb
\_ fuck off. -real physicist
\_ you lie. a real physicist wouldn't call herself
such (maybe "physics grad student" or "physics
prof"). i wont make judgments on whether she'd
be posting to the motd.
\_ doh! you got me! it turns out that i'm the
pompus ass sysadmin knowitall who learns
about the most useless theory in physics
to impress girls at parties, and you're actually
the physicist! my bad! |
| 5/25 |
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| staff.science.uva.nl/~rhd/string_theory.html -> staff.science.uva.nl/%7Erhd/string_theory.html String Theory ROBBERT DIJKGRAAF DEPARTMENT OF MATHEMATICS FACULTY OF MATHEMATICS, COMPUTER SCIENCE, PHYSICS, AND ASTRONOMY U NIVERSITY OF AMSTERDAM String Theory What is string theory? String theory is at this moment the most promising candidate theory for a unified description of the fundamental particles and forces in nature including gravity. As a theory of quantum gravity string theory is at present our best hope to give concretely computable answers to fundamental questions such as the underlying symmetries of nature, the quantum behaviour of black holes, the existence and breaking of supersymmetry, and the quantum treatment of singularities. It might also shed light upon larger issues such as the nature of quantum mechanics and space and time. In string theory all the forces and particles emerge in an elegant geometrical way, realizing Einsteins dream of building everything from the geometry of space-time. String theory is based on the deceptively simple premise that at Planckian scales, where the quantum effects of gravity are strong, particles are actually one-dimensional extended objects. Just as a particle that moves through spacetime sweeps out a curve the worldline string will sweep out a surface the world-sheet In contrast with particle theories, string theory is highly constrained in the choice of interactions, supersymmetries and gauge groups. A D-brane is a submanifold of space-time with the property that strings can end or begin on it. More information on the web Een Nieuwe Revolutie in Stringtheorie , a popular article in Dutch about recent developments, Afleiding 1 1996 7-11 in Dutch, ps-file Nonperturbative String Theory , a somewhat more technical review in English of recent developments. The Second Superstring Revolution, by John Schwarz Some recent popular literature on string theory G. |
| csua.org/u/557 -> www.amazon.com/exec/obidos/tg/detail/-/0521357527?v=glance Problems that have seemed insuperable in previous approaches take on a totally new character in the context of superstring theory, and some of them have been overcome. Interest in the subject has greatly increased following a succession of exciting recent developments. This two-volume book attempts to meet the need for a systematic exposition of superstring theory and its applications accessible to as wide an audience as possible. All Customer Reviews Average Customer Review: Write an online review and share your thoughts with other customers. Anyone interested in learning string theory could perhaps start with the current formulation involving D-branes and M theories. This is certainly possible and will lead one to the frontiers of research. However, it would not perhaps give one an appreciation of string theory that would be obtained by persuing a study that explains how it arose in the study of the strong interaction . This book, written by three giants in string theory, will give the reader such a study, and was the first book to appear on the subject. The book is a monograph, and not a textbook, since no exercises appear, but it could still serve as a reference and required reading for courses in string theory. The learning of string theory can be a formidable undertaking for those who lack the mathematical background. Indeed, a proper understanding of string theory, not just a forma one, will require a solid understanding of algebraic and differential geometry, algebraic topology, and complex manifolds. There are many books on these subjects, but I do not know of one what will give the student of string theory an in-depth understanding of the relevant mathematics. These two volumes include two rather lengthy chapters on mathematics, one on differential geometry and the other on algebraic geometry. The mastery of these two chapter will give readers a formal understanding of the mathematics, and will allow them to perform calculations in string theory efficiently, but do not give the insight needed for extending its frontiers. There have been a few books published on string theory since these two volumes appeared, but they too fail in this regard and some even admit to doing so. To gain the necessary insight into the mathematics will entail a very time-consuming search of the early literature and many face-to-face conversations with mathematicians. The oral tradition in mathematics is real and one must embed onself in it if a real, in-depth understanding of mathematics is sought. The physics of string theory though is brought out with incredible skill by the authors, and the historical motivation given in the introduction is the finest in the literature. Now legendary, the origin of string theories in the dual models of the strong interaction is discussed in detail. The Veneziano model, as discussed in this part, has recently become important in purely mathematical contexts, as has most every other construction in string theory. The mathematical results that have arisen from string theory involves some of the most fascinating constructions in all of mathematics, and mathematicians interested in these will themselves be interested in perusing these volumes, but will of course find the approach mathematically non-rigorous. Some of the other discussions that stand out in the book include: 1. The global aspects of the string world sheet and the origin of the moduli space, along with its connection to Teichmuller space. The world-sheet supersymmetry and the origin of the integers 10 and 26 as being a critical dimension. In this discussion, the authors give valuable insight on a number of matters, one in particular being why the introduction of an anticommuting field mapping bosons to bosons and fermions to fermions does not violate the spin-statistics theorem. The authors show that the manifestly covariant formalism is equivalent to the light-cone formalism and is ghost-free in dimension 10. The light-cone gauge is used to quantize a covariant world-sheet action with space-time supersymmetry, with this being Lorentz invariant in dimension 10. This allows, as the authors explain in lucid detail, the unification of bosonic and fermionic strings in a single Fock space. While the subject of string theory has undergone considerable and radical change since publication of this text and since Polchinskis recent texts takes some of the steam out of this title, overall it remains a relevant part of the literature for a number of reasons. First, vol I clearly serves a vital role as a secondary source to both of Polchinskis text and vice versa: Polchinskis vols I&II update Green / Schwarz / Wittens GSW vol I. Whereas Polichinskis vol I focuses exclusively on the bosonic strings GSW vol I includes both supersymmetric & bosonic string theory. A reader can then go along way on joining vol I of Polchinski and vol I of GSW. But probably the greatest reason to purchase this title is the insight into string theory that is offered by these particular authors - individuals who have each served as principle architects of string theory since its inception and through its many revolutions. In general, the prose is congenial as is the level of sophistication in physical and mathematical argument. The mathematical apparatus of string theory can become very heavy very quickly and these authors orient the reader in that difficult terrain in a truly adroit fashion. Green also bought titles by these authors: Steven Weinberg Michio Kaku A. |