Wright brothers at Kitty Hawk. Rutherford and Soddy radioactivity. Einstein theories of special and general relativity and gravity. Barnard photographs Milky Way. Sound broadcast over radio.
Comet explodes over Siberia.
Mount Wilson 60-inch reflector telescope. Great January Comet brightest of century. Rutherford structure of nuclear atom. Leavitt Cepheid variable stars. Bohr atomic structure.