stroboscope: scientific instrument that provides a flashing light synchronized with the periodic movement of an object; can make moving object appear stationary
scientific instrument: an instrument used by scientists
eutrophication: excessive nutrients in a lake or other body of water, usually caused by runoff of nutrients (animal waste, fertilizers, sewage) from the land, which causes a dense growth of plant life; the decomposition of the plants depletes the supply of oxygen, leading to the death of animal life