Superposition Definition and 685 Threads

Anyone familiar with both quantum mechanics and cosmology here. Say. How much dynamics can occur in the deterministic Schroedinger Equation in its evolution while it is in unitary state (before collapse)? For example. Is it possible for the Big Bang and evolution of stars to solar system and...

How much dynamics can occur in the deterministic Schroedinger Equation in its evolution while it is in unitary state (before collapse)? For example. Is it possible for the Big Bang and evolution of stars to solar system and planets to occur while everything is inside a superposition (that...

Homework Statement I have to find I3, I've already easily found the first component I3| but i don't understand how i can get I3||. I thought about a Wheatstone bridge but doesn't work looking at the data. The result is I3=-7 A

Hi I am currently reading John Preskill's Lecture Notes on Quantum Information and Quantum Computation (see http://www.theory.caltech.edu/people/preskill/ph229/index.html near the bottom of the page). I am confused about what he writes in chapter 2.5.4: Quantum erasure. He starts with the...

Please give an example of pure state without superposition present, is this possible at all?

Homework Statement Show that, if psi1 and psi2 are both solutions of the time-dependent Schr¨odinger equation, so is c(subscipt1) psi1 + c(subscript2) psi2 (where c1 and c2 are arbitrary constants). Homework Equations The Attempt at a Solution every source I've consulted so far...

This has been bothering me for a long time and I can't find an adequate explanation.. Lets say you have an infinite conducting plate with finite thickness D and it is given charge Q the charge will be equally split into two and concentrated only on the two surfaces. Each surface will get Q/2...

Hello. If I have this equation: And this general solution: Would it then be wrong to write the above solution with only positive values of n? In my textbook they often write the result from a superposition with only positive values of n, becasue the negative values of n already...

Quick question, that seems pretty obvious, but I wanted to check. Magnetic fields follow the rules of super-position similar to the way electric fields do, correct?

Hey all, currently I am working on a project, which uses the principle of superposition of two antennas. I placed two antennas on the plane and make sure that they are oriented identically. The distance between these two antennas is around 51cm. I did an experiment, in which I firstly get the...

Intensity and Superposition of waves... Homework Statement Incident wave y=Asin(ax + bt + pi/2) is reflected by an obstacle at x=0 which reudces intensity of reflected wave by 36%. Due to superposition a resulting wave consist of standing wave and traveling wave given by y= -1.6 sinax.sinbt +...

I tried it many times but i don't understand how to start and which are the first steps. I started like this: Solve for V1: Vr1 = V1 * (R1/R1+(R2||(R3+R4))) = 5 V I'1 = Vr1/R1 = 1 A I'2 = I'1 * [(R1+R2)||(R3+R4)]/(R3+R4) = 0,6 A. is that right?

Please teach me this: In QTF theory book,I have not seen what saying about probability of creating or anihilating particle(quantum).So I wonder whether we can apply superposition principle for the states with different numbers of particles in Fock space. Thank you in advanced.

Homework Statement Homework Equations Hi, I have the following superposition theorem problem to find the current in each branch of the network shown in the following figure: The Attempt at a Solution I have removed the voltage sources separately till now by short circuiting the other...

Why do we replace current sources with open circuits when using the Superposition Theorem while we replace batteries with wire?

Homework Statement 3 identically charged charges are placed at corners of an equilateral triangle of sides a. I need to find the force felt by each charge. To do this I have calculated the force from charges - "2 on 1" and then "3 on 1". The answer i get is (2*q^2)/4*Pi*e*a^2. This is not...

This isn't exactly a homework question but just a few conceptual questions I'm confused about. First off on the topic of diffraction I notice many textbooks and other resources say that diffraction is more evident when the width of a slit is close to the wavelength of the wave. However, they...

Homework Statement 1) Given the following circuit: http://img841.imageshack.us/i/electriccircuit1.jpg/ Using the concept of superposition, calculate the partial contribution from each source.2) Given the following circuit: http://img713.imageshack.us/i/electriccircuit2.jpg/ Using the...

I am a little bit versed in the formalism of Hilbert space, the state vector and the matricies and their eigenvector basis of observables in QM. I understand that a pure state in one observable basis may be (is) a superposition in another basis (spin xUP) is superposition of spinyUP, spin yDOWN...

Homework Statement http://img16.imageshack.us/img16/8901/circuit1s.png Homework Equations I need som help with this circuitI need to use superposition to find out the value of Vx. And to do that i need to zero the current source and voltage source The Attempt at a Solution...

Homework Statement A conductor has the shape of an infinite conducting plane except for a hemispherical boss (a raised part on the at surface) of radius a. A charge q is placed above the center of the boss at a distance p from the plane. Calculate the force on the charge. Homework...

Homework Statement A particle in the infinite square well with V(x)=0 for 0<x<a and V(x)=infinity otherwise has the initial (t=0) wave function: psi(x,0)=Ax for 0<x<a/2 psi(x,0)= A(a-x) for a/2<x<a 1) Sketch psi and psi^2 (DONE) 2) Determine A [DONE - 2*sqrt(3)*a^(-3/2)] 3) Find psi(x,t)...

Homework Statement hi guys, Can someone please help me understand superposition and homogeneity in regards to the following graph. (current voltage characteristic of a diode) To be honest i don't understand the terms. The exact question I am asked is Use two test points on Graph to...

Homework Statement Four point charges of +/-Q are arranged on the corners of a square of side L. What is the net electric force that these charges exert on a point charge q placed on the center of the square (formula in terms of Q, q, L and Coulumb constant k)?Homework Equations F=kQq/r^2The...

Homework Statement A system at time t = 0 is in the state |ψ> = a|E1> + b|E2>, where |E1> and |E2> are (normalised) energy eigenstates with two different energies E1 and E2, and a, b are real numbers. Write down the state |ψ, t> for the system at time t. What are the probabilities at time t to...

Hello, The circuit attached below is from Richard Dorfs Intro to Electric Circuits book. The switch is shut for a long time and opened at t=0. The question asks to find the i(t) across R11, which they use nodal analaysis and find it to be 66.67 - 16.666 e^{-t/120} micro Amps, where 66.67 micro...

Homework Statement In this problem, I'm trying to solve for the Reaction, Rb Homework Equations I believe for the distributed load, the deflection equation would be: v = (-qx/24EI) * (L^3 - 6Lx^2 + x^3) For the support, Rb, the deflection equation could be: v = (-Pbx/6LEI) *...

I was reading Merzbacher and it is written that it is a fundamental mathematical assumption. I was doubting if it is an assumption at all. We get the principle of superposition when we solve certain kinds of differential equations (second order, first degree or linear) where we get as...

Homework Statement Use the super position method to find the solution of: y"+6y'+8y=6sin3t 2. The attempt at a solution x^2+6x+8=6sin3t found the x values x= -2,-4 yc=Asin3t+Bcos3t y'=3Acos3t-3Bsin3t y"=-9Asin3t-9Bcos3t sin3t values (8A,-18B,-9A) A=18B-6 cos3t...

Can we test superposition by gravitational effects of particles? For example by measuring gravitational interaction effects of electrons in double slit experiment? I know that such a weak interaction cannot be tested at this time since experimental devices cannot measure such a small...

According to Quantum Physics (or at least my understanding of it), when a particle is not observed it doesn't exist in the way one imagines is to be. Instead, it is a wave function with infinite possibilities (sum-over histories by Feynman), and only when observed it takes on a definite state...

Homework Statement Use the superposition theorem to find Vo in the circuitHomework Equations The Attempt at a Solution i made 8A source 0 so the first equation using KVL becomes: 10i1 = -20 i1 = -2 then making the 20V source 0, the next KVL equation becomes: i think it's 5i2-8 = 0 i2 = 8/5 i...

I am trying read through a chapter on properties of matter waves in Eisberg & Resnick's Quantum Physics. In section 3-4, a superposition Ψ of 7 sinusoidal waves, each with a different reciprical wavelength and amplitude, is shown along with all the component waves(fig. 3-9). He defines the...

Homework Statement y1[t] solves y't]+9.7 y[t]=E^(-0.4 t) Cos[t], with y[0]=0, and y2[t] solves y'[t]+9.7 y[t]=0, with y[0]=1. What numbers p and q do you pick to make y[t]=p y1[t] + q y2[t] solve y'[t]+9.7 y[t]=3 E^(-0.4 t) Cos[t], with y[0]=3...

Homework Statement Find the frequency of combined motion of the following (a) x = sin (12pi.t) + cos(13pi.t + pi/4) (b) x = sin(3t) - cos(pi.t) Homework Equations The book I'm using states that if the periods are commensurable ie if there exist 2 integers n1 and n2 such that n1T1 =...

Homework Statement Consider a particle in a superposition of states given at time t=0 by Y(x,0)=C(y1(x)+y2(x)), where y1(x) and y2(x) are the stationary states with energies E1 and E2 respectively. if y1(x) and y2(x) are orthonormalized, what value of C is required to normalize Y(x,0)...

Hi, I have didn't have an answer to this, so i need someone to tell me whether my work is correct or not. This is the circuit: http://img251.imageshack.us/img251/4081/circuit1.png I need to determine the current I. Remove the first source and calculate the current provided by the...

I'm trying to learn superposition but I'm confused with this part of the video at around 3:50: http://www.youtube.com/watch?v=nisdYIkIYXo&NR=1 The guy makes the current go clockwise from positive to negative in the loop, but I think that's a mistake... Am I wrong to think the current should...

Homework Statement Find the voltage v across the 5 Ohm resistor as shown in the attached drawing. Homework Equations Ohm's law, V=IR The Attempt at a Solution I have done plenty of these using different techniques, superposition/source transformation, nodal or mesh analysis, etc...

Homework Statement See pdf attachment named Superposition .Find Vout Homework Equations Steps of Superposition The Attempt at a Solution I fount Vout1 by replacing the voltage source with a short circuit and doing basic d.c. analysis. My answer = 0.85V However I'm stuck on how...

Superposition Theorem Understanding Problem Hi Guys, The last few weeks in my course I've been studying the superposition theorem, where the total effect of multiple sources in a network can be made into a summation of each of the effects of the individual sources each acting on their own...

Does the superposition principle for wave equations (say electromagnetic) hold also for non homogeneous and anisotropic media? I.e. can one always represent a wave traveling in an arbitrary direction as a sum of waves propagating along the principal axes of, e.g. dielectric tensor \epsilon_{ik}...

Suppose we have three charged particles arranged in a line, the first one being negative, the second being positive, and the third being negative. If we want to find the net force on the third particle, we sum the force from the second particle on the third and the force from the first...

Homework Statement For two waves in superposition, we have, let say \[y_{1} = Asin(kx-wt), y_{2} = Asin(kx-wt+\Phi )\] We use the trig identity sin A + sin B to simplify the combination Whereas for standing waves, we use the trig identity sin(a +/- b) to combine the result. As I...

I am a newbie here, just an enthusiast with an above average understanding of math and physics, but exposed to QM after I left college. I have looked through the posts and did not see a concise summary to the following. Please forgive me if I overlooked some threads. There are some...

Homework Statement This isn't a homework assignment, this is straight from the textbook. They work it out but I'm still not following, would it be possible for someone to go through this step by step and explain it clearly? (How to determine the current due to the voltage source and due to...

If I had a measuring device which causes decoherence of some quantum experiment: Is it possible to put (somehow) this observer/measuring device into a superposition of two different states? So instead of the wave function collapsing to ______/\______ it would collapse to __/\___/\__ (or...

Homework Statement Find v0 and i0 http://img214.imageshack.us/img214/2051/superquestion.jpg Homework Equations KVL and KCLThe Attempt at a Solution I removed the voltage source and redrew the circuit with a short on the bottom left. I then used mesh current analysis with KVL and made a system...

Hi, I'm new, both here and to the quantum world. I understand that an entangled pair cannot violate causality, because by analyzing half of that pair, one cannot determine whether the particles are in a superposition of states or not. Since there is no way to determine if a given entangled...

Einstein proved dualty in light & debroglie suggested dualty in matter.we know superposition takes place in light which destructive & constructive patterns.can't these be possible in particles then? I personally think that such phenomena occur but cannot be detected properly.