#light radiation
- Actinism — A rare historical or technical term used to describe the property or intensity of luminous radiation to produce chemical or structural changes in the materials it traverses or strikes. This phenomenon constitutes the historical basis of photochemical processes, being closely linked to actinism and the study of how solar or artificial light interacts directly with photographic emulsion or other substances sensitive to the ultraviolet spectrum.
- Actinology — An interdisciplinary branch of science dealing with the structural and theoretical study of luminous and electromagnetic radiation (particularly within the ultraviolet and short-wave visible spectrum) and the chemical, photochemical, or biological effects they produce on exposed bodies. Actinology encompasses principles from optical physics, photochemistry, and biophysics to analyze how radiant fluxes interact with organic and inorganic matter.