• Neato@kbin.social
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      1 year ago

      That’s light as an aggregate wave. Photons, actual light, always travel at c. What’s happening in a medium is the rapid absorption and readmission of photons. The probability of admission is based on structure of material causing things like lens or mirrors to work.

      You can think of it as the photons having to jump between platforms before the can continue running at c.

    • there1snospoon@ttrpg.network
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      1 year ago

      But doesn’t relativity explicitly state that c is the speed of light in a vacuum, and travelling through other mediums explicitly changes and is explained by relativity?

      I am 100% a layman and do not know the answer.

      • sushibowl@feddit.nl
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        1 year ago

        Not really no. Special relativity explains the relationship between space and time. General relativity expands on this to account for gravitation.

        One of the postulates (i.e. assumptions) of relativity is that the speed of light in vacuum is the same for all observers. But the theory doesn’t actually require any particular value for c, it only needs it to be constant. And it doesn’t explain the behavior of light in a medium at all.

        In fact, relativity doesn’t explain the mechanism by which light interacts at all, that is the domain of Quantum Electro Dynamics.

        • there1snospoon@ttrpg.network
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          1 year ago

          Wow that is so interesting. So am I understanding that relativity explains space, time and gravity’s interactions with one another, while quantum science explains interactions with much smaller objects like matter?