CHANCES are if you're reading this that the world didn't end at 8.30am today.

The planet didn't snap, crackle and pop during breakfast, the earth didn't break free of its axis. But, then, why would it?

Just as my colleagues on Channel M were saying good morning to Greater Manchester, the men and women in white coats were preparing to switch on the sci-fi sounding Large Hadron Collider on the French/Swiss border.

At precisely 9.30am Central European Time (they're an hour ahead) scientists will have fed the first full beam of protons into a 27km (17 mile) long tunnel, pushed them to a velocity just short of light speed using powerful magnets - and then smashed them together with all the enthusiasm of naughty schoolboys playing conkers.

Just as intriguing is why they should bother.

It's a complicated business, best described as a bid to discover the tiniest possible building blocks of absolutely everything in the entire universe.

The theory goes that the faster each particle collides with another, the more devastating the impact, and the greater the potential for the men in white coats to identify infinitesimal bits of matter which they previously didn't know existed.

Given the recent history of atomic events among the scientific community - Hiroshima, Nagasaki, Three Mile Island, to mention just a few - it's perhaps little wonder that some of the world's boffins believe their colleagues are, quite literally, playing with fire.

Potential

True enough, the LHC might help to label the estimated 96 per cent of all matter in the universe which is still to be identified, unlocking the potential for time travel, intergalactic voyages and who knows what else.

But there is also the potential for an angry reaction when one bit of previously uncharted matter crosses the path of another.

Many members of the team presiding over the so-called 'end-of-the-world' experiment are said to have received death threats.

Some opponents launched legal action in a bid to pull the plug on the LHC, which has taken £4.4bn and decades to build.

Among the white coats is Manchester University professor Brian Cox, whose credentials as a figure in a Hitch Hiker's Guide To The Galaxy-style turn of events couldn't be more certain.

Before embarking on his scientific career, Cox was a keyboard player with the chart-topping band D:Ream, best known for the hit single and Labour Party anthem Things Can Only Get better.

By the time the band split in 1997, Brian was Dr Brian, having gained a first class honours degree in physics from Manchester University and a PhD in high energy particle physics in Hamburg.

He now splits his time between Manchester and a laboratory in Geneva, where he is in charge of the international project which created the ATLAS detectors, which allow scientists to assess what is happening inside the LHC.

He has little time for people who think the world is going to end as a result of the LHC experiment, even using some pretty non-scientific language to describe the meddling menaces who have planted 'end is nigh' theories in normally sane heads.

"I don't think anything bad of the housewife in Macclesfield who has listened to all this nonsense and thinks that something terrible might happen," the surprisingly down-to-earth particle physicist says, speaking a few days before switch-on.

High stakes

"But those conspiracy theorists, the one or two scientists who disagree with absolutely every other scientist in the world about the risks involved, and who have started this silly debate unnecessarily, they really are t****.

"The point is, it's not ridiculous for people to be concerned about new scientific discoveries, including GM crops and genetic engineering, with some level of trepidation.

"But when it comes to the LHC, every single scientist in the world who knows anything about it, says that there's no problem.

"These idiots have caused us problems and cost us money. By threatening to blow the place up, they've forced us to hire loads of extra security.

"In fact, if one of these particles were to hit you, you wouldn't feel it. It would do you less harm than a mosquito bite."

However, Prof Cox does concede that the stakes are high.

Built to 1980s designs and at a cost of £4.4bn, the LHC will only have been properly put through its paces for the first time today. "Things might not work quite how we expect," Prof Cox adds. "It will be a tense time."

If things do go according to plan, the resulting data is expected to trickle in over months and years and it could be a long time before the significance of any findings is established.

Crucially, students at Manchester University, which built part of the ATLAS detectors, will be among those given access to the data.

Cox says that it could be a Manchester student who makes a discovery on a par with man's realisation the world was round or that the planets orbit the sun.

"We are trying to find the building blocks of the universe and what sticks them together. This is an opportunity to take the next step in research which has stood still for decades.

"Constructing the Large Hadron Collider has pushed mankind's abilities to the same extent that the moon landings did. We're only just capable of doing what we've done."

Professor Cox will broadcast live on Radio 4 throughout the day today. A one-off radio edition of the sci-fi show Torchwood has been produced to mark the historic switch-on, also on Radio 4 today.