Astronomer — scientist who studies celestial objects and the universe Astronomer An astronomer observes, models, and interprets celestial phenomena. This article explains methods, tools, history, roles, and how astronomers contribute to science and technology.
Cloud chamber (Wilson chamber) Cloud chamber A cloud chamber is a simple particle detector that makes ionizing radiation visible by producing condensation trails in a supersaturated vapor, used historically and for education.
Slide rule (slipstick): an analog calculator for scientific use Slide rule Overview of the slide rule, its parts and scales, historical origins, typical uses in science and engineering, and why it was superseded by electronic calculators.
