All Questions
11
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How many photons pass through us every second?
I just read this answer https://physics.stackexchange.com/a/229374, which says that, when a magnet rotates, photons are emitted with wavelength $λ=c/f$, where $f$ is the frequency of rotation. And ...
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2
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44
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Is luminescence from impact of fast neutral atoms/molecules on a suitable substance known?
Cathodoluminescence is emission of photons by electrons impacting on a luminescent material.
The Rutherford scattering experiments detected impacting helium nuclei on a phosphor screen.
Many other ...
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-2
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3
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Photons: Why not wave only? [duplicate]
It seems that Einstein's 1905 paper "Concerning an Heuristic Point of View Toward the Emission and Transformation of Light" notes the discrete quanta of light energy, an idea that leads to ...
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2
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2
answers
79
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Why do electrons come to ground state even after giving absorbing energy?
Imagine you have a hydrogen placed under sunlight, now if we look at 1st shell of hydrogen, it has energy of $-13.6$ev now for 2nd shell we have energy of $-3.4$ev.
1st shell -> $-13.6$ev
2st ...
0
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0
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102
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Can Two Electromagnetic waves cancel each other if it 180 degree phase moving in same direction?
If we can send two electromagnetic waves -180 degree out of phase- in same direction, then the interaction of this wave with air molecules will be less due to the low intensity of the combination. So,...
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Why do some electromagnetic waves have more than one photon?
I know that the energy of an EM wave is equal to nhv, where n is the number of photons, but why/how do the number of photons in a wave vary? If a single atom emits an EM wave with an energy of 100 ...
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1
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Are photons really 'particles' of light? [duplicate]
In Einstein's Photon Theory of Light, he proposed that light consists of distinct chunks or distinct packets of energy called photon and the energy of a photon is given by :
$E=hν$
where $ν$ is the ...
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4
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How do we detect infinitely narrow emission / absorption lines within continuous electromagnetic spectra?
This always bothered me, especially in the case of absorption lines. for instance, if you have a blackbody emitting a continuous spectrum, and then a filter in front that only filters out one very ...
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2
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Are there limits for photon energy?
Inspired by this question, I have slightly different question.
One way how photons are produced is through quantum oscillator transition from upper state $E_2$ to lower state $E_1$. The photon energy,...
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1
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Why is the energy expressed in an electron orbital change of state electromagnetic (photon)? [closed]
As I understand it, Schrodinger's wave equation predicts the allowable energy states an electron can have under the electromagnetic forces of a given nucleus (and I assume other 'orbital' electrons). ...
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How many photons are there in free space on average
Estimates of the amount of for example "dark matter" are of interest to the cosmologists. However, I have never seen an estimate of how many "free" photons could be speeding about in the known ...
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