In 1920, astronomers Harlow Shapley and Heber Curtis held a Great Debate. Shapley argued that the spiral nebulae were small and in the Milky Way, while Curtis took a more radical position that they ...

In the mid-19th century, astronomers made this scale more rigorous by defining a difference of five magnitudes as corresponding to a factor of 100 in brightness. In keeping with Hipparchus ...

Timothy Ferris, in the film Seeing in the Dark The stars seem to change little if at all—night after night, century after century ... one of the great tasks of astronomy during the last ...

But they weren't only interested in astronomy. The extraction of iron ... was developed as part of the Age of Enlightenment. The 19th century saw some of the great names of science: people ...