"Not long to go now", said John Humphrys, a little after seven yesterday. "One hour and 17 minutes and counting". That was how long the Today audience had to wait until the Large Hadron Collider at Cern would be switched on, an event of such weight that the Radio 4 schedules and presenter roster had been pulled out of shape by it.

Andrew Marr had been sucked in from Monday morning to anchor the live reports from Geneva and Evan Davis and Humphrys were swirling in an orbital cloud of bemusement, occasionally breaking in to address bread-and-butter issues that weren't going to matter a great deal if the world really did disappear into a black hole.

And as we waited for the critical button-push, we had the opportunity to contemplate another experiment in head-on collision; the engineered impact between the immediacy of Britain's best live current affairs programme and the unyielding abstractions of cutting-edge particle physics.

Marr was at pains to remind us that fundamental questions were at stake here: "Why is John Humphrys heavy?" he asked. "Or to put it another way, why do we all have mass? We don't know. About 4 per cent of the universe is matter. What about the other 96 per cent? Are there other dimensions? These are huge questions which are all going to be... or may be... resolved by what happens."

But not, sadly for Today, by 8.59am. Tasked with bridging the gap between the average listener's understanding of particle physics and that of the scientists he was surrounded by, Marr laboured heroically. "The protons are kind of champing at the starting gate," he said, summoning an image of horses pawing the ground with their hooves. Soon they had climbed into Zeros and wrapped rising sun scarves round their heads: "They're going to behave I suppose a bit like kamikaze aircraft, eventually they're supposed to crash into each other."

First though the machine had to be turned on, a button press which caught Marr in mid-sentence. "Oh! It's happened!" he said. "The beams are into the collider – a historic moment for world science." After which, apparently we had to wait for the next historic moment, which would be along in just a few minutes, all being well: "This is the final barrier being removed and then there's five seconds during which nobody knows quite what's happening", Marr said – vastly underestimating the quantity of bafflement that the event was generating. Then there was a hiccup: "They've stopped the beam," said Marr. "I don't entirely understand why... but it's got something to do with a dump."

Then we heard a French scientist counting down – and another spatter of applause as a screen flickered into life. "This is one eighth of the job done so far," said a British scientist proudly, as champagne corks popped. Odd how one eighth of an indubitably historic moment can sound almost the same as an anti-climax.