Then in 1984, "there was a moment, a day," says Green, "which I remember well, when suddenly everything fell into place at once. We were working on a particular aspect which we hoped – there was no reason to expect it to, but we secretly hoped – would work. And it did. But immediately, within a couple of hours, something else worked, which went far beyond that. And that was totally unexpected."
Green gave a talk on it a few days later. "There weren't exactly gasps, but clearly what happened was that someone then sent a message to Princeton, where there's a man called Edward Witten, who's amazing. And then the first thing that happened was that he produced a paper before we could, using what we'd done to do something more – which was astonishing, because we had no idea it could be used that way. And it was really his paper that triggered interest among other people."
Although he does not like the term revolution, that moment in 1984 is now called the first revolution in superstring theory.
There have now been thousands of papers on string theory, which attempts to reconcile quantum mechanics with relativity by arguing that subatomic particles are strings vibrating through space and time, differing merely in the ways in which they vibrate – through 10 or 11 dimensions.