Public Lecture Series

More than a billion years ago, two black holes collided. In the final second of their long life together, the black holes banged out a rhythm like mallets on a drum, creating gravitational waves – ripples in the shape of spacetime. One hundred years ago, Albert Einstein predicted the existence of such waves, though it seemed improbable – if not outright impossible – that we’d ever be able to actually detect them. They were long considered too faint for any earthbound experiment to measure. Undaunted, experimentalists were determined to measure these Lilliputian ripples, and after many decades of work and collaboration, they built LIGO – the Laser Interferometer Gravitational-Wave Observatory. This incredible sophisticated and sensitive instrument was made to listen for the beat of that distant drum. In 2015, a billion years after the two black holes collided, their waves rippled through the LIGO detectors in Louisiana and Washington. With these remarkable new observatories, we can now capture the soundtrack to accompany the silent movie of the history of our universe.

Mathematics can be tasty! It’s a way of thinking, and not just about numbers. Through unexpectedly connected examples from music, juggling, and baking, Dr. Eugenia Cheng will demonstrate that math can be made fun and intriguing for all. Her interactive talk will feature hands-on activities, examples that everyone can relate to, and funny stories. She will present surprisingly high-level mathematics, including some advanced abstract algebra usually only seen by math majors and graduate students. There will be a distinct emphasis on edible examples.

The Hubble Space Telescope has completely revolutionized our understanding of the universe, and has become a beloved icon of popular culture. As revolutionary as Hubble has been, we have pushed it to its scientific limits in many ways. Hubble’s successor, the James Webb Space Telescope, has been in the works for almost two decades and is scheduled to launch in late 2018. It will be 100 times more powerful than Hubble. In her Perimeter Public Lecture, Dr. Amber Straughn will provide an update on the progress of building the world’s largest-yet space telescope, and will give an overview of the astronomical questions we hope to answer with Webb. These questions get to the heart of what it means to be human: Where did we come from? How did we get here? Are we alone?

Twenty-first century finance is built on complex mathematical tools developed by “quants,” a different breed of investor with expertise in fields such as physics, mathematics, and computer science. These models have been the basis for both new trading strategies and new financial products, leading to untold wealth. In some cases, however, these models have done more damage than good, making markets less stable and introducing new systemic risk. In this talk, Dr. James Weatherall will tell the story of how in the aftermath of World War II, some innovative physicists and mathematicians saw surprising connections between physics, gambling, and finance, and put those connections to use to become the first quants. Dr. Weatherall will introduce some of the ideas behind modern quantitative trading and show how the history of mathematical reasoning in finance reveals that these models can be extremely useful-but only if we understand their limitations.

Imagine going beyond treating the symptoms of disease and instead stopping it and reversing it. This is the promise of regenerative medicine.

In her Perimeter Institute public lecture, Prof. Molly Shoichet will tell three compelling stories that are relevant to cancer, blindness and stroke. In each story, the underlying innovation in chemistry, engineering, and biology will be highlighted with the opportunities that lay ahead. 

To make it personal, Shoichet’s lab has figured out how to grow cells in an environment that mimics that of the native environment. Now she has the opportunity to grow a patient’s cancer cells in the lab and figure out which drugs will be most effective for that individual. 

In blindness, the cells at the back of the eye often die. We can slow the progression of disease but we cannot stop it because there is no way to replace those cells. With a newly engineered biomaterial, Shoichet’s lab can now transplant cells to the back of the eye and achieve some functional repair. 

The holy grail of regenerative medicine is stimulation of the stem cells resident in us. The challenge is to figure out how to stimulate those cells to promote repair. Using a drug-infused “band-aid” applied directly on the brain, Shoichet’s team achieved tissue repair. 

These three stories underline the opportunity of collaborative, multi-disciplinary research. It is exciting to think what we will discover as this research continues to unfold.

When small, hard particles are suspended in a fluid, they make it more resistant to flow. The higher the particle concentration, the higher the viscosity. Add enough particles and fluid stops flowing entirely, becoming a jammed solid - this makes intuitive sense.

Less intuitive and more intriguing are suspensions that flow smoothly if pushed gently, but that suddenly solidify if you push too hard. This behaviour is called Discontinuous Shear Thickening (DST). You can try it yourself by mixing cornstarch with water - in the right proportions, the mixture will flow smoothly when stirred gently, but will refuse to flow at all if stirred too hard.

More than an interesting kitchen trick, DST has important real-world consequences. It can cause catastrophic failure of industrial pumping equipment, but can also have life-saving applications to bulletproof vests.

For many years, the mechanism behind DST was unclear, but we have very recently found a new and stunningly simple explanation based on the idea that the contacts between particles become less lubricated and more frictional as the force between them increases. Although this dependence is typically gradual, when a fluid gets close to the “jamming” point, global instabilities can result in the sudden switching from liquid to solid.

Michael Cates (Lucasian Professor of Mathematics, University of Cambridge) will explain this peculiar form of “bulletproof custard” with a few equations, plenty of diagrams, and even some hands-on demonstrations.

Even the greatest scientists have made some serious blunders. "Brilliant Blunders" concerns the evolution of life on Earth, of the Earth itself, of stars, and of the universe as a whole.

In this talk, astrophysicist Dr. Mario Livio will explore and analyze major errors committed by such luminaries as Charles Darwin, Linus Pauling, and Albert Einstein. Dr. Livio will scrutinize the various types of blunders and attempt to explain how they happen. Blunders are not only inevitable, argues Dr. Livio, but also an integral component of the process of science.

How well can we predict our future climate? If the flap of a butterfly’s wings can change the course of weather a week or so from now, what hope trying to predict anything about our climate a hundred years hence? In this talk I will discuss the science of climate change from a perspective which emphasises the chaotic (and hence uncertain) nature of our climate system. In so doing I will outline the fundamentals of climate modelling, and discuss the emerging concept of inexact supercomputing, needed - paradoxically perhaps - if we are to increase the accuracy of predictions from these models. Indeed, revising the notion of a supercomputer from its traditional role as a fast but precise deterministic calculating machine, may be important not only for climate prediction, but also for other areas of science such as astrophysics, cosmology and neuroscience.

By creating an ultra-clean underground location with a highly reduced radioactive background, otherwise impossible measurements can be performed to study fundamental physics, astrophysics and cosmology. The Sudbury Neutrino Observatory (SNO) was a 1,000 tonne heavy-water-based neutrino detector created 2 km underground in a mine near Sudbury, Canada. SNO has used neutrinos from 8B decay in the Sun to observe one neutrino reaction sensitive only to solar electron neutrinos and others sensitive to all active neutrino flavors. It found clear evidence for neutrino flavor change that also requires that neutrinos have non-zero mass. This requires modification of the Standard Model for Elementary Particles and confirms solar model calculations with great accuracy. The 2015 Nobel Prize in Physics and the 2016 Breakthrough Prize in Fundamental Physics were awarded for these measurements. Future measurements at the expanded SNOLAB facility will search for Dark Matter particles thought to make up 26% of our Universe and rare forms of radioactivity that can tell us further fundamental properties of neutrinos potentially related to the origin of our matter-dominated Universe.

The ordinary atoms that make up the known universe, from our bodies and the air we breathe to the planets and stars, constitute only 5 percent of all matter and energy in the cosmos. The remaining 95 percent is a recipe of 25 percent dark matter and 70 percent dark energy, both nonluminous components whose nature remains a mystery.

In her March 2 public lecture, Katherine Freese will recount the hunt for dark matter, from the discoveries of visionary scientists like Fritz Zwicky, the Swiss astronomer who coined the term "dark matter" in 1933, to the deluge of data today from underground laboratories, satellites in space, and the Large Hadron Collider.

Neutron stars are a celestial gift to scientists. These incredibly dense collapsed stars act as very precise cosmic beacons that help shed light on some of the most challenging problems in modern physics.

In her Feb. 3 talk at Perimeter Institute, astrophysicist Victoria Kaspi will explore these strange objects, explain how astronomers are using them to study issues ranging from the origins of the universe to the very nature of matter, and even let the audience hear the cosmic symphony they create.