Visible light includes radiation with wavelengths between 400 nm and 700 nm, meaning that far infrared photons have less energy than visible light photons.

The most abundant ion in space plasmas is the hydrogen ion-a bare proton with no excitable electrons to emit visible photons.

If there were a way to combine two visible light photons to break apart the water molecule, then everything would have a ready solution.

The mystery substance is in fact just the kind of light-absorbing pigment we would expect if visible photons were being added together to break down water and generate molecular oxygen.

Cryogenic detectors are sufficiently sensitive to measure the energy of single x-ray, visible and infrared photons.

A visible photon is typically 2-3eV; the resulting phonons range from 0.01 to maybe 0.5 eV.

If Monsoon Control could dump kilowatts of infra-red into the basement of the Tower, it could easily spare him a few visible photons.

The scintillator absorbs the X-rays and converts them into visible light photons that then pass onto the photodiode array.

The scintillator must be in complete darkness so that visible light photons do not swamp the individual photon events caused by incident ionising radiation.

In a fluorescent lamp, the phosphor accepts the energy of ultraviolet photons and emits visible photons.