Colloquium Schedule 2025
Schedule
| Date 2025 | Speaker name, affiliation, and topic |
|---|---|
| Jan 16 | Claire Richardson, Arizona St Univ, The mysterious, massive structures in Earth’s deep mantle |
| Feb 13 | Niccolo Veronesi, Washington St Univ, On a quest to discover where stellar-mass black holes merge |
| Feb 20 | Richard Koelsch, NASA, Humanity’s first space station to orbit the Moon |
| Mar 20 | Nicolas Pavloff, University of Paris, Topological pathways to two-dimensional quantum turbulence |
| Summer break | |
| Sep 04 | Konstantin Matveev, Washington St Univ, Modeling of thermofluid processes in liquid hydrogen storage and transfer systems |
| Sep 11 | Kate Grier, Univ of Wisconsin – Madison, Probing Supermassive Black Holes and Quasars with the SDSS-V Black Hole Mapper Reverberation Mapping Project |
| Sep 18 | Jeffrey Vervoort, Washington St Univ, Unraveling the early history of the Earth |
| Sep 25 | Peter Schwindt, Sandia National Laboratories, Measuring the Human Brain with Optically Pumped Atomic Magnetometers |
| Oct 09 | Amin Chabchoub, Okinawa Institute of Science & Technology, Breathers and Rogue Waves Across Physical Systems |
| Oct 16 | Steven Furlanetto, University of California – Los Angeles, How Much Do We Understand About Early Galaxy Formation? |
| Oct 23 | Chris Hamner, University of Hawai’i at Manoa, Optics and Photonics Engineering for Astronomy Applications |
| Oct 30 | Giorgia Busso, University of Cambridge, The Ultimate Stellar Census: Inside ESA’s Gaia Mission |
| Nov 06 | Daniella DellaGiustina, University of Arizona, Exploring Asteroids with the OSIRIS-REx Spacecraft and Samples |
| Nov 13 | Matthew McCluskey, Washington St Univ, Physics of crystal colors |
| Dec 04 | Caroline Piaulet-Ghorayeb, University of Chicago, Beyond Earth 2.0: charting paths to habitable worlds with JWST |
Abstracts
Thursday, December 4, 2025
Caroline Piaulet-Ghorayeb, University of Chicago
Beyond Earth 2.0: charting paths to habitable worlds with JWST
The quest to understand whether planets beyond our Solar System could harbor life is a driving force in exoplanet science. Two principal types of exoplanets stand out as promising candidates for habitability. Temperate rocky worlds offer an exciting perspective as potential “Earth 2.0″s, but confident atmosphere detections on these planets still remain elusive. On the other hand, cool members of the “sub-Neptune” population – small planets distinct from Earth-like compositions, the most common in exoplanetary systems – may also harbor liquid water oceans albeit in exotic environments. In this talk, I will discuss recent advances in probing exoplanetary habitability, highlighting the need for a comprehensive approach that considers a planet’s internal makeup, its stellar environment, and the importance of 3D climate calculations to interpret observations. I will highlight recent JWST observations of TRAPPIST-1 d, a small temperate rocky planet, and share findings from JWST observations and novel modeling of small sub-Neptunes – results that prompt paradigm shifts in our understanding of the processes shaping these worlds.
Thursday, November 13, 2025
Matthew McCluskey, Washington State University
Physics of crystal colors
While the intrinsic bandgap of a semiconductor can give it color, it is imperfections that account for the variety of optical properties seen in crystals. Electronic or vibrational transitions from impurities lead to well-defined features in the infrared (IR) spectrum. The famous Hope diamond contains boron acceptors that absorb from the IR into the red and green region of the spectrum, giving it a pale blue color. Color centers such as anion vacancies can be created by energetic particles, a useful effect for radiation dosimetry. Ruby and emerald get their red or green color from chromium impurities. Photochromism occurs when a crystal’s color changes after exposure to light. Photochromism (or photodarkening) is closely related to persistent photoconductivity and may originate from the same defect physics. Recent results on potassium tantalate, which show both of these persistent effects, will be discussed.
Thursday, November 6, 2025
Daniella DellaGiustina, University of Arizona
Exploring Asteroids with the OSIRIS-REx Spacecraft and Samples
NASA’s OSIRIS-REx mission became the first U.S. spacecraft to collect and return a sample from an asteroid, delivering over 120 g of material from (101955) Bennu to Earth in 2023. Early analyses reveal that Bennu’s rocks are rich in carbon, nitrogen, and water-bearing minerals, as well as unexpected magnesium-sodium phosphates – evidence that its parent body once hosted liquid water and complex chemistry. These findings illuminate the processes that shaped the early solar system and supplied the ingredients for life to Earth.
Building on this success, the spacecraft has begun a new journey as OSIRIS-APEX to study asteroid (99942) Apophis when it passes extraordinarily close to Earth in 2029. Lessons from Bennu will guide this next encounter, offering a rare opportunity to watch an asteroid’s surface respond to strong tidal forces – and to deepen our understanding of how planetary bodies evolve and interact across the solar system.
Thursday, October 30, 2025
Giorgia Busso, University of Cambridge
The Ultimate Stellar Census: Inside ESA’s Gaia Mission
Gaia is one of the most successful projects from the European Space Agency. Across more than 10 years since its launch, it has transformed our understanding of the Milky Way by precisely mapping the positions, motions, and properties of almost two billion stars. But Gaia also improved our knowledge of closer objects in our Solar System, with a survey of more than a hundred thousand asteroids, and of the furthest objects in the universe, with a catalogue of a few million quasars. I will introduce the Gaia mission concept, from the instruments to the data processing architecture. I will present a selection of the most important results obtained in the latest Gaia DR3 and finally give you sneak peek at the coming DR4 in 2026.
Thursday, October 23, 2025
Chris Hamner, University of Hawai’i at Manoa
Optics and Photonics Engineering for Astronomy Applications
A growing trend in astronomical instrumentation is the development of compact photonic devices to supplement traditional, large-scale optical systems. For these devices to be effective, light collected by a telescope must be efficiently coupled into few-mode waveguides for transport and analysis. My research focuses on combining free space, fiber based, and photonic circuit devices to realize high performance, compact and relatively low cost instrumentation. I will also discuss how our new faculty cohort, the Space Science and Engineering Initiative, is working to support ground based astronomy in Hawaii.
Thursday, October 16, 2025
Steven Furlanetto, University of California – Los Angeles
How Much Do We Understand About Early Galaxy Formation
The “Cosmic Dawn” of galaxy formation is one of the frontiers of modern astronomy. In the past two years, JWST has provided tantalizing clues about sources in the first several hundred million years of the Universe’s history that challenge our understanding this era, including an apparent overabundance of bright galaxies during the early phases, evidence for strong fluctuations in the star formation rate of sources, and a surprising abundance of accreting supermassive black holes. I will use a simple galaxy formation framework to describe how we can leverage these new observations to learn more abut this crucial era.
Thursday, October 9, 2025
Amin Chabchoub, Okinawa Institute of Science & Technology
Breathers and Rogue Waves Across Physical Systems
Breather solutions of the nonlinear Schrödinger equation (NLSE), also known as solitons on finite or continuous backgrounds, have been known since the late 1970s. These pulsating, localized structures capture the nonlinear stage of modulational instability (MI) in a wide range of dispersive media and serve as canonical models for the emergence and control of rogue waves. This talk will review recent groundbreaking experimental observations of fundamental breather dynamics across optics, hydrodynamics, plasma, and Bose–Einstein condensates. Particular emphasis will be placed on applications in hydrodynamics, as well as the modeling and prediction of oceanic rogue waves. Furthermore, we report controlled laboratory observations of exact Manakov-type envelope solitons and breathers in a water wave basin. Despite the challenges associated with generating clean, reproducible crossing-wave conditions, the measurements exhibit excellent agreement with the integrable coupled-NLSE framework. Finally, perspectives will be offered on the broader role of MI in ocean wave dynamics..
Thursday, September 25, 2025
Peter Schwindt, Sandia National Laboratories
Measuring the Human Brain with Optically Pumped Atomic Magnetometers
Over the past decade, optically pumped (atomic) magnetometers (OPMs) have proven to be an exciting new to technology for magnetoencephalography (MEG), the measurement of the magnetic fields produced by the active human brain and the localization of these neuronal currents. OPMs can be placed closer to the brain and can be worn offering new paradigms for MEG measurements for neuroscientists and clinicians. Since 2007, my group at Sandia has been developing OPMs, performing some of the first demonstrations of MEG with compact OPM sensor heads. I will present various aspects of our development efforts. I will describe our first multi-sensor OPM-MEG system where we implemented a 24-channel OPM system inside a person-sized magnetic shield. With the system, we have been able to localize neuronal sources and decode MEG signals using machine learning techniques to determine perceived speech in a closed vocabulary experiment. Next, I will discuss our most recent effort to implement a 108-channel optically pumped magnetometer (OPM) array in a magnetically shielded room. Our four-channel OPM has been redesigned to ease manufacturing, reduce the external temperature, improve the magnetic field control and uniformity, and reduce the required optical power, while maintaining or improving the sensitivity and bandwidth. We are in the final months of installing this system, and I show our most recent progress
in this effort.
Thursday, September 18, 2025
Jeffrey Vervoort, Washington State University
Unraveling the Early History of the Earth
In my research, I use the Hf and Nd isotope record of the early Earth to help better understand its early differentiation and how this relates to the formation and evolution of Earth’s earliest continental crust. A recent focus of my work is on the integrity of that isotope record: to what extent it has been modified by subsequent metamorphic events and how we can assess whether it faithfully records original isotope compositions. To answer these questions, I use coupled U-Pb age and Hf isotope analyses of zircon and U-Pb age and Nd isotope analyses of REE-rich phases (monazite, titanite, allanite, etc.) determined simultaneously by the laser ablation split-stream (LASS) method. Our research indicates that the formation of long-lived continental crust and corresponding depletion of the mantle did not occur significantly until after about 3.8 Ga.
Thursday, September 11, 2025
Kate Grier, University of Wisconsin – Madison
Probing Supermassive Black Holes and Quasars with the SDSS-V Black Hole Mapper Reverberation Mapping Project
One of the major areas of exploration in astrophysics is the study of how galaxies form and evolve. All massive galaxies have a supermassive black hole at their center, and observations suggest that the growth of the galaxies and their central supermassive black holes are linked. In order to understand how galaxies evolve, we thus also need understand how their central black holes grow and how these black holes interact with their host galaxies. To do this, we use observations of active galactic nuclei and quasars, which are actively accreting supermassive black holes that emit a tremendous amount of energy, visible across the entire observable universe. The Sloan Digital Sky Survey (SDSS) is monitoring thousands of quasars over more than decade to explore supermassive black holes and quasars at a wide range of distances. We have collected hundreds of spectra each for thousands of quasars as a part of the SDSS-V Black Hole Mapper Reverberation Mapping Project (BHM-RM). While the main goal of this program is to measure black hole masses using a technique called reverberation mapping, these spectra have also allowed us to explore variability in quasars and learn about supermassive black holes from numerous different angles, ranging from studies of broad absorption-line variability in quasar spectra, to studies of extreme variability events. I will give an overview of the BHM-RM project and highlight some of the work that we have been doing that has been enabled by this unprecedented spectral dataset.
Thursday, September 4, 2025
Konstantin Matveev, Washington State University
Modeling of thermofluid processes in liquid hydrogen storage and transfer systems
Hydrogen is a promising clean and renewable fuel that can help humanity impede the catastrophic climate change. However, to produce, store, and transport hydrogen in the energy-dense liquid form, low cryogenic temperatures are required, as hydrogen boils at about 20 K. Investigation and characterization of liquid hydrogen processes, components, and systems represent the main R&D directions of the Hydrogen Properties for Energy Research (HYPER) Center at Washington State University. In this talk, our efforts on modeling thermofluid phenomena involving cryogenic and liquid hydrogen will be presented. The employed modeling methods range from lumped-element models to high-fidelity computational fluid dynamics simulations. The discussed applications include dynamic processes in liquid hydrogen storage tanks, critical phase-changing flows, para-orthohydrogen conversion for cryocooling, Taconis oscillations that lead to large heat leaks into cryogenic tanks, multiphase flow instabilities important for transferring liquid hydrogen, and other unsteady phenomena. The developed models can help engineers optimize design and operations of liquid hydrogen systems with higher confidence.
Thursday, March 20, 2025
Nicolas Pavloff, University of Paris
Topological Pathways to Two-Dimensional Quantum Turbulence
I shall present combined experimental and theoretical investigations of the formation and decay kinetics of quantum vortices in a two-dimensional turbulent superfluid. I will discuss the relevance of the concept of point vortex in describing superfluid dynamics, tracing its origins back to 19th-century studies of tides by British physicists. Fundamental topological conservation laws require that the formation and annihilation of vortices also involve critical points of the velocity field, namely nodes and saddles. Identifying the simplest bifurcations underlying these processes enables to develop an effective kinetic model that closely aligns with experimental observations, revealing that distinct mechanisms underlie the growth and decay of the vortex population.
Thursday, February 20, 2025
Richard Koelsch, National Aeronautics and Space Administration (NASA)
Humanity’s First Space Station to Orbit the Moon
Gateway is a next-generation space station that will orbit the Moon. It will enable a wide range of research activities and serve as a vital staging point for deep space exploration. As the first permanent infrastructure at the Moon, Gateway is central to NASA’s Artemis missions, which aim to return humans to the lunar surface in preparation for the first crewed missions to Mars. The presentation will provide an overview of Gateway / NASAs Artemis Missions and basics behind life support systems for crewed spacecraft.
Thursday, February 13, 2025
Niccolo Veronesi, Washington State University
On a Quest to Discover Where Stellar-mass Black Holes Merge
Even if almost ten years have passed since the first direct detection of gravitational waves originated from the merger of a binary black hole, and even if such detection has been done for several tens of these systems, their astrophysical origin is still highly debated. The main reason for this lies in how poorly the exact position of the merger can be constrained. The typical localization volume can easily contain several thousands of galaxies. For this reason, a one-to-one association between merger and host environment is in general impossible. In this talk I will discuss how likelihood-based spatial correlation analyses can efficiently constrain how many of the binaries have merged in specific potential hosts, such as Active Galactic Nuclei. I will present how these methods work and show their results, the first observational constraints on the origin of merging stellar-mass black holes.
Thursday, January 16, 2025
Claire Richardson, Arizona State University
The mysterious, massive structures in Earth’s deep mantle
For over a century, seismologists have measured and modeled earthquake waves to determine Earth’s interior structure. Early work by Inge Lehmann, Beno Gutenberg, and Andrija Mohorovičić revealed global internal physical discontinuities, ultimately yielding the basic layer-cake structure of the crust, mantle, and inner and outer core that we see in textbooks. These fundamental discoveries were made from extremely sparse seismic data, and this simple layered model has been and continues to be the first-order understanding of the interior of the Earth. In the 1980s, however, seismologists discovered anomalous waveforms that suggested the existence of two very large structures sitting nearly antipodal on the core-mantle boundary (CMB). These structures, characterized by lower-than-average wave speeds relative to the ambient mantle rock, are referred to as Large Low-Velocity Provinces (LLVPs). Since the initial discovery of the LLVPs, the quantity of data has skyrocketed, theoretical modeling frameworks have advanced profoundly, and computational resources have proliferated. These three factors have fundamentally transformed our understanding of Earth’s deep interior. At the CMB, a boundary layer delineating an even more extreme change in physical properties than between the crust and the atmosphere, they have revealed a tremendously complex landscape dominated by the LLVPs. In this talk, I will give an overview of the discovery of the LLVPs and present the current knowledge and interpretations of the physical nature of the CMB. I’ll also discuss open questions and active areas of multidisciplinary research to improve our understanding of LLVPs as we continue to unravel the mysteries of this complex region of our planet.