Waves are disturbances that propagate throush space and time. Classically, they travelled through a medium, disturbing the particles but not changing their mean position. Electromagnetic waves/particle-waves need no medium; they are disturbances in their respective fields.

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How is it possible for light to be a wave and a particle? [duplicate]

I have always been interested in Physics, and lots of people say that light is a particle and a wave. How is it possible? How can a photon (a light particle) be a wave as well, when its a particle? ...
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44 views

Standing sound wave tube

If there was a standing sound wave tube and a flammable gas was introduced then ignited, would the combustion be more forceful and more efficient since its following a standing wave, than just a gas ...
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48 views

Quantum Excitations

In the context of quantum field theory, is the schrodinger or dirac equation actually describing some sort of an actual wave in some field like light in EM field ? So all particles are actually waves ...
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112 views

Why is sound intensity proportional to the square of sound pressure not to sound pressure alone?

I am trying to understand the physical principles behind the sound intensity and sound pressure. As far as i know, sound intensity is proportionate to the squared sound pressure. Can someone explain ...
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1answer
95 views

Red color has largest wavelenght and violet minimum (in the range of visible light). then why does violet light appears reddish? RED + BLUE = VIOLET [duplicate]

My question is simple. Green light is more similar to red light than violet, then why is violet reddish and green not? in the language of frequencies and wavelengths, red and violet should contrast ...
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what determines the wavelength of waves on the open ocean?

Looking at the picture below, you can totally see that these are tiny boats. The water is practically washing over the hull of these boat models. But the water has boundaries that are very far ...
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22 views

Learning about group velocity, phase velocity and particle velocity [duplicate]

I am studying quantum physics and I would like to know a bit more in detail about group velocity, particle velocity and phase velocity. Can you guys suggest some books/online resources where I can ...
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3answers
681 views

Prove EM Waves Are Transverse In Nature

Why we say that EM waves are transverse in nature? I have seen some proofs regarding my question but they all calculate flux through imaginary cube. Here is My REAL problem that I can't here imagine ...
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23 views

Conduction and propagation

What is the difference between conduction of electric wave in conductor and propagation of electromagnetic wave in dielectric? Why propagation term is used for dielectric and conduction for ...
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0answers
33 views

Math formula for crystal glass resonance [duplicate]

For a music therapy experiment, I have to use several crystal glasses with water and different cylindrical shapes, and make them vibrate and produce different sounds. Is there a math formula that ...
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1answer
172 views

How is the width of a slit related to the intemsity of light passing through it?

Here's a question I got in my final exam this morning. "If in a Young's double slit experiment setup, the ratio of intensity of the bright spot to the dark spot is 25:9, what is the ratio of the width ...
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1answer
274 views

Derivation of Green's Function for Wave Equation

In the textbook Modern Methods in Analytical Acoustics (Crighton-1992) the following relates the 3D Green's function in the time-domain to the frequency domain g(x-y): I cannot see how the ...
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33 views

Query regarding interference

In Young's Double Slit experiment, why is it that two waves vibrating perpendicular to each other doesn't show interference? I know that for interference to happen, the waves must be coherent ( i.e., ...
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What is the fringe separation in Young's double slit experiment?

In the double slit experiment, a pattern of dark and bright bands appears on the screen. Is the fringe separation the distance between two bright bands? Question: In a double slit experiment ...
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1answer
74 views

Help in understanding the derivation for Fresnel Distance?

An Aperture of size $a$ illuminated by a parallel beam sends diffracted beam (the central maxima) in angular width approximately $λ/a$. Travelling a distance $z$, it aquires the width $zλ/a$ due to ...
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1answer
60 views

Why are radio waves in the 1.43 - 2.5 Mhz range invisible?

Visible light diapason is 400 - 700 nm which is 1.43 - 2.5 Mhz. If using an antenna I would broadcast steady sinusoidal wave in this range, why the EM emitted by the antenna are not visible? Suppose ...
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44 views

Fresnel's explanation of rectilinear propagation

How did Fresnel explained the phenomenon of rectilinear propagation of light using concept of half period zones?
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2answers
90 views

Suppose a light wave with wavelength 3m. What happens if one tries to contain that wave within a 1m container?

Suppose a light wave with wavelength 3m. What happens if one tries to contain that wave within a 1m container? If I'm going about this entirely the wrong way or have wrong conceptions about light ...
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0answers
64 views

Phase shifting using the Hilbert transform

I am still struggling to understand how the phase shift of a complex signal works. Today I stumbled over the Hilbert transform and heared that it is possible to phase modulate a signal $f(t)$ ...
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27 views

Calculating Dynamics of a Thick Sheet of Material

So I'm working on a computational neuroscience problem, and I'm attempting to model skin dynamics for use in some perception models. The problem is as follows: Imagine you had a two dimensional sheet ...
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68 views

Derive time difference of phase rotated wavelets

I have one question concerning phase rotation of signals and I am not sure wether it works or not: Let's assume we have a zero-phase wavelet x(t) i.e. Ricker wavelet. Unfortunately, in our ...
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1answer
54 views

Electromagnetic spectrum

I understand that the electromagnetic spectrum is made up of different frequencies of light waves, but is this true in all cases such as with longer wave frequencies? "such as with microwaves". ...
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0answers
71 views

Constructive and destructive interference in De Broglie matter waves

I'm a little confused about matter waves and especially interference. $\lambda = h/p$ The denominator is momentum and is thus reliant on mass. If we assume that the property holds for particles ...
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1answer
149 views

Dispersion relation for TE and TM waves in general anisotropic medium

I want to calculate the dispersion relation (the relation between $\bf k$ and permittivity and permeability tensors and $\omega$) for a TE and a TM wave with wave vector $\mathbf k=k_x\mathbf {\hat ...
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1answer
60 views

Power of Shockwaves

My question is about shockwaves and their power when they are created/how do they lose their power? Let's say that we have ground 0 with 10 grams of TATP on it. The detonation velocity of TATP is ...
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65 views

Rotate the phase of a wavelet

Let's take a zero-phase Ricker wavelet which is given by: $$ \psi(t)=\frac{2}{\sqrt{3\sigma}\pi^{1/4}}\left(1-\frac{t^2}{\sigma^2}\right)e^{-t^2/2\sigma^2} $$ in the time domain which is often used ...
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330 views

The shape of speaker cones

This is related to another question I just asked, but they are different enough I thought it deserved its own spot. Speaker elements seem to always be shaped like a cone with a portion of a sphere at ...
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115 views

The physics of sound boards

As a kid I was bemused at why soundboards worked. A small sound could be demonstrably amplified simply by attaching the source to a surface that is rigid and not too thick. How could the volume ...
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1answer
814 views

The relationship between the energy and amplitude of a wave? Derivation?

From multiple online sources I read that $$E \propto A^2$$ but when I mentioned this in class, my teacher told me I was wrong and that it was directly proportional to amplitude instead. As far as I ...
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1answer
107 views

Can a wave exist on the “face” of a wave?

It would seem that this would be possible with waves in water. What about other waves Clarification: Given a wave starting from a point of impact, in water, at: Time 0:00 and xyz 0,0,0 and the ...
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1answer
104 views

Index of Refraction in Metal: Approximating Complex Perturbation

If you consider waves in a metal, you can write the index of refraction for the metal as, $$ n^2 = 1 - \frac{\omega_p^2}{\omega^2} $$ I am interested in what will happen if the index is perturbed by ...
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1answer
59 views

What does non magnetic and nonconducting mean in reflection and transmission of waves?

So, we were ask to consider the Fresnel Equations for parallel and perpendicular waves (with index of refractions). Then, we are ask to prove some equations in which "... for nonmagnetic ...
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25 views

How much can a thin layer of hi-speed material within a low-speed volume block a wave due to total internal reflection?

Consider a block of isotropic material with compression wave velocity associated with it, $v_1$. Consider a thin flat layer of high compression wave velocity $v_2, v_2>v_1$ that is buried within ...
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52 views

Other frequencies in a cavity

This is a fairly basic question but is something that I've never properly understood. If you have a cavity with perfectly reflecting walls, I understand that there are obviously frequencies which ...
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1answer
103 views

Principle of Superposition for driven oscillator

So I understand the the Superposition Principle states that all the forced oscillations, as determined by multiple external forces, are to be added up in order to get the entire solution. However, ...
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29 views

electron spin separation

I am having doubt whether the electron's up spin moment and down spin moment can be isolated from one another. If it got separated, will each moment acts as magnetic monopole (stable or unstable). ...
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4answers
317 views

Can frequency be equal to 0?

Is correct to speak about frequency equal to 0 ? $$f= \frac{1}{t} $$ If $t\rightarrow\infty$ can I consider that the frequency is equal to 0 ?
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3answers
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Speed of sound at temperatures below 0 °C

How can the speed of sound be calculated for temperatures below 0 °C (down to -40 °C)? Does the calculation $v=331\ \frac{m}{s} + 0.6 \frac{m}{s°C} \times T$ still hold (where T's unit is ...
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1answer
113 views

Can atmospheric pressure literally push electromagnetic waves?

I work for an IT company and some time ago we had an issue with our wireless internet. We are 5 miles away from the ISP's antenna. Our Sys Admin expressed the view that the electromagnetic waves are ...
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2answers
242 views

If electrons behave as standing waves when they are bound to an atom then how do they carry charge?

Today in my physics lesson we learnt that the best way of describing the behaviour of an electron that is bound to an atom is to treat it as a standing wave. I understand that this is the ...
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22 views

Triple axis accelerometer direction-finding

Can I detect the direction of the disturbance source which propagated in the medium by waves, using only triple axis accelerometer? I guess yes, because I already have projections of all three axes ...
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1answer
54 views

Convective derivative of oscillating fluid with bulk motion?

I have a fluid $u$, which comprises a zeroth order constant motion $u_0$ as well as a first order oscillatory motion $u_1$. The convective derivative is $$\frac{\partial u}{\partial t} ...
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3answers
145 views

Electromagnetic Waves

We all know that light is an electro magnetic wave. but is electricity a EM wave? If it is then why light does not requires a medium to travel and why on the other side electricity needs a conductor ( ...
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1answer
233 views

If the k of a wave is negative, is the wavelength negative too?

My friend went to an interview for a reputed scholarship program and was asked this question. A wave has an equation $a\sin(\omega t-kx)$. Sometimes k surely can become -ve. We know that ...
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0answers
71 views

Gerstner Wave Formula to Vertex information $(x,y,z)$

I have created a program, that draws a plane mesh, and allows to me edit or animate all the separate vertices along it. The idea behind it, is for me to be able to create a gridMesh based wave ...
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2answers
95 views

Beginner Physics - Explaining longitudinal waves

I am having difficulty grasping the concept of a longitudinal wave. My textbook definition "In longitudinal waves, the vibration is backwards and forwards in the direction of motion of the wavefront" ...
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2answers
56 views

Mechanical pulse reflection

When we have a rope with one fixed end and we send a pulse through it, the reflected pulse is inverted. My question is as follows - is it correct to say that near the end (when the pulse hits the ...
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0answers
23 views

Help with Hologram problem [duplicate]

Can someone help me out with a simple yet interesting 3D hologram related problem and solution, which can help me understand the subject and then teach the subject to a group of students.
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1answer
251 views

Simple Harmonic Motion Question - Block on Platform [closed]

A platform is executing SHM in a vertical direction with an amplitude of $5$ cm and a frequency of $\frac{10}{\pi}$ vibrations per second. A block is placed on the platform at the lowest point of its ...
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93 views

Inverse of the D’Alembert wave operator

Let $f(x)$ a solution of the wave equation $\square f(x) = 0$. I don't understand why the following operator $$ \mathcal{D} \equiv \frac{1}{2}(\nabla^2)^{-1} (x_0\partial_0 - C) $$ for arbitrary ...