Max Gunther's classic text brought back into print. Luck. We can't see it, or touch it, but we can feel it. We all know it when we experience it. It's an obvious description of obvious events. But does it go deeper than this? And if it goes deeper, does it do so in any way which we can harness to our own and others' advantage?Taking us on a richly anecdotal ride through the more popular theories...