May 30, 2001, 4 pm

Origins

by Daryl M. Tress and Elizabeth H. Simmons

". . . they were suddenly carried away from there, up to their births, like shooting stars."---Plato, Republic (621b)

"Where did I come from?" is a basic human question. The ancient Greeks offer a wide range of answers: some say the four elements---earth, air, fire, water---or human blood and seed, or numbers; others say that a starry substance like pneuma accounts for human life, or that the gods are the responsible agents. Some assert that a human life has no beginning, and no end. Perhaps the most important contribution from Greek antiquity, however, is the close analysis of the concept itself of origins, which is replete with paradox. The philosophers consider why the question of our beginnings eludes a definitive answer and why, nevertheless, we must ask it.

Daryl Tress will discuss several theories and explore the different aims leading to their formulation. The paradoxes that the Greek philosophers discover constrain theories of origination, but they also open significant new ways of conceiving the nature of human life.

Daryl M. Tress is an associate professor of philosophy at Fordham University in New York.

The Origins of the Masses of Elementary Particles by Elizabeth H. Simmons

Nothing exists except atoms and empty space; everything else is opinion.---Democritus as quoted by Diogenes Laertius 

Ever since the Greek philosopher Democritus elaborated his atomic theory, scholars have sought to determine the composition of our universe at the smallest distance scales. Modern physicists engage this question with tools ranging from particle accelerators, which collide protons together at nearly the speed of light, to quantum field theory, which seeks to predict the behavior of the smallest elements of matter.

This presentation will display the many layers of the sub-atomic world---particles within the atoms of which we are made, the fundamental forces through which they interact with the rest of the universe, and other particles so exotic their function is unknown. Patterns and surprises in the values of the masses of the subatomic particles will be revealed and probed for meaning. The top quark, the heaviest elementary particle, will be treated as a case study. Because the top quark is so massive, the mechanism that creates its mass may be particularly amenable to theoretical dissection and experimental detection.

Particle theorist Elizabeth H. Simmons is an associate professor of physics at Boston University.