APL Colloquium

April 10, 2015

Colloquium Topic: The Hunt for the Tachyon

Most physicists remain highly skeptical about the existence of tachyons - hypothetical faster-than-light particles having an imaginary mass that were first proposed in 1962.  In this talk I present a bit of the history of tachyons, and describe my search for the reality of their existence, or more properly the basis of my belief that one or more flavors of neutrinos are likely to be tachyons. After this background information, I consider six observations involving cosmology, particle physics and cosmic rays that are consistent with the hypothesis that the electron neutrino is a m2ve = -0.11 +/- 0.02 eV2 tachyon.  A popular-level account of this work can be found in the press release and the video on my web site, which also contains a link to a the paper that has just appeared in Astroparticle Physics: http://mason.gmu.edu/~rehrlich

Colloquium Speaker: Robert Ehrlich

ROBERT EHRLICH retired from his position as professor of physics at George Mason University in 2013, where he chaired the physics & astronomy department for 13 years.  He began his career after receiving a B.S. in Physics from Brooklyn College in 1959, and a Ph. D. in physics from Columbia University in 1964 in experimental particle physics, having worked on the Nobel Prize winning "two neutrino" experiment.  Dr. Ehrlich has held positions at the University of Pennsylvania, Rutgers University, and the State University of New York College at New Paltz, prior to joining the physics department at George Mason University in 1977 as its chair.  Altogether, he has authored or edited 22 books and over 100 articles in areas including particle physics, science education, physics & society, and energy & environmental topics.  His most recent book: "Renewable Energy: A first Course," was published by CRC Press in 2013.