String Definition and 1000 Threads

I am looking for introductiory books on gauge theory and conformalfield theory and polyakov integrals for research in Bosonic string theory. Any other material recommendations for String theory that are necessary for bosonic string theory or heterotic string theory are definelty apreciated. To...

Homework Statement Block 1, of mass m_1 =2.6kg and block 2 of mass m_2=1.4kg are connected by a massless string. Block 2 then experiences a force F=18N acting in the postivive x direction and at an angle of \theta = 38° . The coefficiant of kinetic friction between the floor and both of the...

I am losing my mind over this, it seems the longer i think about it the further i get from a definitive answer. It started with me trying to understand the variables the would result in a standing wave, ie: what needs to occur, why, and how it occurs. At first i was confused because it seemed...

Homework Statement [/B] A solid cylinder of mass m and radius r lies flat on frictionless horizontal table, with a massless string running halfway around it, as shown in Fig. 8.50. A mass also of mass m is attached to one end of the string, and you pull on the other end with a force T. The...

Homework Statement Two 0.400-kg carts are 100 mm apart on a low-friction track. You push one of the carts with a constant force of 2.0N directed so that the cart you push moves away from the other cart. Determine the acceleration of the center of mass of the two-cart system when the carts are...

In my wave course at the moment we are looking at waves on a string and their applications. At one point we consider the transverse force at a particular point on the string due to a uniform tension throughout a string. Something about this has confused me, the force isn't at all in the form I...

For the first part of the equation, I worked out k constant of a string which extended 12.6cm when a mass of 300g was suspended from it using the equation F = kx where F is the force applied and x its extension. So mg = xk, 300 x 9,81 = 0.126k, the answer was 23357N/m (23kN/m). The question...

The Polyakov action, S=\frac{1}{4\pi\alpha^\prime}\int d^2\sigma\sqrt{-h}h^{\alpha\beta}G_{ij}(X)\partial_\alpha X^i\partial_\beta X^j has the local symmetries, diffeomorphism on world sheet and the Weyl invariance. But is diffeomorphism on the target space also a symmetry? The target space...

Homework Statement Question: "The midpoint of a guitar string oscillates with an amplitude of 2.24mm with a frequency of 400Hz. Calculate: i) The maximum speed at this point ii) The maximum acceleration of the string at this point" Homework Equations Suitable formulas: x=Asin(2*pi*f*t) ...

Ok I understand the idea that a standing wave can be represented as the sum of two traveling waves going in opposite directions with same stuff but what I don't understand is why the waves on a guitar string are sinusoidal. I mean I know looking at them, they look sinusoidal but could they be...

This will, no doubt, sound like a silly question but I am just getting my feet wet in string theory. It seems from what I know so far, that string theory is very far removed from our observable universe. What I mean by that statement is that it seems we just say "well, maybe our universe is a...

Homework Statement A mass,m, hangs from a string and swings with a frequency of 0.8 Hz with a maximum displacement of 0.1 rad. The equation of motion is given by x=Acos(ωt). A) What is the length of the string? B) What is the maximum displacement of the mass in meters? C) What is the velocity...

Homework Statement A 65-cm guitar string is fixed at both ends. In the frequency range between 1.0 and 2.0 kHz, the string is found to resonate only at frequencies 1.2, 1.5, and 1.8kHz . What is the speed of traveling waves on this string? Homework Equations f = v/2l The Attempt at a...

Replace any space ' ' by '_' in 2-character string passCode. Sample program: #include #include #include using namespace std; int main() { string passCode; passCode = "1 "; <student code> cout << passCode << endl; return 0; } I'm super lost on this. I could...

Set hadDigit to true if the 3-character passCode contains a digit. Sample program: #include #include #include using namespace std; int main() { bool hasDigit = false; string passCode; int valid = 0; passCode = "abc"; <student code> if (hasDigit) { cout << "Has a...

Write an expression to detect that the first character of userInput matches firstLetter. Sample program: #include <iostream> #include <string> using namespace std; int main() { string userInput; char firstLetter = '-'; userInput = "banana"; firstLetter = 'b'; if (<STUDENT...

Assign the size of userInput to stringSize. Ex: if userInput = "Hello", output is: Size of userInput: 5Sample program: #include <iostream> #include <string> using namespace std; int main() { string userInput; int stringSize = 0; userInput = "Hello"; <STUDENT CODE> cout <<...

Homework Statement A block of mass M has a string of mass m attached to it. A force F is applied to the string and it pulls the block up a frictionless plane that is inclined at an angle theta. Find the force that the string exerts on the block Homework Equations F=ma The Attempt at a...

Assign the size of userInput to stringSize. Ex: if userInput = "Hello", output is: Size of userInput: 5 Sample program: #include <iostream> #include <string> using namespace std; int main() { string userInput; int stringSize = 0; userInput = "Hello"; <STUDENT CODE> cout <<...

Print the two strings in alphabetical order. Assume the strings are lowercase. End with newline. Sample output: capes rabbits Sample program: #include <iostream> #include <string> using namespace std; int main() { string firstString; string secondString; firstString = "rabbits"...

Hi, so I'm new to this forum and wanted to ask for some advice. I REALLY am interest in string theory and I've read around the topic a lot without actually learning about it. In my school we can do an independent study project or ISP. When students do ISPs they have to have a project that can be...

Homework Statement In the diagram mA is equal to 3.00 kg and mB is equal to 1.07 kg. The angle of the inclined plane is 38.0° (a) Find Acceleration: 6.03 m/s^2 (got this part) (b) Find the tension Tb in the connecting string: Not sure Homework Equations (a) a = (F/mA + mB) (b) t =...

From what I have learned so far a wave propogates on a string by having the point on the string (that is closest to the wave and in the direction the wave is moving) move upwards or downwards depending on the wave and this point moving due to tension causes the next to move simillarly and thus...

Homework Statement A point mass M is concentrated at a point on a string of characteristic impedance ρc. A transverse wave of frequency ω moves in the positive x-direction and is partially reflected and transmitted at the mass. The boundary conditions are that the string displacements just to...

Hi, I'm trying to write a simple program for reversing a string stored in memory. This is what I've come up with. For some reason this code coredumps, so something is wrong. any ideas ? #include <stdio.h> #include <string.h> #include <stdlib.h> char *reverse(char *buf,unsigned...

Im a trying to understand how the string entity relates to its underlying field. Is the field a brane and the string the partice?

I am trying to capitalize the first letter of every word in a sentence. Example. "hey what's up" would be "Hey What's Up". here is my code but nothing is changing the sentence. I thought everything was right. public static String cap(String aString) { String[] sentence = aString.split("...

As Steven Weinberg put it, "the idea of quantum field theory is that quantum fields are the basic ingredients of the universe, and particles are just bundles of energy and momentum of the fields." At least, this is one way to look at QFT. The other approach is to imagine that these particles are...

Hello guys, I've had the following discussion at work: We are currently using a suture with a nylon thread on a tissue, when the thread of the suture is tightened in a force equal to if we've put a 500 gram weight on both ends of the suture line (meaning both end are tied together to the...

I feel curious about why we pay so much attention on standing waves on the string. Doesn't transverse wave on the string can't be used to produce sound?

Here's an idea that I came up with. I've heard over and over again that there is no test yet available to confirm string theory. So what I say is... What if you could derive some fundamental physics equation from string theory principles? Then wouldn't that be a test so to speak...

A disk of mass M and radius R is held up by a massless string. (The two ends of the string are connected to a ceiling and the disk rests on the bottom of the string.) The coefficient of friction between the disk is μ. What is the smallest possible tension in the string at its lowest point...

I was teaching myself standing wave's chapter. It is said in the book that when plucking in the center of the string, it will cause two traveling waves of different directions, one left, one right. Then both of them will reach ends of string and invert back. Before they encounter at the center...

Hi all, I cannot seem to find a way to justify my book's answer to this problem: One end of a string is shaken each second sending a wave with an amplitude of 10cm toward the other end. The string is 5m long and wavelength of each wave is 50cm. How many waves reach the other end of the string...

String effective action: S=-\frac{1}{2\lambda_{\text{s}}^{d-1}}\int d^{d+1}x\sqrt{|g|}e^{-\phi}\left[R+(\nabla\phi)^2+2\lambda_{\text{s}}^{d-1}V(\phi)-\frac{1}{12}H^2\right]+S_m where H^2=H_{\mu\nu\alpha}H^{\mu\nu\alpha}\\ H_{\mu\nu\alpha}=\partial_\mu B_{\nu\alpha}+\partial_\nu...

This is a question currently pondered by many Quantum physicists and theoretical physicists. I was just wondering how many of you prefer ST(string theory) as opposed to LQG(loop quantum gravity.) Please provide points and reasons regarding your answer. I will provide an opinion when a few...

1. Imagine two columns between which is hung a string. The hung string may be expressed graphically and mathematically as a parabola whose nature is exponential. If these columns are moved closer together or farther apart, the hung string becomes more loose or taut according to a trigonometric...

I'm watching a lecture by Edward Witten here: In it, he mentions that String/M-theory seems to be hinting toward a new kind of geometry where you don't talk about space/time points, but the interactions between quantum world sheets (around 37:00 minute mark.) Does this new geometry have...

Hello! (Wave) We are given $2$ strings $A=[1 \dots m]$ and $B[1 \dots n]$ and the following $3$ operations are allowed: Insert a charachter,with cost $c_i$ Delete a character,with cost $c_d$ Replace a character,with cost $c_r$ We are looking for the optimal sequence of...

Hi, I've been looking for a string theory review for a beginner graduate student. However, there is a vast number of reviews so it's easy to get lost. Does anyone know about a review article or any kind of material to begin with String Theory? Thanks.

Hello, Can anybody please explain me how magnetic monopoles, fine structure constant and string theory are related to each other? Thanks

Homework Statement Hi all! I was wondering what the tension is in the string of a pendulum, because I think sparknotes is wrong on this. Sparknotes says that: "Choose a coordinate system: We want to calculate the forces acting on the pendulum at any given point in its trajectory. It will...

Homework Statement An object with a mass of m = 4.80 kg is attached to the end of a string wrapped around a reel of radius R = 0.230 m and mass M = 3.00 kg. The reel is a solid disc. The suspended object is released from rest 1.90 m above the floor. http://imgur.com/ElfqPSX a) Determine the...

I have recently visited CERN, and in the Globe they showed an equation from string theory. My knowledge about it goes only as far as 'The elegant universe', so no mathematics, but i would say that the sketch beneath is about the string coupling constant. Could anyone please explain the...

Homework Statement Write a function called reverse that uses recursion to reverse any one-dimensional string array.Homework Equations The Attempt at a Solution function out = reverse(str) if length(str) == 0 out = str; else out = [str(end) reverse(str(1:end-1))]; end I am having...

Homework Statement A guitr player changes the frequncy of the note produced by a guitar string by pressing his fingers along the string. The fundamental frequency of the string is 264hz. What are the frquncies of the fundamental note if the player plucked the string at 1/4 of the way from one...

Hey guys, I would really appreciate some help for this question I'm stuck on at the moment: "A piece of 2 m long wire is to be cut into two pieces one of which is to be formed into a circle and the other into an equilateral triangle. How should the wire be cut so that the total area enclosed...

Homework Statement can someone teach me on this question? i really don't know how to start with it. the ans is 0.38m and 4.1N Homework Equations The Attempt at a Solution the working is in the second photo

I've heard that the strings in String theory are vacuums, is that right? And if so then how is it expected they form?

Just as particles move through the theoretical Higgs field and gain energy which gives them mass, do the strings in String theory get their energy to vibrate from the Higgs Field as well? And does that mean that the Strings have mass?