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Questions tagged [wavelength]

The wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats, and the inverse of the spatial frequency or wavenumber. Determined by considering the distance between consecutive corresponding points of the same phase, such as crests. Use for wavenumber, wavelength, frequency.

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What is the mathematical support for the formula $f_n = n f_1$, used to calculate the frequency of a standing wave? [closed]

could someone explain to me the mathematical support for the formula $f_n = n f_1$. This formula refers to the fact that the frequency of a standing wave is equal to the number of antinodes times the ...
Santiago Celis's user avatar
15 votes
7 answers
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Why does the length of an antenna matter when electromagnetic waves propagate perpendicular to the antenna?

The optimum length for a dipole antenna is a multiple of half the wavelength that it is designed to receive or emit. Why is this? If an electromagnetic wave has E in the x-axis, B in the y-axis, and ...
user411769's user avatar
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Understanding Loop Formation in a Plucked String

I have a question regarding the formation of loops when a string is plucked at different fractional lengths. In a book I referenced, it is stated that plucking a string at 1/6 of its length produces 3 ...
Engr Fahad Safi's user avatar
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1 answer
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At which wavelengths do photons behave like X-ray?

Hard X-rays of wavelengths of about an angstrom are very different than regular lights in a way that they can’t be reflected or refracted, which means their refractive index is always close to 1 ...
哲煜黄's user avatar
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11 votes
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Can the laser light, in principle, take any wavelength in the EM spectrum?

Can the laser light, in principle, take any wavelength in the EM spectrum? I don't think there is what prevent this in principle, right?
Jack's user avatar
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How can photons interact with nuclei?

How can photons such as X-rays or gamma rays interact with the nuclei of atoms given that, as I understand it, the length scale of a nucleus is around a couple of femtometers? So, shouldn’t the size ...
EigenDragon16's user avatar
2 votes
0 answers
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Why does oxygen green (S1) emission in aurorae only occur at lower altitudes? [duplicate]

Aurorae have a red color at high altitudes caused by the excitation of atomic oxygen and the subsequent emission at about $630 \,\text{nm}$. This happens at high altitudes because at that height there ...
jack_O'Dim's user avatar
2 votes
1 answer
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De Broglie wavelength and how it leads to the wave function

From what I know, de Broglie derived the wavelength equation using Einstein's $E=mc^2$ and the Einstein-Planck equation $E=h\nu$. My teacher explained this by saying an electron literally moves in ...
Darth Nandan's user avatar
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Wavelength and frequency of the peak of the black body radiation [duplicate]

Why does the product of the peak wavelength and the peak frequency of Planck's black body radiation not equal to the speed of light? $$λ_{\mathrm{max}}=\frac{hc}{4.97\mathrm{kT}},$$ while $$ν_{\mathrm{...
Yuan Liu's user avatar
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How does flute work?

I started learning flute a few months ago. Here in India you can buy two types of flute hindustani and carnatic. Hindustani flute has a simple acoustics. Lenth is inversely proportional to frequency. ...
Newtron Malayalam's user avatar
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Could the increasing anisotropy of the universe lead to an additional blueshift?

I'm contemplating the possible sources of a wavelength-shift within our universe: The CMB had a lot more energy when it was produced (around 3000 K). Due to the expansion of the universe, it has been ...
MartyMcFly's user avatar
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Does the energy of a photon in comoving space change?

Assuming a flat FLRW universe that is expanding: In comoving space, does the energy of a photon decrease or stay constant? A physical argument for this would be nice.
Matrix23's user avatar
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Why is the shorter the wavelength, the smaller the object you can image? and vice-versa?

I know that the shorter the wavelength the smaller the object you can image clearly. Why wavelength matters in imaging something? How having big wavelength wont let u image smaller object, like if u ...
nishat tahsin's user avatar
7 votes
5 answers
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Light waves can't have a wavelength

The wave nature of light comes from Maxwell's equations. More precisely, the two wave equations that come from them: $$\Delta\vec{E}=\mu\varepsilon \frac{\partial^2\vec{E}}{\partial t^2}\\ \Delta\vec{...
Krum Kutsarov's user avatar
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Minimum frequency for a dipole antenna to work

Does a dipole antenna need a minimum frequency of AC to make the electric field detach and propagate?
Simon Lin's user avatar
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What do the $x$ and $y$ axes mean on a chromaticity diagram?

I understand that the chromaticity diagram is a plot of visible wavelength colors. Since the visible wavelengths form a curve on the graph, what do the $x$ and $y$ axes mean? My thinking could be ...
Astrovis's user avatar
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Interpretations of wave numbers between open and periodic boundary conditions

I'm curious about the difference in physical interpretation between open and periodic boundary conditions (OBC and PBC) although they are identical in the thermodynamic limit. For simplicity, let's ...
Kitchen's user avatar
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What is a laser spectrum?

What is a laser spectrum? How many wavelengths can we see in it, and why? For a regular laser, the red ones you can buy at the store, is there just one red wavelength in the laser? Or are there ...
qris's user avatar
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2 answers
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What is the upper limit of size for diffracting an object?

All items in the universe can be said to have a De Broglie wavelength which is significant if that wavelength is comparable to the object's size (I don't have to worry about my wavelength diffracting ...
EngineeringMind's user avatar
1 vote
1 answer
41 views

How is wavelength defined when it's changing continuously?

Take an observer, who is receiving an electromagnetic wave signal, which is constantly changing. It can be for example from a source of light falling into a black hole, so the observed wavelength is ...
Mikael's user avatar
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Emission spectrum of a fluorescent lamp

I had to analyze the emission spectrum of a compact fluorescent lamp and find what elements are present in the lamp, based on the spectrum of spikes in wavelengths. Knowing that in our lamp there was ...
Emmannuelle_Legolas's user avatar
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1 answer
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What would happen if my body de Broglie wavelength is significantly large? [duplicate]

I have a question that what would the world be, if matter de Broglie wavelength was large?
Lakshay Sharma's user avatar
-1 votes
2 answers
80 views

What's the difference between the different kinds of EM waves?

I am an A-level student. We have traditionally been taught that different types of EM waves exist only between certain ranges of wavelengths and frequencies. However, I learned that electromagnetic ...
Haram Tanveer's user avatar
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Who wrote $c = λ ν$ for the first time and where can I find it?

I have been surfing for days and still I could not find who wrote the equation $c=λν$ for the first time. Neither I found a name for this equation. A lot about Planck's constant and energy related ...
Pierpaolo Testavuota's user avatar
1 vote
1 answer
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Is this image on harmonics and overtones wrong?

I saw this image and believed this to be the definition of what the relationship between harmonics and overtones to be in strings, closed pipes and open pipes. That the $n^{th}$ harmonic = $n-1^{th}$ ...
John Hon's user avatar
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Can anyone explain the relationship between the refractive index, the speed, wavelength and angle of a wave?

Can anyone explain the relationship between the refractive index, the speed, wavelength and angle of a wave? in my book is states that $$n = \frac{v_1}{v_2} = \frac{\sin θ_1}{\sin θ_2} = \frac{λ_1}{...
dayum's user avatar
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1 vote
1 answer
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In Rayleigh-Jeans radiation law, why are the values of $n$ taken to be non-positive only?

In $k$-space the allowed values for standing waves in a cube of side length $L$ are given by $$\vec{k} = \left(\frac{\pi}{L}\right) (n_1, n_2, n_3)$$ where the $n_i$ are nonnegative integers. Why are ...
iman Bilal's user avatar
1 vote
1 answer
26 views

Spectroscopy on colored flames

When observing colored fire through a spectrometer after adding substances like copper chloride or magnesium sulfate to change its color, what specific spectra are typically observed? How does the ...
Rookynote's user avatar
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1 answer
39 views

What determines the wavelength in absorption?

When looking at absorption or reflectance spectra, say in the range of 400nm to 2500nm, you can see peaks (or dips) at certain wavelengths, that are characteristic for the material absorbing and ...
YPOC's user avatar
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15 votes
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Why color depends on frequency and not on wavelength? [duplicate]

To explain my question lets consider this example: The wavelength of light in a medium is $\lambda=\lambda_{0}/\mu$, where $\lambda_{0}$ is the wavelength in vacuum. A beam of red light ($\lambda_{0}=...
Devansh Mittal's user avatar
3 votes
0 answers
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Why do water surfaces have persistent "average wavelength" patches?

Have you ever stood above a river or lake and noticed that the surface has visible "patches"? It looks like the surface has different average wavelengths in some areas, leading to the light ...
Robert Wegner's user avatar
2 votes
2 answers
95 views

Does gravitational lensing bend light of all wavelengths by the same amount?

Basically I am asking if gravitional lensing is bending or refracting light.
Michael Mcgarry's user avatar
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1 answer
80 views

Mass in de Broglie Formula

Regarding de Broglie formula $$\lambda= h/mv$$ here m is relative mass or rest mass?
SHINU_MADE's user avatar
-3 votes
2 answers
144 views

How many 'wavelengths of length' can a wave have? [closed]

Since a wavelength, $\lambda$, is the length of a entire cycle How many $\lambda$ (complete cycles) can a composed wave have? I mean, for $n \lambda$, how big can $n$ be? And what does it mean, ...
Iberis's user avatar
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5 votes
2 answers
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Ultrasonic whistling

My friend from physics who doesn't know whistling says he is good at whistling, but the resonant frequencies are ultrasonic so others cannot hear it. Could this be right, or is he just bluffing? ...
AlphaLife's user avatar
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How do we realistically calculate the monochromatic flux of an object in space?

If the collecting area of a telescope is ∆A, and it collects light for a time interval of ∆t, do we just build a telescope with a very small ∆A and make ∆t and ∆λ very small as well? Also, how do we ...
Maxine's user avatar
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2 answers
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Rigorous derivation of DeBroglie wavelength

I've scoured the internet as much as I can, and I've yet to find a rigorous derivation of the DeBroglie wavelength. They all go something like this: $$E=\gamma mc^2, \ \gamma \approx 1 \ \therefore\ E=...
JBatswani's user avatar
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1 answer
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Why is wavelength of an electromagnetic wave so much loner than what my scope shows?

I made a simple LC Tank circuit which oscillates at 166 kHz. Looking at it using my oscilloscope I can see one cycle of the sine wave takes about 6 microseconds. Now if I stick and antenna to this I ...
Dan's user avatar
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0 votes
1 answer
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What is the spectrum of a broken square drum?

Given a square drum with sides length equal to $L$, the squared raised frequencies are $(\pi m/L)^2 + (\pi n/L)^2 $ with $m,n \in \mathbb{N}^*$. Here we have four boundary conditions (no vibration on ...
Naima's user avatar
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1 vote
0 answers
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Why doesn't frequency change when the medium of the wave changes, and only depend on the source of the wave? [duplicate]

When the medium of the wave changes, the velocity and the wavelength does change, but not frequency, why?
Chethas Pai's user avatar
1 vote
0 answers
47 views

What exactly is matter wave?

Wavelength of matter wave is given by de-broglie as h/p. I want to know wavelength of what wave is being discussed, or specifically what is matter wave? Is it the 'group wave' that has same velocity ...
SHINU_MADE's user avatar
0 votes
0 answers
42 views

Why Do Harmonic Components Define Wavelength in Diffraction and Interference Phenomena?

I'm exploring the physical principles underlying diffraction and interference, specifically how these phenomena depend on the wavelength of harmonic (sinusoidal) components of a wave. My question ...
CuriousMind's user avatar
0 votes
3 answers
144 views

Why does the equation of a wave contain the term $\omega t$ instead of $vt$ in the wave equation $y=A\sin (kx-\omega t)$?

Why does the equation of a wave contain the term $\omega t$ instead of $vt$ in the wave equation $$y=A\sin (kx-\omega t).$$ I think of the constant $k$ which for higher values increases the frequency $...
Jeffy James's user avatar
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2 answers
188 views

The Role of Harmonic Frequencies in Natural Phenomena

I am deeply fascinated by the apparent intrinsic relationship between harmonic frequencies and the natural world. This relationship is evident not only in the mathematics that simplify our description ...
CuriousMind's user avatar
1 vote
0 answers
83 views

Converting $\rm W/m2/sr/nm$ to $\rm kR/nm$ for any wavelength

I have atmospheric spectra given in W/m2/sr/nm units and wavelength in nm. I want to convert W/m2/sr/nm to kilo Rayleigh/nm (kR/nm) for any wavelength. I tried the following method from this paper: ...
Aadarsh's user avatar
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1 vote
4 answers
208 views

$0$th overtone in closed organ pipes

I know about $1$st, $2$nd or other overtones in the formula of frequency in a one-sided open system (specifically in closed organ pipes) that is $$ f = \frac{\left( 2 n + 1 \right) v}{4 L} \tag{1} \...
phymestri's user avatar
-2 votes
2 answers
176 views

A conceptual question about waves

If the tension in a string with fixed ends is slightly increased then does the wavelength of a wave travelling along the string change, or does only the frequency change?
Madhav Mittal's user avatar
3 votes
2 answers
230 views

How could RGB color system compose a violet color?

In the GRB system, we combine the three primary colors, red, green, and blue, to make some new colors. It's easy to understand the production of yellow because the wavelength of yellow is between red ...
zzzgoo's user avatar
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1 answer
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What does "non-dispersive" mean in terms of waves and group velocity?

I'm confused about the term wave group velocity: It is usually explained in terms of a superposition of harmonic waves with very closely spaced wave vectors and frequencies. It is then easily shown, ...
MichaelW's user avatar
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0 votes
1 answer
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What is the wavelength range of X-rays?

I was reading and came across the following paragraph The X-rays thus produced by many electrons make up the continuous spectrum of Figure 2-10 and are very many discrete photons whose wavelengths ...
Jack's user avatar
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