Wave Definition and 999 Threads

How can we be sure that a system on the scale of atoms can be described by a single scalar field or the wave function ##\psi##. I don't just want to do shut up and calculate, maybe using a wave function and then putting it through the time evolution of the Schrödinger equation works, but why...

In order to trigger this "interaction at a point as a particle" does an entity need to meet a certain criteria? Why doesn't any other entity on its way force this transition? Can the properties of this wave be altered? Thank you.

1.) In electromagnetics, wavelength in a medium is $$\lambda = \frac{\lambda_{0}}{n}$$, where $$n$$ is the refractive index. What is the equivalent formula for sound wave in a medium? 2.) Is there a reference sound velocity, like electromagetic wave speed in vacuum is $$c_{0} =...

I was reading Six easy pieces from Feynman and I got stuck what is electromagnetism 2 years ago. Recently I came across a video and I think I have figured it out. The paragraph says like this: “ If we were to charge a body, say a comb, electrically, and then place a charged piece of paper at...

A sinusoid can be described by the differential equation y'' = -k*y, where the force y'' is proportional to how far away from the center it is. However in many physical systems the force between two bodies decreases with distance squared. So would we still classify the differential equation...

There is lots of good information online about shock waves but I'm not finding what I want. If dynamite has a detonation rate of 6800 m/s does the shock wave travel at 6800 m/s? Is sound we hear 1 mile away the shock wave or the sound? What speed is an atom bomb shock wave? This large horn...

Homework Statement:: This is from 5 ed, Physics 1Halliday, Resnick, and Krane. page 428 about sound waves I have highlighted the equation that I don't understand. How did the author get it? I understand how they get from the middle side to the RHS of the equation, but I don't understand how...

I am refreshing on the pde's, and i am trying to understand how the textbook was addressing change of variables, i find it a bit confusing. I will share the textbook approach, then later share my own understanding on change of variables approach. Here is the textbook approach; My approach on...

I am totally confused about the task. Any help will be nice. Thank you so much

I know for a wave moving from left to right, ##\psi_i = Ae^{i(\omega t - k_1x)}## The first reflection where ##Z_1## is ## R_{12}Ae^{i(\omega t - k_1x)}## The second reflection. The wave moves from 2 to the limit between 2 and 3 then reflect... Thus, ##T_{12}R_{23}T_{21} Ae^{i(\omega t - k_1 x...

Hello, I wonder if it is possible to write Bloch wave functions in momentum space. To be more specific, it would calculate something like (using Sakurai's notation): $$ \phi(\vec k) = \langle \vec k | \alpha \rangle$$ Moving forward in a few steps: Expanding: $$ \phi(\vec k) = \int d^3\vec r...

"Everything is a particle whose position is predicted by a mathematical wave. Light is not a wave but is packet of energy whose position is predicted by the wave.The same goes for an electron. Interference pattern is a probability distribution of where we are likely to find an electron. When...

Hello guys! I am studying the hydrodynamics of a ship in shallow water. In deep water the ship creates 2 wave patterns, one transverse and another divergent, both making an angle of 19°28'. Also, the maximum velocity of a wave in shallow water is given by ##\sqrt{gh}## where h is the depth of...

It is well known that one can solve incident an reflective wave in homogeneous linear media by matching PDE boundary conditions. In the electrical engineering community, one solves similar problem using smith chart and scattering parameters for 1-dimensional propapation of TEM modes in...

Why we know that average speed of a single photon(in point particle view) equal the speed of EM wave?If average speed of a single photon smaller than c then there exist massive photons?

I'm trying to find the wavelength. However, I don't understand why the wavelength is different if the wave is moving in the +z direction. I have ##\Psi(z=15cm,t) = \hat{x} 6 cos (\frac{\pi}{3}t)## ##\Psi(z=12cm,t + 2s) = \Psi(z=18cm,t)## For a wave moving on the -z direction I know that the...

The final wave function solutions for a particle trapped in an infinite square well is written as: $$\Psi(x,t) = \Sigma_{n=1}^{\infty} C_n\sqrt{\frac{2}{L_x}}sin(\frac{n\pi}{L_x}x)e^{-\frac{in^2{\pi}^2\hbar t}{2m{L_x}^2}}$$ The square of the coefficient ##C_n## i.e. ##{|C_n|}^2## is...

https://www.nature.com/articles/s41561-021-00843-9 Popular science version: https://scitechdaily.com/uncovering-the-surprising-secrets-behind-Earth's-first-major-mass-extinction/ Nature paper discusses causes of the second "wave" of mass extinction at the end of the Ordovician (~445mya) Really...

##-w1## and ##-w2## are to shift the cosine graph to the right, and ##\frac{2pi}{\lambda}## is to stretch the graph. But I can't seem to draw an appropriate ##y1+y2## graph (quite irregular) and I struggle to find the resultant frequency and wavelength. Also, why is there angular frequency in a...

Summary:: We are currently studying basics of quantum mechanics. I'm getting the theory part but it's hard to visualise everything and understand. We are given this question to plot the function so if someone could help me in this. Plot the following function and the corresponding g²(x) g(x)...

I don’t get where exactly the lengths start and end in figure.

Hi, First of all, I'm wondering if a beaded string is the right term? I have to find the amplitude of the modes 2 and 3 for a string with 5 beads. In my book I have $$A_n = sin(\kappa p)$$ or $$A_n = cos(\kappa p) $$ it depends if the string is fixed or not I guess. where $$\kappa = \frac{n\pi...

If ##\hat{T} = -\frac{\hbar}{2m}\frac{\mathrm{d^2} }{\mathrm{d} x^2}##, then the expectation value of the kinetic energy should be given as: $$\begin{align*} \left \langle T \right \rangle &= \int_{0}^{L} \sqrt{\frac{2}{L}} \sin{\left(\frac{\pi x}{L}\right)}...

I need an equation to graph a sine wave that act like a unit circle but only positive numbers. so I need it to be 0 at 0, A at 90 , 0 at 180, A at 270, 0 at 360, and A at 450 and so on and so on... Now I know sin(0) is 0 in degrees and sin(90) 1 and I know if you Square a number is...

I understand the part where there will be more nodes produced because number of wave produced will increase (let say from half wave to one wave). But I don't understand the part where the amplitude will be less. How can number of nodes (or frequency) affect the amplitude of standing wave...

Good day. We know how simple objects, such as 1D wires behave when a simple harmonic wave travels along a wire, or two wires knotted togethe.We also know what happens if you excite a circular thin disc with a single frequency. Are there some material I can read on, that considers the effect...

Consider the situation where an observer at rest on the ground measures the frequency of a siren which is moving away from the observer at speed ##v_{Ex}##. Let ##v_w## be the speed of the sound wave. Let ##\lambda_0##, ##f_0##, ##\lambda_D##, and ##f_D## be the wavelengths and frequencies...

But in the notes from teacher, the equation is ##y=A \sin (kx - \omega t)## for wave traveling to the right and ##y=A \sin (-kx - \omega t)## for wave traveling to the left When I transform the equation of the wave traveling to the left using trigonometry: $$y=A \sin (-kx - \omega t)$$ $$y=-A...

How does the photoelectric effect prove the wave-particle wrong? Higher intensity does not mean higher energy. If we were to assume the wave-particle model, an increase in intensity means an increase in the amplitude of the wave right? The energy of light is never dependent on amplitude, it is...

I am trying to create a two phase type setup where I have a square wave in the multi-gigahertz frequency. However, I want the second wave to start once the first one reaches 90 degrees. How can the circuit be configured to do this? Will a phase shifter do or can a square wave be phase shifted at...

I imagine a particle traveling across 1 wave cycle. The total vertical distance traveled across the wave cycle is 4 x the amplitude of the wave. The total vertical distance traveled in 1 minute: 5 cycles in 1 second, thus 5x60 cycles in a minute then 4 x amplitudes effectively traveled per...

A book on optics which is less mathematical maybe a similar one to physics for poets or gamow gravity classics

Hello everyone, I would really appreciate some help on the following problem on plane waves and propagation. Not too sure if my attempt at writing the propagation wave expressions are correct, and how to handle the arbitrary function f(u). For the velocity, the wavelength is not specified, so is...

The full title of the publication is: Rare Events Detected with a Bulk Acoustic Wave High Frequency Gravitational Wave Antenna It is published in Physics Review Letters and reported in Phys Org. They have created a small piezo-electric device (< 2cm, though it gets bigger once you create an...

Hi, I am 16 year old and I am very interested in Physics. This summer I solved Schrödinger equation using griffiths' introduction to quantum physics and other sources. I achieved to get an exact solution of the wave function but I would like to plot it in a programm in order to get the 3d...

What is the difference between an absolutely continuously differentiable function and a wave? Are all absolutely continuously differentiable equations waves?

From hyperphysics, "The unique point in the case of the traveling wave in the string is the element of the string that is at the maximum displacement as the wave passes. That element has a zero instantaneous velocity perpendicular to the straight string configuration, and as the wave goes "over...

Hello! Let's say we have a wave function. Maybe it's in a potential well, maybe not, I think it's arbitrary here. This wave function is one-dimensional for now to keep things simple. Then, we use a device, maybe a photon emitter and detector system where the photon crosses paths with the wave...

I would like to know if any of you think there's any sort of connection, analogy, or common features between, sets in set theory and wave functions in QT? Wave functions lack trajectories, so do sets. Wave functions also distribute over areas, as sets can do. To my understanding, wave...

Why are lights reflecting off horizontal surfaces like the road, water, or snow horizontally polarized? How does the process happen?

Hello, Regarding the wave oblique angle propagation and based on Balanis "Advanced engineering Electromagnetic" book on page 136 ( it has been attached) I need to know why the phase velocity in x direction is not important to keep in step with a constant phase plane( Just equation 4-23). I...

Hi, I have created a sine wave with the following options: 1.) - changing the period/length in days of the sine wave (Cycle Length in Days) 2.) - calculating the start value of the "dummy" so that the sine wave always starts with -1 (Dummy Start at Cycle Trough) when the phase shift is set...

Regarding wave equation we are faced with this form $$\nabla^2 \vec{E}=j\omega \mu \sigma \vec{E}-j\omega \mu\varepsilon \vec{E}=\gamma ^2\vec{E}$$ where $$\gamma ^2=j\omega \mu \sigma -j\omega \mu\varepsilon $$ $$\gamma =\alpha +j\beta $$ where alpha and beta are attenuation and phase...

I started out by finding the w (omega) value for all of the three states but I'm not sure where to go from there.

According to de Broglie, the wavelength of an electron wave is L=h/p. Is there a way to calculate the frequency of such a wave? Thank you!

This is a fluid dynamic simulation. The top area has 100 degrees Celsius. The bottom area has 0 degrees Celsius. And both are filled with an ideal gas which is 1-atmosphere pressure. Two areas are connected through the left small line. Another part is blocked. So heat transfer can only happen...

A wavefront is defined as a surface in space where the argument of the cosine has a constant value. So I set the argument of the cosine to an arbitrary constant s. ## k(\hat{u} \cdot r - c t) + \phi = s ## The positional information is is in r, so I rearrange the equation to be ## \hat{u}...

I recall some time ago seeing a GR equation describing the rate of orbital energy loss from the moving objects in orbit generating gravitational waves. I can no longer find this equation again. I am hoping someone can help me.