Science

THE WORLD'S largest physics experiment is about to spring to life, recreating on earth temperatures and energies not seen since the Big Bang that created our universe almost 14 billion years ago, writes Dick Ahlstrom

It is physically big, occupying an underground tunnel 27km long, and financially enormous, with a pricetag of just over €6 billion.

We are talking of course about the Large Hadron Collider (LHC), an enormous atom smasher built by Cern, the European Organisation for Nuclear Research. Under construction for about a decade and planned for twice as long, the LCH is scheduled on September 10th to send its first atomic particles spinning around the underground tunnel at 99.999 per cent of the speed of light.

The feat will mark yet another milestone for the huge enterprise, and another step on the way to the first atomic collisions which planners hope will come before the end of the year.

The LHC is bigger and more powerful than any collider yet built, and will create unimaginably high energies. For example, it will generate temperatures reaching 100,000 times that found at the centre of the sun. And, at full power, it will smash beams of atomic particles together to produce energies equivalent to that generated by two 400-tonne locomotives colliding, head on, at 150km/hour.

Everything about the LHC staggers the imagination. It almost has to, given it is expected to help scientists answer some of the most complex - and yet disarmingly simple - questions.

Why does matter exist, and why does it have mass? What forces hold it together? Why can we only see about 4 per cent of all the matter that makes up the visible universe? What is the invisible matter and energy out there that makes up the remaining 96 per cent?

These are big questions, that lie at the very heart of our understanding of everything around us. And obviously it was going to take a huge machine to answer such huge questions. Big business usually only involves big numbers, but when it comes to atom smashers, big business also means physically big.

The scale of the enterprise is staggering. It required the construction of a 27km circular tube, through which twin high energy beams of matter will circle at more than 11,000 times per second. The beams are controlled using 1,800 giant magnets which are kept in a bath of liquid helium and chilled down to a frigid minus-217 degrees to help them "superconduct" and deliver more power. These magnets alone required 10,000 tonnes of iron, more than that found in the Eiffel Tower.

There were countless technical and engineering hurdles that had to be overcome to make the whole thing work. All of these required people power, expertise and equipment that kept businesses running, sparked new discoveries that could be commercialised and created jobs, companies and economic activity for those taking part. For this reason, the LHC has been a magnet for business, enterprise and innovation.

It has involved an input from 10,000 scientists and engineers from 500 academic institutions and industrial companies. All of this effort generated salaries, company income and profits for those involved.

The heavy construction phase is over, and now the scientists will take centre stage as they smash atoms to see what happens and watch for new atomic particles that will help answer fundamental questions of physics. But just what's in it for the rest of us?

Quite a bit, really. Staff at Cern were central to the development of the world wide web. They needed a way to distribute the vast quantities of data that was flowing from the LHC's atom-smashing predecessor, the Large Electron-Positron Collider (LEP).

The internet emerged as a way to link computers, in order that the groups conducting experiments at Cern could share their results and data.

Fast forward to the LHC and the need to send even more data. The new collider and the suite of six experiments attached to it will produce enough data to fill about 100,000 high-capacity DVDs every year. The internet is ideal for the distribution of large volumes of data, but this kind of throughput would be a challenge.

The answer to this problem is the Grid, a dedicated network designed to handle the data output coming from the LHC.

The world wide web started as a way to facilitate scientific research and then transformed into what we see today, more a tool of commerce than anything else. The Grid, due to be fully operational by October of this year, will also start life as a scientific tool. But with its huge interconnectivity and carrying capacity, where will it ultimately take us?