To europe!
GENEVA -- A year from now, scientists here will throw a switch sending protons smashing into each other at near the speed of light, bringing thousands of researchers from around the world to study the results.
With that action, the world's center of gravity for high-energy physics research will shift unambiguously to Europe for the first time, a prospect that is leaving American scientists and policy makers increasingly concerned. Already students and researchers are flocking to this side of the Atlantic to help design, build and test what will be the most powerful high-energy physics project ever built.
"Our best scientists will be doing their best work in laboratories overseas," said Robin Staffin, who directs the U.S. Department of Energy's high-energy physics division. "The frontier will be at this machine."
For a U.S. scientific community that has held a leading role in particle physics at least since the Manhattan Project, this is an unfamiliar, and potentially deeply disturbing, change.
Policy makers and educators are already worried about falling interest in math and sciences among U.S. students. Now, the prospect of seeing the world's leading high-energy physics laboratories move overseas is drawing strong calls for renewed investment, and even a few dire warnings of national decline.
"Support for particle physics in the United States has stagnated," warned a recent high-profile report from the National Research Council that argues for taking the lead in the field's next multibillion-dollar project. "A strong role in particle physics is necessary if the United States is to sustain its leadership in science and technology over the long term."
This call to arms is tempered both by scientific and economic realities, however. Projects on the scale of CERN's Large Hadron Collider, or LHC, cost billions of dollars, realistically putting them out of reach of even the richest nations acting alone.
This has been a painful lesson for the U.S. physics community to learn. In the late '80s, the country had launched an ambitious project dubbed the Superconducting Supercollider, or SSC, which would have been even more powerful than CERN's new accelerator and would have helped cement U.S. laboratories' leading position for years to come.
But in 1993, a deficit-shy Congress canceled the project after deep cost overruns, and after finding that other countries were reluctant to contribute financially to a project so dominated by the United States. That action helped open the door for the LHC, which was approved by CERN's European member states the following year.
Science officials say those scars remain fresh in the American political memory, but that any new venture would be handled differently.
"In discussions of large machines, the SSC is something like Caesar's ghost. It's definitely there," Staffin said. "But the LHC shows it can be done. We believe we have learned many of the lessons of SSC, such as the importance of internationalizing it, and the importance of strong oversight."
This complicated mix of international scientific goals and national ambition is now helping drive particle physics' next multibillion-dollar proposal, a cross-border collaboration dubbed the International Linear Collider, or ILC.
Looking Into the Future
Why is another hugely expensive project already needed if CERN's accelerator is viewed with such tremendous optimism? The answer requires a short trip through the guts of the accelerators themselves.
The LHC will reach unprecedented energies for physics experiments, smashing particles together in debris-scattering collisions that scientists hope will create never-before-seen particles. But this massive power comes at a cost.
The particles used in the LHC experiment will mostly be protons, which are themselves made up of three individual smaller particles called quarks. Because scientists won't know exactly how these individual quarks collided, their conclusions will necessarily carry some uncertainty.
The proposed ILC would instead smash together electrons and their antimatter counterparts, positrons. These are themselves fundamental particles, with no smaller components inside. Moreover, they can be tightly controlled in an accelerator beam, so information about their precise characteristics at the time of collision can be known with great confidence.
These two models have complemented each other well in previous generations of accelerators. Fermi National Accelerator Laboratory's Tevatron, today's most powerful machine, is similar to the LHC, smashing protons and their antimatter counterparts together. CERN's previous facility was based on the simpler particles, and thus able to make more precise measurements.
"This concept has worked extremely well over last 40 or 50 years," said Rolf-Dieter Heuer, director of Germany's DESY physics lab, which has played a key role in developing the ILC designs. "One alone is not enough. We would not be where we are today if we only had one model to work with."
All this is a far cry from the long-departed SSC, even if some Americans hope to bring it to U.S. soil. Researchers from around globe collectively identified the ILC as the field's logical next step, and governments around the world have contributed to early research and development.
But ultimately, this borderless collaboration will have to confront the tensions of the political world.
The cost alone will be a serious hurdle. The LHC is costing about $8 billion to build. CERN's European member states are chipping in about three-fifths of that. The rest comes from other countries, including about $500 million from the United States.
As yet, the ILC has no price tag attached, although some scientists say it is likely to be on the same rough scale as the LHC. An international committee tasked with drawing up an initial, provisional cost estimate is slated to report in early 2007, but as yet its early work has remained a closely guarded secret.
Then will come the decision of where to put it. U.S. scientists and policy makers are pushing hard for the United States to make a bid, but Europe, Japan and perhaps others might seek the same role. Once a country wins a bid, retaining truly international funding might become difficult. That prospect triggers some pessimism from scientists, particularly those who lived through the SSC process.
"It has to be located somewhere," said University of Texas at Austin physicist Steven Weinberg. "That host country will be looking for support, and foreign countries will think they'd rather spend at home."
All of this remains in the hazy future of politics and funding, however. Today, CERN's project has brought international physics to the brink of genuinely new discoveries, in which the details of nationality fade quickly away. The cross-border nature of ILC's design process has underscored the field's increasingly collaborative nature, say participants such as Heuer.
"From now on it's going to be like this," said University of Wisconsin physicist Dick Loveless, who has spent the last few years shuttling across the Atlantic for work at the LHC. "When you speak of a machine of this size, you have to speak of coordination. There's no way you can go back to local projects."
