Ellen Zweibel
Ellen Gould Zweibel, PhD

Cosmic Messengers from Cosmic Accelerators
Theories and mysteries of “cosmic ray” proton particles

Guest lecturer: Ellen Gould Zweibel, PhD
William L. Kraushaar Professor of Astronomy and Physics, University of Wisconsin-Madison

The 31st annual Kay Malmstrom Lecture in Physics was held on November 3, 2022. 

Galaxies like our own Milky Way are pervaded by hydrogen gas more rarefied than even the most perfect vacuum achieved on Earth. About one in a billion particles in this highly rarefied gas is a cosmic ray—a proton traveling at nearly the velocity of light. Scientists believe that cosmic ray particles acquire their energies in explosions like supernovae and are trapped in galaxies by magnetic fields. Dr. Ellen Gould Zweibel's research explores how such particles are energized, how they spread through space, and how they alter their environments—questions that have been pondered since the 18th century and are not completely solved today. Her Malmstrom lecture will discuss why cosmic rays are so remarkable and what they tell us about their sources.

Ellen Gould Zweibel, PhD

Ellen Gould Zweibel is a theoretical astrophysicist known primarily for applying plasma physics to astrophysics. Born in New York City and raised in small-town New Jersey, Zweibel's first forays into astronomy were at the University of Chicago, where she majored in mathematics. She acquired a background in plasma physics at Princeton University, where she wrote her thesis on galactic dynamics, and received her PhD in 1977.

After a postdoctoral year at the Institute for Advanced Study in Princeton, Zweibel joined the scientific staff of the High Altitude Observatory, a solar physics research institute in Boulder, Colorado. However, she was soon drawn back to academia, and she began a faculty appointment at the University of Colorado in 1981. In 2003, Zweibel moved to the University of Wisconsin-Madison, where she currently teaches and holds the title of William L. Kraushaar Professor of Astronomy and Physics.

Zweibel's contributions to her field have been recognized many times over. In 2016, the American Physical Society awarded her its James Clerk Maxwell Prize for Plasma Physics for her "seminal research on the energetics, stability, and dynamics of astrophysical plasmas, including those related to stars and galaxies, and for leadership in linking plasma and other astrophysical phenomena." She is a fellow of the American Association for the Advancement of Science; the American Astronomical Society; and the American Physical Society; and a member of the National Academy of Sciences. In 2022, Zweibel was recognized with the Catherine Wolfe Bruce Gold Medal of the Astronomical Society of the Pacific for her “contributions to the understanding of astrophysical plasmas, especially those associated with the Sun, stars, galaxies, and galaxy clusters [and for] major contributions in linking plasma characteristics and behaviors observed in laboratories to astrophysical plasma phenomena occurring in the universe."

About the Malmstrom Lectures in Physics

The Kay Malmstrom Lecture in Physics, part of the Emma K. and Carl R. N. Malstrom Chair in Physics, is an annual symposium on contemporary issues and research in physics. Through this generous gift, Carl R. N. Malmstrom ’36 gives Hamline students access to the outstanding scientific minds of our time. Even after his death in 2010, Carl’s legacy of supporting Hamline students continues to fund collaborative research opportunities, scholarships, and this lecture.

Past lectures

2021 “An Evening on Dark Matter Particles,” Elena Aprile, PhD, Columbia University
2020 “Microscopy in Motion: Understanding How Crystals Grow Through Electron Microscopy Movies,” Frances M. Ross, PhD, Columbia University
2019 "A Random Walk through Physics to the Nobel Prize," Dr. J. Michael Kosterlitz, 2016 Nobel Prize Laureate in Physics for work on the Kosterlitz-Thouless transition
2018 "Mixed-Dimensional van der Waals Heterostructures for Electronic and Energy Applications," Dr. Mark C. Hersam, Northwestern University
2017 "What Can We Do with a Quantum Liquid?" Dr. Anthony J. Leggett, University of Illinois at Urbana-Champaign, 2003 Nobel Laureate for work on superfluidity
2016 "Soft Electronics for the Human Body," Dr. John A. Rogers, Northwestern University
2015 "More Than Moore: When Electronics Drive off the Roadmap," Dr. Mark A. Reed, Yale University
2014 "Relativity, Quantum Physics, and Graphene," Philip Kim, Harvard University
2013 "Innovating Your Own Future," Roger H. Appeldorn, 3M
2012 "When Freezing Cold is Not Cold Enough: New Forms of Matter Close to Absolute Zero Temperature," Dr. Wolfgang Ketterle, MIT, 2001 Nobel Laureate for research on Bose-Einstein condensation
2011 "Exploring the Warped Side of the Universe," Dr. Nergis Malvalvala, MIT (spring)
2011 "E=mc^2: Opening Windows on the World," Dr. Young-Kee Kim, University of Chicago (fall)
2010 "Neutrino Astronomy at the South Pole," Dr. Jordan Goodman, University of Maryland
2009 Superposition, Entanglement, and Raising Schrödinger’s Cat" Dr. David Wineland, National Institute of Standards and Technology, 2012 Nobel Laureate for developing research methods for measuring and manipulating individual quantum systems
2008 "How to Make Atoms Sing and Molecules Dance-Using Fast Light Pulses to Observe and Control Nature," Dr. Margaret Murname, University of Colorado at Boulder
2007 "Modern Cosmology & Superstring Theory: Can They Co-Exist?" Dr. Sylvester James Gates, Jr., University of Maryland
2006 "Stopping Time," Dr. Eric Mazur, Harvard University

Malstrom Lecture, 2005 Dr. Ramon Lopez, Florida Institute of Technology

2004 "Stone Cold Science," Dr. Eric Cornell, University of Colorado at Boulder, 2001 Nobel Laureate for collaborative work involving Bose-Einstein Condensate.
2003 "Our Preposterous Universe," Dr. Sean Carroll, California Institute of Technology
2002 "Sunlight and Ice Crystals in the Skies of Antarctica," Dr. Robert Greenler, University of Wisconsin-Milwaukee
2001 "The Physics of Star Trek," Dr. Lawrence Krauss, Case Western Reserve University
2000 "Almost Absolute Zero: The Story of Laser Cooling and Trapping," Dr. William D. Phillips, National Institute of Standards and Technology. 1997 Nobel Laureate for collaborative work involving the cooling and trapping of atoms with lasers.
1999 "Space Astronomy in the 21st Century," Dr. John C. Mather, Nasa Goddard Lab for Astronomy and Solar Physics. 2006 Nobel Laureate for collaborative discovery of the blackbody form and anisotropy of the cosmic microwave background radiation.
1998 "Voodoo Science," Dr. Robert Park, University of Maryland, author of the controversial weekly commentary, What's New, on science policy issues.
1997 "Quark: The Big And Small Of It," Dr. Melissa Franklin. Harvard University, The Top Quark.
1996 "So Many Galaxies... So Little Time," Dr. Margaret Geller Harvard University, Astronomer, recipient the MacArthur Fellowship
1995 "The Quark And The Jaguar," Dr. Murray Gell-Mann, California Institute of Technology, 1969 Nobel Laureate for classifying the elementary particles.
1994 "Science And The Human Condition," Dr. Daniel Kleppner MIT, quantum optics, and experimental atomic physics.
1993 "Rumors of Perfection: New Ideas About Cosmic Evolution," Timothy Ferris, University of California-Berkeley, Science writer and essayist, wrote and narrated the the PBS special "The Creation of the Universe."
1992 "The Cosmic Quark," Dr. Leon Lederman, University of Chicago, 1988 Nobel Laureate for collaborative work that led to development of a new tool for studying the weak nuclear force.
1991 (Dedication of Robbins Science Building) Dr. Arno A. Penzias, Bell Labs, 1978 Nobel Laureate with Robert K. Wilson for discovering the cosmic background radiation.