Wave Definition and 999 Threads

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...

I have been tasked with building a wave generator in a flume. I need to find out how much force will be required to drive a wedge into a body of water so that we can get the right sized motor. For simplicity sake this wedge is 200mm tall, with a 45deg angle and 600mm wide. It is entering the...

Again I am really confused, but I just put the traveling wave as: ##\psi(x,t) = Dcos(kx- \omega t)## for positive x ##\psi(x,t) = Dcos(kx+ \omega t)## for positive x Then I simply differentiated and plugged in ##x=0## ##F(t) = - T D k sin(\omega t)## and from this ## \langle P \rangle = T D^2 k...

Has anyone ever tried to measure the number of waves in photon wave packets? It seems like that would be an important feature and would be equal to the number of fringes in the double slit experiment (on one side), unless it is a huge number. Also, the decrease in the intensity of fringes as...

Howdy all. The typical image of a three phase electrical system involves 3 sine waves, phase shifted 120 degrees. These sine waves each, individually, represent the 'phase voltage,' which is to a common neutral in a wye configuration. In this wye configuration the line to line voltage is...

Hello, I would like to write a product of two wave functions with a single ket. Although it looks simple, I do not remember seeing this in any textbook on quantum mechanics. Assume we have the following: ##\chi(x) = \psi(x)\phi(x) = \langle x | \psi \rangle \langle x | \phi \rangle## I would...

I have been revisiting my notes from my 2nd and 3rd year physics degree - especially the ones covering Fourier Optics, and other classical wave optics - and it is quite rewarding to revisit the historical / exploratory aspect of the series of discoveries, that built the foundations of this...

OK, so I'm trying to work out a few ideas regarding locality. I've studied at the undergrad level in the past (including quantum), but with professors that slaved away at proving math constructs and never bothered to indulge in clarifying the context of any concepts, so I'm pretty weak here...

From what I have read gravitational waves are caused by the acceleration of massive object causing ripples in space time. What specifically causes this, and how does general relativity predict these. Does it have to be a high density of matter, or a large amount of it. How do these waves affect...

I am having trouble with doing the inverse Fourier transform. Although I can find some solutions online, I don't really understand what was going on, especially the part that inverse Fourier transform of cosine function somehow becomes some dirac delta. I've been stuck on it for 2 hrs...

Homework Statement Wave problem Given data : f = 20 Hz y0 = 0.005 m t = 0.1 s x = 0.4 m1. The end portions of stretched string oscillates in the transverse direction with a frequency of 20 Hz and an amplitude of 0.005 m. Wave , which travels along the string, made in 0.1 second, 0.4 m long...

My textbook explained that it would be hard to see the wavelength properties of a tennis ball because we would have to find a very tiny slit in which to pass the tennis ball through. The wavelength of the tennis ball can be calculated using debroglie formula: wavelength = h/p I was wondering if...

If I’m not mistaken, a system can be described as a wave if it follows the wave equation. On Wikipedia, the general solution for the one-dimensional wave equation is written as u(x,t) = F(x - ct) + G(x + ct). I don’t see the connection between this solution and what I understand waves to be...

I've wondered this for a while but not known how to ask the question, If light is a transverse wave, then what is it transverse to? To elaborate, light travels in three-dimensions, radially. To me, this seems analogous to the sound wave, with pulses of pressure moving longitudinally to the...

So, my game is coming along. My psychic energy shielding protects against EM radiation. The energy used for shielding gets depleted based on the type of EM radiation (the wavelength) and according to the amplitude of the radiation the energy shielding is exposed to. I can't find many numbers...

I understand that waves are function of space and time in nature, so E(x,t) will be fundamental description of a wave. I notice that often people denote a wave as E(t) for instance, an envelop function of a pulse. For this case, E is an oscillation at a fixed spatial point x? So that the point x...

In Classical Mechanics, waves produced in linear systems, like EM waves, obey the Superposition Principle in which the wave amplitudes of, say two input waves, “add up” to create one output wave whose varying amplitude is the sum of the two input waves. One example would be Young’s Double Slit...

Hi everyone! Sorry for the bad english! So, just a quick doubt... Does things collapse from a wave of probability into a quantum field or is the wave in the quantum field the probabilistic wave itself? An example to make it clearer: Suppose we have an atom, it enters an atom interferometer, it...

Is the following true? ψ*∇^2 ψ = ∇ψ*⋅∇ψ It seems like it should be since you can change the direction of operators.

1. Homework Statement Consider a potential field $$V(r)=\begin{cases}\infty, &x\in(-\infty,0]\\\frac{\hslash^2}{m}\Omega\delta(x-a), &x\in(0,\infty)\end{cases}$$ The eigenfunction of the wave function in this field suffices...

Consider a potential cavity $$V(r)=\begin{cases}\infty, &x\in(-\infty,0]\\\frac{\hslash^2}{m}\Omega\delta(x-a), &x\in(0,\infty)\end{cases}$$ The eigenfunction of the wave function in this field suffices $$-\frac{\hslash^2}{2m}\frac{d^2\psi}{dx^2}+\frac{\hslash^2}{m}\Omega\delta(x-a)\psi=E\psi$$...

What Is a wavefront? How can we interpret it?

Just when I thought there couldn't be any more quantum interpretations (I think @Demystifier listed 9 in his recent thread)... :smile: Lee Smolin and several others (Cohen, Cortês, Elitzur) have published a pair of related papers discussing dBB/Bohmian Mechanics and its ability to explain the...

How do I setup an integral to integrate over the following equation: V(t) = 1/(R*C) integral to t Vin(t) dt This is the capacitor voltage over time formula. I want to integrate over a sine wave from 9 to 81 degrees. Frequency of 120Hz, amplitude of 120V. The formula I used in wolframalpha is...

Dear community, I am Pedro de la Torre, now doing my PhD on Cosmic ray propagation. Now, I have started to study reacceleration due to interactions of CR with plasma waves. My problem is that I do not find neither a good book or any kind of review with a detailed demonstration on the...

I am trying to understand the following: 1. Have gravitational wave constructive and deconstructive interference phenomena already been observed or is it that only after making LIGO kind of experiments more advanced, that we might be able to observe such phenomena in the future? 2. Can't...

Homework Statement Ql: Which sound wave will have its crests farther apart from each other - a wave with frequency 100 Hz or a wave with frequency 500 Hz? Homework Equations Frequency= 1/ periodic time The Attempt at a Solution I did it like that: I just found the periodic time for each...

Homework Statement Homework Equations v = d/t Solve for t. t = d/v The Attempt at a Solution In my General Physics 2 course we are doing sound waves I have the answer to the problem which is 90.8m I am trying to understand the concepts of sound wave. So please correct me if I am wrong, 1...

https://arstechnica.com/gaming/2019/01/oxford-scientists-successfully-recreated-a-famous-rogue-wave-in-the-lab/

Dear Everybody, I do not know how to begin with the following problem: you are asked to solve the wave equation subject to the boundary conditions ($u(0,t)=u(L,t)=0$), $u(x,0)=f(x)$ for $0\le x\le L$ and ${u}_{t}(x,0)=g(x)$ for $0\le x\le L$ . Hint: using the...

Dear Everybody, I am confused about how to start with the following problem: using the solution from ex. 3: $u(x,t)=F(x+ct)+G(x-ct)$ "For data u(x,0)=0 and ${u}_{t}=\frac{x}{(x^2+1)^2}$ where x is from neg. infinity to pos. infinity." Thanks Cbarker1

Dear Everyone, Hi. I do not how to begin for the following question: Ex. 5. Using the solution in Ex. 3, solve the wave equation with initial data $u(x,t)=\frac{1}{{x}^2+1}$ and $\pd{u}{t}(x,0)=0$ for $x\in(-\infty,\infty)$. The solution, (I have derived this solution in Ex. 4), that is...

I have a few questions about the wave equation and the D'Alambert solution: 0) First of all, I'm a bit confused with the terminology. Wikipedia says that THE wave equation is a PDE of the form: ##\frac{\partial^2 u}{ \partial t^2 } = c^2 \nabla^2 u##, however there are other PDEs that have...

Homework Statement A. Two identical speakers, with the same phase constant, are arranged along a 1D track. One speaker remains at the origin. The other speaker can slide along the track to any position x. You are on the track at x=10 m. You hear interference maxima when the adjutable...

Suppose a linear polarized light wave front is incident on a double slit. What happens if one places a quarter-wave polarizer in front of only one slit in the double slit experiment? Does one obtain the usual inteference fringes? Or the diffraction pattern only? Else?

Hi, a simple question related to the gravitational wave detection. The net effect of gravitational wave is basically the stretching of the space including all the measurements tools (meter sticks just to illustrate the concept) that could be used to detect it. I am aware of laser...

Homework Statement This is just a question about a question in Serway & Jewett's "Physics for Scientists and Engineers 3rd Ed". It's Objective Question 3 from Chapter 18, building on Example 18.1 from the text. Two identical loudspeakers placed 3.00 m apart are driven by the same oscillator...

Basically, we have a transmission line not matched to load R. So there is a forward wave and a reflected wave. Now when the reflected wave reaches back to source 'S', does it get absorbed by the source? Does that mean the source 'S' gets back some of the power (equal to the reflected power) that...

Is the wave function for the positron the complex conjugate of the wave function for the electron? I've tried to google this, but I can't seem to get a definite answer from a reliable source. It seems that antimatter is derived in quantum field theory which does not concentrate on wave...

Can the wave function for entangled particles be solved perturbatively? Are there virtual processes involved with this? Thanks again.

Is anyone did experiment on wave function collapse in double slit experiment. Could you please share information about that, and also share research paper about that experiment. What kind of observation done here, what kind of equipment used for that?

Homework Statement We have an incident electric field, and there are two cases: 1) the field is polasised perpendicularly to the incidence plane (TE) 2) polarised in the plane (TM) Here I must be able to correctly apply the limit conditions, to find the Fresnel formulas that give the...

Answer is probably not, but is there some connection between the inhomogeneous wave equation with a constant term and the spacetime interval in Minkowski space? $$ 1) ~~ \nabla^2 u - \frac{1}{c^2} \frac{\partial^2 u}{\partial t^2} = \sum_{i=0}^2 \frac{\partial^2 u}{\partial x_i^2} -...

We want to solve the equation. $$H\Psi = i\hbar\frac{\partial \Psi}{\partial t} $$ (1) If we solve the following equation for G $$(H-i\hbar\frac{\partial }{\partial t})G(t,t_{0}) \Psi(t_{0}) = -i\hbar\delta(t-t_{0})$$ (2) The final solution for our wave function is, $$\Psi(t) =...