All Questions
Tagged with electromagnetic-radiation estimation
34
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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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Accelerating Expansion of Universe - Why Not Caused by Radiation?
As I understand it, dark matter and dark energy are used as an 'explanation' for how universe expansion is accelerating; because without it gravity would be expected to cause a long term shrinking.
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How many photons are received per bit transmitted from Voyager 1?
As of 2024, according to https://voyager.jpl.nasa.gov/ , Voyager 1 is around one light·day away from Earth and still in radio contact. When Voyager 1 sends messages to Earth, roughly how many photons ...
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Are these levels of RF radiation harmful?
I live on the top floor of a building that has four 5G antennas on the roof. The house is curved, and from my viewpoint, I can partially see one of the antennas pointing towards me. Curious about the ...
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If microwave ovens run at 2.4 GHz, what is the long-term effect on living tissue of exposure to this frequency, but with a thousand times less energy?
Very low power electromagnetic waves with a frequency of 2.4 GHz can't cook anything. That's obvious, despite the heating effect such radiation has on water.
However, what if such an object containing ...
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What fraction of the universe's energy is contained in photons?
From each point in the universe, the light of billions of stars, galaxies, supernovae etc. can be detected. So there seems to be a lot of energy/momentum "in flight".
Is it possible to ...
- 347
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How much radiation on the surface of the moon during a Coronal Mass Ejection (CME)?
I'm writing a book set on the moon. A Coronal Mass Ejection (CME) as large as the Carrington Event hits it. Three astronauts are caught out during an EVA. They will cover their rover in regolith to ...
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Does 5G affect your physics experiment?
Our institution wants to lease a nearby roof for a 5G mast. Has anyone experienced the installation and operation of telecoms infrastructure - particularly 5G - significantly affecting physics ...
- 537
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How much UVA and UVB is blocked by shadow or being indoors?
I could not find a clear answer online so I though to try this forum instead.
I did find answers on how different types of glass can block different degrees of UVA and UVB. But I was wondering, if I ...
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On which speed the relic microwave background radiation becomes dangerous for the people on space ship?
If we travel with speed close to the speed of light, the light waves becomes shorter and their energy increases (because we flight through much more light for the same time).
So, even background ...
- 768
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Theoretically, could radio waves carry enough energy to destroy bacteria or viruses by resonance?
I've been reading recently about a mysterious and possibly hokey medical device of the 1930s. It was a variable-frequency radio emitter, invented by a Dr. Rife, which was supposed to kill various ...
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Should larger rocky planets eventually crack due to temperature differences between their inner and outer layers?
Should larger rocky planets eventually crack due to temperature difference between their layers? When a tick piece of glass is left to cool down it would eventually crack...but this is caused ...
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Does home cooking induction stove produces any harmful (to humans) electrical/magnetic fields?
An induction cooker, or stove that are based on the principle of electromagnetic induction, and is used much, for cooking food now a days.
My stove had a thick iron circular plate on the top.
Assuming ...
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Stood in front of microwave with the door open [closed]
I was cooking something in the microwave and opened the door early to check on it and the microwave didn't stop. I didn't realize this for a few seconds and when I did I shut the microwave off but I'm ...
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Can you shake a charged object fast enough to create light?
Electromagnetic radiation (a photon) is generated by an oscillating charged particle. Therefore, is it possible to vibrate an object at say 585 THz and create a green light source?
Alternatively: what'...
