A Giant Takes On Physics’ Biggest Questions
Valerio Mezzanotti for The New York Times
At Cern, the Large Hadron Collider could recreate conditions that last prevailed when the universe was less than a trillionth of a second old. Above is one of the collider's massive particle detectors, called the Compact Muon Solenoid.
Three decades after it was conceived, the world's most powerful physics experiment is ready to be powered up.
Engineers will attempt to circulate a beam of particles around the 27km-long underground tunnel which houses the Large Hadron Collider (LHC).
The £5bn machine is designed to smash particles together with cataclysmic force, revealing signs of new physics in the wreckage.
This will re-create conditions in the Universe moments after the Big Bang.
But it has not been plain sailing; the project has been hit by cost overruns, equipment trouble and construction problems. The switch-on itself is two years late.
The collider is operated by the European Organization for Nuclear Research - better known by its French acronym Cern.
The vast circular tunnel - the "ring" - which runs under the French-Swiss border contains more than 1,000 cylindrical magnets arranged end-to-end.
The magnets are there to steer the beam - made up of particles called protons - around this 27km-long ring.
Eventually, two proton beams will be steered in opposite directions around the LHC at close to the speed of light, completing about 11,000 laps each second.At allotted points around the tunnel, the beams will cross paths, smashing together near four massive "detectors" that monitor the collisions for interesting events.
Scientists are hoping that new sub-atomic particles will emerge, revealing fundamental insights into the nature of the cosmos.
Major effort
"We will be able to see deeper into matter than ever before," said Dr Tara Shears, a particle physicist at the University of Liverpool.
"We will be looking at what the Universe was made of billionths of a second after the Big Bang. That is amazing, that really is fantastic."
The LHC should answer one very simple question: What is mass?
 | LHC DETECTORS ATLAS - one of two so-called general purpose detectors. Atlas will be used to look for signs of new physics, including the origins of mass and extra dimensions CMS - the second general purpose detector will, like ATLAS, hunt for the Higgs boson and look for clues to the nature of dark matter ALICE - will study a "liquid" form of matter called quark-gluon plasma that existed shortly after the Big Bang LHCb - Equal amounts of matter and anti-matter were created in the Big Bang. LHCb will try to investigate what happened to the "missing" anti-matter |
"We know the answer will be found at the LHC," said Jim Virdee, a particle physicist at Imperial College London.
The currently favoured model involves a particle called the Higgs boson - dubbed the "God Particle". According to the theory, particles acquire their mass through interactions with an all-pervading field carried by the Higgs.
The latest astronomical observations suggest ordinary matter - such as the galaxies, gas, stars and planets - makes up just 4% of the Universe.
The rest is dark matter (23%) and dark energy (73%). Physicists think the LHC could provide clues about the nature of this mysterious "stuff".
But Professor Virdee told BBC News: "Nature can surprise us... we have to be ready to detect anything it throws at us."
Full beam ahead
Engineers injected the first low-intensity proton beams into the LHC in August. But they did not go all the way around the ring.
Now they will attempt to pass a proton beam around the full circumference of the LHC tunnel.
"We see how far the beam will go," said Steve Myers, head of the accelerator and beams department at Cern, "we will try and make it go round the full 27km sometime on Wednesday morning."
Superconducting magnets are cooled down using liquid helium
Engineers will be on the lookout for any potential problems: "There are on the order of 2,000 magnetic circuits in the machine. This means there are 2,000 power supplies which generate the current which flows in the coils of the magnets," he told BBC News.
"If any single one of them has got the wrong polarity, or has the wrong calibration constant, or whatever, then the beam will not go round.
"If, in any of the channels [in the magnets], there is any piece of debris - it is a very small channel - then the beam will not go round."
Grabbing protons
Mr Myers has experience of the latter problem. While working on the LHC's predecessor, a machine called the Large-Electron Positron Collider, engineers found two beer bottles wedged into the beam pipe - a deliberate, one-off act of sabotage.
The culprits - who were drinking a particular brand which advertising once claimed would "refresh the parts other beers cannot reach" - were never found.
If all goes well, and the beam makes one turn, engineers will "close the orbit", allowing the beam to circulate continuously around the LHC.
Engineers will then try to "capture" it. The beam which circles the LHC is not continuous; it is composed of several packets - each about a metre long - containing billions of protons.
The protons would disperse if left to their own devices, so engineers use electrical forces to "grab" them, keeping the particles tightly huddled in packets.
Once the beam has been captured, the same system of electrical forces is used to give the particles an energetic kick, accelerating them to greater and greater speeds.
After Wednesday's test, engineers will need to get two beams running in opposite directions around the LHC. They can then carry out collisions by smashing them together.
Long haul
The idea of the Large Hadron Collider emerged in the early 1980s. The project was eventually approved in 1996 at a cost of SFr2.6bn.
However, Cern underestimated equipment and engineering costs when it set out its original budget, plunging the lab into a cash crisis.
Cern had to borrow hundreds of millions of euros in bank loans to get the LHC completed. The current price is nearly four times that originally envisaged.
During winter, the LHC will be shut down, allowing equipment to be fine-tuned for collisions at full energy.
"What's so exciting is that we haven't had a large new facility starting up for years," explained Dr Shears.
"Our experiments are so huge, so complex and so expensive that they don't come along very often. When they do, we get all the physics out of them that we can."
Steve Myers said engineers would break out the champagne if all went to plan. But a particular brand of beer will not be on the menu, he said.
John Ellis, a Cern physicist. "If you take astrophysics seriously, there has to be some unseen stuff out there," he said.
Physics, after all, is supposed to be a cerebral pursuit. But this cavern almost measureless to the eye, stuffed as it is with an Eiffel Tower’s worth of metal, eight-story wheels of gold fan-shape boxes, thousands of miles of wire and fat ductlike coils, echoes with the shriek of power tools, the whine of pumps and cranes, beeps and clanks from wrenches, hammers, screwdrivers and the occasional falling bolt. It seems no place for the studious.
The physicists, wearing hardhats, kneepads and safety harnesses, are scrambling like Spiderman over this assembly, appropriately named Atlas, ducking under waterfalls of cables and tubes and crawling into hidden room-size cavities stuffed with electronics.
They are getting ready to see the universe born again.
Again and again and again — 30 million times a second, in fact.
Starting sometime next summer if all goes to plan, subatomic particles will begin shooting around a 17-mile underground ring stretching from the European Center for Nuclear Research, or Cern, near Geneva, into France and back again — luckily without having to submit to customs inspections.
Crashing together in the bowels of Atlas and similar contraptions spaced around the ring, the particles will produce tiny fireballs of primordial energy, recreating conditions that last prevailed when the universe was less than a trillionth of a second old.
Whatever forms of matter and whatever laws and forces held sway Back Then — relics not seen in this part of space since the universe cooled 14 billion years ago — will spring fleetingly to life, over and over again in all their possible variations, as if the universe were enacting its own version of the “Groundhog Day” movie. If all goes well, they will leave their footprints in mountains of hardware and computer memory.
“We are now on the endgame,” said Lyn Evans, of Cern, who has been in charge of the Large Hadron Collider, as it is called, since its inception. Call it the Hubble Telescope of Inner Space. Everything about the collider sounds, well, large — from the 14 trillion electron volts of energy with which it will smash together protons, its cast of thousands and the $8 billion it cost to build, to the 128 tons of liquid helium needed to cool the superconducting magnets that keep the particles whizzing around their track and the three million DVDs worth of data it will spew forth every year.
The day it turns on will be a moment of truth for Cern, which has spent 13 years building the collider, and for the world’s physicists, who have staked their credibility and their careers, not to mention all those billions of dollars, on the conviction that they are within touching distance of fundamental discoveries about the universe. If they fail to see something new, experts agree, it could be a long time, if ever, before giant particle accelerators are built on Earth again, ringing down the curtain on at least one aspect of the age-old quest to understand what the world is made of and how it works.
ng,” said a Cern physicist, John Ellis, “in some sense then, we theorists have been talking rubbish for the last 35 years.”
Fabiola Gianotti, a Cern physicist and the deputy spokeswoman for the team that built the Atlas, said, “Something must happen.”
The accelerator, Dr. Gianotti explained, would take physics into a realm of energy and time where the current reigning theories simply do not apply, corresponding to an era when cosmologists think that the universe was still differentiating itself, evolving from a primordial blandness and endless potential into the forces and particles that constitute modern reality.
She listed possible discoveries like a mysterious particle called the Higgs that is thought to endow other particles with mass, new forms of matter that explain the mysterious dark matter waddling the cosmos and even new dimensions of spacetime.
“For me,” Dr. Gianotti said, “it would be a dream if, finally, in a couple of years in a laboratory we are going to produce the particle responsible for 25 percent of the universe.”
Halfway around the ring stood her rival of sorts, Jim Virdee from Imperial College London, wearing a hardhat at the bottom of another huge cavern. Dr. Virdee is the spokesman, which is physics-speak for leader, of another team, some 2,500 strong, with another giant detector, the poetically named Compact Muon Detector, which was looming over his shoulder like a giant cannon.
In the beginning God covered the earth with broccoli, cauliflower and spinach, with green, yellow and red vegetables of all kinds so Man and Woman would live long and healthy lives.
Home is where you hang your @.
We will be looking at what the Universe was made of billionths of a second after the Big Bang 
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