From: Zardoz ® 04/11/2001 19:32:28 Subject: re: COSMOLOGY FAQ post id: 484055 What is quantum foam? All fledgling theories of quantum gravity also make a more general and even weirder prediction: the structure of space and time is very different from the gentle curves predicted by general relativity. The American physicist John Wheeler realised in the 1950s that if you look at things on a scale of about 10-35 metres, quantum fluctuations become powerful enough to play tricks with the geometry of the Universe. Space and time break down into "fuzziness" or "foaminess". A spaceship that size could find itself negotiating virtual black holes, or getting sucked into one wormhole after another and tossed back and forth in time and space. If you think this idea of a space-time foam sounds horribly vague, you're in good company. So do the researchers. "It's a very vague thing," says Chris Isham, a theoretician at Imperial College, London. "General relativity is about space-time, and quantum theory tends to involve quantum fluctuations in things. Therefore, if you talk about quantum gravity, there might be some sort of fluctuation in something to do with space-time. It's that sort of level of argument." Quantum foam