ITHACA, N.Y. -- Maury Tigner, professor emeritus of physics and director of the Laboratory for Elementary-Particle Physics at Cornell University, is one of 12 winners of the American Physical Society's (APS) 2005 Leo Szilard Lectureship Award for work on boost phase intercept systems for national missile defense.

The annual prize, established "to recognize outstanding accomplishments by physicists in promoting the use of physics for the benefit of society in such areas as the environment, arms control and science policy," was awarded to members of a study group formed by the APS in early 2001. The group, which includes physicists and engineers with a variety of scientific and technical backgrounds, analyzed intercontinental ballistic missile (ICBM) systems and delivered a report concluding that intercepting incoming ICBMs in their boost phase (just after launch, when they are still under power) would be challenging at best.

The full report was published in March as a special issue of the APS' Reviews of Modern Physics.

ICBMs are difficult to intercept in their midphase (when they are gliding without power) because they can be indistinguishable from decoys. Intercepting them in their boost phase was considered an alternative, but the group's work showed the strategy comes with its own host of problems.

"In general, it would be an extremely difficult thing to do," said Tigner. "You have to have detection stations very close to the launch site, and often you just can't get close enough. Then, you have only a limited time to launch your anti-missile missile. And there are quite a large number of measures that could make it more difficult to figure out the trajectory of the enemy missile."

The APS award, whose previous winners include Hans Bethe and Andrei Sakharov, was established in 1974 to honor Hungarian-born physicist Leo Szilard, who proved the possibility of a nuclear chain reaction and helped initiate the Manhattan Project. After World War II, Szilard took an active role in policy issues, becoming one of the first to call on scientists to devote their time and expertise to issues of public concern.

Daniel Kleppner, the Lester Wolfe Professor of Physics Emeritus at the Massachusetts Institute of Technology and co-chair of the APA study group, noted that Szilard's work was an inspiration for the group. "The tradition of capable scientists devoting themselves to such studies is now an established element of the culture of physics and the broader scientific community," Kleppner said.

The award, endowed by donations from the John D. And Catherine T. MacArthur Foundation, the Energy Foundation, the David and Lucille Packard Foundation and others, includes travel expenses for recipients who give lectures at educational institutions.