Maury Tigner: Building the largest machines on Earth

Cornell physicist Maury Tigner

By Larry Klaes

Two of the largest machines ever conceived by scientists were described at the American Association for the Advancement of Science on Feb. 19 by one of the world's leading experts on particle colliders, the massive and expensive machines used to explore inner space by smashing particles together at super-fast speeds.

Cornell physicist Maury Tigner, director of the Laboratory for Elementary Particle Physics (LEPP), is playing a major role in two of these machines: the Large Hadron Collider (LHC), being built at the European Centre for Nuclear Research (CERN) in Geneva, for which he serves as chairman of the machine advisory committee, and the International Linear Collider (ILC), being planned by an international team, for which he is chairman of the steering committee.

Tigner opened his talk by discussing the reasons for building such colossal and expensive machines to study the ultimate building blocks of all matter, and in particular to search for the Higgs boson, known as the God particle because of its postulated commanding role in explaining how subatomic particles interact with each other.

LHC is nearing completion in the 27-kilometer (17 miles) circumference tunnel originally created for CERN's Large Electron Positron collider. When completed in 2007, LHC will be the largest such device on Earth. It will slam protons (one type of hadron particle) together with an energy "seven times that of the largest such collider running now, the [the Fermi National Accelerator Laboratory] Tevatron, outside Chicago," said Tigner.

He voiced the hope that the LHC will help scientists answer such questions as: Where does mass come from? What is the dark matter that permeates most of the universe? How many dimensions do we need to describe the physical world?

The ILC, a multibillion-dollar colossus that will require unprecedented international scientific cooperation, will be complimentary to CERN's LHC. The ILC actually would be two linear accelerators colliding electrons and positrons in a tunnel 40 kilometers (25 miles) long, 10 times as long as the current longest linear particle accelerator, the Stanford Linear Accelerator (SLAC).

"The advantage of a machine that collides electrons and positrons together is that, unlike protons, they are elementary particles, so you know exactly what the energy is in any reaction that you see," said Tigner. "Certain phenomena can only be seen with electron and position collisions. Thus ILC will make a good discovery machine."