Photons are electromagnetic waves. They exhibit particle-like qualities in many situations and have zero rest mass.
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What is the mass of a photon moving at the speed of light? [duplicate]
What is the mass of a photon moving at the speed of light?
And if it does not have mass, how is it affected by gravity?
Also why does Einstein's general relativity support that a gravitational wave ...
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Conservation of Angular Momentum: atomic transitions vs exciton decay
I have a question about the role of photon angular momentum in two different sets of selection rules:
In atomic transitions within the dipole approximation, I've seen the selection rule as:
$\Delta ...
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Seeing colors: photons vs waves
As an atmospheric physics major I am familiar with electromagnetic radiation in the atmosphere and what dictates what wavelength objects will emit at. When observing radiation in the atmosphere it is ...
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176 views
Does a photon have mass? [duplicate]
I have seen questions assume photons have no mass. But I have not seen any questions that directly ask whether or not photons have mass.
If photons have no mass, then how do they occupy space? How ...
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Quantum Electrodynamics
I was wondering if anyone could give a simple explanation of how light interacts with matter. From what I have read in QED, electrons will repel each other because of their ability to emit and ...
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166 views
Are there “gaps” in light, or will it hit everywhere?
Not sure how to word my question.
Picture a light source in vacuum, so nothing disturbs the light (or similar conditions), 2d.
If I move very, very far away, will it happen that some of the light ...
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hurdles in creating (close to) infinite images
Let's put an object(hypothetical superman) inside a "well sealed" box containing only mirrors. Is it possible to create number of images that will be close to infinity, assuming that resolution of our ...
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Are there 2 kinds of photons, one that mediate the electromagnetic interaction and the other the quanta of light?
It is usually said that photons are the force carriers or the mediators of the electromagnetic forces between electric charges. At the same time we know also that electromagnetic waves on the quantum ...
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What is the brightest color a light source that only emits blue frequency light can achieve? [migrated]
Let's say there is a luminous light bulb that only emits blue light, and you (or a camera if you prefer) look at it from a close distance. Will the maximum brightness perceived not have any "white" to ...
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How photons represent colors that you see?
Right now, my understanding is that, a mixture of photons of many different frequencies is perceived as white by your eye. While no photons at all, is perceived as black. And photons with the blue ...
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Do protons exchange photons with electrons?
I'm sorry for this question but, I just don't get it. According to the electromagnetic field theory, electrons repel each other by exchanging photons. How do protons attract electrons, by photon ...
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If light is linearly polarized, does it have some spatial extent?
If light (a photon) is linearly polarized, say vertically, does it have some vertical spatial extent (perhaps in amplitude)?
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Couldn't we measure electrons with good enough technology? [duplicate]
I am a bit confused about the Heisenberg's Uncertainty Principle - just read about it in How to Teach Physics to Your Dog, by Chad Orzel. He states that the reason electrons can't be measured is ...
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How can photons exert gravity if they are wave-like?
As a reference, see this question: Does a photon exert a gravitational pull?
It turns out the answer is "Yes" -- but this does not seem consistent with light being wave-like.
I am imagining a ...
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Is this mental picture of photon correct?
What is exactly meant by a statement like "there are about 400 photons per cubic cm in certain region"? Should I mentally picture this as 400 discrete photons enclosed in that volume, each moving at ...
