Aspen Center for Physics

    2019 Heinz R. Pagels 
    FREE Physics Talks

    Thursdays at Aspen Center for Physics

    5:30 to 6:30 PM Public Talks

    View a 13-minute Video about the Aspen Center for Physics
  • June 6, 2019
    Exploring the Dark Side of Our Cosmos: “Seeing" the Invisible.
    Speaker: Mustafa Amin, Rice University
    In the past three decades, a robust standard paradigm of cosmology has emerged which is consistent with existing observations. This paradigm necessarily includes two important components, dark matter and dark energy, which are different from regular matter that we, and the stars are made of. Together, they make up 96% of our cosmos. These components barely interact with regular matter or light - they are invisible. How do we “see”/know about these dark components? I will discuss how we arrived at this "dark" model, what these dark components might be, and how we plan to understand their properties better in the future.
    Watch the lecture.
  • June 13, 2019
    A Dark Matter Hunter's Guide to the Galaxy
    Speaker: Kathryn Zurek, Lawrence Berkeley National Laboratory
  • If you can’t see dark matter, how do you know it exists?” We take a survey of the galaxy (and Universe) to find out. We also describe how scientists search for dark matter interactions with ordinary matter in laboratory experiments.
    Watch the lecture.
  • June 20, 2019
    Physics and the HIV Virus
    Speaker: Robijn Bruinsma, University of California Los Angeles
  • Despite decades of intense research, the HIV virus still is not well understood. The lecture will discuss how physics has provided insight into questions concerning the very curious assembly and disassembly processes of this virus. The lecture also will discuss arguments indicating that the HIV virus may have “invented" a physical mechanism - selective nucleation - that appears to be unknown in the physics literature.
    Watch the lecture.
  • June 27, 2019
    How Much Number Theory Does it Take to be a Sunflower
    Speaker: Leonid Levitov, MIT
  • One of humanity’s earliest mathematical inquiries might have involved the geometric patterns in plants. The arrangement of leaves on a branch, seeds in a sunflower, and spines on a cactus exhibit repeated spirals, which appear with an intriguing regularity providing a simple demonstration of mathematically complex patterns. Surprisingly, the numbers of these spirals are pairs of Fibonacci numbers consecutive in the series 1, 2, 3, 5, 8, 13, 21, 34, 55... obeying a very simple rule 1+2=3, 2+3=5, 5+8=13 and so on. This talk will discuss how physics helps to understand the origin of this interesting behavior.
    Watch the lecture.

  • July 11, 2019
    Making Crystals Clear - from Food to Phone
    Speaker: Emilia Morosan, Rice University
  • What do you think of when hearing the word “crystal”? Table salt? Precious rocks?  A few people may think of pencils or chocolate; fewer may think of eggshells; fewer still may think of microphones or sonars. Yet, crystalline materials are present in the electronic devices we all depend on. Professor Morosan will shed some light on what crystals are, how they form in nature, how they can be grown in the lab or the kitchen, and why we need and want crystals?
    Watch the lecture.

  • July 18, 2019
    Information processing in a single cell: what and how does E. coli compute?
    Speaker: Yuhai Tu, IBM Research
  • Living systems exhibit fascinating behaviors -- even a single cell. For example, a bacterium cell such as E. coli can detect a trace amount of chemical (nutrient or toxin) in its environment and move towards/away from its source, a behavior called “chemotaxis”. How does E. coli sense its environment? How does the cell process the chemical information? Does E. coli have a memory? What kind of computation does the cell do to detect the source of the chemical? In this lecture, Dr. Tu will address some of these questions on what and how E. coli computes with its molecular machinery to guide its chemotaxis behavior.  
    Watch the lecture.

  • July 25, 2019
    The Brain Inside a Cell: Adaptation and Learning with Cellular Networks
    Speaker: Naama Brenner, Technion
  • Cells have multiple gene-regulation “programs” to answer specific challenges. Still, they are sometimes required to address unforeseen challenges for which no response is readily available. Here, exploratory dynamics can provide an in-principle unlimited repertoire of new responses and cell states.  This process is, in some respects, similar to learning. We study exploratory adaptation both experimentally and theoretically, with focus on properties of biological networks that allow such exploration in high dimensional space to converge.
    Watch the lecture.

  • August 1, 2019
    Richard Feynman's Adventures in Biology: Forgotten History with Implications for Today
    Speaker: Curtis Callan, Princeton University
  • Richard Feynman was one of the great theoretical physicists of the 20th century. He received the 1965 Nobel Prize in Physics for showing us how to tame the infinities of quantum electrodynamics (the precursor of today’s “Standard Model” of fundamental physics), and the “Feynman diagrams” he invented to do this are an essential part of the theoretical physicist’s toolkit even today. In addition to his scientific achievements, Feynman's flamboyant personality and his ability to explain abstruse science in engaging no-nonsense terms (delivered in a strong Noo Yawk accent) made him an iconic figure to the general public, as well as to his peers. What is less widely known is that Feynman was (to use his words) “a curious character”, and spent much time and energy learning how to do things other than physics (including drawing and bongo playing). In particular, he paid very close attention to biology, and spent a sabbatical year in the late 50s in a lab at the forefront of the molecular biology revolution then taking place. This experience did not make a biologist of Feynman, but it laid the foundation for a host of insightful observations about the relation between biology and physics that he would make over the years. Biology today is going through another revolution, driven by a data flood coming from new experimental techniques, and physicists are again turning their attention to biology, hoping to respond to the need for mathematical frameworks to comprehend and exploit this data flood. In this lecture I will give a synopsis of Feynman’s history with biology, and then discuss how Feynman’s various expressions of opinion sbout the relation between biology and physics might be adapted to, and hopefully illuminate, today’s situation.
    Watch the lecture.

  • August 8, 2019
    Graphic Talk About the Universe
    Speaker: Clifford Johnson, University of Southern California
    There should be other ways to get readers engaged with science besides just putting words on a page, representing the voice of the author. What if the reader could get multiple voices, and different points of view? What if they could see and relate to a variety of people engaged with the ideas? Maybe see glimpses of the language and tools that the scientists actually use when they develop scientific ideas and discover truths about our universe? What if these things could all take place on the page at the same time? Is there a kind of book that can do all that?

    Yes! Graphic novels, sequential art, comics - whatever term you prefer to use - are a unique narrative form that can communicate serious, multifaceted scientific ideas to sophisticated readers. In fact, they are perfectly suited to physics! Johnson demonstrates this in his book “The Dialogues: Conversations about the nature of the Universe” (MIT Press), listed by Science Friday as one of the year’s best books in 2017 and in 2018. In this talk he discusses some of the scientific and artistic ideas contained in it, and how he came to write and draw the book.
    Watch the lecture.

  • August 15, 2019
    Dark Matter Genesis: Tales from an Agnostic
  • Speaker: Josh Ruderman, New York University
    We believe that most of the matter in our Universe is dark matter.  We don’t know what dark matter is, and we don’t know where it came from. But the challenge is not that we don’t know how to explain dark matter. It’s that we have multiple possible explanations and we don’t know which among them is correct -- if any. I will tell several “stories” of how dark matter may have been produced during the Big Bang and the challenges of testing these “stories."
    Watch the lecture.

  • August 22, 2019
    Particle Physics at the Crossroads
    Speaker: Csaba Csaki, Cornell University
  • Particle physics had a triumphant march since the 1950's, which culminated in the discovery of the Higgs boson in 2012 at the Large Hadron Collider (LHC) in Geneva, Switzerland. Our current picture of fundamental particles and their interactions, the Standard Model, explains all collider experiments performed to date. This provides the most quantitatively accurate predictions in the history of science. This remarkable success puts particle physics in an unusual situation. Should we still expect new particle physics discoveries or did we already learn everything we could? What would be the signals of potential new physics? Conversely, what would be the implications if there were no more discoveries? Does it still make sense to build bigger experiments? In general, when should we consider an experiment (for example the LHC) to be successful?  Professor Csaki will first review the Standard Model. He will then provide a glimpse of the Higgs boson and why it is was important to find it. Finally, he will try to answer some of these fundamental questions that keep particle physicists up at night.
    Watch the lecture.

  • August 29, 2019
    Tuning Stars into Gold: The Discovery of the First Kilonova
    Speaker: Iair Arcavi , Tel Aviv University
  • On August 17, 2017, gravitational waves launched by two merging neutron stars were detected on Earth for the first time in history, and an alert was sent to astronomers across the globe. Within hours, several teams, using a variety of telescopes, were able to quickly capture the flash from the "kilonova" explosion accompanying the merger, marking the first time ever that gravitational waves and light were detected from the same event. This discovery has provided staggering insights about our Universe, perhaps more than any other single astronomical event in our lifetime, all while charting the course for a new age in astronomy.
    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."