R. MEGNA / FUNDAMENTAL PHOTOS / SCIENCE PHOTO LIBRARY R. MEGNA / FUNDAMENTAL PHOTOS / SCIENCE PHOTO LIBRARY
Mercury discharge tube. Blue light emitted by a mercury vapour discharge tube. The tube contains mercury vapour at low pressure. When a current is applied, electrons in the mercury atoms are excited. Light is emitted when the excited electrons fall back to lower energy levels.
Model release not required. Property release not required.