Wave function Definition and 878 Threads

  1. Einstein's Cat

    What Happens When a Collapsed and Non-Collapsed Wave Function Combine?

    For theoretical sake, would a collapsed wave function combined with a non-collapsed wave function result in a wave function between that of a collapsed and non- collapsed wave function? Thank you and please excuse the stupidity of the question
  2. Einstein's Cat

    Solve Schrödinger's Wave Function Equation: Explained

    Could someone please explain Schrödinger's equation and what each letter in it represents and how to apply it? Thank you
  3. A

    How Do You Apply the Del Operator to a Momentum-Dependent Wave Function?

    I've been given the question "What is ∇exp(ip⋅r/ħ) ?" I recognise that this is the del operator acting on a wave function but using the dot product of momentum and position in the wave function is new to me. The dot product is always scalar so I was wondering if it would be correct in writing...
  4. Adoniram

    Finding most probable position for given wave function

    Homework Statement A particle has a given wavefunction: ##ψ(x) = C e^{-x}(1-e^{-x})## (many steps in between) ... Find the most probable position of the particle Homework Equations Most probable is where the probability density's derivative = 0. Right? ##P(x) = |ψ(x)|^{2}## The Attempt at a...
  5. T

    Wave Function: Normalization Constant

    Homework Statement Consider a free particle, initially with a well defined momentum ##p_0##, whose wave function is well approximated by a plane wave. At ##t=0##, the particle is localized in a region ##-\frac{a}{2}\leq x \leq\frac{a}{2}##, so that its wave function is...
  6. abrogard

    B What Is Surprising About Wave Function Collapse?

    Excuse my ignorance. I've been googling trying to understand but they always seem to just state it without explaining why. They say the electron could be anywhere within this area of probability but we don't know why until we look and then the wave function 'collapses' and we know where it is...
  7. N

    Electron wave function in quantum cascade laser?

    How are these pictures taken of the electron wave function without the wave function collapsing? Does this mean that electron wave functions are real waves after all? Wikipedia Quantum cascade laser will give you the discription
  8. C

    What is a Prolate Spheroid wave function?

    What is a Prolate Spheroid Wave Function and how does it apply to EEGs and brain mapping ?Approximate formulae for certain prolate spheroidal wave functions valid for large values of both order and band-limit http://www.sciencedirect.com/science/article/pii/S1063520306000650...
  9. BTBlueSkies

    Is the wave function more like a soccer ball, or a golf ball

    I have been trying to understand the wave function around an atom.. Is it more like a soccer ball where the shell is smooth but is more likely to be found in say the dark areas, or is it more like a golf ball where it is not only angularly undulating, but also radially undulating?
  10. C

    Wave function of multiple particles

    I've got a question for you all. if there is a wave-function for a single particle, such as a photon.. and there is a wave-function for an electron.. "A wave function in quantum mechanics describes the quantum state of an isolated system of one or more particles. There is one wave function...
  11. avito009

    What does Wave Function actually measure?

    From what I understand in laymans terms (Since I am a beginner). In quantum mechanics, particles don’t have classical properties like “position” or “momentum”; rather, there is a wave function that assigns a (complex) number, called the “amplitude,” to each possible measurement outcome. The...
  12. Cobalt101

    What actually triggers the collapse of the wave function ?

    I am wondering if there are some views on this. One of the key mysteries of the double slit experiment boils down to when the observation mechanism is placed by one of the slits - and switched on it triggers the change from wave-like outcomes to particle-like outcomes. Is it the observation or...
  13. Quandemonitum

    What is the wave function for the whole system/atom ?

    For example, let's say that psi(q) is the wave function of an electron(which describes/represents the electron) that is located in an atom and isolated/unentangled from the rest of the system. What is the wave function value of this psi(q) ? What is the wave function for that whole atom(with...
  14. Quandemonitum

    What is the wave function for the whole system/atom?

    For example let's say that psi(q) is the wave function of an electron(which describes/represent the electron) that is located in an atom and isolated/unentangled from the rest of the system. What is the wave function value of this psi(q) ?What is the wave function for that whole atom(with only...
  15. Vaibhav DixiT

    Help in Normalization of a Wave Function

    Hello Guys, I am trying to Normalize the following wave function but I am getting stuck in between (Maybe maths is the problem here for me). Can anyone please provide some hints. The Wave Function is ψ = e - |x| sin (α x)Please help.
  16. H

    Interpretation of a wave function collapse

    Suppose the system is in a state of superposition of two determinate states (of an observable) and has equal probability of getting each determinate state, when observed. An observation forces the collapse of the wave function to either one of the determinate state (say, states A and B). Since...
  17. S

    Coefficients of wave function of a hybrid orbital

    Assuming the 2s and 2p wavefunctions are normalized, determine the coefficients in the hybrid orbital: Ψ(sp3) = aΨ(2s) + aΨ(2px) + aΨ(2py) + aΨ(2pz) (the other 3 hybrids have – signs for some of the coefficients. I have no clue where to start. I know this is a tetrahedral hybrid orbital but...
  18. J

    What is the wave function interpretation in quantum mechanics?

    What is wave function?? For example Prepare identically same system and observe position. Then collect result of all position value. Is it position wave function??
  19. A

    Wave function for transverse waves on a rope

    Homework Statement Serway's Physics for Sciencetists and Engineers with Modern Physics, 9th Edition (current), Chapter 16, problem 19:[/B] (a) Write the expression for y as a function of x and t in SI units for a sinusoidal wave traveling along a rope in the negative x direction with the...
  20. Avatrin

    Units of Wave function (Schrodinger equation)

    Hi I thought I knew the answer to this question until I encountered the following question: What is the unit of R(r)? We are of course talking about the radial part of the solution to Schrodinger's equation in spherical coordinates (i.e. \psi(r,\theta,\phi) = R(r)\Theta(\theta)\Phi(\phi)). I...
  21. Shahab Mirza

    How to interpret this Wave Equation (Derivation) Help ?

    Hi dear people , Hello I waw studying super position of two Sound Waves , traveling in same medium with same frequency , same wavelength and same amplitude while differing in phase . quick derivation : Wave 1 displacement y1= A sin (kx-vt ) and wave 2 displacement y2= A sin (kx-vt-phase...
  22. adi adi

    Finding amplitude from superposition

    Homework Statement so there is this problem : find the amplitude from the superposition of Z1 and Z2 where Z1 : 8 sin 100t, A1= 8m and Z2 : 6 sin (100t-pi/2), A2=6m Homework Equations i know that all we need to do is add them and do the trig using sine additon, but i couldn't do that because...
  23. Ryan-Duddy

    Do Virtual Particles Cause The Wave Function To Collapse?

    I was just wondering, when particles interact with a force (which would be all the time) , does it cause the wave function to collapse? If so does that mean particles interact with forces in small time periods, since we know particles exist as a probability function? I just assumed that fields...
  24. gfd43tg

    Wave Function Linear Combination: How to Approach Homework Problems?

    Homework Statement Homework Equations The Attempt at a Solution a) I am not sure exactly what they are looking for, but I said that the operators associate, distribute, and do not necessarily commute. b) I know by definition ##\langle a' \mid a \rangle = \int a'^{*}a dx = \delta_{a'a}##...
  25. D

    The Significance of the Hermition Conjugate in Wave Functions

    Suppose there is a wave function for a particle. What is the actual meaning of hermition conjugate of the wave function? Does the conjugate represent any other state of the wave function? What is the physical meaning of product of wave function and its conjugate? Please explain. Thanks in advance.
  26. X

    The free particle wave function <x|p>?

    I am following the math of scattering theory in Sakurai, Revised Edition pp.380-381 For a free particle, one can find that the solution is a plane wave that can be written (in position space) as, <x|\phi>=\frac{e^{ip \cdot x}}{(2 \pi \hbar)^{3/2}} However, how does one obtain ##<x|p>?## In...
  27. E

    Gauge transformation which counteract wave function

    Gauge transformation can be written as: ##\psi(\vec{r},t)\rightarrow e^{-i \frac{e}{\hbar c}f(\vec{r},t)}\psi(\vec{r},t)## http://quantummechanics.ucsd.edu/ph130a/130_notes/node296.html Does it have any sense that we choose such function ##f##, that all right side is constant in time. Is this...
  28. E

    Photon wave function and "QED: the strange theory of light "

    I read that a wave function of the photon does not exist in coordinate space. But, when I read Feynman's "QED: the strange theory of light and Matter", for instance, when the photons travel through the glass, it seems like wave functions of photons. How it is with this?
  29. J

    Dirac Wave Function: Schrodinger Equation Coupling

    Hi, is the wave function that couples to the Dirac equation the same as that which couples to the Schrodinger equation? Thanks.
  30. B

    Explain delayed choice quantum eraser without consciousness

    I'm trying to understand the delayed choice quantum eraser experiment without consciousness. As I understand it, photons will either interfere or not depending on whether or not "which-path" information is randomly hidden and rendered unkowable to the experimenter. That is, rather the by any...
  31. C

    Difference Between Two Thoughts on Wave Function Collapse?

    I've recently been reading the book The Dancing Wu Li Masters which is supposed to be a very basic introduction to quantum physics. I have a question on the following quote: "Up to now, we have said that the collapse occurs when somebody looks at the observed system. This is only one point of...
  32. R

    Quantum Mechanics: Translation and Wave Function

    Homework Statement Let ##|\psi\rangle \to |\psi'\rangle = \hat{T}(\delta x)|\psi\rangle## for infinitesimal ##\delta x##. Show that ##\langle x \rangle = \langle x \rangle + \delta x## and ##\langle p_x \rangle = \langle p_x\rangle.## Homework Equations ##\hat{T}(\delta x) =...
  33. Hamza Abbasi

    What is the value of A in Ψ=Acos^2(x) for a particle's wave function?

    Homework Statement The wave function of a certain particle is Ψ= A cos^2(x) for -π/2 < x < π/2. Find the value of A. Homework EquationsThe Attempt at a Solution My answer is coming out to be zero wheres as the correct answer is under root 8/3π ... Please help me out !
  34. evinda

    MHB What is a Wave Function? Exploring k and $\omega$

    Hello! (Wave) A function of the form $$u(x,t)=A \cos{(kx-\omega t)}, \text{ where } k>0, \omega>0, A>0$$ is called wave function. If in addition $u(x,t)$ is the solution of a differential equation with partial derivatives we are talking about a solution of the differential equation in the...
  35. J

    Wave Function Collapse: Does Interaction of Photons & Objects Force It?

    While I was daydreaming in my boring math class today I came across a weird problem. What ACTUALLY causes a wave function to collapse. I had a discussion with my teacher the week prior and she was telling me that it has something to do with your brain. I didnt really believe her, I just thought...
  36. P

    Non changing variables in wave function.

    Hi. I would like to know which variables in the wave function are constant (in this local context) and which are not. The wave number for instance varies in the article I was reading (WKB approximation). Why is this so? What other variable in the wavefunction can vary? Please help me as I am...
  37. F

    Is the wave function the invariant thing?

    Is the wave function of quantum mechanics considered to be the quint-essential invariant object? Is it the wave function that must not change with space, time, gravitational field, etc? It would seem to me that the relative probabilities that things happen is the thing that can not change with...
  38. S

    Question on wave function of free particle

    Hi, I was studying the solution of Schrodinger equation with no potential and found that the wave function is just a single plane wave eikx for movement of the particle in positive x direction. But when the phase velocity of a single wave is calculated it turns out to be less than the...
  39. N

    Light like interval in wave function

    I have read the following from what seems a reliable source: The identification of the spacetime interval with quantum phase applies to null intervals as well, consistent with the fact that the quantum phase of a photon does not advance at all between its emission and absorption. Hence the...
  40. T

    What is the relation between wave function on a photon

    ... and its classical wave equation? Suppose in our double sit experimental setup with the usual notion of d,D we have a light of known frequency (v) and wavelength (L)- so its y=Asin(kx-wt). It passes through the two hole and move ahead doing the usual interference stuff, so final wave equation...
  41. Joy Prakash Das

    Wave function for a potential barrier

    Suppose I have a region from 0 to L. I have a barrier potential V from x1 to x2, such that 0<x1<x2<L. The potential is 0 everywhere. I have obtained the wave-function by considering the propagation from left to right. Now if I consider the propagation from right to left should I get a different...
  42. N

    Coefficients in wave function for potential step

    Edit: I forgot to add the picture, and I'm having trouble adding it from Tapatalk. I'll add it soon. I'm trying to understand the derivation in my textbook of the wave function for a potential step. The derivation reaches the step shown in the attached photo, which I am fine with. However, the...
  43. B

    Step Potential with incident and reflected waves

    Homework Statement A woman is walking along a road. She has a mass of 52 kg and is walking at 1 m/s. (a) She is not paying careful attention and is walking straight towards the wall of a nearby building. Assume that the wall is infinitely hard and that she can be described as a plane wave (a...
  44. B

    Wave function with a certain wavelength

    I have a number of questions about the wave function - 1. Do photons have wave functions like the one in Schrodinger equation? 2. If they do, when you send out a wave function with a certain wavelength, then because you know the momentum with no uncertainty the uncertainty of the position...
  45. Z

    How do you mathematically describe wave function overlap?

    Is there a way to mathematically describe the space where wave functions overlap like with how wave functions describe the space a particle could exist. Then if that is possible can you determine the time period at which that overlap will occur.
  46. Bassa

    Transvese Velocity of a Standing Wave

    λ∂Homework Statement Aguitar string lies along the x-axis when in equilibrium. The end of the string at x=0 (the bridge of the guitar) is fixed. A sinusoidal wave with amplitude A=0.750 mm and frequency f =440 Hz, corresponding to the red curves in Fig. 15.24, travels along the string in the...
  47. J

    Find the time dependent wave function

    If you are given the state of a system at t=0 in vector form, how do you find the wave function for arbitrary t?
  48. N

    Is the collapse of the particle wave function?

    Is the collapse of the wave function of the electron in the double slit experiment based purely on the act of observation? Or could it be that the way the instrument used to measure the electron caused it to collapse by how it physically interacted with the electron? Keep in mind the delayed...
  49. Dethrone

    MHB Probability Wave Function

    I am trying to find the most probably distance of the electron from the nucleus of a ground state hydrogen atom. The wave function is given as the following: $$\psi_{1,0,0}(r,\theta,\Phi)=R_{1,0}(r) \cdot Y_{1,0}(\theta, \Phi)$$ I remember that the probability function is $\psi^2$, but why do...
  50. quantumfunction

    What happens to the Hamiltonian of the wave function after measurement?

    As I understand it, the Hamiltonian is the kinetic plus the potential energy of the wave function. When a measurement is done what happens to the kinetic and potential energy? Does it dissipate? Is it conserved in the measured state? Does it decrease? Does the Hamilton or kinetic+Potential...
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