Wave Definition and 999 Threads

Homework Statement: Hi there, I'm currently taking an Optics course and the teacher is expecting us to have an understanding of the complex representation of waves. Although, hardly any of us have even heard of this yet. I've tried to google how to convert a cos(obj) and sin(obj) to an...

In Landau-Lifsits's book about non relativistic QM it is said that if I have a particle described by a plane wave ##\phi = e^{ikz}## (I think he choses the ##z## direction for simplicity) the wave function after the scattering event is (far from the scattering event) $$\psi \approx e^{ikz} +...

Would an A36 steel tube filled with liquid mercury be able to transmit a shock wave longitudinally through the liquid mercury with a peak pressure higher than the yield strength of the steel tube? My thinking is that since the shock wave is traveling normal to the tube wall, it should not be...

I use the equation ##\psi \left ( x, t \right ) = e^{-iEt/\hbar} \psi \left ( x,0 \right )## to calculate ##\psi \left ( x , t \right)##, and the result is ##\psi \left ( x , t \right) = \frac 1 {\sqrt {2 \pi \hbar}} exp \left [ \frac {ip_0 x} {\hbar} - \frac {i p^2 t} {2m \hbar} \right...

So when the source is not vibrating, it is not setting waves due to vibration? But it is moving so it is still causing disturbance in the medium ... And I happened to read that if the source is moving faster than the speed of sound, a shock wave is set up. How ?

I need to recursively generate a quadrature signal which fits exactly into a grid NxN, where N is a large power of two. After unsuccessful research, I decided to develop my own solution, starting from the waveguide-form oscillator taken from Pete Symons' book 'Digital wave generation, p. 100'...

We have been taught that the there is no experiment designed to detect wave and particle nature of light simultaneously. Also, that light propagates by the virtue of its wave nature and interacts by the virtue of its particle nature. let us take an electron beam passing through two slits...

Starting from the simple case, there is a single wave ##e=a\cos(2\pi ft+\frac{2\pi}{\lambda}x+\phi_0)##, and integrate in such a way, where ##T_{eye}## stands for the response time of human eyes' response time towards energy change: $$I=\int_{0}^{T_{eye}}e^2dt$$ The calculation includes...

I don’t understand how to approach this. So I couldn’t make an attempt at a solution. Please help me understand better. Thank you in advance.

Electrons passing through a double slit is in a superposition of passing through the left slit and the right slit, thereby producing an interference pattern on the screen. But when a detector is placed to detect which slit the electrons pass through, the interference pattern is destroyed. How...

Is there a simple model I can use to describe the damping of a wave on a string? Is c = 2*mu*sqrt(T/mu) where mu is damping coefficient, mu is linear density and T is tension a valid option? I replaced k and m with T and mu from the simple equation found here. What I am interested in showing is...

dear yall with tranditional wave equation on the gre book it says by the linearity in function f which represents wave. it leads to the principle of superposition. I get an intuition about with a standing wave with cos(x)cos(t) you can break it down to pair of left and right moving waves. i...

Why can't the general state, in the presence of coupling, take the form $$\psi_-(r)\chi_++\psi_+(r)\chi_-$$ where ##\psi_+(r)## and ##\psi_-(r)## are respectively the symmetric and anti-symmetric part of the wave function, and ##\chi_+## and ##\chi_-## are respectively the spinors representing...

This thread is to look at the notion of wave function collapse and relativity of simultaneity. The other thread I started on QFT has helped to clarify a lot, so hopefully this one can do the same. I may have this all wrong, but I will outline my question and hopefully someone can point out...

Classical problems for hookes law generally give either mass or spring constant. What if I have a graph of a wavelike structure that is oscillating which I can use to measure for example: T (period), t (time), Δx (displacement), v (velocity), a (acceleration) and other variables is this...

Fermions such as the electron and proton can be described by wave function in momentum and in position, and it is possible to get the momentum wavefunction from space wave function and vice versa by Fourier Transform. what about photons? can photons be described by position wave function? If...

Consider a gaussian wave packet whose wave function at a particular instant of time is Its time dependence is implicit in the "constants" A, a, <x> and <p>, which may all be functions of time. But regardless of what functions of time they may be, these constants will take on some values at...

Hi there I am teaching resonance and standing waves in stringed instruments at the moment at high school. The theory states that a number of standing waves simultaneously (harmonics) exist in a naturally vibrating musical string, but with varying amplitudes, the 1 st harmonic being loudest...

Summary: The problem: If one wants to make a digital record of sound such that no audible information is lost, what is the longest interval, Δt, between samples that could be used? ( it gives a hint that humans can hear sound waves in the frequency range 20 Hz to 20 kHz. It should be a very...

Jan Sperling et al., Wave-particle duality revisited: Neither wave nor particle, arXiv:1907.09836 From the abstract:

I would like to model the dynamics of a plate. Is it ok to use just the 2d wave equation if the plate will be under tension and fixed at the boundaries? I am a bit confused what the point of the Kirchhoff plate equation is in that case, is it for when the plate is self supporting? Many thanks

I cannot find the correct answer anywhere online and the answer I keep getting is 5.4 (incorrect) Please show me the process to get to the answer! Thank you

(As a quick note, 'wave flume' should be taken rather generally. I basically just mean the sort of experiments involved in the flow of water which may use instruments such as pressure gauges, load cells, wave gauges, and ADVs. I know that they're not always done in a flume per say -- the...

We always think in terms of isolated particles. It's better to analyze it with solids. If wave functions were just calculational tools. Molecules like the following still interact by wave functions, right? So how can it be calculational tool? And if it is, then what model do you use to...

In interpretations where the wave function represents something real, like Many worlds, Copenhagen with objective wave function and spontaneous objective collapses. I'd like to understand which of them has true non-locality. First. Is Many Worlds not having true non-locality due to the...

Suppose one measures the position of a photon without destroying it. From my understanding, the wavefunction of the photon should collapse, and will return to a more spread out state over time. How would one calculate this, specifically the rate at which the wavefunction spreads out from the center?

I noticed that if I hold two small rounded quartz stones together in front of my eye, with light shining on them from the other direction, I see what looks like a very distinct, black, noisy waveform between them. Does anyone know the detsals about wy this happens?

Dear All, I would like to better understand how the Principle of Least Action applies in observations / measurements in quantum physics. Does the wave function of a particle correspond directly to the principle of least action, as in, the positions with higher probability of detecting the...

In D Alembert's soln to wave equation two new variables are defined ##\xi## = x - vt ##\eta## = x + vt x is therefore a function of ##\xi## , ##\eta## , v and t. For fixed phase speed, v and given instant of time, x is a function of ##\xi## and ##\eta##. Therefore partial derivative of x w.r.t...

I have calculated the normalization constant, but I'm struggling with the discontinuities in the derivatives of the wave function. Due to the symmetry, it should suffice to consider the first two cases. The results should be (according to WolframAlpha): \left( \frac{\partial^{2}}{\partial...

Considering pilot wave interpretation, a singular particle measurements are fully defined (?) by knowing its wave function (a pilot wave) and the position of the "particle" (some hypotetical point particle riding on the wave). This should provide some sort of "realistic" explanation of how a...

If I'm trying to solve the problem of a particle in free space (H = P2/2m ). the eigenfunctions of the Hamiltonian cannot be normalized. now assume I have a legitimate wave function expressed in terms of the eigenfunction of H and I want to measure its energy. what will happen to the...

Case (a) is the textbook of a planar incident wavefront and below it in the figure is the known simple formula for the central spot and fringes, or minima and maxima, angular distribution with respect to the optical axis. So, the question here is regarding case (b). The position (usually...

Hi On page 81 of the book "A student's guide to waves by Fleisch and Kinneman a conclusion is made while differentiating D Alembert's solution to the wave equation. Will someone explain this please ? The details are in the attachment TIA

I have heard that wavelike interference patterns are observed in the double slit experiment even when electrons are fired one by one. https://physicsworld.com/a/the-double-slit-experiment/ My knowledge on the experimental setup is very basic. The reason I am posting here is out of curiosity...

Hi, I'm reading "Wave Physics" by S. Nettel and in chapter 3 he introduces the Green's function for the 1-dimensional wave equation. Using the separation of variables method he restricts his attention to the spatial component only. Let ##u(x)## be the spatial solution to the wave equation and...

I've been troubled by this problem for some time now and have received several answers to it none of which I find compelling, so I am posing it again in hopes of getting something more convincing. Here's the problem. Consider one had a large optical interferometer with two siderostats place...

Hello, I am a high school physics teacher, and I have been thinking about a way to model quantum mechanics in an intuitive way in order to teach it better, but I don't want to lead my students down the wrong path. I am certainly no expert in quantum theory. In looking at the guidelines, I...

As we see in this Phet simulator, this is only the real part of the wave function, the frequency decreases with the potential, so lose energy as moves away the center. we se this real-imaginary animation in Wikipedia, wave C,D,E,F. Because with less energy, the frequency of quantum wave...

The graph provided is below. The problem asks for the speed of the wave at 0.12s. I used the formula v=w*xmax*cos(wt), provided in our textbook where xmax is the amplitude of 2 cm, w (omega) is 2pi divided by the period of 0.2. However, for some reason this formula doesn't give me the correct...

I'm confused by this question, from minimal coupling shouldn't the answer simply be ## \nabla^a \nabla_a F_{bc} = 0 ##? Any help would be appreciated. EDIT: I should also point out ##F_{ab}## is the EM tensor.

Hello, I am going to be doing a project in which I'll be looking at how sound waves change the shape of an object. Specifically how sound waves can compress something. My question is, can I approximate a sound wave as a force in this case? I know a sound wave is much more complicated than a...

## \frac{1}{v^2} \frac{∂^2y}{{∂t}^2} = \frac{∂^2y}{{∂x}^2} ## and general solution ## y = A sin(kx+ωt)+ B cos(kx+ωt) ## http://blogs.bu.edu/ggarber/archive/bua-py-25/waves-and-sound/standing-waves-in-strings-and-pipes/ In case fixed at both ends The condition is ##y(0,t) = 0 ## and ##y(L,t) =...

I am working with a simulation which generates multiple identical functions that overlap differently (i.e., they are generated with randomly different phases from each other). When I calculate the composite wave, the shape of the combined wave will differ depending on the relative phases of...

Hello! I know that a square or saw tooth wave consists of infinite amount of sinousoids each having different frequency and amplitude. But when I look at their plot they seem to have a well defined frequency or period. Which term in the Fourier series determines their frequency? Does a saw...

From many sources (Internet, Landau & Lifshitz, etc.), it is claimed that the Schrödinger's equation is a wave equation. However I do not understand why for the following reasons: It is Galilean invariant, unlike the wave equation which is Lorentz invariant. Note that the diffusion/heat...

Quantum fields have wave functions that determine a particle position in space. It solves non-locality, double-slit paradox, tunnel effect, etc. What if the wave function is also in time? Won't it solve the breaking of causality at quantum level? (Delayed Choice/Quantum Eraser/Time) Not much...

I'm trying to derive the electric and magnetic fields of a plane wave from the four-potential ##\mathbf{A} = (A^t , \mathbf{a}) ## in the Lorenz gauge. Given: ##\mathbf{A}(\mathbf{R}) = \Re \left( \mathbf{C} e^{i \mathbf{K} \cdot \mathbf{R}} \right)## for constant future-pointing lightlike...

I am a high school teacher and we were discussing waves and electricity in class today. One of my students asked me if electricity is a longitudinal wave or not and I had no idea how to answer. So, I realize that electric fields are what drive electrons to move through conducting wires, but...

I have found on the internet an article from Gizmodo magazine, in which a LIGO team member answer some readers’ questions, regarding gravitational waves, and found a specific question and answer in that article, to be very interesting. The question relates to weather gravitational waves are...