Published online by Cambridge University Press: 12 April 2016
Until the last century, virtually all humans knew the appearance of the dark night sky. Even unschooled urbanites knew some constellations and planets. By 1909, light pollution made authors admonish readers to do their skywatching from the countryside rather than the city. The warnings have escalated along with the light pollution. Light pollution’s effect on professional and volunteer observational astronomy, along with telescopes’ changing focal ratios, largely determine which kinds of astronomy are done in which institutions. In times and places where individuals perceive little possibility to change their culture, astronomers cope as best they can. When activism earns results in other cultural matters, astronomers sometimes become activists to fight light pollution. Chabot Observatory has felt many of these influences in its 105-year history, and they can be read in its plans for the future as well. Despite winning some battles, the war against light pollution is still being lost, so a different approach is suggested.