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0 votes
1 answer
100 views

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 ...
Flamethrower's user avatar
10 votes
1 answer
1k views

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 ...
2080's user avatar
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