Amazing stuff in this article.
General relativity led Einstein to the most famous scientific equation in the world (perhaps the only famous scientific equation in the world): E=mc². With it, Einstein showed that mass can be converted into an immense amount of energy. Historically, that led to the end of World War II in the Pacific, when atomic bombs were dropped on the Japanese cities of Hiroshima and Nagasaki.
...
"Without Einstein's theory of the photon, we would have no lasers. Without Einstein's general theory of relativity, we would have no way of understanding the evolution of the early universe. Worst of all would be to be without Einstein's special theory of relativity; we would have no understanding of elementary particles and the atomic nucleus."We would have no computers without quantum theory, and airplanes would fly off-course if global positioning systems failed to make adjustments due to general relativity. Computers, travel and communication as we know it would not exist. These things are consequences of Einstein's work, but he was interested in the bigger questions. Specifically, the biggest question of all.