Dispersion refers to the frequency dependence of the properties of a wave.
Questions tagged [dispersion]
508 questions
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What is Chirped Pulse Amplification, and why is it important enough to warrant a Nobel Prize?
The 2018 Nobel Prize in Physics was awarded recently, with half going to Arthur Ashkin for his work on optical tweezers and half going to Gérard Mourou and Donna Strickland for developing a technique called "Chirped Pulse Amplification".
In general,…
Emilio Pisanty
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Why does my wooden door disperse light into a rainbow color spectrum?
On a clear morning, light comes through this window (viewed from the inside)
It then hits the door on the opposite side (so viewing from the outside the door straight on the other side)
There is nothing particularly special going on.
However, if…
Zach Saucier
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Why do prisms work (why is refraction frequency dependent)?
It is well known that a prism can "split light" by separating different frequencies of light:
Many sources state that the reason this happens is that the index of refraction is different for different frequencies. This is known as dispersion.
My…
Brandon Enright
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Why does ice make such peculiar sounds?
I've come across a couple of videos where some interesting sounds are produced using ice.
(Click on the images to see the video.)
Here, they drop a block of ice into a deep crevice and as the block falls, you can hear some strange sounds. These…
AlphaLife
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A Rainbow Paradox
I was studying the phenomena of the formation of a rainbow. In my book, the following diagram is given:
So, the rays at the red end of the spectrum make a larger angle with the incident ray than the rays at the violet end of the spectrum. However,…
golden_hawk21
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$\lambda=\frac{2h}{p}$ instead of $\lambda=\frac{h}{p}$?
I am studying quantum physics and there is something I don't understand:
I know that for any particle $E=hf$ (Einstein relation) and
$v=\lambda f$ ($v$ is the speed of the particle).
I also know that the kinetic energy is $E_k=\frac{mv^2}{2}$.…
snickers
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Why is the speed of oceanic waves not a constant like sound?
I cant understand this, according to what I read here. The speed of a wave depends on its wavelength and its depth, through the relation
$$
v=\sqrt{\frac{g\lambda}{2\pi}\tanh\left(2\pi \frac d\lambda\right)},
$$
where $\lambda$ is the wavelength,…
papajo
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Do all frequencies of light have the same speed?
Is there any speed difference between blue or red light? Is there ever a speed difference? Or do all types of light move at the same speed?
Ted Wong
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How does light, which is an electromagnetic wave, carry information?
We see an object when light from a source strikes the object and then reaches our eyes. How does light, which is an electromagnetic wave, gets encoded with the information about the object? Do the individual photons get encoded with this information…
schizoid_man
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Why doesn’t a normal window produce an apparent rainbow?
When light refracts in a prism it creates a rainbow. My question is, why don’t all windows or transparent objects create this dispersion, i.e. why is the refractive index dependent on frequency in a dispersive prism, and not in a window? (My guess…
Melvin
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Do eyeballs exhibit chromatic aberration?
Fairly straightforward question. If not, why not?
I suspect that if they do, it is not perceived due to the regions of highest dispersion being in one's region of lowest visual acuity.
Richard Terrett
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Why does the light passing through a prism get bent in the same direction twice?
Whenever I see a 2D drawing of dispersion occurring when light travels through a solid prism, I see the rays get bent downwards on entry and downwards on exit again. For example here: https://www.wikiwand.com/en/Dispersion_(optics)
To my…
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Do colors differ in terms of speed?
Here is a very simple question about light. As far as I remember from the school program, each color is merely one of the frequencies of light. I also remember that each color's wave length is different. On the other hand, when talking about the…
brilliant
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Why are red and blue light refracted differently if they travel at the same speed in the same medium?
When I look at Snell's law
$\frac{\sin\theta_2}{\sin\theta_1} = \frac{v_2}{v_1} = \frac{n_1}{n_2}$
I don't see any reference to wavelength.
If red and blue have the same speed in the same medium, why they refract differently?
What am I missing?
João Pimentel Ferreira
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Understanding group velocity
Group velocity as a concept in Classical Waves confuse me. It's very easy to point out visually, like in this really helpful graphic here. Okay, it's the speed of the moving bulge, which, notably moves opposite to the phase velocity.
I see what it…
sangstar
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