Understanding 71 us to predict this future even though there is no clue from the motion of Venus today. Understanding allows us to predict discontinuous events: a system changing its state or a star running out of fuel. We see the same predicament in stock markets. Stock markets normally behave in a linear fashion but, when they go wrong; they go very wrong. Recent recessions have been made much worse by the failure of hedging systems to handle market disruption. Some even think the crises were caused by the automatic trading strategies of these hedging systems. The quants —- as mathematicians in banks are called — spend considerable effort modeling financial instruments to show that if one stock goes down, another will go up at the same time. If the stocks are held together your investment is safe because, on average they will remain constant. The problem with these correlations, which often hold reliably for many years, is that when trouble hits they fall apart. Historical correlations don't give us understanding of the future: something that was only meant to happen once in a million years has happened within six months. As they say on your investment papers, past performance is no predictor of future results. Do Computers Understand? Today’s computers don't have our general-purpose ability to understand. Watson was thrown off by badly formatted English. The human contestants, by contrast, had no problem with this. Just how good would Watson have to be, to call it - or should I say ‘him - intelligent? How could I judge this had happened? Alan Turing proposed an ingenious test in his 1950 paper Computing Machinery and Intelligence using “The Imitation Game? We now call the Turing Test. If we ask a series of questions to a computer and we cannot tell its responses from those a human would give, then the computer is, for all practical purposes, the same as a human. Since we are intelligent — or at least we hope we are — the computer must also be intelligent. QE