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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reproducing double-slit experiment with sunlight

Is it possible to reproduce Double-slit experiment at home with sunlight probably in a larger scale? Thanks for all the answers (and special thanks to Chris for the effort),so i understand that it ...
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1answer
38 views

What are diferent reflection percentages of different colors?

I don't need any accurate answer. Suppose reflection percentage for white is 100% (which is not even true for mirrors) then what will it be like for different colours like violet, green and red etc of ...
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3answers
182 views

Physical interpretation of source term in wave equations

Let me start with an example. If we base our calculations on the Newton's second law without any further mathematical treatment, then our equation describes equilibrium of forces, i.e. it is of the ...
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1answer
36 views

What are some of the empirical proofs of electromagnetic polarization? [closed]

I am aware of how polarization follows from Maxwell's equations, and how it is possible in transverse waves in general. I also know that Huygens, in his great Treatise on Light, first discovered and ...
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0answers
19 views

Forces associated with acoustic levitation

I recently learned about acoustic levitation, and I am interested in creating such a device using two loudspeakers. In my attempts to do the math, the following problem arose - assume I have a ...
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0answers
17 views

Can waves change their roll axis?

If I roll a laser emitter 90 degrees on its roll axis, will the "up" and "down" motion of the laser-light wave also roll with orientation to the emitter so that to me it is now osculating "side" to "...
5
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1answer
61 views

Overtones of Bells Over A Distance

The hourly bell tower sound at Indiana University Bloomington sounds like a higher frequency when heard from ~1.4 km away, compared to standing right next to it. Is this effect likely due to the ...
3
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0answers
68 views

Linear KDV eq. asymptotics

The question arises from the book Solitons by P. G. Drazin about the linearized KDV eq. $$ u_t+u_{xxx}=0 $$ My first step was to take a Fourier transform of the equation, find that the dispersion ...
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1answer
49 views

Demonstration for the existence of longitudinal electrostatic oscillations

How could I demonstrate that in a linear, homogeneous and isotropic medium without losses but electrically charged, Maxwell's equation admit as solutions longitudinal electromagnetic waves, beyond ...
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1answer
57 views

Determining the phase delay between H and E fields

I want to determine the phase delay between H and E fields in a medium with losses and not electrically charged. In this medium we also have $\sigma_c\approx \varepsilon \omega$. The enunciation of ...
2
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1answer
81 views

Einstein's 1905 “Concerning an Heuristic…emission and transformation of light”

I'm currently attempting to read Einstein's annus mirabilis papers, starting with his introduction of the quantization of light in the paper: "Concerning an Heuristic Points of View Toward the ...
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2answers
48 views

Diffraction of light

If $l_1$ and $l_2$ are parallel how can they both can hit same spot? Why their difference in path length is $l_2 - l_1 = d \sin \theta$ instead of 0?
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1answer
41 views

Power and frequency of photons and its relationship with biological safety

I understand that x-rays are more dangerous than radio waves because they are of higher energy, since they have higher frequency. However, it’s less dangerous to stand near a radio station with a ...
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1answer
87 views

Can one make a propagating field along a waveguide only have longitudinal/transverse components?

We know that in free space, a propagating electromagnetic wave is always transverse. However, along a dielectric waveguide, the propagating wave can have longitudinal components. The exist of the ...
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1answer
98 views

Finding the range of frequencies to which a receiver should be set

I'm working on a study guide for a test for my Modern Physics class, and ran across a question I'm having trouble with. A radar transmitter emits a pulse of EM radiation with $\lambda=0.225\,\...
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1answer
163 views

Intensity of sound vs Speed of sound

I am finding out the relationship between intensity of sound and speed of sound. To do that, I am using this equation: $$I =\frac{∆P^2_{\rm max}}{2ρv}$$ where ∆P max = Pressure amplitude, I = ...
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1answer
55 views

How does energy travel past the first node established in a standing wave

wanted to ask as mentioned above that how can energy transfer from the first node established in a standing wave by the superposition of two equal and oppositely directed waves,that is when the waves ...
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0answers
33 views

Measure amplitude of a sound wave

I am trying to find out the amplitude of a sound wave. What equation or apparatus can I use to achieve this?
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0answers
40 views

The relationship between the standing wave energy and its harmonic

My question is this: suppose we create two different standing waves in a string . So, is the energy of the standing wave dependent on the frequency of the wave ?(assume that the amplitude is unchanged)...
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2answers
77 views

Amplitude equation

I came across this amplitude equation from this website : http://formulas.tutorvista.com/physics/amplitude-formula.html It states that 'amplitude = distance / frequency'. This means that as the ...
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0answers
66 views

Proof of reflected and refracted waves being in the same plane as that of the incident wave and its projection on a planar interface

Please give a proof of reflected and refracted waves being in the same plane as that of the incident wave and its projection on an ideal planar interface between two linear, homogeneous, isotropic, ...
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2answers
63 views

Describing 3-slit interference patterns

I'm typing up some physics notes about wave interference patterns and want to include a graph of the wave produced by a 3-slit experiment: Does anyone know what formula produces this kind of curve? ...
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0answers
54 views

Amplitude of wave in a medium varying mass density

Suppose you have a stretch string under uniform tension but consists two section of unequal mass density namely section A and B. Section A has higher density, so lower velocity of wave. Now consider ...
3
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1answer
42 views

What is the equation of motion for multiple simultaneous pressure waves in a medium? (In the context of stimulated Brillouin scattering)

My overall motivation is to derive the behavior of Brillouin scattering in a birefringent fiber. Brillouin scattering is a nonlinear interaction between light and sound. In classic Brillouin ...
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2answers
86 views

Mechanical equivalent to electric circuits

Could one build a mechanical equivalent to electric circuits ? I'm considering mechanical waves (like shock waves) travelling through a medium here. I'm aware that due to the high loss and practical ...
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2answers
129 views

Light always particle in vacuum because it has no medium

My physics teacher told me that light in a vacuum is always in the particle form. So what happens if you perform the double slit experiment in vacuum? Will the light spread like a wave or will it have ...
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3answers
84 views

In a sound wave, is there rarefactions at both ends?

I was reading my book Physics, For scientists and Engineers, Third Edition, by Randall D. Knight, studying the first chapter on waves. This diagram is provided on page 565: The diagram is easy to ...
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4answers
1k views

Wave reflection and open end boundary condition intuition

I need to understand one seemingly simple thing in wave mechanics, so any help is much appreciated! When a pulse on a string travels to the right toward an open end(like a massless ring that is free ...
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3answers
177 views

How to propagate $E_x (x,t) = \exp(-t^2/\tau^2-i\omega_0 t) \exp(-x^2/w_0^2)$ in finite difference time domain (FDTD) analysis

Finite difference time domain (FDTD) allows to solve differential equations for time evolution. For example, we can analyze ultra-short pulses in free space by solving the Maxwell's equations. The ...
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1answer
66 views

Sound when traveling faster than sound

I was wondering, if I am running at the speed of sound while playing music on my iPod will I be able to listen to my iPod while running at the speed of sound? or we cant hear anything while running at ...
3
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1answer
91 views

Where exactly is the antinode of an air column with open-closed boundary conditions?

Suppose that I have an air column with closed-open boundary condition. The air pressure at the open end of the tube is constrained to match the atmospheric pressure of the surrounding air. Therefore,...
2
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2answers
176 views

What is the need of complex functions in wave analysis?

It is commonly known that waves can be express in terms of sine or cosine function. But when I study further, I seen that for analyising the waves, it is common to use complex functions in the form $$...
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2answers
70 views

Wave disturbance conceptual question

My book states: The wave disturbance travels from $x = 0$ to some point $x$ to the right of the origin in an amount of time given by $t=\frac{x}{v}$, where $v$ is the wave speed. So the motion of ...
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2answers
849 views

In wave motion of a string both kinetic energy and potential energy are minimum at $y=y_\text{max}$ then why does the string comes down again?

In wave motion of a string both kinetic energy and potential energy are minimum at $y=y_\text{max}$ then why does the string comes down again? As everything in tries to attain lowest energy possible ...
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2answers
169 views

Electromagnetic wave properties of light vs radio waves

Both light and radio waves are electromagnetic waves.that means they have almost similar properties. Both are EM waves ,E and H fields are there in both waves.....but My question is "radio waves can ...
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2answers
30 views

Undamped oscillations of sound wave

I read in google that When we hit some metal or object, then a sound is generated by that object. If we hit that object with more force, then we can hear a sound of more amplitude than previous one ...
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0answers
101 views

Fresnel diffraction approximation (parabolic waves)

The Huygens-Fresnel principle (Introduction to Fourier Optics, Goodman), $$ U(x,y)=\frac{z}{i\lambda}\int_\Sigma U(\xi,\eta)\frac{e^{ikr}}{r}d\xi d\eta\,, $$ where $\cos \theta=\frac{z}{r}$, shows ...
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1answer
19 views

Neglecting some wave functions by assuming that the angle between tension force and horizontal is small in the derivation of wave equation in $1D$

In the derivation of the wave equation in classical mechanics in one dimension in a string. It's assumed that the angle between the tension and the horizontal line is small. This is assumed to allow ...
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1answer
104 views

Thin film interference [closed]

There is a light wave that travels through a thin film of oil (index of refraction is $1.25$) of thickness $d$. The total length of this "portion" of the wave in oil would be $\Delta x = d$ If this ...
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1answer
84 views

Show that for the harmonic wave equations, $A^2 = B^2 + C^2, \cos(\phi) = \frac{B}{A}, and \sin(\phi) =\frac{ C}{A}$ [closed]

A harmonic wave can be expressed with the equation $\psi(x,t)=A\cos(kx+ ωt + \phi)$. It can also be written as $\psi(x,t)=B\cos(kx+ ωt) - C\sin(kx+ ωt)$. How can we show that, for the same harmonic ...
4
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2answers
153 views

Why don't constant motion charges produce waves?

I'm a little confused about the origin of electromagnetic waves. Although I can understand their origin mathematically, I get a little confused about the physical intuition of... Information ...
0
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1answer
102 views

Am I absorbing radio waves?

I have bluetooth speaker that I can control (via bluetooth) with my phone. One day I happened to roll on top of my phone with my chest and the music stopped playing (until I rolled off of it and it ...
0
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0answers
26 views

Intermediate shape of a closed string vibrating with 2 bumps switching to 1 bump?

So if you have a closed string that's only capable of having a standing wave with an integer number of bumps, and is currently vibrating in a sine wave with 2 bumps, when it eventually loses enough ...
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1answer
69 views

What does the kilogram-hertz relationship stand for?

The value of the kilogram-hertz relationship [$(1kg)c^2/h]$ physics constant is 1.356 392 608 $\times 10^{50}\,\mathrm{Hz}$. What does this constant stand for?
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0answers
95 views

Wave equation - Cases where separation of variables doesn't work

Separation of variables combined with the Fourier's theorem is the most common technique of solving D'Alembert's wave equation: $$ \Delta\Phi-\frac{1}{c_0^2}\frac{\partial^2 \Phi}{\partial t^2}=0 $$ ...
12
votes
3answers
284 views

Crown shape in water waves?

Watching this slow motion video of waves caused by a droplet falling on water, I am puzzled by the first wave shape. The first wave rises with circular symmetry as I expected, but is not even in ...
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2answers
45 views

Does observing an EM wave take energy from it?

Here is the question that got be started on this: Suppose 1,000 people were sitting in a room with their laptops out and a WiFi transmitter in the front of the room. If everyone was connected to the ...
3
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1answer
230 views

What is the basis of Huygens principle?

When we were studying mechanical waves like sound waves, and waves on strings in class, we never studied Huygens' principle with these - and nor did we really derive the laws of reflection or ...
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1answer
45 views

In a lattice, what, technically, are random (thermal) atomic motions?

I'm familiar with normal modes and their periodic nature. And I know that the term 'independent mode' is used to describe how each individual atom in a lattice can move (degrees of freedom). But, ...
2
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1answer
460 views

Why can we hear sound better on the water than on land?

If we sit in a boat on a lake we can often hear people talking on the shore clearly in contrast to sitting in an empty field and hearing the people talk over the same distance. I heard that this ...