It may sound like a job at a Walt Disney theme park (where designers are called imagineers), but ‘visioneer’ is Patrick McCray’s portmanteau word combining ‘visionary’and ‘engineer’ – not a hand-waving futurologist, but a scientist or engineer who is coming up with blue sky ideas that are, nonetheless, based on the projection of solid science and engineering. The two key figures here are physicist Gerard O’Neill, who devised space colonies, and engineer Eric Drexler who was at the forefront of the nanotechnology movement, both dating back to the heady days of the 1970s. Their ideas are put in the contrasting context of limits – an influential group, the Club of Rome had recently published dire warnings of the limited resources available to human beings, and arguably both these threads were about ways to escape the limits, either by reaching outside the Earth, or into the microcosm. The opening of the book promised a lot – it looked as if it was going to be really exciting and enga