1882 - 2007

125th Anniversary of RSC


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2007 - Victoria Michelle Kaspi

Victoria Kaspi is a world leader in astrophysics. Recently she and her students showed that the objects known as soft gamma repeaters and anomalous X-ray pulsars share a common nature, as predicted uniquely by the magnetar model in which they are both extremely magnetized neutron stars. As her record shows Kaspi is an exceptionally talented physicist, who is internationally renowned for her work on neutron stars, pulsars and supernovae remnants. Victoria Kaspi's important work is being done at the cutting edge of current research in physics, and indeed of all science.

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2006 - Aephraim M. Steinberg

Department of Physics, University of Toronto

Professor Steinberg works at the forefront of experimental quantum optics and quantum information. He is internationally known for his seminal work, both experimental and theoretical, on "superluminal" effects in tunnelling and optical propagation, as well as for his ongoing projects using ultracold atoms and entangled photons to study the subtle mysteries of quantum mechanics along with their potential applications to information processing. Dr. Steinberg has rapidly become a world leader in two major areas of quantum physics.

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2005 - Peter Grütter

Peter Grütter, Professor and Dawson Scholar in the Department of Physics, McGill University, is one of the world's experts in nanoscience. He has made seminal contributions to magnetic force microscopy and has contributed broadly to all aspects of scanning probe microscopy, particularly related to the quantitative understanding of the images produced. Grütter's group machines the tips of his scanning probe microscopes atom by atom, thereby permitting characterization, control, and design at the nanometer scale. With this refined tool, Grütter has made important contributions to the understanding of, for example, fundamental issues of quantum transport, micromagnetic switching in magnetic media storage, and superconducting quantum vortices, amongst other issues.

Specific scientific breakthroughs include his seminal work as co-creator of the magnetic force microscope, and in particular on dissipation-based methods of magnetic force microscopy. Related important work includes his study of magnetic switching, which will be essential for the application of magnetic cellular automata. Grütter's work on tip-sample interaction set the stage for quantitative scanning probe microscopy. Overall, Grütter has remained at the forefront of rapid developments in science, and has been a pioneer in the development of nanoscience.

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2004 - Sajeev John, FRSC

Professor in the Department of Physics, University of Toronto, Sajeev John, FRSC, is one of Canada's foremost theoretical physicists and one who has made revolutionary contributions to condensed matter physics, especially in the areas of optical properties of micro structured materials and high temperature superconductivity. He is internationally recognized as the founder in 1987 of a new branch of science related to his pioneering suggestions of a new class of materials known as photonic crystals. These are periodically structured materials which are capable of controlling the flow of light just as semiconductor crystals control the flow of electronics. His contributions span both the fundamental and applied sides of physics and include novel lasing mechanisms, low threshold nonlinear optical bistability and all-optical transistor action, and single-atom optical memory in photonic band gaps. His work has stimulated intense world-wide activity in physics, chemistry, materials science and engineering and has opened new vistas for information science and optical circuits. Several international conferences are held annually on the subject of photonic crystals.

In recognition of past work, Sajeev John has received numerous awards, including J.S. Guggenheim, Killam and Alexander von Humboldt Fellowships as well as the Steacie Prize in Natural Sciences from the National Research Council, the Ontario Premier’s Platinum Medal for Science and Medicine, and the King Faisal International Prize in Science.

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2003 - Misha Ivanov

Perhaps because he works in the company of experimental physicists, or perhaps because that is his nature, Misha Ivanov is a theoretical physicist who can put difficult physical concepts into simple terms. Although his calculations are invariably in atomic units, he never loses sight of the physical significance of what he is predicting. He often wants to learn the details of experimental procedures so that he can better understand the linkage between theory and experiment. It has been recently discovered that experiments work better when Misha is present in the lab.

Misha's interests cover a remarkably broad range of subjects, from atomic physics and quantum optics to chemical physics to condensed matter physics, and he successfully applies concepts developed in one area of physics to other areas. For example, he applied concepts from multiple quantum well electron dynamics to molecular ionization. Ideas from high-harmonic generation from atoms were applied to microwave generation in quantum wells. He also bridges the gulf between quantum, semiclassical and classical mechanics.

Misha, Senior Research Officer at the National Research Council, has made seminal contributions to the understanding of dynamics of atoms and molecules in intense laser fields.

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2002 - Christopher Thompson

Christopher Thompson, Professor, Canadian Institute for Theoretical Astrophysics, University of Toronto, has a reputation for originality, technical ability and deep physical insight unsurpassed by anyone in his age group in high-energy astrophysics. In particular, one of the major areas of development in astronomy now is gamma-ray bursts and Chris is an international leader in the theory and the interpretation of the data. His proposal that "soft gamma ray repeaters" are highly magnetized neutron stars, which he dubbed magnetars, has been brilliantly confirmed by subsequent observations, and has stimulated much further theoretical and observational work. He is also known for the breadth of topics he covers, passing easily from cosmology to plasma physics and dynamos to black holes, neutron stars and supernovae to planetary systems, all topics on which he has written influential papers.

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2001 - Matthew W. Choptuik

This award of the Rutherford Medal to Matthew W. Choptuik, Department of Physics and Astronomy, The University of British Columbia, is in recognition of his stature as the world leader in the field of Numerical General Relativity. His discovery of the Choptuik effect, the demonstration via careful numerical work that the Black Hole formation has many of the attributes of a phase transition including critical scaling and discrete self similarity at the critical point where an infinitesimal black hole is formed, has deepened our understanding not only of black holes, but of critical phenomena in other areas of physics. He has also been a leader in the development of techniques for calculating the gravitational wave emission during the formation of astrophysical black holes, information which will be crucial to the operation of the gravity wave detection facilities now coming on line world wide. By emphasizing the importance of careful numerical analysis of these incomparable difficult problems, he has been responsible for placing the field on a solid footing, and making it into a tool for understanding these most violent of astrophysical phenomena.

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2000 - Jerry X. Mitrovica

Professor Jerry Mitrovica, Professor of Physics, University of Toronto, is an internationally renowned geophysicist whose research is characterized by unparalleled breadth, innovation and productivity. He has made seminal contributions in areas as diverse as Earth rotation and orbital dynamics, global geodynamics, climate and sea-level change. He is credited with helping to establish a new branch of Earth system science that links geophysical processes with orbital dynamics and the long-term evolution of the Earth's climate. His research on the internal structure of the planet has resolved a 50-year old controversy in geophysics. He has also proposed novel mechanisms to explain enigmatic changes in continental topography and global sea-level. These proposals are driving a major re-appraisal of conventional theories in geodynamics.

Professor Mitrovica has coauthored 40 articles in the last six years, appearing in major geophysics journals, in Science and in Nature. His work has been the subject of national and international media attention on three occasions in the last few years. His students and fellows have moved on to prestigious faculty and post-doctoral appointments, in addition to positions in industry. His passion for science education is also reflected in his legendary relationship with the students in his classes and his receipt of the 1998 University of Toronto Faculty of Arts and Science Outstanding Teaching Award.

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1999 - Robert A. Wolkow

Robert A. Wolkow, Steacie Institute for Molecular Sciences, National Research Council of Canada, has been at the forefront of the increasingly important field of scanning tunneling microscopy (STM) and atomic-scale surface processes for over ten years. He is Senior Research Officer and Scanning Tunneling Microscopy Group leader at NRC. His seminal accomplishments and his profound influence on his field place him as one of Canada's most gifted scientists and among an international elite. Most recently he has achieved two breakthroughs in the understanding of molecule-surface reactions: the direct observation of a precursor (physisorbed) state preceding the formation of a chemical bond (postulated for more than seventy years but never before observed) and the determination of the stereochemistry and absolute chirality of individual molecules on a surface. This work will underpin the development of new hybrid semiconductor-organic devices. That he is still a young scientist makes these achievements all the more remarkable.

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1998 - Martin Grant

Martin Grant, Department of Physics, McGill University, has been at the forefront of one of the revolutions in modern science: Where do complex structures come from, and how can they be understood? His research uses computer models to simulate the properties of liquids and solids in non-equilibrium states, that is, when they are far from their normal operating conditions. Some of the complex systems he has studied include flame fronts, crystallizing eutectics, and self-lubricating polymer melts. Surprisingly enough, his research shows that many of the properties of these disparate systems can be understood using the common language of scale invariance. These systems involve fundamental issues in science, as mentioned above, as well as common-sense issues related to the physical and mechanical properties of most materials, such as the failure rates of materials, their tensile strength, and ease of fabrication. All his work is done in close contact with experiment, and indeed, McGill University has become a world leader in this area through his efforts.

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1997 - Nicholas Kaiser

Nicholas Kaiser has made deep and original contributions to physical cosmology. He invented the concept of biased galaxy formation, which is fundamental to understanding the dynamical implications of large-scale structure in the universe. He has devised novel observational strategies that greatly enhance the efficiency of redshift surveys, has led the development of Gaussian random fields as a tool for studying structure formation, and has investigated the consequences of a variety of candidate theories for dark matter. More recently, he has exploited weak gravitational lensing to provide direct maps of the distribution of dark matter in rich clusters of galaxies, which can be compared directly to maps of the galaxy an gas distribution.

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1996 - Pekka K. Sinervo

Pekka K. Sinervo is an outstanding young Experimental Particle Physicist who has made seminal contributions to the international search for the top quark. He has played a leadership role in the collider detector at FERMILAB (CDF) collaboration for a number of years and was asked to manage the data processing, software development and computer systems support for the collaboration in 1993, a responsibility he just recently relinquished. Dr. Sinervo continues to focus his research on top quark physics, but has also devoted considerable research time over the last six years to the next generation of particle physics experiments. He is currently directing his efforts on ATLAS, an experiment proposed for the Large Hadron Collider in Geneva, Switzerland.

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1995 - David B. MacFarlane

David MacFarlane, McGill University, has made seminal contributions to experimental studies on the interaction and symmetry properties of the charm and the bottom quarks. He played a leading role in the discovery of mixing in the neutral (bd) system (the so-called B meson). In this process the neutral B meson spontaneously transforms to its anti-particle. It occurs through second order weak interaction effects and is sensitive to virtual processes mediated by the elusive top quark. The discovery, in particular the large rate of mixing, opened a new window on the long-standing puzzle of CP violation. It also galvanized enormous international activity to design high luminosity, asymmetric energy electron positron colliders--otherwise known as B factories--to exploit the mixing phenomenon as a new technique to study the origins of CP violation. David MacFarlane's reputation as one of the world's best young particle physicists has propelled him into a responsible position of leadership within Canada and abroad. With the recent decision by the U.S.A. to build a B-factory at Stanford, he will lead a strong Canadian team in an international collaboration to build and exploit a detector for this collider.

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1994 - Michael L.W. Thewalt

Dr. Thewalt, Simon Fraser University, achieved wide acclaim when his Ph.D. research settled a raging international controversy over the existence and properties of bound multiexciton complexes. His unique spectroscopic methods have yielded deep insights into the nature of excitons and biexcitons, as fundamental to the understanding of semiconductor physics as the hydrogen atom H and molecule H2, are to atomic physics. The existence of polyexcitons, analogous to H3, H4 etc., was conjectured in 1972. Dr. Thewalt provided confirmation in 1987 using his newly developed, ultrasensitive experimental techniques. His remarkable successes in applying these techniques to problems of industrial relevance are also well recognized.

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1993 - John W. Hepburn

John Hepburn, University of Waterloo, has made major contributions to chemical physics in the application of coherent extreme ultraviolet (XUV) light to spectroscopy and reaction dynamics. He has been a leader in elucidating the detailed dynamics of small molecule photodissociation, particularly for metal carbonyls, using coherent XUV for product detection. In collaboration with Paul Houston, he demonstrated the use of Doppler spectroscopy for probing photofragment vector correlations. More recently, he has carried out work in photoionization spectroscopy, concentrating on elucidating the detailed dynamics of molecular autoionization. His laboratory is currently involved in forefront investigations of quantum interference effects in photodissociation, effects that could provide the capability of controlling photochemical reactions.

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1992 - François Wesemael

Professor Wesemael is a talented young astrophysicist specializing in the study of stellar atmosphere models and in the analysis of astronomic data. At age thirty-six, Dr. Wesemael has already published over sixty scientific papers, not including conference reports, and has acquired an outstanding reputation in Europe, Canada and the United States. Recipient of the prestigious Herzberg medal awarded to him in 1988 by the Canadian Association of Physicists, Dr. Wesemael is at the forefront of our new generation of scholars. His colleagues are very proud indeed to have with them this outstanding young scientist whose work and personality are so remarkable.

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1991 - Ian K. Affleck, FRSC

Dr. lan K. Affleck is recognized for his contributions to mathematical physics. These have been distinguished by penetrating insight and intuition and a rare ability to absorb details of experiments that are important to his work. He has applied ideas from quantum field theory to a wide range of topics, spanning particle and condensed matter physics and including statistical mechanics, supergravity and superconductivity. His theory of flux phases is widely quoted world-wide in the extremely competitive field of high temperature superconductivity, making him one of the best known theoretical physicists of his generation.

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1990 - Scott Tremaine

Dr. Tremaine is recognized for his outstanding contributions to the field to astrophysics, particularly his spectacular success in predicting the properties of planetary ring dynamics and the extraplanetary objects that control them. He focussed on the application of classical dynamics to astrophysics, a topic so central to astrophysics that his research spanned a broad variety of systems and scales, ranging from the microscopic equilibrium of planetary rings to cosmology and galaxy formation. The record of this achievement in planetary ring dynamics alone is a fascinating catalogue of highly imaginative predictions, subsequently substantiated by observation. Dr. Tremaine's research on comets, their orbits and fluxes has led to a new understanding of the forces that control their behaviour. Such understanding is extremely important for the interpretation of the geological record of cratering events and possible environmental disasters, such as the extinction of the dinosaurs, that could have resulted from comet impacts.

Dr. Tremaine also investigated the possibility that massive neutrinos could provide the dark mass in galaxies. This work still provides one of the solid arguments against massive neutrinos as the dark matter, the findings strongly suggest that the dimensions of the halo and the total mass of the Galaxy are much less than generally supposed. Dr. Tremaine's work on dark matter and galactic halos has major implications for cosmology and the curvature of the Universe, whose importance in modem physics can hardly be overemphasized. His observations on the extreme difficulty of making curvature measurements based on the redshift-magnitude test have, as a result, caused cosmologists to redirect their efforts.

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1989 - Nathan Isgur, FRSC

Dr. Isgur has made important contributions to the field of elementary particle physics, especially to hadron spectroscope and the quark model. His earliest contribution in this field is the explanation of the mixings in isocalar mesons where he pointed out the importance of the annihilation graphs in the pseudoscalar sector where large mixings were known to occur. This mechanism resolved a long-standing puzzle on the mixing angles in pseudoscalar mesons. More recently, Dr. Isgur has generalized the quark model to include excitations of the string connecting quarks to anti-quarks, leading to very interesting predictions for the masses and decay modes of so-called hybrid mesons.

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1988 - Claude Leroy

Dr. Leroy is recognized as an accomplished physicist who plays a leading role in the development of young physicists in Quebec. He has been involved in important experiments in low energy, intermediate energy, and high energy nuclear and particle physics. Dr. Leroy has an impressive record of achievements in Electro-Weak Interactions (including second-class currents, conservation of the electronic and muonic numbers), Strong Interations (including heavy-flavour production, the search for the Quark Glucon Plasma), Calorimetry (he built the first calorimeter which uses silicon as a medium), and the ZEUS project (to be performed at DESY in Hamburg by an international consortium). The main goal of ZEUS is to explore physics beyond the standard model and look for new families of heavy particles as predicted by supersymmetry and technicolour. Dr. Leroy is expected to play a major role at the level of analysis inside the Canadian group working in ZEUS.

Until 1980, Dr. Leroy worked as a researcher both in experimental and theoretical physics, when he chose to pursue strictly experimental activities. Dr. Leroy has been working in the HELIOS experiment since 1984. HELIOS is probably the largest Fixed Target experiment in operation to date with 120 physicists from twenty-two institutes. He leads the McGill group responsible for the operation and physics analysis of the HELIOS Calorimetry System, the world's best performing calorimeter detector.

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1987 - A. John Berlinsky

In his short career, John Berlinsky has established himself as a physicist of outstanding capability and breadth, making lasting contributions to each of the many fields in which he works, through absolute dedication, a high personal standard of excellence, and tireless encouragement of others. It is a clear indication of his insight into what is important that his work, always timely, also stands the test of time. He began with theoretical studies of libron anharmonicities in solid hydrogen and his thesis represented the most sophisticated work done on solid H2 up to that time. As a postdoctoral fellow, he produced key papers on molecular solids, including work on NMR lineshapes, nuclearspin conversion, the ortho-hydrogen pair spectrum and neutron scattering. At the same time he collaborated on experimental work resulting in the first observation of the microwave spectrum of solid hydrogen and led the theoretical work necessary for interpreting these important spectra. His papers on nuclear spin conversion in solid hydrogen completely changed the field, exposing gross misinterpretations of experimental data that had remained unchallenged for more than a decade, and his work led to new directions.

At the University of Amsterdam in 1975 Dr. Berlinsky wrote two papers that were pivotal in the field of spin polarized hydrogen--the first showed that bulk-spin polarized atomic hydrogen would spontaneously decay via spin excitations and, therefore, be impossible to produce; the second focussed attention on the gas, and Berlinsky was first to derive the elementary excitations of Bose-condensed open-polarized atomic hydrogen. Dr. Berlinsky returned to UBC in 1977 and began a rigorous research program in many areas of condensed matter physics, mainly on low temperature atomic hydrogen, an exciting new field of low temperature physics in whose beginnings he had participated, and he played a key role in establishing and maintaining UBC as one of the top laboratories in atomic hydrogen research. In 1981 he copublished the first calculation of the now famous T bottleneck in spin-polarized hydrogen. His calculation of the low temperature spin exchange coefficient was one of the crucial ingredients in predicting the ultimate performance of cryogenic hydrogen masers. Professor Berlinsky, born in Washington D.C. in 1945, studied at Fordham College, New York, and the University of Pennsylvania where he obtained his Ph.D.

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1986 - William J.L. Buyers

Dr. Buyers is internationally renowned for his work in condensed matter physics. He has made extensive original contributions both theoretical and experimental, to the study of structure and excitations in condensed matter, employing for the most part various techniques of neutron elastic and inelastic scattering. His work has contributed to a significant advance in the theory of spin waves in disordered antiferromagnets. Many properties of excited-state spin waves, soft modes and crystal field effects were elucidated. He has concentrated on two major topics: (i) the magnetic behaviour of the 5f electrons in actinide compounds, and (ii) the spin wave and soliton excitations in one-dimensional antiferromagnets.

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1985 - John J. Simpson

John J. Simpson has made several important contributions to experimental nuclear and particle physics, especially on the problem of the mass and nature of neutrinos, the most elusive of all particles. In the early part of his career, Simpson worked on nuclear physics problems; in particular, he carried out the first experiments to measure quadruple moments of excited states by Coulomb excitation, and pioneered the use of heavy ion reactions to determine the location of high spin states in the region of A = 40 - 80. For example, he located the rotational like bands in 44Ti up to spin 12 +. In the course of this work he also discovered the first example of isospin violating radiative decay of a nucleus (from the lowest T = 2 level of 44Ti) and developed a method of studying isospin mixing in the compound nucleus by looking at Ericson fluctuations in mirror reactions.

In his more recent work, in the last four years, Simpson has made substantial contributions to the physics of neutrinos. He invented a new method of measuring the neutrino mass by implanting tritium in an Xray detector and recording the beta spectrum of tritium decay in situ. Simpson, carrying out this experiment singlehandedly, achieved the best limit available in 1981. This experiment also allowed him to set the best limit on the mass of neutrinos heavier than the lightest one; he measured the tritium-helium three mass difference to an accuracy of 10 eV, and measured the lifetime of tritium to an accuracy of 0.3%. More recently Simpson found an error in the widely publicized experiment of Lyubimov, et al., who had reported non zero neutrino masses. Simpson's criticism was quickly acknowledged by Lyubimov as being correct. Recently, Simpson led a team which built a low background high purity Germanium detector to search for the neutrinoless double beta decay of a Germanium isotope (76Ge). This process can provide evidence of a finite neutrino mass. The first version of this detector has been built and is the largest detector of its type in the world. It has operated for 2500 hours in a salt mine near Windsor and gave a lower limit on the double beta decay lifetime }3.2 X 1022 years, the best limit available. A new version of this detector, three times as large, has now been built and is being tested.

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1984 - Penny G. Estabrooks

Dr. Penny Estabrooks has made important contributions both theoretical and experimental to several areas in elementary particle physics, most recently in the experiments on photo-production of charm at the Fermilab. She is one of the most promising physicists in the Canadian high energy community and at this time she is emerging as a strong leader in the photon physics effort. This effort has been one of the most successful in our High Energy Physics programme over the years.

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1983 - David J. Rowe

David Rowe has made outstanding contributions to theoretical nuclear physics, in particular to the algebraic and geometric approach to nuclear modelling. His first contribution was to expose the essential equivalence of the unified model and the random phase approximations, thus freeing the latter approximation from severe restrictions. Dr. Rowe's major recent research accomplishments arise from his applications of sophisticated modern techniques of Lie algebra, group theory and differential geometry to many-body theory. The goal, which has now largely been achieved, was to fully embed the phenomenological collective models into the microscopic shell model. The required theory would not simply be a small amplitude normal mode theory, like the random phase approximation, but would be one that would admit large amplitude phenomena such as nuclear rotations and fission. Attempts by many researchers over the years to make a transformation to collective and intrinsic coordinates had failed due to the complexity of the problem. The algebraic approach was to forget coordinates and concentrate on Lie algebras of collective observables. The geometric approach was likewise to forget coordinates and think of collective motions as motions on a geometrical hypersurface in the many-particle configuration space. Whether or not the specific models of the nucleus invoked by Dr. Rowe will provide the answers to the major questions of interest remains to be seen, but the uses of modem mathematics in the manner pioneered by him and his students will also certainly remain.

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1982 - William G. Unruh

William Unruh, of the Department of Physics, University of British Columbia, showed early promise which was recognized by the award to him of the Rutherford Memorial Fellowship in 1971. He has amply fulfilled that promise by the subsequent rapid development of his scientific career until now he is considered to be the most original and intellectually powerful theoretical physicist to have emerged in Canada in the past decade or two. Dr. Unruh is a very active pioneer in quantum gravity theory and the theory underlying the ultimate limitations to the delectability of gravity waves and is a leader in the theory of "quantum non-demolition". His analysis of how particle "detectors" "detect" particles and how this is affected by their acceleration relative to a local inertial frame, so that acceleration seems to cause particle creation, is a masterpiece of physical thinking, which illuminates the theory of particle creation at the event-horizon of a black hole. He was the first to give a rigorously sound demonstration that a Kerr black hole spontaneously emits particles. The particle-free vacuum, as he has defined it in current studies of production of particles out of the vacuum by strong gravitational fields, is now widely known as the "Unruh vacuum". Dr. Unruh was awarded the prestigious Sloan Fellowship in 1978, and was an invited speaker at the Einstein Centennial Celebration at Princeton in 1979. William Unruh's scientific interests are not confined to gravity, but extend to the very practical, and apparently very different, science of highly efficient energy storage cells.

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1981 - John C. Hardy, FRSC

John Hardy is perhaps the most ingenious and energetic experimentalist in the aspect of nuclear physics that assesses the role played by the weak interaction in the nucleus. Some of the most exciting recent developments in physics are those concerning the weak interaction, its unification with the electromagnetic interaction and possibly the near future, with the two other interactions--the strong and gravitational. Dr. Hardy and his colleagues at Chalk River have made a large and crucial contribution to our knowledge of the weak interaction through comprehensive and precise studies of superallowed beta decay. In addition, he has for many years played a key role in understanding the phenomenon of delayed particle emission and its use in determining the properties of rare and unusual nuclei. Although primarily an experimentalist, he is well versed in, and contributes to, the theory. At every laboratory in which he has worked, he has been recognized as a leader of research programs.

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1980 - Malcolm J. Stott

Dr. Stott is an outstanding theoretical solid state physicist and is probably the best young physicist in solid state theory in Canada. In his relatively short career he has made several important contributions in a variety of areas. His early work concerned many-body effects in solids, in particular electronic screening of charges in metals. He contributed significantly to the understanding of soft X-ray emission spectra in metals and dilute alloys. He became interested in the behaviour of positrons in solids and with B. Bergersen published an important short paper showing how vacancy properties in metals could be studied using positrons. The use of positrons to study defects in solids is now used in many laboratories throughout the world. Stott has continued to work in the field and made many other contributions to the understanding of positron distributions in metals and alloys. Especially notable is the development of a simple "pseudopotential approach" to the calculation of positron wave-functions and energies, and ideas on positron self-trapping in metals and 4He. He is the world expert in this field. Stott's most recent (and unpublished) endeavours are new ideas about the thermodynamic properties of solids. Going beyond the ideas of Kohn (and students) and of Ziman's "neutral atom", he and his colleagues are developing a "quasi atom" approach to the calculation of a wide range of physical-chemical properties from the energy of alloying, to chemical bonds in molecules. This approach appears very promising and could develop into a new way of thinking about and of calculating atom-atom interactions in solids, surfaces and molecules.

Stott has made contributions in many areas as evidenced by his publications, of which the foregoing are only two examples. Other areas include transport in dilute alloys, nuclear magnetic resonance in metals, problems in liquid 3He and 4He, and various applications of powerful thermodynamic techniques to metals and alloys which, for example, allow calculations at elevated temperatures of a number of problems that could only previously be treated at absolute zero. In all these areas Stott's clear physical insight has resulted in major contributions.

Dr. Stott is an imaginative physicist with a deep understanding of solid state physics. His work is characterized by new and original approaches to problems. He gets right to the core of the problem. He interacts very well with his theoretical and experimental colleagues and is the source of many new ideas for experiment and theory. His simple and often intuitive approach to physics makes even his more subtle ideas appear easy for others to understand once they have been formulated. Although he works primarily with theory he can only be described as a physicist in the best sense, and one whose insight Rutherford would surely have appreciated.