Heaven, reported St John in Revelation, was a cubical city 12,000 furlongs high made of 'pure gold, like unto clear glass'. That was 1,900 years ago, and Heaven as it is today has changed out of all recognition. Sweet Dreams is the account of a recent journey to the metropolis at the nerve-centre of the universe. The journey was undertaken not by a mystical reporter like St John, but by Howard Bak...