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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Huygens' Principle During Reflection: comparing wavelets from before reflection with wavelets from during reflection

I was recently reviewing geometric optics, during which I read about Huygens' Principle and how it could be used to prove the Law of Reflection from the "light is a wave" viewpoint. I'll quote what I ...
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Does sound have a “louder” direction?

I have a question about the propagation of sound waves. We have two TV's in our house that are almost right on top of each other. One is located on the first floor and the other one is located on ...
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Besides vortex rings, are there other types of traveling waves that can carry matter as well as energy?

Vortex rings are a special soliton wave that are known to carry matter over a distance as well as energy. This can easily be demonstrated using a cardboard 'vortex canon' filled with smoke. The smoke ...
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What is the difference between real and imaginary parts of a sinusoid? [closed]

Can somebody explain, without using complicated mathematical formulas, what do real and imaginary parts of the sinus function represent? And what are relations between them? I cannot understand why ...
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Waves - determining whether a given formula represents a wave

Well the basic formula of a wave needs to contain $$y(x,t) = f(x \pm vt)$$ where the sign depends upon the direction of propagation of the wave. However, not every function in the form $y(x,t) = f(x ...
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What is the physical significance of the negative amplitude of a light wave?

I want to understand what is the physical significance of negative amplitude of a light wave? In an ac electrical circuit, I understand that negative amplitude signifies the amplitude measured when ...
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Surface waves on Dr. Miller's planet

In the movie 'Interstellar', the crew land on a water world orbiting a black hole. The gravity is greater than that of Earth and there are huge surface waves present in the ocean that they land in. ...
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Wavefront of a wave?

I'm trying to understand the idea behind a wavefront in a visual manner. Take a look at these surface waves in water Now imagine if I sliced it twice, through the origin, in a vertical plane. I'd get ...
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Why do these standing waves appear to be traveling?

Take a look at this video: https://www.youtube.com/watch?v=TKF6nFzpHBU You would expect guitar strings to produce standing waves, and in fact, the upper, thickest string does often produce long, ...
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Physics of guitar strings

Guitarists normally press down hard on the frets and then pluck a string to obtain a note. However, one can also create notes by just touching the string above a particular fret and plucking. For ...
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What is the wave propagated away from an impulsively excited spherical shell?

Consider a spherical shell of radius $R$ centered on the coordinate origin, and an impulsive excitation $\delta (t)$ distributed over its surface ('ie. a single layer'). Each point on the sphere’s ...
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Phase change on reflection only 0 and $\pi$ allowed

We know that when a wave on a string is reflected from a hard boundary, the phase change is $\pi$, and from a soft boundary, the change is 0. My question is: this two conditions (hard and soft ...
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Pressure wave in a cup of tea casued by a bubble burst

Assume there is a cup of tea with bubbles formed on its surface by the inner wall of the cup. If one of the bubbles bursts, it causes a wavefront travelling on the surface of the tea. Is this wave ...
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Heat wave containing particle and wave like properties [duplicate]

I see heatwaves occur on the road and was wondering if that is visible motion of wave like properties involving particles.
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183 views

How to draw waves in X and Y position like this oscilloscope example?

I would like to know how to "draw sound" so i could achieve shapes like the ones in this video: http://www.modularsynth.ru/en/2014/01/24/ed120_chaotica/ I have programming background ( as in: i ...
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Is light amplitude spacial?

In diagrams I often see light waves depicted as little sine waves that travel through space. And often when describing polarizers, the explainer will angle their hand to show the angle of ...
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116 views

Damping of not harmonic waves

You pluck a (guitar) string so that you create a wave with harmonic frequency and a wave with not-harmonic frequency. Which one will be heard longer? Why? Or ask it differently: Is the wave with ...
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Resultant frequency if 3 harmonic notes (a chord) is played

If I know the frequency of individual notes being played (let's assume D, F# and A), how do I determine the final frequency if they are played (nearly) simultaneously as a chord. To put the problem ...
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Huygens and philosophy of the slit

A single (narrow) slit diffraction pattern, can be explained/described classically with Huygens' principle (1678), and quantum mechanically with the Uncertainty principle. If the pattern on the screen ...
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310 views

Why does sound become louder and increase frequency if I give it a narrow path?

If I put my hand over the speaker of my phone like in the picture, I can clearly hear my music amplified, why does this happen? The only cause I can think about is the fact that all the intensity ...
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How quickly is motion transferred in a solid object?

Just for example: assume an iron bar one foot in length. If you push on one end, the entire bar will move. This seems instantaneous. but actually, from my understanding, the atoms all push against ...
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Is it theoretically possible to project sound in a line, like flashlights?

I was wondering if there is a way to project sound waves on a particular point, like a laser? So that you can you can privately send a voice message to a specific person in crowd. The very first idea ...
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Ripples of flowing water on a smooth road surface [duplicate]

Yesterday some friends and I were walking in the rain. We noticed that, on a smooth tarmac road surface, the sheet of water flowing down the road was forming ripples as it went. Why was it doing ...
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275 views

If wave speed is dependent on medium only, then how to reconcile $v\propto f$?

I have read and learnt in many places that velocity of a wave depends only on the medium through which it travels. It is clear from this that the velocity of a wave doesn't depend on the frequency of ...
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74 views

Light Lab Misunderstanding. Please help

For a Physics lab, this question was asked "As you learned, the wavelength and the separation of the sources affect the number of nodal lines produced. Using your results from steps 2 and 3, determine ...
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295 views

How does a longer wavelength penetrate deeper with Rayleigh waves?

I'm struggling slightly to understand this idea. I've slowly been building up an explanation, so at this stage it might be just some confirmation I'm looking for, but also some guidance if I'm off ...
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Circular standing waves musings [closed]

I'm wondering if there is a mathematical model under which particles can be described as spherical waves with he properties that they can move and repel and attract other such "particle-waves" under ...
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Electron orbitals and the circular membrane vibrations

I just stumbled across the fascinating analogy between electron orbitals and the fundamental waves of a circular membrane in Wikipedia. Now the weird and arbitrary looking orbitals don't look so ...
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53 views

Watertank waves

Say we have a rectangular tank of water and we push it lengthwise. Suppose the surface stays planar. What would be the trajectory of the centre of mass?
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Walter Lewin's physics lecture 8.03 Waves and Oscillation [closed]

Does any of you have the files (lecture notes, assignments, exams) of Walter Lewin's course on Waves and Oscillations? I used to learn from them and it helped so much. Thanks before
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Can “particle” waves break as ocean waves do?

I have heard about electrons surfing on wake fields which got me thinking. Are there analogs to reefs for these waves and can these waves break as ocean waves do when they hit a reef?
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How do electromagnetic waves travel in a vacuum?

This is perhaps a total newbie question, and I will try to formulate it the best I can, so here it goes. How does an electromagnetic wave travel through for example, the vacumm of space? I usually ...
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Explanation of the waves on the water planet in the movie Interstellar?

We will ignore some of the more obvious issues with the movie and assume all other things are consistent to have fun with some of these questions. Simple [hopefully] Pre-questions: 1) If the water ...
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137 views

about to create a standing wave

I think partial of this question being asked before but I have some other doubts.As shown in this post how to add two plane waves if they are propagating in different direction?, reading the third ...
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Frequency of Sound Waves

Is the frequency of the echo (resulted from the reflected sound wave) equal to the frequency of the original sound wave?
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The amplitude of oscillations in sound waves

How can the amplitude of molecules displacement be measured in a sound wave? How can the amplitude of the pressure fluctuation be measured in a sound wave? What are the difference between these two ...
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Electromagnetic Waves Speed

What is the relationship between the speed on the electromagnetic wave and the density of the medium in which the electromagnetic wave travel through?
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Between Constructive and Deconstructive Interference

Is there something other than constructive interference, such as a shift in 1/4 λ or 3/4 λ or even 7/5 λ? Because it would not end in a hill or a valley. It would be someplace between. Would it ...
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The interference pattern of a wave along a line [closed]

Why the answer is B, but not C? Is it true that the pattern cannot go beyond $A_0$ and $-A_0$ at the same instant?
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Why should a solution to the wave equation be finite?

Given the wave differential equation $$\frac{\partial^2 y}{\partial t^2} = k\frac{\partial^2 y}{\partial x^2}$$ Any function that satisfies the wave differential equation represents a wave ...
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What is a wave? What is a particle?

I am reading a David Bohm book on quantum theory. He says the idea that light is both a particle and a wave is incompatible: (1) we know light has particle-like properties through the photoelectric ...
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How would a sound mirror work?

Context: We all know that by galvanizing a plate with a silver coating, this plate will have a very high reflection coefficient and act as a mirror for EM radiation (not for all $\lambda$ ranges of ...
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What is an electromagnetic pulse?

Is an electromagnetic pulse a plain electromagnetic wave with one peak?
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Can a phase array evoke a standing wave at a focal point that has a much higher frequency that the constituent emitted frequencies?

This is a phased array: How can you focus sound? It can focus many waves of weak radio wave or light into a single focal point that's very strong. Now imagine that we delay half of the emitters by ...
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Is it possible to have both a conduction current and a displacement current at the same time?

According to Ampere's law, is it possible to have both a conduction current and a displacement current at the same time? In the classical derivation of the displacement current using a parallel plate ...
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Superposition of electromagnetic waves and energy localization

Sorry for the long question. I didn't know how to make it shorter. I'm trying to understand how energy is spatially localized in an electromagnetic wave. My premises are: Electromagnetic energy is ...
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328 views

Coherence length requirement for interference

One property of light sources that is usually stated, which is of particular importance when trying to create interference fringes, is the coherence length (or coherence time). The equation for the ...
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Why are electromagnetic waves not able to pass through a hole with a diameter smaller than the wavelength? [duplicate]

I am doing research on Faraday cages for school, and I want to know how it works. Faraday cages can have holes in them, and if the diameter is smaller than the wavelength of waves you want to block, ...
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240 views

Why are there dead zones near an antenna using the sky-wave propagation system?

I have heard in my class that there are dead zones near the antennas which use the sky-wave propagation system. I have also been told that cell phones are unable to receive signal near the antennas. ...
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Will the frequency of the reflected wave of a moving source be shifted by Doppler effect?

I want to know if there is a moving source that emits wave to a reflecting object like a wall for example, then, will the frequency of the reflected wave be shifted because of the Doppler effect. As ...