News that nasa's $125 million Mars Climate Orbiter fell into a black hole because one of the two teams responsible for telemetry worked in imperial while the other used metric mensuration can have come as no surprise to veterans of the construction industry's own wonder years. In the decade of decimalisation, such errors were common on building sites and widely publicised. Then, after the Metrication Board was wound up, an eerie silence fell, broken only by gasp-making episodes that could not be suppressed, like the occasional cross-cultural mis-measurement of jet fuel for an airliner, or the so-called 'computer error' that produced enormous and unsustainable credits in a bank account. These glitches apart, it seemed that switching to new units of measurement was something any joined-up thinker could handle easily. Or was it?
Today we buy petrol in litres and measure distances in miles. Our boats still go aground because depth-guages are calibrated in metres, but helmsmen think in fathoms. Our office buildings are costed per square metre, but let in pounds per square foot. We've lost long and short tons, but do we really understand tonnes? And, for that matter, what does anybody really mean by 'a spine-tingling 300PS at 5700rpm and 432Nm of torque at 3800 revs'? Could the truthful answer to the last question really be that the only bit they understand is 'spine tingling' and all the rest is a kind of digital blotting paper to soak up doubts? 'Spine tingling' is code for fast - the rest is just padding. Read the small print in the brochure. It tells you that 300ps is about 220 kilowatts, which is about 72 old- fashioned storage heaters. As for 432Nm of torque; that is 40.2 mkp. What is mkp? It doesn't say in the brochure and if you ask the salesman he doesn't know. He doesn't know what PSs, Nms or kWs are either. All he knows is what 'spine tingling' means in terms of 2.8 nudges and 144 winks, which is about as much as a property developer knows about square feet of prime serviced floorspace.
The simple truth is that the art of mensuration is steadily slipping away from us. It is becoming a subject that can only be managed by machines and is undertaken by humans at their peril. The glass for a rooflight inclined at more than 45degrees can be measured by three separate technicians and still arrive on site the wrong size. Why? Because the manufacturers' software will not accept such a steep angle; the calculation has to be made by a humanoid with a pencil who probably cannot tell a Newton from an mkp.
The government's answer to this issue is characteristically wrong-headed. Confronted with school children who can read 'Eleven Fifty-Six' off a digital clock but still have no idea how close to midday it is, authorities decide to ban calculators for the very young. This of course removes their last chance of ever getting the answers right. If the measurement of size, weight, strength, power, light transmission and so on is all to become a black box process - like environmental engineering by computational fluid dynamics, driving a car or using a camera - there is no point in artificially holding back the moment of technological submersion. Bring it on as fast as possible, like the leap from the Teletubbies to the Tweenies. If it had to intervene at all in the digital dyslexia crisis, the Department for Education should not have restricted pupils' access to calculators, but instead demanded a calculator for every child. It would have to be a calculator with at least 150ps and 216Nm and not a penny less than 16.3mkp.