The magician Derren Brown recently ‘predicted’ the outcome of the UK national lottery, precipitating a kind of science versus society war in my household. While I have seen some clips from the two programmes, I refuse to watch the whole thing on the grounds that it is damaging to the public perception of science and mathematics.
When I see a card trick or a woman being sawn in half, I *know* it’s a trick. No cards or women are actually be harmed in the cause of entertainment (well, I am pretty sure about the women, but the cards might suffer in some cases). The problem with the lottery ‘prediction’ is that most people do not understand the fundamental nature of randomness. Brown’s pseudo-scientific explanation (using the wisdom of crowds) actually makes sense to them. (If you are unfamiliar with the theory, it is where the average of a large number of guesses is more accurate than the vast majority of individual guesses.) The problem is, and this is what makes the trick so effective – but confusing at the same time – it is not possible to predict with any degree of certainty what the next random number might be. In a truly random system, the history of the numbers drawn is entirely irrelevant. The only useful information that can be gleaned this way is whether there are non-random factors at play. So knowing the sequence of results from a roulette wheel might tell you it is not perfectly balanced and therefore slightly prone to choosing some numbers over others. But for a perfectly random system (and lottery equipment is as close as you can get to perfectly random), no amount of contemplation is going to make any difference.
Because of my scepticism, I am now forbidden from discussing the trick any further within earshot of my family (I don’t think they read my blog so I am not worried on that front). And I have to hand it to Darren Brown, its a good trick – even if the ‘predicition’ came shortly AFTER the actual draw. But please, can we have a trick next time that is not going to damage our already impaired understanding of science?