Public Lectures

Einstein's theory of General Relativity has taught us that empty space (or, more precisely, spacetime) is in itself a dynamical and wonderfully rich entity for both theoretical physicists and science fiction authors alike. Although it may stretch our imagination, astrophysical observations leave little doubt that spacetime can bend, move and vibrate. If we want to explain these phenomena from an underlying microscopic and more fundamental structure, we need to bring in quantum theory, leading to even more exotic possibilities such as spacetime foam and wormholes. Do they really exist? How would we know? Are they in conflict with known physics? At least some of these questions may already be within the reach of our fundamental physical theories, not just qualitatively, but also quantitatively. In this talk, Professor Loll will share her insights into how much we know and how much we can still hope to learn about quantum gravity - the elusive quantum theory of space and time.

Since its launch in 2007, the website Galaxy Zoo (www.galaxyzoo.org) has become the largest astronomical collaboration in history, involving more than 250,00 volunteers in classifying galaxies. Humans outperform computers at this kind of visual classification, and the results from Galaxy Zoo have been spectacular. As well as reviewing the intimate connections between the delicate process of galaxy formation and the evolution of our Universe, this talk will include a review of the weird and wonderful objects identified by Galaxy Zoo users and a few tales from the ups and downs of citizen science.

Does quantum mechanics really tell us that particles, molecules, and maybe even cats, can be in two places at once? Does it force us to deny a reality that is independent of our observation? How can scientists disagree about what quantum mechanics means and yet still agree that it is right? Joseph Emerson, co-writer of the award-winning documentary “The Quantum Tamers”, will address these questions and then describe, drawing on preview clips from the documentary, how the weirdness of the quantum world is now being harnessed for a ‘quantum information revolution’ that includes quantum teleportation, super-secure quantum communication, and the exponential power of quantum computation.

For centuries, scientists have attempted to identify analytical laws that underlie physical phenomena in nature. Despite today’s computing power, the process of finding natural laws and their corresponding equations has resisted automation. A key challenge to finding analytic relations automatically – that is, building an autonomous robot - is defining algorithmically what makes a correlation in observed data important and insightful. Scientists are gradually uncovering an ‘alphabet’ that can be used to describe the simplest to most complex physical systems – and by seeking dynamical invariants, researchers go from finding simple predictive models to discovering deeper natural laws. Dr. Lipson will demonstrate the process on a variety of mechanical, biological, and robotic systems.

The top quark is the heaviest known type of quark, and possibly the last. Particle physicists sometimes refer to it as the "truth” quark, not always with tongue in cheek. The top quark might be just an ordinary quark, no stranger than the "strange" one, but it might hold the key to major questions of Nature through its connection to the origin of mass, the Higgs boson, and cosmic dark matter. At the Fermi National Accelerator Laboratory outside Chicago, hundreds of these heavy quarks have been observed and some first snapshots of their behavior have been obtained. At the Large Hadron Collider at CERN, millions of the heavy quarks will be produced. This lecture will review current knowledge of the top quark and explain how this knowledge has been obtained through experiments at the giant particle accelerators. Future experiments, which might reveal the top quark's deeper mysteries, will also be described.

Astronomers believe our Universe began in a Big Bang, and is expanding around us. Brian Schmidt will describe the life of the Universe that we live in, and how astronomers have used observations to trace our Universe's history back more than 13 Billion years. With this data a puzzling picture has been pieced together where 96% of the Cosmos is made up of two mysterious substances, Dark Matter and Dark Energy. These two mysterious forms of matter are in a battle for domination of the Universe, and Schmidt will describe experiments that are monitoring the struggle between Dark Energy and Dark Matter, trying better understand these elusive pieces of our Universe, and predict the ultimate fate of the Cosmos.

Black holes are regions of space with gravity so strong that nothing can escape from them, not even light. This isn't science fiction - there's even a gigantic black hole at the center of our galaxy. It's hard to imagine a more effective way to irrevocably erase and destroy a computer's hard drive than to drop it into a nice big black hole. But is the information on that drive really gone forever? Paradoxically, there's a good chance that not only does the information come back, it comes back in the blink of an eye. This surprise return of the information is based on the same principles that might someday make reliable quantum computers a reality. In fact, engineers are already exploiting these principles to help distribute software and stream video over the internet. And that's where the tornadoes come in...

Our present Core Theory of matter (aka “standard model”) was born in the 1970s, a Golden Age for fundamental physics. To date it has passed every experimental test, extending – by many orders of magnitude – to higher energies, shorter distances, and greater precision than were available in the 1970s. Yet we are not satisfied, because the Core Theory postulates four separate interactions and several different kinds of matter, and its equations are lopsided. In this lecture, Prof. Wilczek will describe powerful and extremely beautiful ideas for restoring unity and symmetry to the fundamental laws. These ideas are firmly rooted in empirical reality, but at present the evidence for them is circumstantial. The Large Hadron Collider (LHC) will provide critical tests. If Nature has been teaching, not teasing, discoveries at the LHC will inaugurate a new Golden Age, bringing our fundamental understanding of the physical world to a new level. Standard model, fundamental physics, experiment, LHC, unification, particle physics, supersymmetry, vacuum fluctuation

There is now a great deal of evidence confirming the existence of a very hot and dense early stage of the universe. Much of this data comes from a detailed study of the cosmic microwave background (CMB) - radiation from the early universe that was most recently measured by NASA\'s WMAP satellite. But the information presents new puzzles for scientists. One of the most blatant examples is an apparent paradox related to the second law of thermodynamics. Although some have argued that the hypothesis of inflationary cosmology solves some of the puzzles, profound issues remain. In this talk, Professor Penrose will describe a very different proposal, one that suggests a succession of universes prior to our own. He will also present a recent analysis of the CMB data that has a profound bearing on these issues.

At the beginning of the 20th century Einstein published three revolutionary ideas that changed forever how we view Nature. At the beginning of the 21st century Einstein\'s thinking is shaping one of the key scientific and technological wonders of contemporary life: atomic clocks, the best timekeepers ever made. Such super-accurate clocks are essential to industry, commerce, and science; they are the heart of the Global Positioning System (GPS), which guides cars, airplanes, and hikers to their destinations. Today, atomic clocks are still being improved, using Einstein\'s ideas to cool the atoms to incredibly low temperatures. Atomic gases reach temperatures less than a billionth of a degree above Absolute Zero, without solidifying. Such atoms enable clocks accurate to better than a second in 60 million years as well as both using and testing some of Einstein\'s strangest predictions. This will be a lively, multimedia presentation, including experimental demonstrations and down-to-earth explanations about some of today\'s most exciting science. Low temperature physics, atomic clock, global positioning system, laser cooling, Bose Einstein condensate, photoelectric effect, Brownian motion, special relativity