“The more quantum theory develops, the sillier it looks”, wrote Einstein in a letter in the 1920's. Since then quantum physics has been verified by experiment and been central to many of the scientific and technological advances of the last century. But the problem that troubled Einstein remains: quantum mechanics renders the universe fundamentally unknowable. Heisenberg's Uncertainty Principle means that science is in principle unable to predict behaviour at a quantum level. He concluded: "Elementary particles are not real; they form a world of potentialities or possibilities rather than one of things or facts".
Should we accept that quantum mechanics has made the universe unknowable? And if so, how should we proceed if the way the world is depends on our observations? Is science at play in a world of competing models none of which can ultimately describe the universe, or is Einstein's hunch right and can we uncover a theory that eliminates uncertainty and enables the correct description of the universe independent of any observer?