For much of the modern era, scientists followed Nicolaus Copernicus, Galileo Galilei, and Isaac Newton in believing the cosmos to be eternal and unchanging. But in 1917, when Albert Einstein applied his theory of relativity to space-time as a whole, his equations implied that the universe could not be static; it must…
It was into this fiery climate of the 1920s that the Protestant-raised Hubble, adorned with the cape, cane, and British accent he had adopted while at Oxford, returned after the war. He arrived at the Carnegie Institution of Washington-funded Mount Wilson Observatory outside Pasadena, California, insisting on being…
Georges Lemaitre was a pudgy, pinkish Belgian Jesuit abbe—a Catholic priest—who also happened to be a skilled astronomer. Lemaitre had noticed that Einstein's general theory of relativity would have implied that the universe was expanding but for a troublesome little mathematical term called the cosmological constant…