"Jennifer Brook, who makes artists’ books and iPad apps, speaking earlier this year: “Craftspeople are technologists, and technologists are craftspeople; the only difference is the velocity of the material they choose to work.” Humbly, I would add a further qualification, a further dimension. Celerity, or “proper velocity”, is velocity which takes the effects of relativity into account: the observer is travelling too; we are all travelling in time. The material has its own celerity." Oh, gosh, that's marvellous. Both parts.