"Living Nightmares: Facing the Growing Threat of Biological Terrorism" will be the subject of a talk to be given on the Cornell University campus May 3 by Steven M. Block, professor of biological sciences and of applied physics at Stanford University.

The talk will be his first in the series of Bethe Lectures at Cornell. As a molecular biologist, Block has written about the parallel rise of biotechnology and terrorist activity, which, he says, arguably poses a greater threat to humankind than the nuclear menace that overshadowed the Cold War.

Block believes it is necessary to contemplate the danger to health and security that would accompany the release of genetically engineered pathogens. The next generations of biowarfare agents, he says, will have the potential to become true biological weapons of mass destruction.

The talk, which is free and open to the public, will be at 7:30 p.m. in Schwartz Auditorium, Rockefeller Hall.

Other scientific lectures by Block in the Bethe series will be: "Sensory Transduction: Clever Physics by Dumb Organisms," a physics colloquium May 8, 4:30 p.m., in Schwartz Auditorium; and "Kinesin Motors: Mastering the Molecular Mechanism of Movement by Mechanoenzymes," a biophysics colloquium May 10, 4:30 p.m., 700 Clark Hall.

Block, who is from Durham, N.C., obtained his undergraduate and graduate degrees in physics at Oxford University in England and his Ph.D. in biology at the California Institute of Technology. He was a faculty member at Harvard and Princeton universities before joining Stanford last year. He is a member of the U.S. Nonproliferation Center's advisory panel.

The Bethe Lectures, established by the Cornell physics department and the College of Arts and Sciences, honor Hans A. Bethe, Cornell professor emeritus of physics, whose description of the nuclear processes powering the sun won him a Nobel Prize in physics in 1967. The lectures have been given annually since 1977.