Waves are disturbances that propagate through 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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Current Electricity

If $$ \frac{dQ}{dt} = I $$ and if an accelerated current produces E.M. waves (radiation), does that mean $d^2Q/dt^2$ (second derivative of a charge w.r.t. time) will give me the magnitude of the wave ...
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Why does sound wave suffer more diffraction than light waves generally?

Why do sound waves suffer more diffraction than light waves generally ? I would like more of a logical explanation rather than mathematical .
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What is the wavelength of the light and how far away from the central maximum are the first and second maxima? [on hold]

A single, monochromatic light source is shined through an etched, flat prism with a slit separation of 0.025mm. The resulting interference pattern is viewed on a screen 1.25m away. The third maximum ...
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What is the small angle measurement from the central maximum to the first maximum? [on hold]

Two thin slits with separation of 0.0200mm are placed over monochromatic red laser of wavelength 632nm. What is the small angle measurement from the central maximum (zero degrees, in-line with source) ...
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22 views

Velocity profile of a viscously damped wave

For a test case, I want to determine the velocity profile of a viscously damped standing wave. By linearizing the density ($\rho=\rho_0+\rho'$) and velocity ($ux=ux'$), the continuity and ...
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Waves interfere in angle equation

If we had two waves perpendicular to each other, with equations: $x=αsin(ωt)$ (1) $y=βsin(ωt+π/2) ==> y=βcos(ωt)$(2) $sin(ωt)^2+cos(ωt)^2=x^2/α^2+y^2/β^2=1$ $x^2/α^2+y^2/β^2=1$ is an equation ...
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2answers
69 views

Why is a sine wave considered the fundamental building block of any signal? Why not some other function?

It is mathematically possible to express a given signal as a sum of functions other than sines and cosines. With that in mind, why does signal processing always revolve around breaking down the signal ...
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30 views

baryon acoustic oscillation

I have one question about baryon acoustic oscillation. I understand why we should have the baryon-photon fluid sound wave before recombination: Suppose we have a spherical overdense region. This ...
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31 views

How are standing waves a result of constructive and destructive interferences?

For constructive I can understand. But destructive I can't. I can not picture the shape of two pulses or waves maybe that form the resulting standing wave. The places where waves are canceled just ...
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2answers
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Is sonic boom louder than the sounds that a object traveling at the speed of sound makes, if so why?

Here are the wave-front models for both: I am in an introductory physics course. Just learned about this. I am not entirely sure if sonic boom is louder. But from what I saw, it's loudness is ...
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Reflection of an Electron

When a mechanical wave goes from one material to an other, some fraction of it returns back. Same thing with light (massless), but what happens with an electron? When the "wave function" changes ...
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What maximum theoretical speed can reach spaceship with EM Drive in space? [on hold]

There are several studies (by Institute of Aerospace Engineering, Technische Universität Dresden and by NASA) that are concluding that the EM Drive produces thrust. So I am wondering: if the EM Drive ...
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Question about intensity of EM waves

For electromagnetic wave if it's reflected from a perfect conductor standing wave can be form. I wonder why Poynting vector can be used to describe the intensity of standing EM wave. (see p.19 of ...
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Numerical Solution of the Convection Dispersion equation

I have asked this question on Computational Science and also on Mathoverflow, but no satisfactory answers so far. I thought maybe the physics community could shed some insight on the issue. I am ...
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0answers
24 views

concerning the effects of temperature and density on the speed of sound [duplicate]

here is my relatively broad question: how does the temperature and density of a medium effect the speed at which sound travels through it? Now I shall elaborate: it is my understanding that there ...
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3answers
55 views

What do light wave oscillations look like?

High school physics student here, so please bear with me for a moment. I know that light waves oscillate, but I don't know how. In textbooks and diagrams they're portrayed as wavy lines traveling ...
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Two supersonic planes. Do they hear each others sonic boom?

Plane A is traveling at Mach 2 and is over taken by plane B traveling at Mach 3. Does plane A hear the sonic boom from plan B? If so when? Does plane B hear the sonic boom from the slower Plane A? ...
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Can a standing wave form on a string with both end open

I am fascinated with an idea of an standing wave forming on a string with both end open. If we assume two identical waves coming in of an infinitely long string then for a short period of time, they ...
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Is an infinite Doppler effect plausible?

When I was young (which I still am) I was amazed by the sound jet fighters make when they break the sound barrier - a sound similar to an explosion which caused my school to shake. Later I learned on ...
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How to model radio wave attenuation by seawater?

From the very limited literature I can find regarding radio waves in saline-water solutions (as in seawater), I have been able to find very few corroborating models of radio wave propagation through ...
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Electron wave function seen in Quantum Cascade Laser?

http://sciencequestionswithsurprisinganswers.org/images/qcllevels.gif How did they observe and take a picture of the electron wave function without collapsing it? Does this prove that the wave ...
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33 views

Interference of Beams with Different Polarizations

I have read in many places that orthogonally polarized light beams do not interfere. However, I also know that orthogonal vectors, such as force, do affect each other and give a resulting force. So, ...
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what is the effect of a sound wave at the opposite side of its direction?

We know that a sound source produces a sound wave and a high pressure area is followed by a low pressure area, while they travel with 300m/s. My question is, if the sound source travels with 50m/s in ...
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Mechanical waves with slower speed than sound

Sound is mechanical waves of high and low air pressure transmitting with 300m/s. Are there high and low air pressure waves transmitting with lower speeds? How are they produced?
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Which is has the highest (greatest) sound intensity - Sine, Square or Sawtooth waveform?

From this, http://electronics.stackexchange.com/questions/42904/square-wave-sine-wave-is-more-audible I now understand that a Square soundwave will be perceived louder than that of a Sine sound wave ...
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Relationship between the frequency and amplitude of wave

I wonder is there any relationship between frequency and amplitude of wave. Generally, most of the people say that frequency and amplitude are independent to each other. But in this case, where it is ...
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Few doubts regarding waves acting on strings

First let's take a look at the image below XY and YZ are two different strings. Strings XY and YZ are connected each other at Y. Now what I do is, I create a wave pulse by shaking the composite ...
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What is the wave in an electron? [duplicate]

For Photons, their 'waves' are oscillating electromagnetic fields. From what I've heard, electrons are also some kind of wave. So what 'field' is exactly oscillating for electrons, which makes them a ...
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1answer
60 views

What does a light wave look like (3d model)

What does a light wave look like? The only models I can seem to find online are 2D waves, they just look like sin() graphs. I have seen the models of the two components of "light waves" (electric ...
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27 views

Is there a limit to how thin EM radiation can be spread out?

Sorry if this is completely off base but from my understanding, electromagnetic radiation, such as light, becomes less intense the further away it gets from the source. I assume the reduction of ...
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Why do some types of waves disperse?

We know that some mediums/waves are non-dispersive such as air for sound waves, and waves on a string. But, why do some waves, for example deep water waves, disperse? I am trying to understand the ...
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phonon dispersion with random masses

In order to see how phonons should be affected by disorder, I've been playing around with a model involving a 1D chain of masses linked by springs, where the spring strengths are all the same but the ...
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Light travels in a medium

According to Snell's law : $${n_1 \over n_2} = {v_2 \over v_1}$$ $v_2 = v_1 n_1 / n_2$ Assuming that $n_1$ is vacuum , we will find the following equation: $$v = c / n$$ (We may find the same ...
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Why does medium not affect the frequency of sound?

I read in various places that frequency does not change with medium. Instead, wavelength changes in different mediums due to a change in speed. I understand why speed changes with medium, but I'm not ...
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2answers
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Huygen's principle and why can't we see atoms with light

First of all, I'd like to discuss Huygen's principle. In order to explain waves diffraction, it says that every point in a wave front behaves as a source, so the next wave front is the sum of all ...
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Need mathematical explanation for different musical notes sound different on different instruments

I am not expert in music. There are number of musical instruments. One (especially a person who knows about music) can blindly recognize which instrument is being played just by listening to it. I ...
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Poisson Spot vs. Shadows

In textbooks, whenever I read about the Poisson spot, it involves a disk, and having light waves diffract around it and interfere constructively in the center. At the same time, when I read about ...
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2answers
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What determines the point of energy spillover to higher modes of a standing wave resonator?

One of the better known physics demonstrations for standing wave resonance is the singing rod . By holding the rod exactly in the middle the demonstrator constrains the first mode of excitation - the ...
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The role of amplitude, frequency, and intensity in mechanical vs. EM waves

As far as I know (correct me if I’m wrong), for a mechanical wave (e.g. sound), the frequency determines the pitch, the amplitude determines the loudness, and the amplitude is proportional to the ...
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50 views

Energy and the modes of standing waves

If you induce a higher mode in a standing wave, does the wave then carry more energy? If so, does that differ for a mechanical or EM wave? (Perhaps I should elaborate on why I am asking this ...
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How can shock waves travel faster than sound?

A shock wave can be caused by the disturbance of air by an airplane. When it propagates, shouldn't the mechanism be the same as that of a longitudinal sound wave? Why can a shock travel faster than ...
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Pefectly electrically conducting Neumann boundary conditions

I have a rather subtle question regarding necessary boundary conditions. To solve Maxwell's source-free equations as an initial boundary value problem in a volume $\Omega$ bounded by a perfectly ...
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32 views

Transfer function of a space varying wave equation

$$\frac{\partial ^2 \psi}{\partial x^2}-\mu \epsilon \frac{\partial ^2 \psi}{\partial t^2}-\mu \sigma \frac{\partial \psi}{\partial t}=0$$ Is the wave electromagnetic wave equation in lossy, source ...
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1answer
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$\sqrt{\frac{\omega ^2}{c^2}-k_z^2}$ in cylindrical harmonics

The radial component of the solution of the wave equation in cylindrical coordinates is $$J_\nu \bigg(\rho\sqrt{\frac{\omega ^2}{c^2}-k_z^2}\,\,\bigg).$$ But I always thought that $\frac \omega c$ ...
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99 views

Worthington jets explanation: fluid phenomenon

I don't understand the reason behind the formation of Worthington jets I've been reading a bit about Worthington jets Video 1, this phenomenon is caused when something is thrown to the water as we ...
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1answer
66 views

Why we get a force when a bus or car is going beside us? Is there any mathematical relation?

Suppose you are standing beside a road. A bus is running on the road, when it is crossing you, you feel a push of wind. Why its happen? Is there any mathematical relation?
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105 views

Why intensity of light(wave) is proportional to the square of its amplitude?

I am confused, Classical wave theory says that Intensity of the light(wave) is the proportional to square of the amplitude. How intensity is proportional to the square of the amplitude?
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“X-rays”, “gamma rays”, “sun rays”… But electromagnetic waves are NOT rays and DO NOT consist of rays?

In a separate question I'm struggling to figure out the nature of EM waves. But it's a vast topic and I'm trying to narrow it down to small specific questions. It turns out that all electromagnetic ...
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Is the wobbly rope depiction of a radio wave inherently wrong? And how do vectors of parallel waves align with each other?

I don't have a scientific education, yet I'm scientifically curious. Among other things, I'm struggling to understand the nature of electromagnetic waves. What I have recently realized is that the ...
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48 views

Question about standing wave

By considering the superposition of two waves propagating through a string, one representing the original or incident wave and the other representing the wave reflected at the fixed end, if both ends ...