photon

fotoni puhekieltä The quantum of light and other electromagnetic energy, regarded as a discrete particle having zero rest mass, no electric charge, and an indefinitely long lifetime. It is a gauge boson.
{{quote-magazine|year=2013|month=July-August|author=http://www.americanscientist.org/authors/detail/fenella-saunders Fenella Saunders
puhekieltä English photon