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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Light and transparency

As we know, light is reflected by a mirror, so we can see our image, it is mostly reflected by a white wall (that does not get hot) but we cannot see our reflection, it is absorbed by a black wall, ...
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How could I measure the colour spectrum of a light bulb and investigate how closely it matches a black body radiation curve?

Here is my research question: What is the colour/spectrum produced by each globe type? What is the temperature equivalence? How closely does a globe match a black body radiation curve? I will be ...
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How can a wavelength be defined for a laser where a photon's travel distance over a pulse duration is less than a wavelength?

Femtosecond laser pulse are widely used in experimental physics. Femtosecond lasers like Nd:YAG systems produce coherent light at wavelength 1053nm. The distance traveled by a photon in 1 fs is 300nm; ...
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Proof of de Broglie wavelength for electron

According to de Broglie's wave-particle duality, the relation between electron's wavelength and momentum is $\lambda =h/mv$. The proof of this is given in my textbook as follows: De Broglie first ...
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Wavelength-division multiplexing (WDM) and white light spectrum wavelengths differ

I am a newbie to Optical fiber communications and was going through the article on WDM on wikipedia here: WDM Wikipedia I also went through the below article on prism diffraction of white light into ...
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556 views

Relationship between Wien's law and Stefan-Boltzmann's law

I'm studying Quantum mechanics by Bransden and Joachain and in the introduction chapter it says: Wien showed that the spectral distribution function had to be on the form $$\rho(\lambda,T)=\lambda^{-...
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What is the wavelength of electrical current?

I am trying (as an exercise) to determine the force between two wires, in a similar nature to this question here. This suggests a solution based on the wavelength of the wave. However, the ...
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113 views

Will a reflection phase change work regardless of wavelength?

If I have a gamma photon traveling in air and it shoots off towards a glass mirror and bounces off it, when I measure its phase, will it have changed by 180${}^\circ$? I was reading the wikipedia ...
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Will overlapping two different beams of coherent light with different wavelength cause interference?

If I use two different wavelength lasers to transmit light into a single mode optic fiber will they interfere with each other? If so, how much will be that interference.
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The color of a refracted ray

My textbook explains the cause of the refraction of light as the "difference between the speeds of light when passing from medium 1 to medium 2". The same textbook explains that the cause of the ...
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507 views

Phase of a plane wave is an invariant quantity

As described by Jackson's Classical Eletrodynamics [1], the phase of a plane wave is an invariant quantity for all coordinate frames. Jackson justifies this statement using the fact that the phase of ...
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Filter for RGB separation

Looking at Bayer filter of a typical consumer camera, one can easily see that sensitivity of the filter for each color is all over the place. Are there filters similar to Bayer that do a better job at ...
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Are there unabsorbable wavelengths (frequencies) in the electromagnetic spectrum?

The electromagnetic spectrum is continuous. It can have any frequency since the ways of emission depend on velocity of electrons, energy levels, or vibrational modes of connections in molecules. On ...
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A Photon's wavelength is Color, but an Electron's wavelength is a Probability? [closed]

If a photon of 475nm strikes my retina, my brain registers it as "blue," whereas a photon of 650nm is "red." If I ask the question "what is oscillating, and therefore causing the change in wavelength (...
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Electronic transitions in potassium

Potassium atoms in the electronic ground state absorb laser light at 769.9, 766.5, 404.7, 404.4, 344.7 and 344.6 nm. Obviously, these absorption lines exist because an electron is excited from the ...
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Where can I find the light damage threshold of a specific material (in this case, latex)?

I am a part of the University of Maryland Balloon Payload Program, which sends student-built payloads via helium weather balloon to the upper atmosphere. I am interested in developing an Early Flight ...
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Why we can't see objects smaller than wave length of light?

I would like to ask, why we can't see objects smaller than wave length of light under traditional microscope. I know that there is some way to see them and the scientists who discover this. Why we ...
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938 views

De Broglie wavelength [closed]

Ok so the question is: an electron of kinetic energy E has de Broglie wavelength λ. What is the de Broglie wavelength of an electron with kinetic energy 2E. I keep getting the answer as λ/2 but the ...
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If kinetic energy increases 16 times, what's the percentage of change of De-Broghlie's wavelength? [closed]

seems easy but I'm not very convinced, if I made a mistake please tell me K.E1 = $\frac 12$m$v^2$ increases 16 times so K.E2 = 8m$v^2$ so that means the momentum $mv$ must increase 16 times as ...
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What am I failing to understand about a light in a material?

In a material, a photon's velocity becomes slower, photon's wavelength becomes shorter, but photon's frequency doesn't change. If there is a material that makes low frequency photons have very short ...
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When the gap size is less than the wavelength, the angle through which the wave is diffracted remains a maximum . What does this mean? [closed]

When the gap size is less than the wavelength, the angle through which the wave is diffracted remains a maximum while the intensity decreases as the gap gets smaller than the wavelength. I understand ...
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Wavelength scalar/vector ambiguity?

I have seen the de Broglie relation for wavelength written as $\lambda$ = $\frac{h}{\gamma(\vec{v})m_o\vec{v}}$ I know wave propagation in the one - dimensional case makes wavelength a scalar, as ...
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Light wavelengths and intensity at 10 m depth in coastal water

I’m planning an experiment in tanks under controlled conditions in which we’ll collect marine animals and observe their behaviours. We want to replicate to the best the light that they receive under ...
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Why would tsunami be dangerous because of long wavelength, which is opposite to x-ray?

I know x-ray is dangerous because it has short wavelength and hence has high energy. But I often heard that tsunami wave is more destructive than normal waves because it has longer wavelength and has ...
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How to compress a range of wavelengths into a single wavelength?

Given the light spectrum from 400 to 500 nano-meters, How can I convert all wavelengths in the range to one wavelength of say 450nm?
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Is there a significant error in using De Broglie's equation for an electron at really high speed?

I was wondering if using the De Broglie equation $ \lambda = \frac{h}{p}$ for object traveling at really high speeds would result in a significant error. For example if an object travelled at $0....
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Multi wavelength lasers

At the lab I work at, we have a laser capable of emitting light at a spectrum of wavelength. As far as I know, this spectrum is continuous, in that it can emit from 800 nm to 1200 nm for example. ...
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Acoustic subwavelength reflection

Acoustic Microscopy is usually used for inspection of airgaps in material. I am looking for any source (textbook, paper) that discusses the percentage of reflection of an acoustic wave from an airgap ...
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Fourier transforming between time space and wavelength space

Recently, we talked about a homework assignment, which seemed rather odd to me. Let the Fourier transformed $ F(\xi) $ of a function $f(x)$ be defined via: $$F(\xi) = \int_{-\infty}^{\infty}f(x) e^{-...
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Unable to get the correct wavelength for the Lyman-alpha transition in Positronium

I am tasked with the following question: Positronium is an exotic atom consisting of an electron and a positron (its antiparticle). What is the reduced mass ...
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Is the event horizon of a black hole wavelength-specific?

The event horizon is the boundary surrounding a black hole from which not even light can escape. There's a certain negative potential energy level associated with the event horizon. Now, some shorter-...
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Conditions for forming a stationary wave?

Does it only require two waves of the same frequency / wavelength travelling in opposite directions? My teacher says that one wave needs to be reflected and then superimpose with this reflection for a ...
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Derivation for wavelength bandwidth

I've been told that for wavelength bandwidth $\Delta\lambda$, it can be shown that: $$\Delta\lambda = \frac{(\lambda^2 \Delta\nu)}{c}$$ Where $\Delta\nu$ is the frequency bandwidth and $c$ is the ...
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Does the continous EM spectrum contradict discrete energy? [duplicate]

After some research, it seems apparent to me that the EM spectrum is continuous, but this would contradict a physics fundamental that energy is discrete. Is there a conflict here?
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What phase of an electromagnetic wave is the ground state?

I have read that the uncertainty principle applies to electromagnetic radiation, and the ground state could not be sitting on the lowest energy point, because then it would have definite position and ...
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Can a radio station's wavelength be measured by driving through its interference?

The other night, while driving I was listening to KGO radio. KGO is a San Francisco AM station that broadcasts at 810khz. I was driving north, away from the station, at about 70mph. I notice that the ...
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Black Bodies, why is $\nu_{max}\neq {c}/\lambda_{max}$? [duplicate]

I am trying to find Wien's law from Planck's equation but instead of $\lambda$ I am finding frequency. I found it: $$\nu_{max} = \frac{(2.82)k_bT}{h}.$$ The following question asks: Why $\nu_{max}\...
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Finding out the wavelength of a wave on a composite string (made of two materials)

We have a composite string of two materials A and B which have been joined end-to-end to form the string. The free ends are clamped to two supports and the system looks like this: Objective: Find $\...
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What causes color change on the surface of blade in picture?

What causes this color distribution in the knife shown below? A chemical that causes light to change wavelength? A product of the heating process?
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Are we exposed to more blue light than any other colour?

it's my first post so nice to meet you all. Is blue light more abundant on the Earth's surface than any other colour? I know that if this is extended to non-visible EM radiation then radio waves are ...
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Why does electron orbital circumference have to be in multiples of de Broglie wavelengths?

Electron orbit circumferences have to be in multiples of its de Broglie wavelength, but what do those 2 have in common?
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Can the wave length of a photon be stretched out caused by expansion of spacetime? [closed]

Strictly speaking perhaps it is not right to say that a photon is a wave so its wave length can't be stretched out; a photon is actually just a point. So is its wave property only a relativistic ...
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For a sine (or cosine) wave, how can the $kx$ be different from $\omega t$?

I'm trying to learn wave mechanics and came across the equation that states wave as a function of $x$ and $t$ and specifically $(kx - \omega t)$. In my faulty imagination, the $kx$ is always equal to $...
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How far do electrons go in an antenna?

Do you know what is the distance electrons cover in an antenna during the production of a radio wave? Does the extension of the oscillation vary with the frequency or the power of the radiation? Is ...
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Does redshift only affect particles of visible light?

May seem really daft but I don't know of any ways of detecting redshift in the rest of the EM spectrum, so was just wondering
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Why car tail lights look red?

The car's tail light is made from red plastic material, and when the bulb from the inside switches on we see red colour, why? Is it just that the bulbs light illuminates that red plastic or wavelength ...
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Can a rainbow be seen from above

I saw this picture of a "rainbow from above" Based on what I understand about rainbows, some googling and my experience chasing them, if I saw one and try to fly above it, the phenomenon will ...
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Single slit diffraction pattern for electrons?

Reading about Young's double slit experiment for electrons, it is stated that the diffraction pattern is observed when both slits are open but not for a single slit (I suppose this is equivalent to ...
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How to take measurements for wavelength in an experimental wave tank?

To anyone familiar to the experimental hydrodynamics field, how does one experimentally measure the wavelength of the waves generated in a plunger type wave tank or any wavetank for that matter. From ...
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electromagnetic waves: $ f(t) = A \sin(Bt) $ [closed]

I recently saw this question which was slightly lacking in formulation, but I was still interested in solving it; but I can't. Light can be seen as electromagnetic waves, which in vacuum, moves ...