Measurement of Light Speed

Date: November 21, 1676 • Location: Rome, Italy

The Danish astronomer Ole Rømer presents the first quantitative measurements of the speed of light.

An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers study astronomical objects, such as stars, planets, moons, comets and galaxies, by some combination of observation and the application of astrophysical models. Examples of topics or fields astronomers study include planetary science, solar astronomy, the origin or evolution of stars, or the formation of galaxies. A related but distinct subject is physical cosmology, which studies the universe as a whole.