Relativity at the centenary

When I was a first-term graduate student in the late 1960s, it was said that the field of general relativity was ^a theorist's paradise and an experimentalist purgatory^. There were some experiments–Irwin Shapiro, for instance, had just measured the effects of general relativity on radio waves as they passed the Sun – but the field was dominated by theory and by theorists. This seemed to reflect Einstein's own attitudes: although he had a keen insight into the workings of the physical world, he felt that the bottom line was the theory. As he once famously said, when asked how he would have reacted if an experiment had contradicted the theory, 'I would have felt sorry for the dear Lord. The theory is correct'.