• Entropius@lemmy.world
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      2 years ago

      Acceleration and Velocity are vectors. Changes in a velocity vector are an acceleration. Therefore when photons change direction technically it’s a form of acceleration.

      • metallic_z3r0@infosec.pub
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        2 years ago

        I thought photons are always moving in straight lines from their perspective, and it’s space that’s bent. Unless it’s through a medium, then they just get absorbed and re-emitted, sort of.

        • Entropius@lemmy.world
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          2 years ago

          Space bending is a general relativity thing, which isn’t really related much to how mirrors work.

          Regarding the medium bit, photons being absorbed and remitted can’t explain how light moves slower in glass. This is just an extremely popular myth. Photons are only absorbed by atoms at very specific frequencies. Also, the entire reason glass is transparent to begin with is that it’s not absorbing the photons (requires too much energy to bump the electron’s energy level so the photon isn’t absorbed and it keeps on trucking). Also photon absorption and remission is stochastic so there’s no way to control the direction it happens in or how quickly it happens. Random directions of remitted light would make glass translucent, not transparent. So for a few reasons, that’s not how it works.

  • Tb0n3@sh.itjust.works
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    2 years ago

    Does a photon actually accelerate? Sure seems like it always goes at light speed through whatever medium from its creation.

    • Vilian@lemmy.ca
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      2 years ago

      well, if it get reflected and change direction it going to be at light speed, so it can be interpreted (probably incorrectly lol) that it “accelerated instantly to the other direction after the reflection”?

      • Kogasa@programming.dev
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        2 years ago

        This is an interesting question. Instant acceleration is mathematically implausible, but I don’t know if there’s a better physical interpretation for what happens to a bouncing photon. I’m guessing this is one of those “less particle, more wave” situations where the instantaneous velocity of the photon is undefined.

        According to some random internet sources, reflection is the not-quite-instantaneous process of the photon being absorbed and then emitted by the electrons in the mirror.

        • sj_zero@lotide.fbxl.net
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          2 years ago

          There’s a hard rule about quantum physics. It goes: “it’s all fun and games until you’re at the Quantum level, then everything is all fucked up”

          According to what we know, electrons don’t “move between” energy states on an electron, they’re just in one one moment and another the next. That’s so disconnected from reality we perceive it still breaks my brain.