Journey back to the Big Bang

A massive multi-billion euro 'time machine' deep under the Jura mountains could unlock the secrets of the universe - if it doesn…

A massive multi-billion euro 'time machine' deep under the Jura mountains could unlock the secrets of the universe - if it doesn't destroy the Earth first

A €4 BILLION time machine is about to spring to life under the Jura mountains between France and Switzerland. It is a monstrous construction that will re-create conditions as they were just after the Big Bang, that explosive instant when time, space and matter began.

It is an international enterprise that involves dozens of countries and 10,000 participants working with the most advanced device of its kind anywhere in the world. It will produce energy and temperatures not seen in our universe for almost 14 billion years.

The time machine in question is the Large Hadron Collider (LHC) built by Cern, the European Organisation for Nuclear Research. It is a particle accelerator, a device for smashing atomic particles together at colossal speeds. Its sole purpose is to send two beams of stripped-down atoms speeding around the LHC's 27km-long ring in opposite directions before crashing these particles together at velocities approaching the speed of light.

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Particle physicists are interested in such collisions because it teaches them about the constituent parts of the original atoms. Cosmologists are also keen to study these collisions because it provides insights into the formation of the universe and its current structure.

A great irony of this work is that it is at once capable of teaching us a great deal about the smallest of things and the largest of things. Ultimately, the experimental results of these collisions will help bridge the enormous gap that lies between theoretical suppositions about matter and the reality of what matter actually is.

Such a big question needs a big solution and the Large Hadron Collider readily fits that bill. It is physically enormous and will be colossal in terms of energies and temperatures.

The collider is a hollow metal ring, which in turn sits in a tunnel burrowed through rock under the French-Swiss border. The ring provides a channel through which groups of ions - hydrogen atoms stripped of their electrons - will travel.

They will circulate in two "beams", travelling in opposite directions and moving at an astonishing 99.99999 per cent of the speed of light. A single circuit goes by in less than the blink of an eye, 89 millionths of a second, and the two beams will complete 11,245 laps each second.

Needless to say, it takes something special to keep these two beams moving so quickly and on track. The collider accomplishes this with a sequence of 1,600 powerful electromagnets. These, however, are no ordinary magnets.

Their 10,000 tonnes of iron - more than is built into the Eiffel Tower - are wound with very fine niobium-titanium wires bundled together from filaments. If the filaments were unravelled, there would be enough wire to reach to the sun and back five times, with enough left over for a few trips to the moon.

The wound iron, in turn, must sit in the largest refrigerator in the world, one that chills things down to a startling -271.3 degrees, the temperature at which helium becomes a liquid. At this temperature, the niobium-titanium wires begin to "superconduct", that is carry electricity without resistance, allowing the magnets to deliver enormous magnetic fields.

ALL OF THIS infrastructure is necessary because, when it comes to accelerators, size matters. Higher energies deliver more information. And there is nothing to compare when it comes to the collider.

Physicists measure energy in "electron volts". Things change, however, when you talk about accelerator energies. They pass through millions and billions of electron volts and beyond. The highest accelerator energies achieved, by Fermilab in the US, stand at a million millionelectron volts.

When the Large Hadron Collider starts up, each of its two hydrogen ion beams will carry seven times more electron volts than Fermilab, so that the combined beams will carry 14 million million electron volts, about the energy of two speeding locomotives colliding head-on. Yet, the thing to remember about these energies is that they are not being delivered across the full front of a locomotive, but at less than the point of a needle - down, in fact, to the size of an atom.

There is more. Once in full service, the collider will also circulate beams containing stripped lead ions and collide them with the hydrogen beam. These will deliver collision energies of 1,150 million million electron volts.

These collisions won't start for some months but even so the LHC has reached a milestone. Next Wednesday, Cern scientists will finally switch on the full accelerator and send a beam of particles racing around the collider, the first full "circuit test" of its beam control systems.

"Our aim for the 10th is to get a beam to make one full turn of the 27 kilometres and that would be a breakthrough," says Irishman Steve Myers, head of Cern's accelerators and beams department, a role which has given the Belfast man the nickname the Lord of the Ring. Much remains to be done before this test can occur, he says. "We are putting on the final touches and there is still technical work to be done and hardware tests. It is going to be tight but we should be ready for the first circuit test on the 10th."

To describe the team at Cern as "excited" about the circuit test is a serious understatement, he suggests. "After so many years we can now see the end of construction and the beginning of operations."

A satisfying part of the buzz is not knowing how far the experiments on the day might go. Successfully accomplishing a single circuit in one direction would be a monumental event, but they may take the next step. "We might send a beam in the opposite direction that afternoon. We won't know until we get there on the 10th."

And they may go further, establishing the first circulating beam in the Large Hadron Collider.

BUT TO BORROW a line from the classic film, Marathon Man, "Is it safe?" Some physicists have theorised that the enormous energies generated inside the collider could bring about no less than the destruction of the Earth.

The fear arises because of cosmology research into something called string theory, explains Dr Brian Dolan, a lecturer in NUI Maynooth's mathematical physics department and a research associate at the Dublin Institute for Advanced Studies (DIAS).

String theory allows for multiple dimensions and the idea holds that the collider could reach high enough energies to trigger exceptional gravitational fields in alternate dimensions, which in turn could produce "mini black holes" inside the machine. These could consume not just the collider but the Earth and anything else in our cosmic neighbourhood.

Dr Dolan is dismissive of the notion, however. The Earth has already experienced these high energies, delivered naturally by cosmic rays arriving from deep space to spray the upper atmosphere. None of these has triggered mini black holes.

"One of the biggest risks is if the superconducting magnets go critical," he says. These contain enough potential energy to melt 50 tonnes of copper if released in a single event.

A theorist who anxiously awaits the first experimental data from the collider, Dr Dolan is happy to see the higher energies. "It is like mountaineering, once you get to the top of one peak you see another and want to get to the top of that. By seeing what comes out [of collisions] you get an idea of what things are made of and by going up to higher energies you get finer and finer detail."

Dr Ronan McNulty of University College Dublin knows exactly what Cern expects to get out of the collisions. His research group is directly involved in one of the key experiments, called LHCb (which will study antimatter).

UCD is a major collaborator on LHCb although Ireland is not a paying member of Cern. This arises because of Dr McNulty's direct connections with LHCb collaborators in the UK.

Dr McNulty heads the only experimental research group of its kind in Ireland. "Even if you are a theorist, you have to have a collider and detectors to prove your theories. They also need to interact with experimental people to see what is achievable, can we reach the necessary energies," he says.

For this reason he regrets that Ireland has yet to become a member of Cern. "If you are not involved in Cern, you will end up with people with ideas but no way of validating them. Because we are not members of Cern we don't have the right to spend time out there or send out students."

There are also other theorists at DIAS, Dublin City University, NUI Galway, NUI Maynooth and at Trinity College Dublin. All hope for the day when Ireland becomes a full member, opening up the opportunity to participate in this research.

It doesn't get much more profound than revealing the secrets of the universe and the collider will help in achieving this. There are six major experiments attached directly to the collider, each carrying detectors that will capture the elusive, momentary results of the collisions.

LHCb, which McNulty is involved in, for example, will study anti-matter and why our universe has so little of it. The Big Bang should have delivered equal amounts but now we only see ordinary matter. Why?

Another device, Atlas, will look at the mysterious dark matter and dark energy. Ordinary matter, the stuff we are made of, makes up only about 4 per cent of the universe, with 23 per cent an unknown substance dubbed dark matter. That leaves a huge 73 per cent attributed to dark energy, the strange force that seems to be spreading our universe out further and further.

PERHAPS THE MOST celebrated hoped-for discovery from the Large Hadron Collider is the Higgs boson or subatomic particle. All of physics is dependent on what is known as the Standard Model, a theory which attempts to encompass all of the natural forces in the universe. These include forces which hold atoms together and gravity which effects the motions of stars and planets.

The Standard Model has predicted many missing particles that accelerators at Cern and Fermilab have finally confirmed, including the W and Z bosons found by Cern in 1983 and a particle called the top quark found by Fermilab in 1995.

The Higgs boson has remained unconfirmed because no accelerator had the power to reveal it until now. The LHC should be able to produce Higgs bosons, if indeed they do exist.

CERN EXPLAINED THE QUEST TO UNRAVEL THE MYSTERIES OF THE UNIVERSE

What is Cern?

Cern is the European Organisation for Nuclear Research, not as in nuclear power but as in atomic nucleus. Cern studies the component parts of atoms by smashing them together at high speed in devices known as particle accelerators.

What is the LHC?

The Large Hadron Collider is Cern's latest particle accelerator, the most powerful yet built. It will accelerate two separate beams of particles almost to the speed of light (about 3x108 metres or 186,000 miles per second) and then collide them, recording the event to see what happens.

Why is it so special?

Size matters when it comes to particle accelerators because you need a large accelerator to reach high energies and the higher the energy the better. LHC is a doughnut-like ring 27km around, built in a tunnel under the French-Swiss border. The ring has all the air sucked out of it to achieve a vacuum 10 times lower than that experienced on the moon. Twin beams will circulate in opposite directions through this vacuum at 99.99999 per cent of light speed, kept on track by 1,600 powerful electromagnets. These are chilled to -271 degrees, allowing them to "superconduct", producing exceptionally powerful magnetic fields. Each beam will have the energy of a car travelling at 1,600km/h, imparting incredible energies when the particles collide. LHC will first deliver energies seven times higher than existing records, but could reach energies more than 1,150 times higher.

Why is it in the news?

The LHC is now almost ready for its first major test. On Wednesday, Cern staff will send a beam of particles (hydrogen ions, atoms that have been stripped of their electrons) on a first full lap of the LHC ring. At near light speed this will take just 89 millionths of a second. If things go well, staff may also send a beam for one lap in the opposite direction and may also try a "circulation test", sending a beam circulating around the ring at 11,245 laps per second.

How much did LHC cost?

The LHC itself cost about €3 billion, but the total, including the related recording devices and computer equipment, rises to about €4.2 billion.

Who paid for it?

Cern's member countries pay annual fees and others such as the US and Japan also contribute,

the payback being that the country participates directly in the research going on at Cern. Unfortunately, Ireland is one of only a small number of European countries that are not Cern members. Not joining makes it much more difficult for Irish scientists to take part.

What benefits come out of this?

More than you would think. The worldwide web arrived when Cern scientists needed a way to send vast amounts of data to one another. Medical devices used in cancer treatments arose from accelerator designs. Data coming from Cern helps us understand atomic structure and the nature of the universe itself.