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

Basically I am asking if gravitional lensing is bending or refracting light.
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Mass in de Broglie Formula

Regarding de Broglie formula $$\lambda= h/mv$$ here m is relative mass or rest mass?
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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, ...
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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? ...
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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 ...
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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=...
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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 ...
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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 ...
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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
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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 ...
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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
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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 $...
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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 ...
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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: ...
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$0$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
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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
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2 answers
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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 ...
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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, ...
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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 ...
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Are intensity vs wavelength graphs really continuous? [duplicate]

For hot bodies we generally draw graph between intensity and wavelength similar to one in picture. My question is this graph really continous? If it is continuous, does it not mean there are infinte ...
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Does a photon form a black-hole when it is squeezed into a box of Planck length? [duplicate]

Is it true that if there is a photon with a wavelength that could fit in a box that is equal to or smaller than the Planck length, then it forms a black-hole? Originally I thought, since a Planck ...
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The physics behind the circle / spiral of fifths

In music theory, there is this thing called the circle of fifths. If you take a string, and you divide it in two equal parts, you get a so called octave. It is, to our ear, kind of "the same tone&...
Willem van Houten's user avatar
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How did Kurlbaum and others measure the intensity of each wavelength to get blackbody radiation curve?

In 1900 Plank was faced with data that didn't agree with the Plank-Wien law. This data that plots different temperature curves - wavelength on the horizontal and intensity on the vertical (or rather ...
Michael Cole's user avatar
6 votes
2 answers
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Wavelength of "complementary colours"?

In physics/chemistry/the life sciences there's a common experimental method of determining the concentration of a sample using spectrophotometers. We can measure the absorbance of the sample at a ...
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Finding the Bremsstrahlung in diffraction patterns of NaCl

I recently got the chance to measure the diffraction pattern of a NaCl crystal using the Bragg-Brentano method. I can see the peaks caused by the characteristic lines of the used X-ray tube (in this ...
Space junk's user avatar
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Will light of 405nm wavelength behave in a single mode (SM) fiber , in multimode manner?

Since the wavelength of 405nm is substantially shorter than the wavelengths of 1310-1550nm, and since the ratio of the diameter of a single mode fiber core to the wavelength, at 405nm, is several ...
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Is reflected color not from the wavelength corresponding to that color?

I was reading through Josef Albers' interaction of color (a classical art color theory book), where he makes this point: If I see a substance, or pigment of a particular color, doesn't that mean I'm ...
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Derivation of optical resolution

I'm trying to prove optical resolution formula from scratch and im having a hard time doing it. I dont know much about optics (im studying cosmology) and i need a detailed proof of optical resolution ...
Arian Esmaieli's user avatar
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2 answers
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How does a string thickness affect the frequency of its harmonics?

The harmonics of a theoretically infinitely small diameter string are pure integer multiples of the fundamental frequency. However, a real string has a thickness, and when vibrating in a harmonic, the ...
Don Rechtman's user avatar
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0 answers
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Does our sense of color depend on frequency of source or the wavelength of light?

I was taught that the colors we see are results of the corresponding wavelength, but each wavelength also has a distinct frequency since speed of light is fixed for a specific medium (same goes for ...
Ashutosh's user avatar
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8 votes
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Do colours which are not visible to human eyes exist?

Are there any colours that our human eye cannot comprehend but other animals can see? The ability to see colours is the property of our eyes. For example an average dog would see less colours than us. ...
Aleph's user avatar
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1 answer
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Why can't we use polychromatic light for making laser?

As far as I have read in my textbooks, we can only use monochromatic light for making a laser. Why can't we use polychromatic one? What if we try to make a laser out of a polychromatic light?
Syeda Hasnain's user avatar
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2 answers
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What is the colour of an atom? [closed]

We know that when an electron jumps from shell to shell it produces light waves which produce the sensation of vision to our eyes. But can anything be said about the colour of an atom in particular. ...
Soumyadip Das's user avatar
1 vote
3 answers
71 views

Wavelengths of light outside our solar system

The question might have been asked before. Our Sun's rays decompose into 7 elementary colors by using a prism or spectrometry. Can the the colors (their number and wave length in the spectrum ) be ...
Narasimham's user avatar
1 vote
3 answers
361 views

The Uncertainty in momentum and the de Broglie wavelength

I'd like to pose a straightforward question by providing a brief example to determine whether my current approach is correct or incorrect. Imagine I have an electron confined within a box measuring $1\...
Anky Physics's user avatar
1 vote
0 answers
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Natural Harmonics on a String

Consider the Dirichlet boundary value problem of a guitar string stretched between two fixed points which is made to oscillate by pinching and releasing the string. It can be shown in quite ...
Tom's user avatar
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de broglie thesis

Quoting Thesis (1924) "Propagation is, therefore, analogous to a liquid wave in a channel closed on itself but of variable depth." What is meaning of depth here? edit as new image
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What is the smallest possible wavelength? [duplicate]

I was thinking about this the other day after a quantum mechanics lecture (unrelated to the lecture I was taking) and pondered "Is there a minimum wavelength for a photon?", through ...
Groving's user avatar
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2 answers
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Why do parabolic antennas need to be the same width as their wavelength?

I am reading the wikipedia page for parabolic antennas, and have a question about the below quote: In order to achieve narrow beamwidths, the parabolic reflector must be much larger than the ...
Andrew Baker's user avatar
1 vote
1 answer
132 views

Can something become hot enough that it stops glowing?

So I understand that matter emits EM waves when hot. And that the higher the temperature, the shorter the wavelength, so cooler flames start off orange and the hotter flames reach light blue and white....
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Graphical depiction of one photon

If a photon has a wavelength and a frequency and we depict a graph with multiple hills and valleys like done in basically every explanation regarding photons and their wave/particle behavior, like in ...
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Water vapor: refractive index and extinction coefficient ($n$ and $k$)

Looking for optical properties of water vapor (index of refraction and extinction coefficient) as a function of wavelength.
Iris's user avatar
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1 vote
2 answers
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Does refraction depend on the colour of light?

Consider passing red and yellow lights separately through the same interfaces and with the same angles of incidence. Light of which colour will be refracted more? This question was given to me. All I ...
Sahaj's user avatar
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Phase difference of standing waves

The phase difference of a standing wave is zero. The above statement is found online when searching about standing waves. However, it doesn't make much sense to me. Consider the above diagram of a ...
Jeremy Clarkson's user avatar
1 vote
1 answer
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Harmonics in closed and open pipes

What exactly would happen if we sent a frequency that was not one of the harmonics into a closed and open pipe? What would happen if we gradually increased this frequency? From my understanding, I ...
Jeremy Clarkson's user avatar
-1 votes
2 answers
203 views

Phase difference of antinode and node? [duplicate]

How do I determine the phase difference between particles A and C? Particles A oscillates up and down, but particles C remains unchanged. So it seems that the phase difference varies between A and C ...
James Chadwick's user avatar
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Phase difference problem

What's the phase difference between A and B on the following diagram. Where it is a standing wave. This question doesn't even make sense to me as from watching animations of standing waves, points A ...
Jeremy Clarkson's user avatar

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