Caught an excellent programme on the BBC World Service this afternoon discussing calculations of crowd sizes. The programme was devised in the wake of the rather embarrassing disputes concerning the size of the crowd at the recent Inauguration of the President of the USA in relation to previous inaugurations. It was instructive to listen to experts explaining the workings of their calculations, particularly the contribution of one guy who has refined his trade managing crowds on the Hajj. That's obviously a high pressure situation in which the science behind the decisions that need to be made on the ground involves frighteningly high stakes - and has been known to go horribly wrong when that science is misapplied, or just ignored.
The refreshing side of all this is that if you're prepared to do the hard work and think with clarity and logic it is possible to arrive at reasonably definite conclusions and know the margins of error involved. In a world in which there are some who would us believe that somehow 'definites' no longer exist I think this is important for as many people to know as possible. Sometimes in classrooms full of intelligent people a curious sense emerges that everything comes down to a matter of opinion. No, in most areas of human experience this is not the case, and even in those areas which do seem to finally hinge on opinion some opinions are better than others. Mine especially, by the way.