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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Is there any limit to distance between two waves when used in Huygens principle?

when I used Huygens principle to determine the spherical wavuefront of radius $R/2$ created by reflection from a spherical concave lens of radius $R$, I got amazingly different results for different ...
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30 views

Standing waves as plane waves

We learned and prooved in class this property of plane waves: Bz(x,t) = Ey(x,t). So my question is, why doesn't this work for standing waves? I understand that standing waves are a superposition of ...
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16 views

How does superfluid helium interact with ultrasound?

Containing liquid helium in it's superfluid state is of course known to be problematic. Escape by crawling up container walls to 'leak' through solid containers and similar difficulties being a ...
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42 views

Wave reflection, boundary conditions?

When a wave-pulse is reflected such that initially it was moving in the denser medium, and towards the other side of the interface lay the rarer medium, will there have been a phase change post ...
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1answer
98 views

Can acoustic waves travel through human body?

If I stand inside a perfect anechoic chamber in front of a unidirectional acoustic waves emitter, I would hear the tone played either using my ears or using a microphone for ultrasonic waves. But what ...
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294 views

Why doesn't a backward wave exist? [duplicate]

Huygens principle says every point of wavefront emit wavelet in all directions. Then why does a back ward wave not exist? Can any expert tell real answer? On different sites I get different and ...
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81 views

Does diffraction take place in Young's double slit experiment?

In diffraction experiments interference takes place along with diffraction? Does diffraction take place in Young's double slit experiment? If it does take place then why don't we get the pattern of ...
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32 views

Waves hitting opening in wall (inteference)

Say you have two openings close to each other in a wall. Why does the length of the openings have to be equal to or less than the wavelength of the waves in order to create an interference pattern?
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Difference between Youngs double slit experiment and Double slit diffraction?

Both these experiments have double slits but in one interference takes place and in the other both interference and diffraction. If diffraction takes place in double slit diffraction then it should ...
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105 views

Can wifi signal reception be improved by opening a door? [closed]

Use Case A wifi user is in a different room than the router. The computer is having a hard time connecting and receiving the wifi signal. Engineering Question Can the wifi signal from the router to ...
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71 views

Vibrating string, free end boundary condition

When discussing the vibrating string problem with one end (or both) free to move in the vertical direction but constrained in the longitudinal direction (achieved by placing the "free" end in a ...
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0answers
57 views

Characteristic X Ray and Intensity-Wavelength Graph

This is somewhat the kind of graph given in my book. Questions- Q.1- Why is the intensity much higher for the characteristics rays than the continous spectrum? I understand that the wavelengths ...
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45 views

Can TE and TM modes propagate together in a waveguide?

I recently came to understand the TE and TM modes. As it is defined that E=0 for transverse electric and vice-versa. I have a few basic questions in mind which I thought to ask in one thread only. ...
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Confusion in phase and group velocity

This question is based on this question asked in physics SE. In this question, they say that phase velocity greater than velocity of light. Ok, greater than velocity of light for phase velocity is ...
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Resonance of a system featuring a collection of individual resonators?

Suppose you had a number of harmonic oscillators, each with different resonant frequencies in a system. Does this imply that their is an overall system resonance that is dependent on the individual ...
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1answer
39 views

Boundary behaviour of a mechanical wave

Let us assume we have a taut rope and I introduce a pulse in it by whipping one end. Now if instead of a clamp, I have tied the other end of the rope to a denser rope, a part of the energy is ...
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1answer
69 views

An intuitive explanation regarding propagation of mechanical waves

I was studying mechanical waves today and have questions regarding how a pulse is propagated on a string and its reflection and transmission at a boundary and I hope I can find help here. First, ...
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28 views

Determine Height of Satellite Using Path Difference

I have a question regarding the height of a satellite given only four parameters: the speed of the satellite, the distance between two radio emitters of the same frequency and amplitude, the ...
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21 views

What is the definition of dispersion? Does it exist in a musical show? [closed]

What is the definition of dispersion? And does it exist in a concert or musical show? Why? According to Feynman lectures book ch 31, dispersion is the difference of index which affect frequency, but I ...
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54 views

Simulation software for wave optics

I am using COMSOL multiphysics Optics module for wave optics simulations and I am wondering if there is better simulation software for wave optics simulations (no multiphysics needed). Like software ...
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19 views

Reflection and absorbtion of EM-wave in dielectric plate (calculate through dipole)

The task: there is a plate with thickness $h$. Also $\sqrt{|\epsilon|}kh \ll 1, k = \omega/c$. Find reflection and absorbtion of EM-wave in this plate. EM-wave falling normally on plate. What I did ...
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27 views

Sound waves in and out of phase [closed]

A sound ray is emitted from a point source and is then reflected off of a flat surface onto a detector. The reflection shifts the sound wave by 0.5 wavelengths. What does the shifting mean?
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51 views

What does matter wave oscillate? [closed]

We know by Maxwell equation, light is an Electro-magnetic wave, the light is oscillating the magnetic field and electric field and propagate Sound will oscillate the air, water, or whatever and ...
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1answer
30 views

Plane wave normal incidence on dielectric, direction of fields

I'm having an extremely hard time to figure out the direction of the $\vec E_R$ (reflected electric field) and $\vec H_R$ (reflected magnetic field) as well as the transmitted fields. I've been ...
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48 views

solutions of wave equation with cubic term

Does the following equation $$ \nabla^\mu \nabla_\mu \psi + a \psi^3 = b \psi $$ where $\psi$ is a real function, $a$ and $b$ are real constants, have other solutions that extend beyond a one ...
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86 views

Is this “modified wave equation” (with opposite signed derivatives) used?

This is the wave equation: $$(\partial_t^2 - \nabla^2) \psi = 0$$ What is the following equation? $$(\partial_t^2 + \nabla^2) \psi = 0$$ What's it like? What can you do with it? Does it show up ...
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29 views

Resonance and harmonics: change in phase difference, and force due to a non uniform magnetic field

I am doing an experiment (at school) on oscillating wires and I am following a lab script. Along the way, it asks some questions that I am supposed to answer. The only problem with this is that we ...
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Transmitted Power and Poynting's theorem contradiction?

I was reading Chapter 12.1 in Hayt & Buck "Engineering Electromagnetics" 8-th edition. Here they discuss the reflection of uniform plane waves at normal incidence. They derived the following ...
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3answers
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What experimental evidence shows that sound velocity is the same for all wavelengths?

I'm studying sound waves with Halliday's book, and after reading the whole chapter, one of the questions suggested was: What is the experimental evidence that allows the assumption that the sound ...
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40 views

How to explain the motion of these pendulums? [duplicate]

Got very interested recently in a video I saw running thru my feed: https://www.facebook.com/PortalAECweb/videos/913996365374257/ Well, I got very intrigued about the physics of it and wanted to ...
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103 views

Simple harmonic motion versus oscillations

I want to see whether certain oscillations in my daily life, such as the oscillation of violin strings when plucked, are simple harmonic motion or not. Can we identify whether an oscillation is simple ...
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64 views

What boundary conditions in a wave simulation would avoid reflections?

In simulating an elastic medium as a series of mobile points connected by ideal springs, it's straightforward to model conditions corresponding to a fixed endpoint, which results in an incoming wave ...
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3answers
100 views

What is the oscillating quantity in matter waves? [duplicate]

Every wave is characterised by some periodically changing disturbance. For example, that entity is air pressure for sound waves and electric,magnetic fields for EM waves. What is that disturbance for ...
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62 views

Diffraction pattern in one continuous slit

Will a noticeable diffraction pattern appear if I use a single continuous slit, say a ring shaped one?If yes, can it be explained how the slits were paired for interference observations , and is there ...
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45 views

Index of refraction for travelling EM wave problem

Let $n_1$ be the index of refraction of the first medium and $n_2$ be the index of the second medium. When $n_2>n_1$, then for an incident angle of $90^{\circ}$ we get a refracted light at a ...
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Can we produce a wave by oscillating current? [closed]

If Radio waves can be generated by using oscillating current so if we changed the properties of current to produce less wavelengths or light waves - I'm not asking about the possibility of producing ...
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170 views

Refraction: Energy flow, tunneling and Evanescent EM waves

In the full internal reflection case where we have a refracted evanescent wave, If another object is nearby, then we could have wave tunneling phenomenon(frustrated total internal reflection). I am ...
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37 views

Wave like behaviour

Sorry if this is a repeat but I'm curious if wavelength=h/p then does that imply that we would be able to observe the wavelike properties of a very still object? For example an average human weighing ...
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55 views

Argument of a Cosine function (referring to Principles of QM by R. Shankar)

On Page 72, Shankar solves the differential equation: $$ \frac{d^2}{dt^2}\langle m\rvert\psi(t)\rangle=-\left(\frac{m^2\pi^2}{L^2}\right)\langle m\rvert\psi(t)\rangle$$ as: $$ \langle ...
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What exactly is wavefield extrapolation?

I am trying to understand what exactly wavefield extrapolation is. I can understand extrapolation of a function, 'wave' and 'field' as well; but could not understand the meaning or the problem ...
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56 views

Two double slit experiments after each other

Does the act of observation forever destroy a photon or electron's wave like behaviour? What would the result be if the electron was observed, and instead of displaying the two lines or particle like ...
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1answer
48 views

How many waves from a boat wake

How many visible waves does a boat wake create? How do boat size, speed, and other factors determine how many waves there will be? Define "visible wave" as a wave with amplitude greater than or equal ...
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60 views

How can one change the virtual position of a sound source with a fixed array of speakers?

I have a question about signal processing: How to make a person, sitting between array of two loudspeakers (one from the left and one from his right), hear the sound that came from both loudspeakers, ...
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2answers
33 views

Enhancing of EM waves through a materal or waveguide

I'm wondering whether there are materials for which an incident EM wave would behave as $\vec E(z,t)=\vec E_0 e^{\kappa z}e^{i(kz-\omega t)}$ where z describes how far from the surface the fields are ...
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123 views

Double slit experiment and pilot waves [closed]

Why do almost all books on quantum start out with the double slit experiment and show how a single particle interferes with itself and say its a wave and particle when Yves Couder has shown on a ...
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13 views

Addition of Colors and Fluorescence

In fluorescence, you have an excited electron returning to ground state in multiple transitions, each emitting a photon of a lower frequency than the photon that excited the electron in the first ...
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1answer
37 views

Details on the magnetic field of a linearly polarized electric wave

Suppose we are in vacuum and we have an electric field $\vec{E}$ which we assume is simple harmonic wave that propagates through $z$ and is linearly polarized in the $x$-$y$ plane along $x$ i.e. ...
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30 views

Why doesn't a stationary wave completely destruct, instead of just at the nodes, when the waves are in fixed positions (see examples)

Example 1: I understand that two progressive waves, say π out of phase, travelling in the same direction with the same frequency and amplitude will completely destruct. This is due to the principal of ...
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146 views

Acoustical wave equation from Hamilton's principle

It is common to show the features and power of the Hamilton's principle by deriving the equation of vibrating string, membrane etc. using this principle. But I have never seen that used for deriving ...
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Waves and osciilation [closed]

When intensity of sound increases increases to 10 times level of sound increases by 10 decibel why and how the sound intensity is related to sound level