Economists, I generalise from a sample of a few, underestimate the tardy pace of technological change, as do the general public, who think that inventions and innovations are blinding flashes producing instant illumination. Far from it; even simple things take centuries; a shift in one area, an innovatory new machine assembled from pieces made for other purposes, and a little specific invention, may stand like Athena fresh from the head of Zeus, but it may be a while, and this is the crucial point, before the human minds around it are themselves ready to make the most of the thing.

Anything far from thermodynamic equilibrium is very hard won. The low entropy structure of the device is only slowly achieved, and that assemblage takes a great deal of testing (trial and error is the best, the most informationally sensitive, not a humble, last resort mode of proceeding). But even when it stands there, much remains to be learned about how the device, whatever it is, a thought or a bicycle, can be made to work. Indeed, bicycles are a good example: The machine as we currently have it has been about since the 1880s, but, and this is almost unbelievable, it is only in the last decade or so that we have learned how to teach the riding of the instrument. My now 19 year old son learned, 15 years ago, with stabilisers bolted to the back wheel, and learned slowly, and with some painful unlearning after the stabilisers were removed. My four year old son learned with hardly a fall over the last year, beginning with a 'balance bike', an invulnerable plastic bike equipped with brakes but without pedals, and then in the last week with a standard pedal bike, on to which he climbed and coasted away, and then with a word from me put his feet to the pedals and powered off like racer. Within a day he was standing and running on the machine as if born to it. When the learning of balance (and braking) is separated from the learning of pedalling, the whole thing becomes straightforward.

Technological progress has several dimensions, and progress along one may proceed that on others. If it takes this long to understand something so simple as a bicycle, imagine how little we probably know about cars, computers, and even some of our best ideas.