Wonderful retrospective in the Economist on one of the intellectual triumphs of the twentieth century. A few quotes give the flavour of real advance without an impact statement in sight.
General relativity was presented to the Prussian Academy of Sciences over the course of four lectures in November 1915; it was published on December 2nd that year. The theory explained, to begin with, remarkably little, and unlike quantum theory, the only comparable revolution in 20th-century physics, it offered no insights into the issues that physicists of the time cared about most.
Some people might be satisfied just to let each theory be used for what it is good for and to worry no further. But people like that do not become theoretical physicists
A century ago general relativity answered no-one’s questions except its creator’s