Questions tagged [electromagnetic-radiation]
Propagating solutions to Maxwell’s equations in classical electromagnetism and real photons in quantum electrodynamics. A superset of thermal-radiation.
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Is it really possible to break the speed of light by flicking your wrist with a laser pointer?
Minutephysics has a popular YouTube video called "How to break the speed of light". In the video it states that if you flick your wrist while pointing a laser that reaches the moon, that the spot of ...
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Can you bend light to go in a circle?
Is it possible to bend light so that it forms a circle and goes round and round indefinitely without losing energy?
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If both radio waves and gamma rays can travel through walls
and they are on opposite ends of the electromagnetic spectrum, then why can't light travel through walls which is right in the middle of the spectrum?
This question has already been asked here. ...
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Can light exist in $2+1$ or $1+1$ spacetime dimensions?
Spacetime of special relativity is frequently illustrated with its spatial part reduced to one or two spatial dimension (with light sector or cone, respectively). Taken literally, is it possible for $...
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Why does wavelength change as light enters a different medium?
When light waves enter a medium of higher refractive index than the previous, why is it that:
Its wavelength decreases?
The frequency of it has to stay the same?
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Why do the neutrinos (with mass) from a supernova arrive before the light (no mass)?
I've already read the below questions (and their answers) regarding neutrinos vs. electromagnetic waves propagating through space, but I'm still not clear on something.
Neutrinos arrived before the ...
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Is there an infinite amount of wavelengths of light? Is the EM spectrum continuous?
The electromagnetic spectrum is a continuum of wavelengths of light, and we have labels for some ranges of these and numerical measurements for many.
Question: Is the EM spectrum continuous such that ...
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Why does laser light not affect glowing materials?
I have this childrens rubber ball which glows in the dark after it's exposed to light. I "charge" it with a flash light then play with my dogs at night. I thought to try a very intense green laser, ...
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Does old light contain clues to its age?
Light from celestial objects is old. In the case of galaxies, it's millions of years old. It seems plausible to me that light might show signs of its age.
I was surprised that a Google search only ...
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Why doesn't light kill me?
Why does each individual photon have such a low amount of energy? I am hit by photons all day and I find it amazing that I am not vaporized.
Am I simply too physically big for the photons to harm me ...
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Why exactly do atomic bombs explode?
In atomic bombs, nuclear reactions provide the energy of the explosion. In every reaction, a thermal neutron reaches a plutonium or a uranium nucleus, a fission reaction takes place, and two or three ...
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Can you be blinded by a 'dim' light?
From what I can tell, if you pick a color near the extreme of the visible light spectrum, let's say red, and trace a path across the spectrum until you are outside of the visible range, at some point ...
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Redshifting of Light and the expansion of the universe
So I have learned in class that light can get red-shifted as it travels through space. As I understand it, space itself expands and stretches out the wavelength of the light. This results in the light ...
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How can wifi penetrate through walls when visible light can't?
I did search the question on Physics S.E considering it would be previously asked. I found this
How come Wifi signals can go through walls, and bodies, but kitchen-microwaves only penetrate a few ...
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Why are only infrared rays classified as "heat rays"?
I've often heard that Infrared rays are called "heat rays". However, I feel like this term is a misnomer. Don't all the wavelengths of electromagnetic radiation carry energy?
Judging by how ...
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