Strings Definition and 548 Threads

Baez et al revised the title of their March 2006 paper to say "strings" instead of "loops" and reposted it http://arxiv.org/abs/gr-qc/0603085 Exotic Statistics for Strings in 4d BF Theory John C. Baez, Derek K. Wise, Alissa S. Crans 41 pages, many figures. New version has minor corrections and...

I was wondering, OK it is a gedakenexperiment because it is beyond observation, but... how is space-time supersymmetry (no worldsheet susy) supossed to appear from the point of view of states of the fundamental string? Do we observe entities with spin 0 and spin 1/2 having the same mass? And...

Hey guys I know you're probably going to laugh at me for this question, but what is the name of the pendulum thing with five balls suspended on strings? You know, the thing that every boss has on his desk in every movie? I have been trying to figure it out for a while now.

I have been reading about string theory, most recently about twistor string theory. I think that I have a basic understanding, but certainly am no expert. The helix is an important structure in transmitting information of various types: - music theory mathematics [wave and matrix] - only...

The image I get from reading the popular literature is that, according to string theory, there is a one to one relationship between strings and particles. Another way of saying this is that there are exactly as many strings in the universe as there are particles. The way that the string vibrates...

A particle P of mass m is attached to one end of a light elastic string of natural length L whose other end is attached to a point A on a ceiling. When P hangs in equilibrium AP has length \frac{5l}{3}. Show that if P is projected vertically downwards from A with speed \sqrt(\frac{3gl}{2}), P...

A particle P of mass m is attached to one end of a light elastic string of natural length L whose other end is attached to a point A on a ceiling. When P hangs in equilibrium AP has length \frac{5l}{3}. Show that if P is projected vertically downwards from A with speed \sqrt(\frac{3gl}{2}), P...

Are there string theories based on unidirectional paths or strings? I ask because the polysigned numbers have some strong unidirectional qualities. In a lattice environment loops are the only way to return to a source point. These loops are inherently unidirectional...

I watched the elegant universe and one scienetist noticed the euler beta function seemed to explain what he was doing and it had properties of a vibrating string. So I'm wondering if I could find his original paper, explanation or some additional info.

I have to read a list of strings in from stdin and store them, stopping when a blank line is entered. Here's what I tried... const int LINE_CAP = 100; const int MAX_LENGTH = 80; char *strings[LINE_CAP]; int strings_index = 0; char buffer[MAX_LENGTH]...

Does string theory touted as TOE offer a possible explanation of what happens beyond the event horizon? If not what may?

http://arxiv.org/abs/gr-qc/0509091 A liquid crystal analogue of the cosmic string "We consider the propagation of light in a anisotropic medium with a topological line defect in the realm of geometrical optics. It is shown that the effective geometry perceived by light propagating in such...

Three objects are connected on a table as shown in the http://www.cybertrails.com/~reedaz/pic1.JPG . The table has a coefficient of kinetic friction of 0.350. The objects have masses of 4.00 kg, 1.00 kg, and 2.00 kg. The pulleys are frictionless. Determine the acceleration of each object and...

Hi, If elementary particles are nothing but a mode of vibration of a string, and if strings are on the order of Planck's length, then how did we end up with particles that are as big as 10^20 times Planck's length?

In special relativity we say that a particle traveling at the speed of light uses all its energy to do so and thus has no energy for anything else. ie (movement through time) This begs the question; what is giving the string the energy to vibrate? Or does its maximum vibration equate the speed...

For your thoughts... a theory of mine... A Method by which shape shifting strings may explain: 1. Plasma 2. Hydrogen 3. Helium 4. Neutrons 5. Gasses 6. Liquids 7. Solids Consider the following: If a string, was a string, in shape, in only one STATE of its existence, then one...

In the list of talks on the program for Strings 06, how many titles do you expect will mention background independence? Looking at the Strings 05 program, you see this year the number is ZERO http://www.fields.utoronto.ca/programs/scientific/04-05/string-theory/strings2005/speakers.html...

Is there an explanation for gravitational time dilation in string theory? String theorists say their equations can make the same predictions as general relativity, so I would assume string theory predicts gravitational time dilation, but how would that work? If gravity is no longer mediated by...

Is there an obvious reason why the compactified dimensions of string theory are never invoked as a “medium” for quantum theory’s nonlocal communication? Lightspeed restrictions apply in the extended spatial dimensions but it would seem that all parts of the universe would be in touch almost...

Is light composed of "strings"? I read Professor Michio Kaku book Hyperspace and have tried to create an online paper asking if light waves are composed of the elusive "strings" and if the light or strings could be manipulated without the energies required by Plank constant...

If particles are made out of strings then it seems to follow that strings are, or can be, both local and non-local. Is this correct? I haven't seen any discussion of the wave-particle nature of strings (or the property of strings that allows particles to be also waves) so I assume I'm wrong...

Are lightwaves related "strings" I am asking if the waves in light could be related to strings in superstring theory as explained on this website: http://www.geocities.com/certvolunteer/physics/index.html I am a layman and not math oriented. Chris w

I'm obviously not going to ask how many strings there are in the universe. :wink: my question. To each quark how many strings are there? Just one unique one? Billions and Billions? Also does Brian Greene's book. "The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for...

I often think about this subject, would it be a fair assumption to say that our electronic bits are a equivalent and more simple "thing" of that we assume to be the more elementar "particle" of the universe, a string, acording to the theory, it is the vibrating state of certain string that...

If I attached a long string from the ground to a geostationary satellite in orbit, and plucked it, would the wave created by the string be affected by gravity? The particles in the string move sideways, so the wave itself should not be affected by the Earth's gravity, should it?

I probably won't be able to ask this question as well as I envision it in my mind. So please bear with me and try and decipher my babbling gibberish as best you can. :smile: According to my very limited knowledge of Strings and Branes...(theory) Strings are the smallest things in the...

Hello everyone, I'm a undergraduate student in the field of physics. I'm working toward a BS in Physics from University of North Carolina at Wilmington. I've been thinking about string modes of resonance lately and wonder if the theory allows strings to stop vibrating or change resonance...

If everything is made out of strings as described in string theory, or, M - Theory, then how do the strings know how to collect themselves to form an electron of the exact mass of 9.10939 x 10^-31 every time, and also form all the other particles (Proton, Positron, photon)? :rolleyes: You...

I am not really sure how to start this problem, and I have tried searching everywhere. If you could help me that would be great...just to know how to get started. I'm in 2nd Year, Intro to discrete mathematics, if it matters. Thanks Let G be a graph whose vertices correspond to the...

Hi, you have two strings, one has force constant K1, the other Force Constant K2. You hook the two strings together. I need to see a derived euqation using K1 and K2 to find KTOTAL (the force constant when he two strings are placed together). Please keep things as simple as possible...

Hey! Was just wondering if someone could shed some light on the whole stationary waves thing. I've done about them in my A-Level Physics course and I can't for the life of me figure out what it's about. I mean, why can you only have a certain number of nodes, hence certain frequencies...

Standing waves on strings... :smile: I understand how to produce standing waves on a string when we have a vibrator at one end, as you usually use in demonstrations in physics classes. ie - increase frequencies until we achieve the correct kind of interference to produce standing wave...

Is it possible to convert open strings to closed strings in string theory. Perhaps, we can convert out rest mass into gravitons, and appear in other dimensions. Is this a possibility? Or does string theory not predict this behavior?

In his book "the universe in a nutshell", stephen hawkings is discussing the possiblity of time travel to the past (ch. 5 How to protect the past). He introducted the concept of cosmic strings to explain that. would anyone here could explain this concept and it's relation to time travel...

Is there someone out there who could explain string theory and loop quantum gravity to me in plain English, please? I have no mathematical ability whatsoever, so I'm looking for an explanation of the concepts. Numbers leave me scratching my head. I am not suggesting that my numerical stupidity...

My thesis requires that i tabulate a guitar input (recorded in wav format) and then processed to obtain its respective tablature... However, i couldn't find the right algorithm to distinguish if the note played is strummed or plucked... please help me! Here are some things I've learned...

I'm not going to say anything about the anthropic principle (strong or weak form) because that's so clearly stupid that it speaks for itself. I'm also not going to say anything about the lack of observational evidence, because, let's be honest, we're all in the same boat on that one, probably...

Could any of you clever people answer me this.. Whenever I have read a 'popular' book on string theory, I get the impression that the strings themselves aren't nessecary. They are described as a vibrating string that wraps around a folded dimension, and so say an electron is particular type of...

Do physicists have any idea how much a string or brane would mass?

In a recent article in New Scientist Mag they are making claims of possible evidence of strings. Though I read the "The Elegant Universe" by Brian Greene and I once wrote to Greene with a question (his e mail address is on the web), I have pretty much looked the other way from strings because...

Ok about M-theory, are the P-branes or strings or closed and open loops suppose to be made out of matter/energy? if they are then how could that be possible if matter/energy is suppose to be composited out of particles to explain chemical reactions, that would mean for the strings to move they...

Two identical violin strings, when in tune and stretched with the same tension, have a fundamental frequency of 440.0 Hz. One of the strings is retuned by adjusting its tension. When this is done, 1.5 beats per second are heard when both strings are plucked simultaneously. -By what...

Do strings move in spacetime ? If at every Planck size point in spacetime there is a Calabi-Yau manifold. Do the manifolds move with the expansion of the universe so that the strings always have a constant vibrational pattern that determines their effect/elemental property or are the...

If string theory is based mainly on Minkowsi "flat" spacetime, then how do they account for the proven curvature of our spacetime? Thanks to all, - Alisa :bugeye:

how is it that some strings have mass (spin 1/2 particles) while others have no mass at all (spin 2 particles and force carrying particles)? all strings are the same, its just how they move and vibrate that they change from particle to particle, but wouldn't this mean that all strings either...

Help needed urgently! Question A string vibrates according to the equation: y=0.6sin px/4 cos 45pt p = pi , x and y = cm , t=s (i) what are the amplitude and velocity of the component wave given rise to this vibration? (ii) what is the distance between nodes? (iii) what is...

Q A 420 gm rock is whirled on the end of a string 44 cm long which will break under a tension of 21 N. a) What is the highest speed the rock can reach before the string breaks? (Neglect gravity.) For this I used F = mv2/r and calculated velocity in m/s which is correct. b) If two...

In Zwiebach's book "A First Course in String Theory", I read that the endpoints of an open string move at light speed. Do any of the interior points of a string also travel at light speed?

Q. Three strings, in the horizontal plane, meet in a knot and are pulled with three forces such that the knot is held stationary. The tension in string 1 is T1 = 3 N. The angle between strings 1 and 2 is q12 = 130° and the angle between strings 1 and 3 is q13 = 120° with string 3 below string...

Problem : Three strings, in the horizontal plane, meet in a knot and are pulled with three forces such that the knot is held stationary. The tension in string 1 is T1 = 2.5 N. The angle between strings 1 and 2 is q12 = 130° and the angle between strings 1 and 3 is q13 = 120° with string 3 below...