Cosmic Quest - Plumbing the Depths - the Birth of Astrophysics

Heather Couper presents a narrative history of astronomy. Galileo realised that the Milky Way was a glowing band of stars across the sky and philosopher Immanuel Kant recognised that our Sun was just one member of a vast star system. But for centuries, few recognised the true nature of our galaxy. In the late 19th century, William Herschel realised that the Milky Way was a giant body of stars, but still his discovery was ignored. It was not until early in the 20th century that Harlow Shapley began to estimate the distances of the stars and hence map out the Milky Way in three-dimensional detail. Radio astronomy finally yielded the ability to penetrate the dark clouds towards the galactic centre and see the true distribution of matter in the skies.