Quantum Computers and Parallel Universesbr Australian Broadcasting Corporation - Sydney Writer's Festivalbr The two towering achievements of modern physics are quantum theory and Einstein’s general theory of relativity. Together, they explain virtually everything about the world in which we live. But almost a century after their advent, most people haven’t the slightest clue what either is about. Radio astronomer, award-winning writer and broadcaster Marcus Chown talks to fellow stargazer Fred Watson about his book Quantum Theory Cannot Hurt You.