Civilisation is built on Physics (alas), not on Business Studies You remember being at school, and looking at the timetable with a lurching horror. You've just been doing something cushy, like playing football or snoozing through a movie about global warming in Double Geography. Or perhaps, if you have been really cunning with your options, you have been making biscuits with lovely Mrs Sindall in Double Cookery. And then you look at your schedule to see how your teachers propose to divert you for the last two periods of the day; and a shadow passes before your face and your hair stands on end, as though you had been plugged into a van der Graaf generator. Omigosh, you say, it's Double Physics, and there's no way out. It's an hour and a half of struggling to understand what's watt, and who's an amp when he's at ohm, and frankly you'd do almost anything to skive. You'd rather be dipped in liquid helium and hit with a rubber mallet; you'd rather be locked in a cyclotron and humanely dispatched with subatomic bullets; you'd rather give a personal demonstration of the properties of potassium cyanide, because the only thing you can remember about Physics (or is it Chemistry?) is a poem to the effect that "Sir Humphrey Davey /Abominated Gravy;/ He lived in the odium/ Of having discovered sodium" - an odium you believe to be richly deserved. And as the Physics keenies take out their lavishly illustrated homework, with swotty little drawings of electric circuits, you have only three options. advertisement You can throw a sickie and bunk off to the local chip shop. You can sit there in a coasting daydream, looking forward to the next Double Cookery, occasionally making discreet grunts of assent and endeavouring not to catch the teacher's eye. Or else you can try. You can really try. You can wait for the moment, perhaps five minutes into the class, when you cease to understand what the teacher is saying; you can wait for the clouds to descend, as they will - even on the cleverest - with all the inevitability of an English August, and then, instead of giving up, you can battle on. You can strain all your faculties until your brain feels as though it is about to give birth. You can take out your panga and hack hack hack through the dense undergrowth of your stupidity until - kazam! - you get it; for one brief, shining instant, you stumble into a clearing. The clouds part and you can see straight up to the heavens and the fundamental facts of the universe, and, in that instant, you will look on your Physics teacher with new eyes and, instead of a torturing old pedant, you will see a prophet and a man blessed, like the first great atomist, because he was able to understand the Causes of Things. Of course, if you are anything like me, you will find that your Physics weather forecast is still cloudy-bright, and that the fog soon envelops you again. But you would surely agree that, in that delirious moment of understanding, you have had more intellectual pleasure than in all the long, happy hours of doing the softer subjects. In your heart, you know that grasping one hard point in Physics beats all the cake-baking and Religious Studies and making up stories for Media Studies (an excellent preparation for the real thing, by the way) and pretending to be a baked bean in Drama. The trouble is that, in your heart, you also know that Physics means pain. It means moments of palpitating panic when you may be asked to explain something you don't get, and above all you know that, in Physics, it is much harder to get an A at A-level. Worse still, your teachers know that, and partly because we live in a mad world of school league tables, where an A in Drama is apparently as valuable as an A in Greek and an A in Mathematics is as good as an A in Business Studies, there has been a huge incentive to steer children away from the crunchy subjects, and towards the softer options, so that, every year, a bigger crop of A grades can be presented to the ludicrous tithe barn of the Department of Education, and every year ministers can make absurd speeches of congratulation, redolent of the 1950s Soviet Union hailing the record production of grade A* tractors in the factories of Minsk. No one really believes in this equivalence of A-levels. Children don't believe it; we all know that the guy who comes top in maths is smart; the guy who comes top in English is smart; and the girl who comes top in both is out of sight. We don't have the same respect for Business Studies, nor does British business, and nor do top universities. So thank heavens for Cambridge, which yesterday had the guts to inform applicants that they would need A-levels in at least two crunchy subjects, and that an application based on History, Business Studies and Media Studies would not do. We must stop this flight from the crunchy subjects, not just because it is slowly denuding the country of scientists - it is hardly surprising that 30 per cent of university Physics departments have closed in the past eight years, when the number of Physics candidates at A-level has slumped from 46,606 in 1985 to 28,119 in 2005. We must stop this disaster because we are cutting the roots of our civilisation: when I think what has happened to Latin and Greek and modern languages in the maintained sector, I alternate between rage and black depression. We must encourage the uptake of crunchy subjects with an equitable system of financial incentives not just for those who teach them but also - why not? - for the students who excel in them; and we must do it as a simple matter of social justice. Cambridge has revealed which subjects it really values. The tragedy is that the A grades in the sciences, advanced maths and languages are increasingly ghettoised in the grammar schools and the independent sector, and when the Blair Government is brought to the bar of history, it will be one of the single heaviest charges that, by failing to tackle the crunchy subjects in state schools, a Labour government presided over a shocking decline in social mobility.