But to find it, Einstein had to move to Berlin.

Breakthrough in Berlin

Einstein’s life until then had been peripatetic. Born in Ulm, Germany, in 1879, he moved when an infant to Munich and then as a teenager to Milan, Italy, having dropped out of high school. He went back to school in Switzerland, eventually graduating from college in Zurich. Failing to find an academic job, he joined the Swiss patent office in 1902, and the next year married Mileva Marić.

During his years at the patent office, Einstein produced an explosive output of papers poking holes in traditional physics, including reports on his special theory of relativity and Nobel Prize–winning work on quantum physics. Eventually those papers led to sufficient recognition in the physics world to get a faculty appointmentwas indeed expanding led Einstein to renounce lambda. But it has been revived by modern cosmologists to explain the apparent increase in the universe’s rate of expansion that was discovered in the late 1990s.

Throughout all these moves, Einstein’s personal life deteriorated. Growing apart from Mileva, he pursued a relationship with his cousin Elsa. And Mileva did not relish the idea of life in Berlin. In July 1914 she took their two sons back to Zurich, and Einstein was left in Berlin free to ruminate about general relativity to his heart’s content. During the following year his freedom nourished a fertile few months in which he saw a new path to success. In mid-1915 he saw that there was a way to make relativity truly general. Rather than imposing