The Welsh Lectures in Physics

2017 H.L. Welsh Lectures in Physics
An annual physics event since 1975!

The Welsh Lectures in Physics have been held annually since 1975 in honour of H.L. Welsh, a distinguished former faculty member in the Physics Department. They are the major public event in the life of the Department of Physics and are intended to celebrate discoveries in physics and their wider impact. They are intended to be broadly accessible to an audience drawn from across the university, other academic institutions and the interested public.

The Speakers for 2017

Prof. Nergis Mavalvala


Nergis Mavalvala is the Curtis and Kathleen Marble Professor of Astrophysics and Associate Head of the Department of Physics at the Massachusetts Institute of Technology (MIT). She received a B.A. from Wellesley College in 1990 and a Ph.D. from the Massachusetts Institute of Technology in 1997. She was a postdoctoral fellow and research scientist at the California Institute of Technology between 1997 and 2002, and has been on the Physics faculty at the Massachusetts Institute of Technology since 2002. Professor Mavalvala’s research focuses on interferometric gravitational waves and quantum measurement and she has been involved with the Laser Interferometer Gravitational-Wave Observatory (LIGO) since her early years in graduate school at MIT. She was the recipient of a MacArthur Fellowship in 2010. For the discovery of gravitational waves, Professor Mavalvala shared in the Special Breakthrough Prize in Fundamental Physics, the Gruber Cosmology Award, and the Rossi Prize.

Prof. Leon Balents

University of California, Santa Barbara

Leon Balents is a Professor of Physics at the University of California at Santa Barbara (UC Santa Barbara) and a permanent member of the Kavli Institute for Theoretical Physics. He received his B.S. from the Massachusetts Institute of Technology in 1989 and a Ph.D. from Harvard University in 1994. He was a postdoctoral fellow at the Institute for Theoretical Physics at UC Santa Barbara, then a permanent member at the Bell Laboratories before returning to UC Santa Barbara to join the Physics faculty. Professor Balents is a theoretical physicist who studies quantum condensed matter systems. He has received a National Science Foundation Career Award, an A. P. Sloan Foundation Fellowship, and a David & Lucile Packard Foundation Fellowship. Professor Balents is also a fellow of the American Physical Society and the leading scientist in numerous international collaborative research efforts.

Public Talks

The Department of Physics invites faculty, students and the public to our 44nd annual celebration of physics.


MAY 4, 2017


Earth Sciences Centre
5 Bancroft Avenue
Auditorium (ES 1050)


1:30 p.m.

Prof. Nergis Mavalvala

"The Warped Universe: The One Hundred Year Quest to Discover Einstein’s Gravitational Waves"

In 2016, scientists announced the first-ever detection of gravitational waves from colliding black holes, launching a new era of gravitational wave astrophysics. Gravitational waves were predicted by Einstein a hundred years earlier. I will describe the science, technology, and human story behind these discoveries that provide a window into some of the most violent and warped events in the Universe.

3:00 p.m.

Coffe Break

3:30 p.m.

Prof. Leon Balents

"Strange Stuff: A Second Quantum Revolution"

Weird but true: quantum mechanics tells us that reality is not what it seems. The glass is not necessarily empty or full, but can be both at the same time. Erwin Schrödinger, one of the founders of quantum theory, imagined a cat that is simultaneously alive and dead. In practice, while such odd quantum states are common for microscopic particles, they are harder and harder to arrange for larger objects. But more recently, researchers have turned this question around to ask: what sorts of weird quantum states can be achieved? The answers are surprising. Quite strange quantum behavior is possible even in large assemblies of electrons and atoms, realizing new forms of matter. These ideas are influencing not only our understanding of matter, but also that of information and gravity. In my talk, I'll introduce you to this second quantum revolution and its implications for the future.

Sponsored by the Department of Physics: (416) 978-7135 or or



Prof. Harry L. Welsh

Prof. Harry L. Welsh

Prof. Harry Welsh's distinguished research activity in molecular spectroscopy at the University of Toronto spanned a period of forty years. He pioneered the study of collision-induced infrared absorption and of molecular complexes, and of the infrared and Raman spectra of liquid and solid hydrogen. During his years as chair in the 1960's, Prof. Welsh guided a period of rapid growth of the Department of Physics. The H.L. Welsh Lectures in Physics were begun in 1975 on the occasion of his 65th birthday and have become an annual event.

Past Speakers

  • 2016
    Dr. Nima Arkani Hamed (Princeton University)
    Dr. Andrea Ghez (University of California, Los Angeles)
  • 2015
    William Bialek (Princeton University)
    Prof. Serge Haroche (Collège de France, Paris)
  • 2014
    Rolf Dieter Heuer (CERN)
    Zhi-Xun Shen (Stanford University)
  • 2013
    Jean-Loup Puget (Institut d'Astrophysique Spatalie, Universite Paris Sud)
    Robert Austin (Princeton University)
  • 2012
    Kerry Emanuel (MIT)
    Roger Bilham (University of Colorado)
  • 2011
    Deborah Jin (JILA and University of Colorado)
  • more past speakers...

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