String theory used to get everyone all tied up in knots. Even its practitioners fretted about how complicated it was, while other physicists mocked its lack of experimental predictions. The rest of the world was largely oblivious. Scientists could scarcely communicate just why string theory was so exciting why it could fulfill Albert Einstein's dream of the ultimate unified theory, how it could give insight into such deep questions as why the universe exists at all. But in the mid-1990s the theory started to click together conceptually. Researchers came up with ways it might be tested experimentally. The outside world began to pay attention. Woody Allen satirized the theory in a New Yorker column in July 2003—probably the first time anyone has used Calabi-Yau spaces to tell a story about interoffice romance.