The world's biggest, most highly-anticipated physics experiment comes online this week, as the first beam of particles begins to circulate around a 17-mile underground racetrack that lies beneath France and Switzerland.
The $9 billion Large Hadron Collider, 20 years in the making, represents the work of at least 7,000 scientists from 60 countries, including a contingent from the Boston area that spent years, or entire careers, working on this project.
Their excitement is testimony to the importance of the mission: to recreate in an underground tunnel the conditions of the early universe, just a trillionth of a second after the Big Bang. From that, they hope to fill in gaps in physics knowledge, search for hidden dimensions, and understand why particles have mass.
The collider soaks up superlatives like no other science project. But no whiz-bang insights are expected immediately, or even this year. The inaugural beam is just the critical first step in what will be years of research. So the revving up this week of the world's largest particle accelerator will be punctuated with emotion, not eureka. "It's the culmination of my career," said James Bensinger, 67, a physicist from Brandeis University who has been working on the project for 15 years. "It will certainly outlive my scientific life; it very well may outlive me, period. It's not that unusual in the human experience. The people who built cathedrals - often times their sons saw it completed. But still, they thought it was something much bigger than they were and kept it going."
The Large Hadron Collider is operated by the European Organization for Nuclear Research, also known by its French acronym, CERN. The circular underground tunnel, in which the particle beams ramp up to 99.99 percent of the speed of the light, lies more than 300 feet below the earth, at the foot of the Jura Mountains. The accelerator dwarfs its closest cousin, the Tevatron at Fermi National Accelerator Laboratory in Batavia, Ill., and because it can reach higher energies, it will be used to search for evidence of some of the most evanescent particles.
One of physicists' most vexing unanswered questions is: What are the origins of mass in the universe? The answer may lie in a theoretical particle called the Higgs boson first predicted in 1964, that has been bugging scientists for decades. The elusive particle, also called the "God particle," was inserted into scientific theory to make physicists' models work, but it has never been seen.
"For my entire career, since I got my PhD at Cornell in the early 70s, there's been something called the standard model that has explained all the phenomena that has been observed in high energy physics basically through my entire my career," said Frank Taylor, an MIT senior research scientist. "But there's one part that's missing, so in a sense the program would hopefully be the fulfillment of this one missing piece of the exploration."
Taylor, Bensinger, and other Boston-area scientists collaborated on building a detector that will be used within the collider to detect muons, particles that are signatures of the elusive particles expected to be created in the collisions. Scientists from Boston University, Brandeis University, Harvard University, MIT, Northeastern University, Tufts University, and the University of Massachusetts at Amherst worked on various research programs within the Large Hadron Collider.
Fifteen years seems like a long time to wait to build a single experiment, especially when scientists may have to wait additional months and years before the scientific breakthroughs start to percolate out. But many of the Boston-area physicists who worked on building a detector already had their patience tested before; they were alums from another major scientific experiment that was never built, called the Texas Superconducting Super Collider. Some had already devoted years to that project, estimated to cost $11 billion, when it was halted by Congress in 1993.
Back then, "There was a lot of soul searching, and a lot of saying, 'What do we do now?' " said George Brandenburg, a senior research fellow at Harvard University. But since then, Brandenburg and colleagues have been able to do in Europe the same work they once intended to do in Texas.
The United States is heavily involved in the Large Hadron Collider, paying $531 million to support it, but the new project does shift the center of such physics research to Europe. Still, "as a scientist, how can you be unhappy if the project is being done and you can be a part of it?" Brandenburg said.
Over the years, some physicists have shifted their research focus to different areas, yet they remain excited about the launch of the Large Hadron Collider.
"This could be an epic program, honestly," said Tony Mann, a physicist from Tufts University who worked on the detector, but has now resumed work on another area of particle physics. "This is potentially the most exciting experimental endeavor ever launched. There's a part of me that looks at that with curiosity, and a little bit of envy. I hate to miss a great party."
What scientists discover at the Large Hadron Collider will also help set the path for the next big experiment, the International Linear Collider, which will smash together another family of particles, called leptons.
But there's always the possibility that against all expectations, this massive game-changing experiment will come up empty-handed. It could take years to find out if it represents the dawn of a new era of physics - or not.
"This could be the last experiment ever done, or we could discover all kinds of extraordinary, exciting things," said Steve Ahlen, a BU physicist working on the collider. "I'm just ecstatic this thing got built."
Carolyn Y. Johnson can be reached at cjohnson@globe.com. http://www.boston.com/news/science/articles/2008/09/08/all_eyes_on_collider_as_it_comes_to_life/?page=2
