Osher Lifelong Learning Institute
2025-2026 Membership is now Open for Registration.
Master Class I: Astronomy & Astrophysics
This Master Class spotlights the new astronomy & astrophysics Department at UC San Diego and introduces new faculty members to the Osher Institute. These scientists will discuss their research and their personal journeys into the study of the universe.
January 7: Dark Matter Physics in the Sky
Professor Ethan Nadler
This lecture will discuss what dark matter is and how it shapes our universe. Despite being invisible, it leaves clues in the properties of the smallest galaxies and how light bends as it travels through space. New telescopes are discovering thousands of gravitational lenses and tiny galaxies, while new simulations show how these systems respond to fundamental dark matter physics. Combining these tools will allow us to map dark matter structures that contain no stars at all, revealing the universe’s invisible scaffolding for the first time.
January 14: The Cosmic Microwave Background: What We Can Learn From It and How We Measure It
Professor Kam Arnold
In the Big Bang model, the universe has been expanding and cooling for its entire history. We can observe light that was emitted before there were any stars, galaxies or planets—light from when stable neutral hydrogen first formed in the universe— called the Cosmic Microwave Background (CMB). Measuring it requires detectors cooled to a tenth of a degree above absolute zero on telescopes in some of the harshest environments on earth. This lecture will discuss what we learn from the CMB and the new Simons Observatory led by UC San Diego in the Atacama Desert of Northern Chili.
January 21: The Dynamic Lives of Black Holes, Neutron Stars and White Dwarfs in Globular Clusters
Professor Kyle Kremer
The dense centers of globular clusters are home to an entire zoo of exotic astrophysical phenomena. This lecture will discuss the unexpected events experienced by compact objects—black holes, neutron stars, and white dwarfs—within these dense stellar systems. Over the past decade, the groundbreaking detections of gravitational wave signals have opened a new window to the cosmos. We will discuss ways these gravitational wave events can form in globular clusters. The lecture will also describe the department’s uses of the Keck and Hubble telescopes to search for new black holes in nearby globular clusters in the Milky Way.
January 28: Black Hole Paleontology: A New Frontier to Explore Our Vast Cosmos Using Gravitational Waves
Professor Floor Broekgaarden
Gravitational waves have opened a revolutionary window onto the Universe. Black hole paleontology uses the ripples from colliding black holes as "fossils" to uncover the formation, lives and deaths of massive stars across billions of years. This emerging field bridges astrophysics, cosmology and data science, offering unprecedented insights into stellar evolution, galaxy growth and the fundamental processes that shape our universe-and our place within it. This lecture will guide us on a journey into black hole paleontology and the hidden mysteries it reveals about our cosmos.
February 4: The Explosive Universe
Professor Griffin Hosseinzadeh
Over the past decade, a new generation of high-cadence sky surveys has revolutionized the field of time-domain astronomy, the study of astronomical phenomena that vary on timescales of days to months. Astronomical transients-the explosions, mergers, and disruptions of stars and stellar remnants-uniquely probe the extremes of stellar evolution that are not accessible via typical stars. This lecture will introduce various types of astronomical transients, explore what they can teach us about the universe, and discuss the technology required for these time-sensitive observations.
Speaker Bio
Presenter: Kam Arnold is an associate professor of astronomy & astrophysics and Physics at UC San Diego. He has been developing new technologies to measure the CMB and interpreting the results of those measurements for more than two decades. He is one of the leaders of the newly operating Simons Observatory. He received his PhD from UC Berkeley.
Professor Kyle Kremer The dense centers of globular clusters are home to an entire zoo of exotic astrophysical phenomena. This lecture will discuss the unexpected events experienced by compact objects—black holes, neutron stars, and white dwarfs—within these dense stellar systems. Over the past decade, the groundbreaking detections of gravitational wave signals have opened a new window to the cosmos. We will discuss ways these gravitational wave events can form in globular clusters. The lecture will also describe the department’s uses of the Keck and Hubble telescopes to search for new black holes in nearby globular clusters in the Milky Way.
Presenter: Floor Broekgaarden is an assistant professor of Astronomy at UC San Diego, where she leads a research group in Gravitational Wave Paleontology. Actively involved in COMPAS, the Einstein Telescope, and Cosmic Explorer, she enjoys tracing cosmic trails with gravitational waves-and San Diego's trails as an avid trail runner. She earned her PhD in astrophysics from Harvard University and was a Simons Junior Fellow in New York before joining UC San Diego.
Presenter: Griffin Hosseinzadeh is an assistant professor in the Department of Astronomy & Astrophysics at UC San Diego. He was previously a postdoctoral fellow at the University of Arizona's Steward Observatory and the Center for Astrophysics | Harvard & Smithsonian. In his free time he likes to play music (trombone, bass, etc.) and go on long bike trips. He got his PhD from UC Santa Barbara.