A fish, swimming through the visible spectrum at the Moody Gardens aquarium in Galveston, Texas.
He didn't know what he was passing through. The diffraction grating split the tank lighting into clean spectral bands — red, orange, yellow, green, blue, indigo, violet — stacked like a ladder of pure color. He swam through it anyway.
Joseph von Fraunhofer invented the diffraction grating in 1813. The fish was his uninvited guest.
A diffraction grating splits light into the full visible spectrum — what you're seeing is real light, photographed, not edited.
