1920 in science

astronomy debate held on 26 April 1920 at the Smithsonian Museum of Natural History between Harlow Shapley and Heber Curtis about whether spiral nebulae were different galaxies or part of the Milky Way

experiment providing information on classical conditioning of human infantile subject

overview of natural science-related events during the year of 1920

star in the constellation Cygnus

20th-century partial solar eclipse

20th-century partial solar eclipse

high frequency vacuum tube electronic oscillator

series of scientific expeditions to the South Pacific