All Questions
Tagged with electromagnetic-radiation photons
622
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How to understand the Orbital angular momentum of a photon that is not an integer？
How to understand the topological charge that is not an integer, how would the signal OAM crosstalk if one were to model its transport in turbulence, for example, if the beam carries a topological ...
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Does a running motor generate photons?
Since a motor consists of electric field generated through AC current and a fixed magnetic field (permanent magnets), does it generate photons?
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4
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How does an antenna emit photons at a specific frequency if the antenna is made up a specific metal (Al) for example?
My base assumptions...
An antenna emits energy over long distances in the form of photons.
A photon is emitted when an electron changes energy state from higher to lower levels.
A photon's "...
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If photons are massless, how are they reflected and blocked by something that has mass? Shouldn't they pass right through any object?
If photons are massless, how do they get reflected, blocked when something comes in its way? Shouldn't the particle just pass right through any object?
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Why does light interact with normal matter but not with other light?
Why does light interact with normal matter but not with other light?
Assumptions:
Light does not interact with other light at all.
Light does interact with other matter, i.e reflection/refraction.
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Left-handed antiphotons in negative-index material?
Do “left-handed” antiphotons propagate in negative-index metamaterials?
https://pubs.aip.org/physicstoday/article/57/6/37/914849/Reversing-Light-With-Negative-RefractionMaterials
Some quotes from the ...
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Why is UV radiation below 200nm strongly absorbed by Oxygen?
According to https://en.wikipedia.org/wiki/Ultraviolet#Subtypes Ultraviolet radiation below $200$ nm is considered to be Vacuum Ultraviolet, due to being strongly absorbed by atmospheric Oxygen.
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"Artificially" time dilated photons
If you bang on the table you create a single thump, but if you keep doing so with shorter and shorter intervals, eventually it'll start to sound like a note with a particular pitch.
Now, if I used a ...
- 313
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QED photon path (direction of photon emission)
In QED we look at all possible path a photon could go from S to P, and I understand the most significant contributions to the final arrow are the few near straight paths connecting S and P while other ...
- 161
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Light wave/photon doppler effect
So I understand the explanation/derivation of doppler effect from the perspective of wave crests emission being stretched out as the source moves. But how does this work from the photon point of view?
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- 161
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587
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Compton scattering with free electron
When the photon is incident on free electron, we say that compton happens. Though, we require that photon is x-ray or gamma ray. I wonder why at least x-ray is required.
I have my own observation and ...
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How to calculate the change of the density of photons in different frames?
I have a problem in getting the transformation of the intensity of light.
1>> Using the transformation of the energy-momentum tensor $T^{ik}$, we can obtain
We have used the fact that $T^{00}=W$...
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195
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What happen to the electromagnetic waves when a photon's "wave function" collapses?
We interpret the electron's wave function as a probabilistic wave function. During a measurement, it has the probability to collapse to any of the eigenstates of the measurement operator based on the ...
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Max Planck - what does 'per wavelength' mean?
Planck says
$$B_\nu(T)=\frac{2hc^2}{λ^5}\,\frac{1}{\mathrm{e}^{hc/λk_BT}-1}.$$
It's defined as energy emitted per unit volume per wavelength. I'm not sure if this includes per solid angle, but I ...
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Max Planck - what's the $B$?
Planck says
$$B_\nu(T)=\frac{2\nu^2}{c^2}\,\frac{h\nu}{\mathrm{e}^{h\nu/k_BT}-1}.$$
It is power emitted per unit area per unit angle per unit frequency. This is what I'm curious now.
Let's say we ...
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