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So this just means that they reflect uv rays not that they have some sort of glow in the dark system recharged by the sun during the day to help them see at nig

So this just means that they reflect uv rays not that they have some sort of glow in the dark system recharged by the sun during the day to help them see at night.

dexwiz 3y ago
Bit more complex than reflection. Reflection preserves the wavelength. Fluorescence is where light is absorbed, some energy is transformed to heat/motion, and then photon is re emitted at a lower energy. In UV fluorescence the initial wavelength is invisible and the final one is visible. Technically you can visible to visible fluorescence also, but it’s less impressive to us.
- saltcured 3y ago
  And then there is multi-photon fluorescence where several low energy photons are absorbed simultaneously to pump up the electron state and then it can emit a higher energy photon! This is used in a lot of biomedical imaging with infrared illumination yielding visible wavelengths.