Last weekend, my eight-year-old climbed into the cockpit of a Spitfire to have his photograph taken at the Southport Air Show. No sooner was he out of the plane's bucket-seat than his mother was climbing in for a picture. She was followed by her father.

I ought not to have been surprised. My son's granddad was a radio operator in the RAF, and my wife had followed in her father's footsteps, ending up in the office of the Chief of the Air Staff. Whether by nature or nurture, the smell of aircraft fuel is clearly in the blood.

Children pick up all manner of propensities by osmosis from the family in which they grow up. So it comes as something of a shock when they strike off into territory that is distinctly their own. The airwaves yesterday morning were buzzing with the build-up to the switch-on of the Large Hadron Collider at Cern. The suppressed schoolboy excitement in the air on the Today programme was picked up by my son, who began to ask those simple questions to which there are no simple answers.

Just as my scientific illiteracy was about to be exposed, Radio 4 trailed a programme promising to probe not just this great scientific event, but also the shape of the universe and validity of the Big Bang. "Can I listen to that tonight?" my son asked, while struggling to do his school tie.

As he bustled off to a day in the classroom, I resolved to pay a little more attention than my arts education had hitherto inclined me to do. I had just a few hours to come up with some plausible scientific answers. I clicked on to the net, but within minutes had been diverted into a metaphysical musing on the gulf of incomprehension between the two cultures of science and the arts. Why, as C P Snow asked half a century ago, are sophisticated arts graduates not as embarrassed by their ignorance of the second law of thermodynamics as a scientist would be if he didn't know the plot of Hamlet? Those with an arts education know as much about science as did their Neolithic ancestors.

Guilty as charged, I conceded, before surfing to a site exploring the postmodernist update of this divide – between those who insist that science allows us to make objective, empirical statements about the world, and those constructivists who insist that the scientific method is embedded within language and culture and is, in practice, a thinly disguised plot to maintain a patriarchal white élite in power over women, minorities, and animals.

But this was not getting me anywhere near being ready for the return home of my inquisitorial son. I focused on the simple stuff. The Big Bang is likely because we observe the universe to be expanding; run the clock backwards and you must get to a point where it could contract no further – a day without a yesterday. So far, so good.

Then there is dark matter, the stuff that keeps the stars apart in space where there's no gravity. Hmmm. This unlocking the secrets of the universe business was going to be tricky. I turned on the telly. BBC News 24 was having the same problem. "I wish I'd paid more attention at school," the anchor was saying.

The TV people took refuge in circumstantial trivia. Why were most engineers men, whereas there were quite a few women among the physicists? See how the scientists are taking photos of one another against plasma screens recording the historic data as the particles complete their first 27km loop. A chap from the Daily Mail came on and asked the scientists' leader if the day made him proud to be a Welshman. "I'm always proud to be a Welshman," he replied, looking more perplexed than when asked tricky scientific questions.

In the end, it was the metaphors that hit home. Lining up the particles had to be as precise as firing two needles at one another across the Atlantic and getting them to collide. It was all technologically trickier than putting men on the Moon. Or, best of all, in an attempt to explain how particles get heavier as they get faster, was the image of a person making their way across a room at a cocktail party. If they are unimportant, no one stops them; if they are Margaret Thatcher (which dates this simile) people gravitate to her, increasingly slowing her progress. The party guests, we were told, were the Higgs bosons, and Mrs T was a top quark.

We always suspected as much, especially since, in the high days of Thatcherism, funding to Cern was slashed because it was of no practical use. Cern then came up with the World Wide Web, as a by-product of its work, and is now perfecting The Grid, a system that will link computers across the globe into a single, all-powerful processing union.

Not that the scientists are aiming at anything so practical. This most challenging machine in the history of humanity may produce nothing at all of practical use in its search to understand the very fabric of the universe.

"It will be as pointless as a symphony or a great painting," one scientist said. Perhaps the worlds of arts and science are not so far apart after all. Maybe I'll ask my eight-year-old.