It's like a new Formula One car, excited scientist says of accelerator

GENEVA - The largest and most powerful particle accelerator in the world successfully went into operation outside the Swiss capital yesterday, bringing scientists one step closer to discovering the building blocks of the universe and showing that if you want to discover the smallest particles, you have to build the biggest machine.

"It's a fantastic moment," said Lyn Evans, project leader for the Large Hadron Collider. Coming in at about $8 billion, the project is considered the most expensive scientific experiment in history.

"We can now look forward to a new era of understanding about the origins and evolution of the universe," he said.

The historic day, which began at 10:30 A.M. Israel time, was long-awaited by thousands of physicists and engineers at CERN, the European Organization for Nuclear Research, whose laboratory hosts the collider, which is about 100 meters underground.

The scientists involved have been working for more than 15 years on building the particle accelerator and detectors considered to be major technological achievements. A proton beam was sent around the circular collider; working from a control room above, scientists directed it to various stations along the 27-kilometer track. Dozens of scientists crowded into the control room for the ATLAS detector, the last stop on the proton-beam track, in a state of high expectation. Only a few sat down. Many of them walked around between tables and looked at computer screens to see the beam making its slow progress. It came close to ATLAS, and, as planned, the proton beam hit an obstacle some 150 meters before the detector.

As a result of the collision, tens of thousands of muons - a heavier sibling of the electron - reached the detector. A large screen on the wall showed green and red hits, and the room was filled with applause, happy shouts and even a few tears of joy. For the scientists present, the moment presented the first evidence that the detector works as planned.

ATLAS technical coordinator Marzio Nessi, an Italian physicist who had worked on the project for more than 15 years, just stood on the side and smiled. Looking around the room, he pointed out all the happy people and said they had all contributed significantly to ATLAS and know they have a part in the process. Nessi, by contrast, seemed calm. If I got excited every time something happened, he said, I would have a heart attack every two days.

Some 2,000 scientists from nearly 40 countries, including Israel, are involved in the ATLAS project. ATLAS is a large, general-purpose particle detector used to look for signs of new physics, such as the origins of mass and extra dimensions. It is one of six detectors used in the particle accelerator.

On the heels of the successful first proton beam came several others. In the coming days the scientists will accelerate and concentrate the beams, and in the next few weeks they will start colliding them. Although this collider is seven times more powerful than the second-most powerful particle accelerator in the world, it is not expected to reach its full power before the winter.

The torch is now being passed to physicists who will be collecting the data from the planned collisions. Only after a few months, or possibly even years, of data collection and analysis are the initial findings expected to be released.

Nessi compared the particle accelerator to a new Formula One racing car. The good news, he said, is that the car works and is at the forefront of technology. But now, he added, we have to learn how to drive it and find out where we can go.

"What's exciting about this experiment, more than with previous accelerators, is that we don't know exactly what we're going to get from the collisions," said Hebrew University Prof. Eliezer Rabinovici, who heads an Israeli committee responsible for liaison with CERN. "Almost anything can happen."

Scientists are hoping to find the Higgs boson, popularly known as the "God particle," because it is a hypothetical particle that has not yet been observed but is predicted to exist, and would help explain how elementary particles that have no mass could cause matter to have mass. Theoretical physicists are also looking out for dark matter, the discovery of new particles and evidence to back up string theory, a theory of gravity that attempts to provide a unified description of the structure of the universe.

By yesterday afternoon, the physicists at CERN stood out by their broad smiles and heartfelt handshakes. They gathered on the lawns, where old particle accelerators had been set up like sculptures, and around the cafeteria tables. Bright rays of sunlight, which didn't need any detectors to be observed, lit up Mont Blanc, the highest mountain in Europe.

"If you ask any of the thousands of scientists here why they're here, they'll answer, 'for the knowledge,'" said Rabinovici, who has held several positions at CERN. "Nobody's here for the money. The experimenters, whose big day this is, are enjoying the construction of a machine they never thought was possible; the theoreticians want to know how the world works. What unifies everyone is the scientific aspiration to acquire as much knowledge as possible about the world."

Rabinovici added: "There are a few parameters according to which this experiment is greater than putting man on the moon. But what makes the real difference is the human spirit that exists here. Cooperation among the scientists of different countries is maybe how the United Nations was supposed to look. It's not an American project like the space program, and it's not meant to defeat the Russians. It's an international project that will advance the whole world."