Wednesday, September 17, 2008

Collider test called a 'great milestone of mankind'

On Wednesday morning, just outside of Geneva, scientists shot a particle beam fully around a 17-mile loop in the world's most powerful particle accelerator -- the Large Hadron Collider (LHC). Twenty years after development of the collider began, a particle beam made the full journey around the accelerator for the first time. It's a forebear to the time when scientists will accelerate two particle beams toward each other at 99.9% of the speed of light.

Smashing the beams together will create showers of new particles that should recreate conditions in the universe just moments after its conception, giving scientists the chance to answer one of humanity's oldest questions: How was the universe created?

"This is truly one of the great engineering milestones of mankind," said Harvey Newman, a physics professor at the California Institute of Technology. "It was characterized as having gone as 'smooth as silk,' considering everything that had to work."

Newman told Computerworld that scientists sent one beam around the tube and then sent a beam in the opposite direction -- each going one at a time. Each beam made one circle around the accelerator. And they hit 99.999998% of the speed of light.

"It's actually very exciting," said Bolek Wyslouch, a professor of physics at MIT who has been working on the collider project for the past seven years. "We were anxiously waiting, with the whole world watching, to see how this worked."

Wyslouch said he's not sure when scientists will run the first particle-collision experiment, but he estimated that it will be closer to days or weeks away rather than months.

"That's really exciting because just a few minutes of [that experiment] will give us a hint of where this is going … and confidence that we are on the right track," he added.

Scientists predicted that they will be running particle-collision experiments for the next 10 to 15 years.

The $9 billion LHC project, which sits astride the Franco-Swiss border, operates a tunnel buried 50 meters to 150 meters below the ground. The tunnel, or tube, is designed to facilitate and control a head-on collision between two beams of the same kind of particles -- either protons or ions. Traveling through a vacuum comparable to outer space, the beams are guided around the tube by more than 1,000 superconducting magnets.

According to documents from CERN, as the European Organization for Nuclear Research is known, each of the two beams will contain about 3,000 bunches of particles. Each bunch will hold as many as 100 billion particles. Despite these huge numbers, the particles are so tiny that a collision between any two is quite small. However, since the beams will be traveling at near light speed around the 17-mile tube, they'll cross each other about 30 million times per second, resulting in an estimated 600 million collisions.

If a beam circulates around the tunnel for 10 hours, for instance, it will travel more than 10 billion kilometers, which is the distance it would take to travel to Neptune and back.

With the Big Bang theory, scientists largely believe that more than 13 billion years ago, an amazingly dense object the size of maybe a coin expanded into the universe that we know now -- with planets, stars, black holes and life.

A main goal of the experiments is to find the elusive Higgs particle, which is believed to be responsible for giving other particles their mass. Though its existence hasn't been proven yet, it's believed that Higgs particles are what give electrons their weight, for instance.

Scientists are also hoping that the particle collider will give them information about so-called dark energy and dark matter.

"This is part of the quest to explore our surroundings. It's part of the quest to understand our world and ourselves," Wyslouch said in a previous interview.


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