The Compass Lecture Series is a collection of research talks given by Berkeley researchers in the physical sciences. These talks are unique in that they are designed for an undergraduate audience. The goal of the lecture series is to introduce undergrads to as many areas of research as possible using language and physics concepts they can understand. The lectures take place on the Fridays listed below at 3:10 PM (a.k.a. 3PM Berkeley time) in 325 Physics South (unless otherwise noted).
The Spring 2025 Lectures:
Lecture 1 (February 21, 2025): Is Anybody Out There? What’s New in the Search for Extraterrestrial Civilizations?
Lecture 2 (February 28, 2025): Astrophysical Impacts of Self-Interacting Dark Matter
Lecture 3 (March 7, 2025): Improving electron microscopy with an ultra-high-intensity laser
Lecture 4 (March 14, 2025): Machine Learning & the History of the Cosmos
Lecture 5 (April 4, 2025): When a Symmetry Breaks
Lecture 6 (April 18, 2025): The Cosmic Game of Hide-and-Seek: Chasing Dark Matter Across the Stars
Lecture 7 (May 2, 2025): Recreating the Big Bang 50,000 times a second: the LHC heavy ion program
Lecture 1: Is Anybody Out There? What’s New in the Search for Extraterrestrial Civilizations?
Speaker: Dan Werthimer, Research Scientist in Space Science Lab
Date & time: Friday, February 21, 2025, 3:00 – 4:00 PM PDT
Location: 375 Physics North
Talk description: What is the possibility of other intelligent life in the universe? Can we detect radio, infrared, or optical signals from other civilizations? Current and future searches for extraterrestrial intelligence (SETI) projects may provide an answer. Dan Werthimer will describe the rationale for past and future searches and will show how new technologies are revolutionizing SETI. Dan will describe SETI@home and the new PANOSETI wide field all-sky-all-the-time project, as well as concepts for future SETI.
Lecture 2: Astrophysical Impacts of Self-Interacting Dark Matter
Speaker: Bashi Mandava, PhD Candidate in Physics
Date & time: Friday, February 28, 2025, 3:00 – 4:00 PM PDT
Location: 375 Physics North
Talk description: In this talk, I’ll jump into how dark matter sculpts galaxies and clusters, and why its behavior on smaller scales can have long-lasting impacts on our cosmic neighborhood. I’ll introduce the idea of self-interacting dark matter—where dark matter particles can bump into each other just like normal baryonic matter, reshaping galaxy cores and sometimes even causing dramatic halo collapses. I’ll explore how the remnants of such a collapse can serve as cosmic clues to bring us closer to understanding what dark matter really is!
Lecture 3: Improving electron microscopy with an ultra-high-intensity laser
Speaker: Petar Petrov and Jessie Zhang, Postdoctoral Researchers in Physics
Date & time: Friday, March 7, 2025, 3:00 – 4:00 PM PDT
Location: 375 Physics North
Talk description: Transmission electron microscopes (TEMs) are widely used by biologists to study the structures and interactions of biomolecules. When the electron beam passes through the sample, it undergoes a scattering process, and this allows us to record an image of the transmitted beam which contains information about molecular structure at the angstrom level. Unfortunately, this technique requires high-energy electron beams which rapidly destroy the sample, leaving us with images that have low contrast and high noise. Our team has developed an optical resonator which we use to shoot an ultra-intense laser beam through the electron beam of the TEM. This causes a phase shift of the electron beam, and as a result it maximizes the contrast of the image. We will talk about the theory behind this “phase-contrast TEM” approach, how we build our optical resonator, and how we operate it inside a TEM to enhance the capabilities of the microscope to observe biomolecules.
Lecture 4: Machine Learning & the History of the Cosmos
Speaker: Cooper Jacobus, Undergraduate Researcher in Astronomy
Date & time: Friday, March 14, 2025, 3:00 – 4:00 PM PDT
Location: 375 Physics North
Talk description: In this talk, we explore two of the largest frontiers in modern physics; the history of the cosmos and the use of machine learning to discover and interpret complex physical systems. We discuss what these ideas have to do with one another and consider what breakthroughs might be coming in the next century of physics, particularly focusing on the future of computer simulations and data in physics. I will finally present some of my own work using machine learning to accelerate computer simulations of the evolution of structure in the cosmos.
Lecture 5: When a Symmetry Breaks
Speaker: Hitoshi Murayama, MacAdams Professor in Physics
Date & time: Friday, April 4, 2025, 3:00 – 4:00 PM PDT
Location: 375 Physics North
Talk description: What is common among a magnet, a halibut, a rack of laundry, your heart on the left side of your body, and the Higgs boson? The concept of spontaneous symmetry breaking is ubiquitous among many natural phenomena. I’ll describe the basic concept and its applications. In particular, the original theorem from Anderson, Nambu, Goldstone, and Higgs do not quite work in many systems that include a magnet on your fridge. I generalize the theorem so that it is applicable to all known natural phenomena around us. I also discuss applications to dark matter and matter antimatter asymmetry.
Lecture 6: The Cosmic Game of Hide-and-Seek: Chasing Dark Matter Across the Stars
Speaker: Orion Ning, Graduate Student in Physics
Date & time: Friday, April 18, 2025, 3:00 – 4:00 PM PDT
Location: 375 Physics North
Talk description: Dark matter is one of the most outstanding problems in modern physics. It’s also one of the most tangible, which makes its nature even more perplexing. For nearly a century, physicists have been playing a grand game of hide-and-seek with dark matter to uncover its true particle identity. While it leaves macroscopic fingerprints in, e.g., the structure and formation of galaxies and clusters, we still don’t understand what exactly it is or what form it really takes. From its initial discovery in astrophysical observations to today’s ambitious efforts to identify its particle nature, this talk will delve into the long, storied, and glorious search for dark matter. We’ll explore its astrophysical origins, investigate its theoretical possibilities at the particle level (e.g. WIMPs? Axions? etc.), and discuss how astrophysicists and particle physicists tackle this problem together, highlighting the latest developments in the field in terms of both the particle theory and the real searches being done today.
Lecture 7: Recreating the Big Bang 50,000 times a second: the LHC heavy ion program
Speaker: Tucker Hwang, Graduate Student in Physics
Date & time: Friday, May 2, 2025, 3:00 – 4:00 PM PDT
Location: 375 Physics North
Talk description: For about one and a half months every year, the Large Hadron Collider in Geneva, Switzerland smashes heavy lead nuclei together in collisions over 100,000 times hotter than the center of the Sun. These collisions produce droplets of the quark-gluon plasma (QGP), a state of matter that existed in the first microseconds of the Universe following the Big Bang. Learning about this exotic material has deepened our understanding of the strong interaction that binds 99% of ordinary matter, but has revealed just as many new questions than it has answered. This lecture will be a crash course of everything we’ve learned and everything we hope to learn from the LHC heavy ion program, from the micro- and macroscopic properties of the QGP and the strong interaction to neutron stars and new particles beyond the Standard Model.
For past lectures, see Past Compass Lecture Series, or check out our YouTube channel!