CERN Turns 50
Five decades of breakthroughs, from the W particle to the World Wide Web
On 29 September, the particle physics laboratory in Geneva known as CERN--the European Organization for Nuclear Research--celebrated its 50th birthday. In the past half century, CERN has emerged as the world's preeminent laboratory for the study of elementary particles, and it serves today as a focal point of European pride.
At present, CERN is building the most powerful particle accelerator yet, the Large Hadron Collider, or LHC, which is set to switch on in 2007 and put the finishing touches on what physicists call the Standard Model--the basic theory of how the fundamental forces and particles interact [see photo, " Tunnel to the Future"]. Two decades ago, CERN scientists were honored with a Nobel Prize for their discovery of the W and Z particles, a major milestone along the way to achieving a unified view of the physical world.
But besides advancing theory, CERN has again and again produced practical technology and feats of engineering that have pushed the state of the art to its outer limits. Among the lab's most noteworthy technical accomplishments are:
The World Wide Web . The enormously numerous and complex data generated in CERN's accelerators were of limited value if they could not be shared with physicists around the world. So it was at CERN that Tim Berners-Lee invented a file sharing protocol and added it to his hypertext markup language, or HTML, to form the basis of the Web.
Grid Computing . Today, together with the Argonne National Laboratory in Illinois, CERN is leading the way in development of distributed supercomputing for all manner of large-scale scientific applications--from climate prediction to genome analysis.
Superconducting Magnets . Those developed for CERN's accelerators have produced fields unequaled in any other large-scale applications. The ones for the LHC, cooled with liquid helium, are expected to generate fields of 9 tesla; the magnets in a typical magnetic resonance imaging machine generate just 1.5 T.
The All-electronic Detector . A generation ago, particle collisions were tracked in a cloud chamber, a familiar instrument in undergraduate physics labs. Images had to be analyzed by hand and could not be produced by specific sought-after events. Working at CERN in the late 1960s, the physicist Georges Charpak invented the first all-electronic detector. Called a multiwire proportional chamber, the detector is in trials now for use in medical X-ray imaging, where it could greatly reduce the amount of radiation needed to form an image.
Stochastic Cooling . CERN engineer Simon van der Meer developed arcane control techniques to make bundles of particles that tend to fly apart cohere, so as to boost the probability of collisions in a particle accelerator. Together with Charpak's detector, the techniques led to the discovery of the W and Z particles.