Physicists and astronomers

I-J

Ingen-Hausz, Jan1730-1799
Dutch physicist. Discovered that green plants absorb carbon dioxide by day. Comparison of thermal conductivities of rods.

Jansky, Karl 1905-1950
Radio astronomer. He accidentally discovered naturally occurring radiation from a part of the Galaxy ouside the Solar System in 1931. The foundation of radio astronomy.

Jeans, Sir James Hopwood 1877-1946
British physicist, mathematician and astronomer. Major contributions to the kinetic theory of gases. Radiation formula the Rayleigh-Jeans law.

Joule, James Prescott 1818-1889
One of the founders of the idea of energy conversion. The unit of energy is named after him. Paddle wheel experiment. Initially interested in the efficiency of electric motors. Born in Manchester, England to a wealthy brewing family.