The Road to Fusion Power with the Centrifugal Mirror

The centrifugal mirror is a magnetic confinement concept that is remarkable for its engineering simplicity compared to other fusion concepts. It consists of a minimum of two circular electromagnets linearly arranged such that the magnetic field between them acts as a potential well that traps the hot plasma that can then be heated to thermonuclear conditions. Plasma heating and stabilization is achieved in the centrifugal mirror by imposing a radial electric field at the axis of the configuration, such that plasma experiences an azimuthal drift that is naturally sheared. This shear in turn leads to viscous heating and prevents the plasma from drifting radially outwards, achieving self-heating and dramatically better confinement than magnetic mirrors without rotation. The Centrifugal Mirror Fusion Experiment (CMFX), a research effort led by UMBC in partnership with the University of Maryland, College Park, has been funded since 2020 by ARPA-E to test the physics of centrifugal mirrors and demonstrate magnetic confinement at parameters relevant to sustained fusion production. The CMFX is the second-generation centrifugal mirror at Maryland, but the first one in the world to use superconducting coils, with a maximum field of 3-T. It is also the first one to achieve sustained operation for up to 10 seconds (limited only by the passive cooling of components). Temperatures, densities, and momentum confinement times in CMFX are now high enough to produce small amounts of fusion energy when experimenting with deuterium plasmas. The success in CMFX has spurred the ongoing engineering design of the next centrifugal mirror machine, led by the commercial spinoff of CMFX, the Terra Fusion Energy Corporation. This new machine will be aimed at demonstrating net energy gain in a small (1 – 10 MWe) modular system that can be used in industrial facilities that require resiliency, such as data centers, and will serve as an intermediate step for systems that can provide 100 MWe or more for regional power generation.

Where is high-energy physics heading to? A viewpoint from CERN

The LHC physics program is advancing successfully and its results have reshaped our views about the particle world. Preparations for the high-luminosity phase of the LHC are in full swing. At the same time, CERN is considering future projects to continue research in the high-energy domain after the LHC. I will review the ongoing decision process and highlight the most promising directions that are currently pursued.  

Physics of Deep Learning

Deep learning has revolutionized fields ranging from image recognition to natural language processing, but its theoretical foundations remain an open frontier. In this colloquium, we will explore how tools and concepts from physics provide a powerful lens for understanding the mechanisms and behavior of deep neural networks, as well as lead to practical engineering advances.

Surprises in Self-Deforming Systems

In classical mechanics we typically study systems that can be represented by point-like particles and are subject to external forcing. In contrast, in living systems we encounter extended objects which undergo internal forcing to generate cyclic changes in shape or configuration. Such dynamics occur across scales, from proteins undergoing conformational changes to cells crawling on surfaces to centipedes wiggling through soil and debris. The physics of such “self-deforming” systems is remarkably rich, especially when coupled to non-trivial environments. In this talk I will narrate a few examples of surprising emergent dynamics in living and nonliving (robot) systems arising from the interplay of traveling waves of body bending and environmental heterogeneities. I will describe how undulatory limbless robophysical models that mix wave and particle-like properties can mechanically “diffract” in regular arrays of obstacles and exponentially localize in disordered environments. Such insights have proven useful in highlighting the importance of mechanics in living systems, e.g. the role of passive dynamics in the locomotion of snakes and nematode worms in heterogeneous environments. Discovery of principles of self-deforming systems is informing and guiding the commercialization of elongate robots (e.g. in a startup company I co-founded) that can self-propel effectively in dirty, dull, and dangerous situations.

Shedding Nano-light on Quantum Materials

Optical spectroscopies have contributed immensely to the present understanding of metals,
superconductors and semiconductors. Unfortunately, optics encounters problems when it comes to “seeing” effects at length scales below the diffraction limit of light and also with probing physics outside of the light cone. Both capabilities are highly desirable for the exploration of quantum physics of new quantum materials. Over the last decade or so, our group has developed and deployed scanning-probe nano-optical methods for the nano-scale spectroscopy and imaging of complex materials. In this talk, I will discuss recent examples of the progress we have made in understanding and controlling the electronic phenomena in quantum materials, all empowered by deeply subdiffractional nano-light.

Photonic Time Crystals and Timetronics

Light-driven nonreciprocal forces in arrays of nano-opto-mechanical oscillators can underpin the functionality of Time Crystals, a many-body interacting system that exhibits a spontaneous mobilization transition to the robust state of oscillation under an infinitely small change of the external driving force.
Such time crystals are a form of Active Matter with life-mimicking dynamics accompanied by the breaking of time translation symmetry, ergodicity, and local entropy decrease. This is of interest to optical “timetronics” – a data processing and communications technology relying on the unique functionalities of time crystals.

Science communication and miscommunication

Science is by the people and for the people. But the people doing science don’t always have an easy time making themselves understood by the rest of the people. I will discuss why science communication is important, give some examples of dramatic misunderstandings of science by the general public, share my personal journey through science communication, and give some advice to early career researchers enthusiastic about communicating with the public. 

From arXiv to 'story's live': How physics gets reported in the press

Physics journalism is often a mystery to its primary subjects: physicists. In this talk I will try to demystify physics journalism by discussing the principles and processes that physics journalists use. I'll break down the stages of reporting a story, from conceptualization to publication, and I'll explain what different parts of a story do and how they are constructed. I will also disclose aspects of my own process—emails, interview notes, and rough drafts—to help explain specific editorial choices. As case studies to illustrate the practice of physics journalism, I will use one news story and one feature story, both about an exciting new development in fundamental physics: the observation of the fractional quantum anomalous hall effect (FQAHE) in moiré quantum materials. 

Quantum Signal Processing: Making Schrödinger Cats and Other Exotic States of Microwave Photons

The Schrödinger Cat idea was an early thought experiment intended to point out the weirdness of quantum mechanics. It is a paradigmatic example of the quantum principles of superposition and entanglement. With the vast experimental progress in the last two decades, we can now routinely carry out this experiment in the laboratory. In this pedagogical talk, I will present a ‘quantum signal processing’ recipe for how to create a Schrödinger Cat in a system consisting of a superconducting microwave resonator (a harmonic oscillator) and a superconducting qubit (a two-level artificial atom). Extensions of this recipe now allow us to create even more exotic states of microwaves that can be used as quantum error correction codes.

Communicating What Science Knows in a Polarized Time

The talk will explore ways to reduce resistance to knowledge about topics ranging from arctic sea ice extent to vaccination safety.   

 
Kathleen Hall Jamieson is the Elizabeth Ware Packard Professor at the Annenberg School for Communication of the University of Pennsylvania, the Walter and Leonore Annenberg Director of the university’s Annenberg Public Policy Center, and Program Director of the Annenberg Foundation Trust at Sunnylands. She has authored or co-authored 18 books, including Democracy Amid Crises: Polarization, Pandemic, Protests, and Persuasion (2023) with the Annenberg IOD Collaborative, Creating Conspiracy Beliefs: How Our Thoughts Are Shaped (2022), and Cyberwar: How Russian Hackers and Trolls Helped Elect a President, which won the Association of American Publishers' 2019 R.R. Hawkins Award. Six of the books that Jamieson has authored or co-authored have received a total of 12 political science or communication book awards (Cyberwar, Packaging the Presidency, Eloquence in an Electronic Age, Spiral of Cynicism, Presidents Creating the Presidency, and The Obama Victory). She co-edited The Oxford Handbook of Political Communication and The Oxford Handbook of the Science of Science Communication.

In 2020, the National Academy of Sciences awarded Jamieson its Public Welfare Medal for her “non-partisan crusade to ensure the integrity of facts in public discourse and development of the science of scientific communication to promote public understanding of complex issues.” In 2022, the Roper Center for Public Opinion Research awarded Jamieson the Warren J. Mitofsky Award for Excellence in Public Opinion Research. In 2023, Jamieson was elected to the Board of Directors of the American Association for the Advancement of Science (AAAS). Jamieson is a member of the American Philosophical Society and the National Academy of Sciences, and a Distinguished Scholar of the National Communication Association. She also is a fellow of the American Academy of Arts and Sciences, the AAAS, the American Academy of Political and Social Science, and the International Communication Association, and a past president of the American Academy of Political and Social Science.

Jamieson has won university-wide teaching awards at each of the three universities at which she has taught and has delivered the American Political Science Association’s Ithiel de Sola Pool Lecture, the National Communication Association’s Arnold Lecture, the NASEM Division of Behavioral and Social Sciences and Education's Henry and Bryna David Lecture, and the keynote lecture at the CDC's Charles C. Shepard Science Awards (2022). Her paper “Implications of the Demise of ‘Fact’ in Political Discourse” received the American Philosophical Society’s 2016 Henry Allen Moe Prize. She is the co-founder of FactCheck.org and its SciCheck project, and director of The Sunnylands Constitution Project, which has produced more than 30 award-winning films on the Constitution for high school students.

TBA

Black Holes, Quantum Mechanics, and the Emergence of Space and Time

Quantum mechanics is the theory which governs the behavior of matter at the atomic scale, but so far we have not succeeded in making it compatible with gravity.  This tension is highlighted by Stephen Hawking's famous "black hole information paradox", which argues that any self-consistent combination of quantum mechanics and gravity must violate some fundamental principle of physics.  In recent years consensus has been building that the principle which must be given up is the existence of spacetime as a fundamental entity: instead space and time are emergent notions, valid only in certain situations and only in some approximation.  What does it mean for space and time to be emergent?  When can they fail to emerge and how badly?  In this talk I will give a broad overview of these ideas, building towards recent developments which put the emergence of spacetime on a firm mathematical footing by relating it to ideas from the theory of quantum computation. 

Daniel Harlow is an Associate Professor of Physics at MIT, working on quantum aspects of black holes and cosmology.  He grew up in some combination of Cincinnati, Boston, and Chicago, and attended Columbia University (BA) and Stanford University (PhD). Harlow received the New Horizons in Physics Prize in 2019 "for fundamental insights about quantum information, quantum field theory, and gravity.” He is an avid hiker and pianist.