Download A PEEK INSIDE THE PERIMETER INSTITUTE

FOREWORD
A PEEK INSIDE THE PERIMETER INSTITUTE
“Every great advance in science has issued from a new audacity of imagination.”
– John Dewey
“It doesn’t matter how beautiful your theory is, it doesn’t matter how smart you are.
If it doesn’t agree with experiment, it’s wrong.”
– Richard P. Feynman
W
e were delighted to be invited to prepare this
theme issue of Physics in Canada, and we hope
you will enjoy the glimpse provided here into
the diverse research activities at Perimeter
Institute (PI).
From its inception, spacetime and quantum theory have been
at the heart of PI research. While these topics might at first
sight seem abstract and somewhat remote from the real world,
we hope that you will see in these pages that here at PI, we
still live by the maxim that nature and experiment are a theorist’s best guide.
One of Perimeter’s unique features is its group working on
quantum foundations. Rob Spekkens and Lucien Hardy eloquently lay out the case for their field, describing both the
motivations and the impact it has had. Among these was the
recent experimental confirmation of Hardy’s Paradox by
groups at both the University of Toronto and Osaka
University, which may in time yield practical applications.
Christopher Fuchs also gives his perspective on a fresh
approach to unraveling the conundrums of quantum mechanics with the help of Bayesian probability theory.
Quantum information science emerged as an offshoot of
quantum foundations, and now flourishes with the promise of
new technologies which may transform our society. Perimeter
was instrumental in launching the Institute for Quantum
Computing (IQC) at the nearby University of Waterloo, both
partners with which PI enjoys strong synergistic relations. In
two articles here, we see the synergies between quantum
information and other areas of theoretical physics. In their
article, Urbasi Sinha, Raymond Laflamme and colleagues
give an account of a new triple slit experiment which tests the
basic tenets of quantum mechanics following a proposal by
PI’s Rafael Sorkin. Then Daniel Gottesman describes how
work on quantum computational complexity classes has provided unexpected insights into spin glasses.
On PI’s spacetime theme, we begin with two thoroughly different accounts of black holes. Once an exotic toy in the theorists’ playground, these phenomena of ultra-strong gravity
have become the workhorses of modern astrophysics. In their
article, Luis Lehner and Latham Boyle describe new astrophysical observations which may teach us more about black
holes through their impact on light and gases caught in their
immense gravitational fields. In contrast, Bill Unruh, one of
PI’s Distinguished Research Chairs, hopes to tame these
dynamos in his ‘bathtub’. His article tells a remarkable story
about how doing experiments in a tank of water may provide
a better understanding of Hawking radiation leaking from
black holes and, perhaps, even of quantum gravity.
While quantum gravity delves into spacetime at unimaginably small scales, Lee Smolin and Sabine Hossenfelder
describe how we may nevertheless find fingerprints of the
quantum nature of short distance physics via experiments
measuring phenomena over cosmological scales. Similarly,
cosmological observations provide important clues about the
physics of the very early universe, which in turn may provide
hints as to the ultimate theory of nature. With this motivation,
Cliff Burgess describes how we might find fingerprints of
string theory through its impact on cosmic inflation.
Dark energy and the present acceleration of the universe represent one of the greatest puzzles in cosmology today. They
provide vital clues as to the ultimate theory and call for a radical reworking of the standard theory of cosmology,
Einstein’s theory of gravity, or both. Niayesh Afshordi outlines his own efforts to rethink gravity at the largest scales,
which have intriguing cosmological signatures. Particle theorists Maxim Pospelov and Brian Batell relate exciting new
proposals for the properties of dark matter, the other great
enigma dominating large scale phenomena in the universe,
which may explain several curious new observational results.
Particle physics is entering a particularly exciting new era as
CERN’s Large Hadron Collider (LHC) is beginning to
explore physics at a new energy frontier. Michael Trott gives
us a theorist’s perspective on the motivations, challenges and
possible discoveries for physics at the LHC. Freddy Cachazo
describes his work on the foundations of quantum field theory which, unexpectedly, provides new tools for analyzing
upcoming accelerator experiments. Alex Buchel, Rob Myers
and Aninda Sinha tell us how novel techniques developed in
string theory are helping us to understand a remarkable new
phase of nuclear matter.
The lifeblood of physics, as we all know, is brilliant young
people. John Berlinsky writes about Perimeter Scholars
International, an innovative graduate research training course
which we launched in the fall of 2009. As you read this issue,
the first class of 28 students, drawn from 16 countries, is
graduating. With PSI we are attempting to reinvigorate the
training of young theorists and the initial results of our experiment are highly promising.
Aside from research, an equally vital part of PI’s mission is to
share the joy and the power of scientific discovery with the
wider community through educational programs and events,
and Greg Dick and John Matlock explain why we feel outreach is so important.
Rob Myers <rmyers@
perimeterinstitute.ca>,
Senior Faculty member
Neil Turok <nturok@
perimeterinstitute.ca>,
Director
Perimeter Institute for
Theoretical Physics,
31 Caroline St. N.,
Waterloo, ON
N2L 2Y5
We hope you enjoy this peek “inside the Perimeter”. Happy
reading!
—Rob Myers and Neil Turok, Guest Editors
The contents of this journal, including the views expressed above, do not necessarily represent the views or
policies of the Canadian Association of Physicists. Le contenu de cette revue, ainsi que les opinions
exprimées ci-dessus, ne représentent pas nécessairement les opinions et les politiques de l’Association
canadienne des physiciens et des physiciennes.
PHYSICS
IN
CANADA / VOL. 66, NO. 2 ( Apr.-June 2010 ) C 67