what is the simplest way of describing string theory?
106275
These are very thorough answers.  But you asked for "simple," so here goes...\n\nAccording to string theory, "strings" are the fundamental building block of all matter...the old fashioned ones (atoms and/or their consituent parts) are in fact nothing more than strings vibrating a certain way.  If they vibrate one way, they're electrons.  If they vibrate another way, they're protons.  And so on.
1120091
String theory is a physical model whose fundamental building blocks are one-dimensional extended objects (strings) rather than the zero-dimensional points (particles) that were the basis of most earlier physics. For this reason, string theories are able to avoid problems associated with the presence of pointlike particles in a physical theory.\n\nM-theory: M-theory is a cutting-edge theory of physics that deals with the extension of superstring theory. It is somewhat contentious in the physics community, in the absence of experimental backup. If ever experimentally verified, M-theory and string theory would represent remarkable advances in science.
1131781
Superstring theory is an attempt to explain all of the particles and fundamental forces of nature in one theory by modeling them as vibrations of tiny supersymmetric strings. It is considered one of the most promising candidate theories of quantum gravity. Superstring theory is a shorthand for "supersymmetric string theory" because unlike bosonic string theory, it is the version of string theory that incorporates fermions and supersymmetry.\n\nThe deepest problem in theoretical physics is harmonizing the theory of general relativity, which describes gravitation and applies to large-scale structures (stars, galaxies, super clusters), with quantum mechanics which describes the other three fundamental forces acting on the microscopic scale.\n\nThe development of a quantum field theory of a force invariably results in infinite (and therefore useless) probabilities. Physicists have developed mathematical techniques (renormalization) to eliminate these infinities which work for the electromagnetic, strong nuclear and weak nuclear forces, but not gravity. Thus the development of a quantum theory of gravity must come about by different means than were used for the other forces.\n\nThe basic idea is that the fundamental constituents of reality are strings of the Planck length (about 10−35 m) which vibrate at resonant frequencies. The tension of a string (8.9×1042 newtons) is about 1041 times the tension of an average piano string (735 newtons). The graviton (the proposed messenger particle of the gravitational force), for example, is predicted by the theory to be a string with wave amplitude zero. Another key insight provided by the theory is that no measurable differences can be detected between strings that wrap around dimensions smaller than themselves and those that move along larger dimensions (i.e., effects in a dimension of size R equal those whose size is 1/R). Singularities are avoided because the observed consequences of "big crunches" never reach zero size. In fact, should the universe begin a "big crunch" sort of process, string theory dictates that the universe could never be smaller than the size of a string, at which point it would actually begin expanding.
62175
Actually, the wiki on this one is unusually good (and right, for once):\nhttp://en.wikipedia.org/wiki/Cosmic_string\n\nCosmic strings are sometimes confused with the strings of string theory.  There's considerably more observational evidence for the former than the latter. \n\n(I say they're different things, but every time someone like me says something like that, some party-pooper like Bohr comes along and makes a liar out of us.  There's a chance, in my mind at least, that they could be closely related somehow since, supposing either of the things even exist, they're both topological defects in space.  But, that's pure conjecture on my part).\n\nMichio Kaku of the City College of New York has written on both.  If you're looking for something on string theory, and not cosmic string theory, Barton Zwiebach has written the only introductory book worth reading.  If you really did mean cosmic strings, there are several recent journal publications listed in that wikipedia article (and they're all, for once, actually referreed journals).\n\nAs an aside, I see a lot of people posting on both of these around here as though they were somehow proven fact.  There is almost no observational evidence for cosmic strings, and there is none at all for string theory.  There isn't anything wrong with thinking about things like this -- that's where new answers come from.  It's just that I'd like to see the certainty levels turned down a bit.  In the case of string theory, the theory is in much better shape than it was a few decades ago, but it still has no real central theme, it has no real sharp predictions (like the Higgs-Boson, for example, of the standard model of particle physics), and absolutely no experimental verification or support of any kind.\n\nIt just kind of torques me a little that so many people run around on these boards decrying the theory of evolution as unproven, wild-ass conjecture (when, in fact, the evidence supporting the theory of evolution has been more exhaustively catalogued than it has been for probably any other theory in history), while still others are lauding string theory as something as sure as Maxwell's equations.  String theory is a fun idea, and probably a necessary one, but it isn't a sound idea just yet.
1087038
lets see there are different theroies about the fundamental particles............but answering you qestions i will say the "strings" are the fundamental particles and we physicist now belive that all the fundamental particles which we have establish through some experiments are basically made up of these strings......a string in a perticular mode behaves as a perticular fundamental particle like protron neutron electron or quarka etc
460477
42- the theory from Hitchhiker guide to the Galaxy Clever\n\nString Theory- although this is anUnified theory of everything it is not the lone one. \n\nThe theory of everything is a single theory that unifies everything else. Something that would tie for instance F=ma to E=mc^2 and still be able to explain chaos theory, it's pretty new cutting edge stuff.
336869
They can't be explained. That's why the aforementioned string theory hasn't met a wide acceptance. There are other difficulties with string theory, but they would take a while to explain.
552057
i string theory is just cool as it integrated all the basic forces of nature and is attempt to bring everything in physics under 1 theory. but like all theories, it has its draw backs.
157131
Bosonic string theory was the first version of string theory. Bosonic string theory, which dealt with string’s vibrational patterns, emerged in the 1970s. This was replaced by supersymmetrical string theory. M-theory in 11 dimensions gives rise to five string theories in 10 dimensions.
994795
No. Actually, the string theory is dominating physics. The string theory tries to combine the Theory of relativity and the quantum mechanics, forming the so-called " theory of everything". This theory should combine all the four elementary and fundamental  forces - Gravity, Weak Nucleur Force, Strong Nucleur Force, and the electromagnetic force. The String theory is still in progress. If you want to know more about this from me, e-mail me at supratim1_dey@yahoo.co.in.\nI am actually a theoretical scientist researching on the string theory. You have a very nice question. I will recomend you two books of Stephen Hawking - 1- Brief History of Time and 2 - Black Holes and Baby Universes.
328729
Well, if you want to break it down even more, the universe only consists of minscule, vibrating strings.  At least, that's the most widely accepted theory in fundamental physics right now.\n\nThe beauty of it all is how much complexity can arise from such simple fundamentals.
891719
In all honesty you can't. String theory is so mathematically complex that you basically need a PhD in string theory to understand it, in fact most PhD physicists who are not string theorists don't understand it, nor do the want to (and a lot of them are opposed to it).\n\nString theory is a very dangerous endeavor. Some of the stuff it suggests (like time travel) are fun to think about, but it has yet yielded an experiment that could be used to test its validity. There has never been anything observed, no measurement taken, that could prove sting theory true or false. So far, it is only a set of very complicated mathematical expressions that may or may not describe the world we live in. \n\nI think its great that your cousin has taken an interest in physics. But I think it would be best if you steer him away from books on string theory. There are many fascinating physical phenomena that have been observed that have nothing to do with strings. I would suggest that he read "1 2 3 ... infinity" by Gamow.
500423
A super string is a model for an elementary particle.\nIn the Standard Model, quarks, electrons and the like are considered to be pointlike. This gives problems at short distances where for instance the electromagnetic force between two of time becomes infinite.\n\nThe basic idea of super strings is that the fundamental constituents of matter are strings of a length of order of 10^35 m which vibrate at specific frequencies. However, the simplest string theories give more problems then they solve and consistent theories requires more then four dimensions.
258791
This might not be one sentence, but might help in understanding the concept easily. \n\nOk...now...in simpler terms..\nWe all are familiar with an atom. Atom is made up of core nucleus and electrons around the nucleus. If you look inside the Nucleus, you will find protons and neurtons. If you further look inside protons and neutrons, you will have quazars. We were stuck there until the string theory came along. Now...Sting theory suggests that quazars has something inside and that is nothing but a vibrating string of energy(light), which gives it the structure. \n\nSo in sense, its like saying..we have different atoms because deep inside, the string of engery is vibrating with different nodes. Difference in string vibrations is what gives difference in structure of atoms from inside, which is translated outside. Its an interesting concept. \nBoth scientists and philosophers are equally interested in this because string theory says that it all boils down to the vibrations of strings of energy in the subatomic level. So that is like saying....matter might look solid but deep inside, its just energy...more like an invisible light. \nHope this explanation helps. Ofcourse there is more to it than what i explained. There is tons of mathematical calculations and revolutionary ideas in quantum physics that goes with string theory. They are still working on it. Try watching "The elegant universe". It was originally aired in PBS, but i guess you can buy it in bookstores like Barnes&Nobels. Its fantastic. You can understand it easily since they show animations of it.
518055
Ever since man took an interest in the sciences, from perhaps the time of Aristotle onwards, from time to time great ideas have been put forward. Some of these have seemed initially ludicrous, and turned out to be so. Others, with a little development, have given us a great insight into the way that the world works and enabled us to move on. \nAt a given moment of time, it may appear that what we know is fairly correct and will correct timelessly. However, history has shown that this is not the case. Eventually, perhaps, we will know everything, but right now this is far from the case. \nTake one of the fundamental aspects of physics, for instance. For a long time now people have thought that the matter is made up of tiny, invisible particles; atoms and their sub-components. This is the model we learn and that everyone worked around. \nYet in recent times, this has been challenged, by what is known as string theory - and it now seems that this is a better model, perhaps the more 'correct' one. \nString theory, against the traditional theory of matter, says that matter is caused by the vibrations of a string-like structure. These are the fundamental building blocks of matter. It is a bizarre sounding radical theory at first, but now has much support. \nJust like a violin string when plucked will produce sounds, and different sounds when plucked in different ways, so it is with the universe - with string theory, the fluctuations give rise to matter. On this view, the universe may romantically be described as a symphony. The framework of the vibrating string causes the song that we see around us.
1141293
1-4 are 3 spacial and 1 time\n\n5-11 are the what string theory are trying to prove, being really small dimesions curled up into little multidimensional balls.. \nthese dimensions would explain things like electromagnetism and gravity
621133
Oh my, have you opened up a can of nightmarish confusion.\n\nYou are referring to String Theory, and it is way too complicated to describe here.  Here is an exerpt from an article on wikipedia of String Theory that describes these extra dimensions:\n\nOne intriguing feature of string theory is that it predicts the number of dimensions which the universe should possess. Nothing in Maxwell's theory of electromagnetism or Einstein's theory of relativity makes this kind of prediction; these theories require physicists to insert the number of dimensions "by hand". The first person to add a fifth dimension to Einstein's four was the German mathematician Theodor Kaluza in 1919. The reason for the unobservability of the fifth dimension (its compactness) was suggested by the Swedish physicist Oskar Klein in 1926.\n\nInstead, string theory allows one to compute the number of spacetime dimensions from first principles. Technically, this happens because for a different number of dimensions, the theory has a gauge anomaly. This can be understood by noting that in a consistent theory which includes a photon (technically, a particle carring a force related to an unbroken gauge symmetry), it must be massless. The mass of the photon which is predicted by string theory depends on the energy of the string mode which represents the photon. This energy includes a contribution from Casimir effect, namely from quantum fluctuations in the string. The size of this contribution depends on the number of dimensions since for a larger number of dimensions, there are more possible fluctuations in the string position. Therefor, the photon will be massless - and the theory consistent - only for a particular number of dimensions.\n\nThe only problem is that when the calculation is done, the universe's dimensionality is not four as one may expect (three axes of space and one of time), but twenty-six. More precisely, bosonic string theories are 26-dimensional, while superstring and M-theories turn out to involve 10 or 11 dimensions. In bosonic string theories, the 26 dimensions come from the Polyakov equation (see technical details in the preprint "Quantum Geometry of Bosonic Strings - Revisited"). However, these results appear to contradict the observed four dimensional space-time.\n\n \nCalabi-Yau manifold (3D projection)Two different ways have been proposed to solve this apparent contradiction. The first is to compactify the extra dimensions; i.e., the 6 or 7 extra dimensions are so small as to be undetectable in our phenomenal experience. The 6-dimensional model's resolution is achieved with Calabi-Yau spaces. In 7 dimensions, they are termed G2 manifolds. Essentially these extra dimensions are compactified by causing them to loop back upon themselves.\n\nA standard analogy for this is to consider multidimensional space as a garden hose. If the hose is viewed from a sufficient distance, it appears to have only one dimension, its length. Indeed, think of a ball small enough to enter the hose but not too small. Throwing such a ball inside the hose, the ball would move more or less in one dimension; in any experiment we make by throwing such balls in the hose, the only important movement will be one-dimensional, that is, along the hose. However, as one approaches the hose, one discovers that it contains a second dimension, its circumference. Thus, a ant crawling inside it would move in two dimensions (and a fly flying in it would move in three dimensions). This "extra dimension" is only visible within a relatively close range to the hose, or if one "throws in" small enough objects. Similarly, the extra compact dimensions are only visible at extremely small distances, or by experimenting with particles with extremely small wave lengths (of the order of the compact dimension's radius), which in quantum mechanics means very high energies (see wave-particle duality).\n\nAnother possibility is that we