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Impossible Crystals
PIRSA:06090000 -
A discrete, Lorentz-invariant wave equation and its continuum limit
Perimeter Institute for Theoretical Physics -
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Faster than the Speed of Light - Could the laws of physics change?
Imperial College LondonPIRSA:06060057 -
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A Night with Nobel - The Origin of Mass and the Feebleness of Gravity
Massachusetts Institute of Technology (MIT) - Center for Theoretical PhysicsPIRSA:06060002 -
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Programming the Universe
Massachusetts Institute of Technology (MIT) - Center for Extreme Quantum Information Theory (xQIT)PIRSA:06040020 -
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Time and Motion
University of OxfordNewton\'s first law of motion - and the very meaning of inertia - has been described as either completely obvious (D\'Alembert) or a \'logician\'s nightmare\' (ex-editor of the American Journal of Physics). Sometimes the simplest things in physics are the most subtle. The first law will be described in historical context, explaining a connection with the ancient Greeks distinction between natural and violent motion and with Descartes\' natural philosophy. You will also learn why it still requires careful handling and what it tells us about time in physics. \'Time and Motion\', Harvey Brown, time, motion, relative, Copernicus, Ptolemy, Galileo, Copernicanism, Descartes, inertia, Newton, standard of time, Fitzgerald, duration, inertial frame -
A Madman Dreams of Turing Machines: Limits of Truth and Mind
Columbia UniversityPIRSA:06100005From Levins recent book comes a strange if true story of coded secrets, psychotic delusions, mathematics, and war. This story of greatness and weakness, of genius and delusion, circulates around the parallel lives of Kurt Gödel, the greatest logician of many centuries, and Alan Turing, the extraordinary code breaker during World War II. Taken together their work proved that there are limits to knowledge, that machines could be taught to compute, that one day there could be artificial intelligence. Yet Gödel believed in transmigration of the soul and Turing concluded that we were soulless biological machines. And their suicides were complementary. Gödel, delusional and paranoid, starved himself to death fearing his food was poisoned. Turing ate a poison apple, driven to suicide after being arrested and convicted of homosexual activities. These two men were devoted to truth of the highest abstract nature, yet were unable to grasp the mundane truths of their own lives. Through it all, you will explore, along with these two odd heroes, if any of us can ever really grasp the truth. Madman Dreams, Turing Machines, Turing, Truth, Godel, Mathematical Theory of Everything, Liar\'s Paradox, Turing machine, limits, mathematical truth -
Impossible Crystals
PIRSA:06090000This is a story of how the impossible became possible. How, for centuries, scientists were absolutely sure that solids (as well as decorative patterns like tiling and quilts) could only have certain symmetries - such as square, hexagonal and triangular - and that most symmetries, including five-fold symmetry in the plane and icosahedral symmetry in three dimensions (the symmetry of a soccer ball), were strictly forbidden. Then, about twenty years ago, a new kind of pattern, known as a \'quasicrystal,\' was envisaged that shatters the symmetry restrictions and allows for an infinite number of new patterns and structures that had never been seen before, suggesting a whole new class of materials. By chance, solids with five-fold symmetry were discovered in the laboratory at about the same time. Even so, for nearly twenty years, many scientists continued to believe true quasicrystals were impossible because, they argued, such a pattern could only be formed with complex and physically unrealistic inter-atomic forces. In this talk, you will see simple, beautiful patterns and a series of geometrical toys and games that demonstrate, with subtlety and surprise, how this last conceptual barrier has been recently overcome - leading to new insights on how to grow perfect quasicrystals and inspire new technological applications. About the Speaker: Paul J. Steinhardt is the Albert Einstein Professor in Science at Princeton University and is on the faculty in the Department of Physics and in the Department of Astrophysical Sciences. He received his B.S. in Physics at Caltech in 1974; his M.A. in Physics in 1975 and Ph.D. in Physics in 1978 at Harvard University. He was a Junior Fellow in the Harvard Society of Fellows from 1978-81 and on the faculty of the Department of Physics and Astronomy at the University of Pennsylvania from 1981-98, where he was Mary Amanda Wood Professor from 1989-98. He is a Fellow in the American Physical Society and a member of the National Academy of Sciences. In 2002, he received the P.A.M. Dirac Medal from the International Centre for Theoretical Physics. Steinhardt is a theorist whose research spans problems in particle physics, astrophysics, cosmology and condensed matter physics. He is one of the architects of the .inflationary model. of the universe, an important modification of the standard big bang picture which explains the homogeneity and geometry of the universe and the origin of the fluctuations that seeded the formation of galaxies and large-scale structure. He introduced the concepts of .quintessence,. a dynamical form of dark energy that may account for the recently discovered cosmic acceleration. He has also explored novel models for dark matter. Recently, Steinhardt and Neil Turok (Cambridge U.) proposed the .cyclic model. of the early universe, a radical alternative to big bang/inflationary cosmology in which the evolution of the universe is periodic and the key events shaping the large scale structure of the universe occur before the big bang. In condensed matter physics, Steinhardt and Dov Levine (Technion) introduced the concept of quasicrystals, a new phase of solid matter with disallowed crystallographic symmetries. Steinhardt continues to make contributions to understanding their unique mathematical and physical properties. He has written over 200 papers, edited 4 books, and holds three U.S. patents. Impossible Crystals, Paul Steinhardt, symmetry, crystal, three-fold symmetry axis, five-fold symmetry axis, two-fold symmetry axis, quasicrystals, rotational symmetry, Penrose, Penrose Tiler, Gummell-Tile, quasi-unit-cell, non-local iterations, period array, platonic crystal -
A discrete, Lorentz-invariant wave equation and its continuum limit
Perimeter Institute for Theoretical Physics -
Do background independent approaches to quantum gravity have something to say about this question?
Utrecht UniversityThe question of how to describe a natural ultraviolet cutoff in an expanding space-time is of significance in several respects. First, it concerns the fate of general covariance in the presence of a natural UV cutoff. Second, it concerns the continued generating of degrees of freedom through expansion, which carries with it the possibility of an associated generating of vacuum energy. Finally, through inflation, a natural ultraviolet cutoff may have left observable imprints in the CMB. -
Faster than the Speed of Light - Could the laws of physics change?
Imperial College LondonPIRSA:06060057The laws of physics are usually meant to be set in stone; variability is not usually part of physics. Yet contradicting Einstein\'s tenet of the constancy of the speed of light raises nothing less than that possibility. I will discuss some of the more dramatic implications of a varying speed of light. João Magueijo is Professor of Physics at Imperial College London. He is currently visiting Perimeter Institute and the Canadian Institute for Theoretical Astrophysics in Toronto. He received his doctorate in theoretical physics at Cambridge University, and has been a visiting scientist at the University of California at Berkeley and Princeton University. Joao Magueijo, Theory of Relativity, speed of light, VSL, varying speed of light, Dirac, cosmology, geometry, dimensional, dimensionless, Bekenstein, Brans-Dicke, varying constant, Einstein, time dilation, length contraction, horizons, Big Bang, grand-unified theory, Planck length, Planck time, gravity, space, time, quantum gravity, varying alpha, Kelvin, quasar, laws of physics -
The Quantum and the Cosmos
University of ChicagoPIRSA:06060005Long before the emergence of planets, stars, or galaxies, the universe consisted of an exploding quantum soup of elementary particles. Encoded in this formless, shapeless soup were seeds of cosmic structure, which over billions of years grew into the beautiful and complex universe we observe today. The lecture will explore the connection between the inner space of the quantum and the outer space of the cosmos. The inner space/outer space connection may hold the key to the nature of the dark matter holding together our galaxy and the mysterious dark energy pulling apart our universe. Edward W. Kolb (known to most as Rocky) is a founding head of the NASA/Fermilab Astrophysics Group at Fermi National Accelerator Laboratory and a Professor of Astronomy and Astrophysics at The University of Chicago. Presently he is the Director of the Particle Astrophysics Center at Fermilab. A native of New Orleans, he received his Ph.D. in physics from the University of Texas. Postdoctoral research was performed at the California Institute of Technology and Los Alamos National Laboratory where he was the J. Robert Oppenheimer Research Fellow. He has served on editorial boards of several international scientific journals as well as Astronomy magazine. In addition to over 200 scientific papers, he is a co-author of The Early Universe, the standard textbook on particle physics and cosmology. His book for the general event, Blind Watchers of the Sky, received the 1996 Emme Award of the American Aeronautical Society. Rocky teaches cosmology to non-science majors at the University of Chicago and is involved with pre-college education enrichment programs. He has traveled the world, if not yet the Universe, giving scientific and event lectures. He has appeared in several television productions, and can also be seen in the OMNIMAX/IMAX film The Cosmic Voyage. His distinctions include: Fellow of the American Academy of Arts and Sciences, Fellow of the American Physical Society, recipient of the 2003 Oersted Medal of the American Association of Physics Teachers, winner of the 1993 Quantrell Prize for teaching excellence at the University of Chicago, Harlow Shapley Visiting Lecturer and Centennial Lecturer with the American Astronomical Society. He has also presented event lectures at the Royal Society of London, and in Rio de Janeiro, Valencia, and Barcelona. cosmos, quantum, cosmology, universe, galaxies collide, Barnes, Hibbard, Newton, Einstein, relativity, space, time, origin of the universe, dark energy, expansion history, vacuum quantum, Vera Rubin, invisible universe, dark matter, quantum universe, Higgs potential, Big Bang Theory, Hubble, WIMPS, cosmic background radiation -
A Night with Nobel - The Origin of Mass and the Feebleness of Gravity
Massachusetts Institute of Technology (MIT) - Center for Theoretical PhysicsPIRSA:06060002Einstein\'s famous equation E=mc2 asserts that energy and mass are different aspects of the same reality. It is usually associated with the idea that small amounts of mass can be converted into large amounts of energy. For fundamental physics, however, the more important idea is just the opposite. Researchers want to explain how mass itself arises, by explaining it in terms of more basic concepts. In this lecture targeted for a general audience, Prof. Wilczek will explain how this goal can, to a remarkable extent, be achieved. He will also discuss some of the consequences - an explanation of why gravity is so feeble - and suggestions for new physical phenomena at the Large Hadron Collider (LHC) in Geneva. Prof. Wilczek is a distinguished scientist and lecturer. He is the author of Fantastic Realities: 49 Mind Journeys and a trip to Stockholm and co-author of Longing for the Harmonies. In addition to many distinguished memberships and affiliations, he is a member of Perimeter Institutes Scientific Advisory Committee. -
The Search for Miss Leavitt
The New York TimesPIRSA:06050003Inside Harvard College Observatory in 1904, a young woman named Henrietta Swan Leavitt sat hunched over a stack of glass photographic plates, patiently counting stars. The images had been taken by a telescope high in the Peruvian Andes, and Miss Leavitt was given the tedious chore of measuring the brightness of thousands of tiny lights, something that would now be done by machine. Her job title was \'computer,\' but during the next few years she rose above her station as a tabulator of data and discovered a new law, one that would change forever our view of the universe. George Johnson, the author of Miss Leavitt\'s Stars: The Untold Story of the Woman Who Discovered How to Measure the Universe, writes about science for The New York Times from Santa Fe, New Mexico and is winner of the AAAS Science Journalism Award. His other books include A Shortcut Through Time: The Path to the Quantum Computer, Fire in the Mind: Science, Faith, and the Search for Order and Strange Beauty: Murray Gell-Mann and the Revolution in 20th-Century Physics. He is co-director of the Santa Fe Science-Writing Workshop and can be reached on the Web at talaya.net. A graduate of the University of New Mexico and American University, his first reporting job was covering the police beat for the Albuquerque Journal. Miss Leavitt\'s Stars, George Johnson, Leavitt, astronomy, cephoid, Magellanic cloud -
Programming the Universe
Massachusetts Institute of Technology (MIT) - Center for Extreme Quantum Information Theory (xQIT)PIRSA:06040020The universe computes: every atom, electron, and elementary particle registers bits of information, and every time two particles collide those bits are flipped and processed. By hacking the computational power of the universe, we can build quantum computers which store and process information at the level of atoms and electrons. This computational capacity underlies the generation of complex systems, and provides insight into the origin of life and its future. Seth Lloyd is a professor in the Department of Mechanical Engineering at the Massachusetts Institute of Technology (MIT). He is the author of \'Programming the Universe: A Quantum Computer Scientist Takes On the Cosmos\' which asks the startling question \'Is the universe actually a giant quantum computer?\'. Programming the Universe, Seth Lloyd, capacitor, information processing, Big Bang, quantum computer, quantum mechanics, wave-particle duality, Schrodinger, complex universe, algorithmic, decode -
Mission to Mars: Still Roving on the Red Planet
Smithsonian InstitutionPIRSA:06020003An expected 90 day robotic odyssey on Mars has stretched into a two year scientific marathon. Dr. Grant, a geologist with the Center for Earth and Planetary Studies, helped pick the landing sites and works on day-to-day operations of the Spirit and Opportunity Rovers. Youll see the latest photos, learn what Martian mysteries have been uncovered and find out how scientists plan to push the limits of future robots in space. Dr. John A. Grant, III joined the Smithsonian in the fall of 2000 as a Geologist at the Center for Earth and Planetary Studies at the National Air and Space Museum. He has been a member of the Science Team for the Mars Exploration Rovers since 2002, is one of six Science Operations Working Group Chairs and is co-leading site selection activities for the 2009 Mars Science Laboratory mission to Mars. Since 2001, Dr. Grant has served as a Co-Investigator on the High Resolution Camera (HiRISE), which is being flown on the 2005 Mars Reconnaissance Orbiter, currently on its way to Mars. In addition, he is leading development of a ground-penetrating radar for possible future deployment on a Mars rover and conducts fundamental research related to the history of geologic processes on the Earth and Mars. He has been interested in Mars ever since reading Ray Bradburys The Martian Chronicles as a child. Dr. Grant earned his bachelors degree from the State University of New York College at Plattsburgh and received his masters in geology at the University of Rhode Island and his doctorate in geology at Brown University. He maintains a strong connection to the classroom and has held several professorial and teaching posts at both Rhode Island College and SUNY College at Buffalo. He has authored or contributed to numerous articles in many professional journals, including Science, Geology, Geomorphology, and the Journal of Geophysical Research. Mission to Mars, John A Grant, Mars, exploration, red planet, NASA, Spirit Rover, hematite, geology, air and space, outcrop, Mars Reconnaissance Orbiter, -
Are You Conscious?
Discovery Channel CanadaPIRSA:06010000The scientific approach to consciousness is a relatively new pursuit, but it has already revealed some startling facts about the cavalcade of feelings, images and thoughts that stream through our heads every waking moment. Jay Ingram will present some of the most surprising of these in a talk based on his best-selling book, Theatre of the Mind. Jay Ingram is the author of several bestselling books, including The Science of Everyday Life, The Barmaids Brain and The Velocity of Honey. He is producer and co-host of the Discovery Channels award-winning show Daily Planet, and also contributes a weekly science column to the Toronto Star. He holds two ACTRAs, the Royal Society of Canada McNeil Medal, the Sandford Fleming Medal from the Royal Canadian Institute, the Michael Smith Award for Science Promotion and three Canadian Science Writers Awards. Are you Conscious?, Jay Ingram, conscious, unconscious, change blindness, inattentional blindness, childhood amnesia