Light always moves at C, but how is that the case when it is reflected? Say light is reflected at a 180° angle. It seems like there must be an infinitesimal amount of time where it is not moving while changing velocity, but physics says otherwise.
In: Physics
What you perceive as reflection (macroscopically) is actually the absorption and immediate re-emission of light by the electrons that make up the molecules and atoms of a substance (microscopically). The original light ends on an electron, and new light is created by the electron. There is no deceleration or change in speed of the light. It (the photon) merely ceases to exist. All light begins and ends on a charged particle (typically electrons).
Light loses energy when it gets reflected by getting dimmer because it’s speed is always constant. A photon that loses all its energy just doesn’t exist anymore.
> physics says otherwise
Does it? My (admittedly hazy) understanding of quantum electrodynamics is that during reflection, a photon is absorbed by and re-emitted by an electron at the surface of the reflector. So it doesn’t “stop”–it ceases to exist, never having slowed down.
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