Conservation of Angular Momentum (C.A.M.)

“Lana’s Aeronautic Machine.” Ambrose William Warren, 1781-1856, engraver. United States Library of Congress. Uncolored etching of the aircraft suggested by Franceso Lana de Terzi (1631-1687), in Prodromo (1670). The four metal globes are evacuated so as to make the craft buoyant. The craft was never constructed and was beyond the technology of the period.

A hot-air balloon in flight during the Bristol international Balloon Fiesta. Photo by Bradley Lewis.

Paulus was the inventor of the first collapsible parachute, as well as an early developer of the pilot chute method of deployment. She performed at airshows around Europe in the late 19th century under the stage name “Miss Polly.”

Planisphæri cœleste, circa 1670, by Dutch cartographer Frederik de Wit.

La Silla Observatory, Atacama Desert, Chile.

Cruiser anchored at Green Island, Panama.

Frontispiece to Selenographia, Johannes Hevelius (1647). It features two of the great astronomer-physicists from history: Arab Ibn al-Haytham stands on the left, holding a geometrical diagram and symbolizing knowledge through reason. Italian Galileo Galilei stands on the right, holding a telescope and symbolizing knowledge through the senses.