Sir Roger Penrose
Oxford and Penn State Universities

The principles of equivalence and general covariance, of Einstein's general relativity, rest uncomfortably with the standard rules of quantum theory. Although in many respects gravitation closely resembles other fields of physics, especially electromagnetism, Einstein's general relativity demands that these basic principles be respected, which is not the case for Maxwell's electromagnetism. Sir Roger argues that continued respect for these principles in a "quantized" gravity will entail a change in the very laws of quantum mechanics. He further argues that such a change should resolve the paradox of quantum measurement and be experimentally observable. Experiments are presently under way in Santa Barbara which are partly aimed at shedding light on this profound issue.