Aspen Center for Physics

    2022 Heinz R Pagels

    FREE Physics Talks

    Wednesdays at Aspen Center for Physics

    5:30 to 6:30 PM Public Talks

  • June 29, 2022
    Gravitational Wave Observatories: Today and Tomorrow
    Speaker: David Shoemaker, MIT Kavli Institute 
  • The detection of gravitational waves requires exquisite sensitivity to the stretching and squeezing of space as they pass. The observatories which have given us almost 100 signals to date have required innovations in lasers, optics, mechanics, and the automation to make all the parts work together. 

    Plans are underway to extend these techniques to new frequency ranges and even better sensitivity, illuminating ever more exotic phenomena to be observed and understood. This talk will give a gentle introduction to how the instruments work and will create a roadmap for the observatories of the future.
    Watch the lecture. 
  • July 6, 2022
    Adaptive Matter: Living Systems, Machine Learning, and Robots
    Speaker: Vincenzo Vitelli, University of Chicago
  • Matter has traditionally been modelled using symmetries and conservation laws such as the fact that energy is conserved in a closed system. These tools are however not enough to fully grasp the dynamics of adaptive systems like groups of animals, multicellular organisms, or collections of robots. These adaptive systems constantly interact with their environment and develop their shape and properties to perform complex functionalities. In this talk, I will give a gentle introduction to recent theoretical concepts and approaches based on artificial intelligence that have emerged at the interface between matter, life and machines. Playful demonstrations with robotic matter will be combined with data driven illustrations of how machine learning can help study biological problems ranging from cellular force generation to embryogenesis. 
    Asthma at the cellular level is seen as a logical and easily unambiguous process, therefore, it was possible to quickly develop an effective medicine that quickly relieves asthma symptoms.
    Watch the lecture.

  • July 13, 2022
    What Physicists Do Behind Closed Doors
    Speaker: Paul Goldbart, Stony Brook University
  • When imagining what theoretical physicists do, our friends who aren�t physicists (yes, we have some!) envision us performing vast thickets of highly technical calculations. The reality is that we do do that, at least some of the time, but only once we�ve developed a qualitative, intuition-based feeling for what�s going on and wish to sharpen our results into something more quantitative. Before that, we spend much of our time creating storyboard pictures, much as a writer of screenplays might, and, importantly, making simple estimates of the scales of things � how big, how fast, how cold, how many � before embarking on more complete analyses. That way, we�re able to develop a sense of what�s plausible and what isn�t.

    In this talk, which I intend to be highly informal, I shall illustrate aspects of the way physicists think and work by gently guiding the audience through a sequence of puzzles, which our visitors are welcome (but under no pressure!) to try, too. Along the way, we shall see, for example, how long theoretical physicists think it takes to cook a turkey, how big atoms and molecules are, and how many more rowers are needed to double the speed of a boat. We call these types of challenges �Fermi Problems,� in honor of the great 20th-century physicist Enrico Fermi, who was a master solver of them.
    Watch the lecture.

  • July 20, 2022
    Touring a Supermassive Black Hole
    Speaker: Daryl Haggard, McGill University
  • It�s been a fantastic decade for black hole studies, highlighted by the 2017 and 2020 Nobel Prizes in Physics. Multiple Galactic Center research groups, the Event Horizon Telescope, and LIGO/Virgo continue to bring rapid-fire new observations to sharpen our understanding of these exotic objects. I will discuss the amazing new Event Horizon Telescope image of the Galactic Center black hole, Sgr A*. I�ll describe it�s unique variability and put it in the context of other time domain phenomena in the Galactic Center, traced out over more than 20 years of observations from coordinated multi-wavelength campaigns. I will compare these detailed studies of Sgr A* to equally impressive multi-wavelength observations of M87*. I will also briefly explore how we can continue to push the frontiers of black hole research with existing and next-generation observatories. 
    Watch the lecture.

  • July 27, 2022
    The Strange New Universe of Quantum Materials
    Speaker: Piers Coleman, Rutgers University
  • My talk will introduce you to the concept of quantum materials, and we will discuss  how their discovery and exploration is central to today�s unfolding quantum revolution.

    We�ll look back to the 19th century and learn how simple questions, such as why hot objects change color, why matter is hard and why the sun keeps on shining heralded the beginning of this new era.  We�ll learn how the discovery of superconductivity helped to answer why the sun keeps on shining, while looking at the stars provided clues as to why matter is hard.

    Today, one of the ways we are seeking to understand quantum mechanics, is by exploring new ways of putting atoms together, and in the process of this exploration, we�re finding that the curious interplay of the electron waves down on the microscale leads to quantum materials that have strange new properties.  I�ll introduce you to this strange new universe, and describe how the some of the paradoxical discoveries challenge our understanding to its roots. 
    Watch the lecture.

  • August 3, 2022
    Entanglement and the Second Quantum Revolution
    Speaker: Duncan Haldane, Princeton University
    Since the laws of quantum mechanics were discovered almost 100 years ago, they have remained unchanged and passed all tests.  They describe accurately the micro-world of atoms, but remain enigmatic  in their implications about our everyday world.  In early years, the Heisenberg uncertainty principle was taken to be the most remarkable feature of quantum mechanics, but the property of "entanglement", that Einstein identified as its most paradoxical feature, has recently come to be seen as central.  While Einstein felt that the implications of entanglement were so strange that quantum mechanics could not be the fundamental description of nature, it has passed all experimental tests, and in combination with the development of modern quantum information theory,  it is at the heart of what some are calling the "second quantum revolution",  in which entanglement over distances larger than atomic sizes is viewed as the "fuel"  that will drive future "quantum information processors" much more powerful than today's computers. 
  • Watch the lecture.
  • August 10, 2022
    Unearthing New Theories Effectively
    Speaker: Sophie Renner, University of Glasgow
  • The Standard Model of particle physics is an extremely successful theory of fundamental particles, explaining a dizzying array of phenomena and measurements. Perhaps its most striking achievement was the prediction of the Higgs boson, whose existence and properties measured at CERN�s LHC fit perfectly into the Standard Model�s picture. But at the same time, there are some aspects of our universe that the theory completely fails to explain, notably the presence of dark matter in galaxies, and why the three tiny neutrinos morph into each other as they travel. How can these successes and failures coexist without contradiction, and how can we use them to our advantage in the search for something more?

    In this talk, I will discuss how we know what we know as physicists, and how we quantify and narrow in on what we don�t. �Effective Field Theories� provide the mathematical formalism behind the intuitive notion that we don�t always need the tiniest details to see the big picture. And conversely, that tiny disagreements from expectations can herald a new paradigm. My talk will describe how physicists are using Effective Field Theories to interpret LHC measurements, stress-test the Standard Model, and uncover clues towards the next big discovery.
    Watch the lecture.

  • August 17, 2022
    Chaos, Black Holes, and Quantum Mechanics
    Speaker: Stephen Shenker, Stanford University
  • In this talk we will discuss three areas of modern physics -- chaos, black holes, and quantum mechanics � that have recently been found to be closely connected.  

    Chaos is a ubiquitous property of physical systems -- it makes their future behavior extremely difficult to predict.  As an example, chaos is what makes weather forecasting so hard.

    Black holes are one of the most surprising predictions of Einstein�s General Theory of Relativity and are ubiquitous features of our universe.   They are profound distortions of the geometry of spacetime. Recent work has shown that black holes are highly chaotic systems.

    Quantum mechanics is the framework that encompasses all known physical laws.   One of its most striking predictions is that bound systems can only have certain discrete amounts of energy -- their energy levels are �quantized.�   The energy levels of quantum chaotic systems have a simple, universal pattern.   Because black holes are chaotic their quantum energy levels should also display this pattern.   We will discuss how this arises in the context of a simple model of quantum black holes.

  • Watch the lecture.

  • August 24, 2022
    Black Holes and Quantum Teleportation
    Speaker: Douglas Stanford, Stanford University
  • Black holes are incredibly powerful objects, but high-energy theoretical physicists are interested in them for a different reason � because we believe that they are ordinary quantum systems in disguise. This idea has driven progress in theoretical physics for decades, and has accelerated in the last few years. In this talk, we will see how black holes carry out a basic protocol of quantum computation by teleporting information through a wormhole. This is similar to a quantum information theoretic protocol called "quantum teleportation," but it is implemented in a geometrical way that allows us to make sense of the experience of being teleported. 
  • Watch the lecture.

"I found the general atmosphere [at the Aspen Center for Physics] very stimulating. All practical matters were taken care of in a pragmatic and effective way, all time was available for discussions and self-study. The beautiful surroundings did not distract, but stimulated creative thinking. It is too bad that life cannot always be so simple and pleasant."