Ångström, Knut Johan

Born Jan. 12, 1857, in Uppsala; died Mar. 4, 1910, in Uppsala. Swedish geophysicist, member of the Stockholm Academy of Sciences (1893). Son of A. J. Ångström.

Ångström became a professor at Uppsala University in 1896. He studied the absorption of infrared rays by various substances and constructed a compensating pyrheliometer (for measuring the sun’s energy as received on earth) and a pyrgeometer (for determining the earth’s radiation).