Brian Toby, Carlos Wagner and Seth Darling of the U.S. Department of Energy’s (DOE) Argonne National Laboratory have been elected Fellows of the American Association for the Advancement of Science (AAAS).
Every year, the AAAS Council elects members whose research has made a significant contribution to advancing science. The honor of being elected an AAAS Fellow began in 1874. New fellows are formally recognized with a certificate at the annual Fellows Forum, to be held in Washington, D.C., in spring 2026.
Enabling discovery in crystallography
Toby, a crystallographer in Argonne’s X-ray Science division, was recognized for “pioneering work in powder diffraction crystallography through instrument, software and technique development.”
Powder diffraction crystallography helps scientists determine how atoms are arranged in materials. This information can explain and predict how those materials will behave and how they can be improved.
“I see being elected a Fellow of the AAAS as recognition of the work that I’ve done enabling other people to do science,” Toby said. “I’ve been an active researcher for many years, but I’ve also devoted a lot of effort to creating tools for other people to use in their science. Many of these have been the highlights of my career.”
Toby joined Argonne in 2005 to oversee construction of the 11-BM diffractometer at the Advanced Photon Source (APS), a DOE Office of Science user facility. The 11-BM instrument is the country’s most sensitive and highest resolution powder diffractometer, which allows researchers to extract more information about complex materials. He also designed and implemented a highly automated system that supports rapid, reliable operation and broad access for users, allowing 11-BM to become one of the most productive beamlines in the world.
Beyond instrumentation, Toby’s impact has been widely felt through the scientific software he has developed and supported over decades. He began writing scientific software as an undergraduate and continued through many generations of computers, often with a practical aim: removing barriers that slow down research and making advanced methods easier to use.
One of his best-known projects is GSAS-II, short for General Structure Analysis System II. GSAS-II is an open-source software package used worldwide to analyze diffraction data and refine crystal structures, helping scientists turn complex measurements into models of how atoms are arranged in materials.
“I think nowadays, I’m best known for the software that I’ve written because it touches thousands, if not tens of thousands, of scientists’ lives,” Toby said. “These contributions allow other people to do science.”
His work also helped advance the adoption of shared data practices in crystallography, enabling researchers to exchange and preserve measurements and results in consistent formats. Such standards help make scientific results easier to reproduce, reanalyze and build upon.
For Toby, the recognition also reflects the community behind the science.
“Over the course of my career, there have been many memorable projects,” he said. “But it’s also the people I’ve worked with. I’ve had the opportunity to learn from some great people, and in turn, I’ve had the opportunity to do some mentoring as well. It’s not only about the papers and the discoveries; it’s also about the network of people that we work with. This honor reflects that to me.”
Building deeper understanding of fundamental physics
Wagner, a scientist in Argonne’s High Energy Physics division and a professor at the University of Chicago, was named an AAAS Fellow in recognition of his “groundbreaking contributions to the mechanism of electroweak symmetry breaking and its phenomenological consequences, and for outstanding mentorship of junior colleagues.”
Wagner’s research focuses on the Standard Model of particle physics, a framework that describes the fundamental particles and forces in the universe. His work has explored the properties of the Higgs boson, a particle that plays a central role in giving mass to other particles. He has also made significant contributions to understanding baryogenesis, the process that explains why the universe is dominated by matter rather than antimatter.
“When I started working in high energy physics, the Higgs boson had not yet been discovered,” Wagner said. “Over more than 20 years, I’ve worked on theoretical calculations for the Higgs boson’s properties, as well as the generation of the asymmetry between matter and antimatter.”
One of Wagner’s key areas of research is electroweak baryogenesis, a process that explains how the universe came to be dominated by matter. In the early universe, matter and antimatter were created in equal amounts, but today, the observable universe is almost entirely made of matter. Wagner’s work has shown how the Higgs boson could play a crucial role in this process. During the universe’s early moments, as it cooled, the Higgs field underwent a phase transition, acquiring a nonzero value. This transition, combined with a phenomenon known as charge-parity symmetry breaking (which distinguishes matter from antimatter), could have led to the observed imbalance.
In addition to his work on baryogenesis, Wagner has made significant strides in calculating the mass of the Higgs boson within extensions of the Standard Model, such as supersymmetry. Supersymmetry is a theoretical framework that predicts the existence of new particles and offers potential solutions to some of the Standard Model’s unanswered questions.
Wagner’s calculations, which incorporated advanced techniques to refine predictions, were among the first to accurately estimate the Higgs boson’s mass in supersymmetric models. When the Higgs boson was discovered at the European Laboratory for Particle Physics (CERN’s) Large Hadron Collider in 2012, its measured mass fell within the range predicted by these models. While this does not confirm supersymmetry, it keeps the theory as a viable possibility.
Those open questions about the universe are what continue to motivate Wagner’s research in particle physics.
“The Standard Model is a fantastic theory and has really amazing properties, but it leaves too many questions unanswered,” he said, including questions about dark matter, how gravity fits into unified theories of the forces of nature and the generation of the matter-antimatter asymmetry. “These are the questions that drive my research, my life in physics, and I hope to see answers to them in my lifetime.”
In addition to his research contributions, Wagner has mentored several graduate students and postdoctoral fellows at the University of Chicago and Argonne. Many of his former mentees have gone on to tenured scientific positions and professorships at leading universities and national laboratories around the world.
“It’s an honor, of course, to be recognized as an AAAS Fellow,” he said. “It reflects many years of work, not just a single publication, but a series of collective works that I have done over more than 30 years.”
Engineering advanced materials for energy and water
Darling is a senior scientist in Argonne’s Chemical Sciences and Engineering division, director of the Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center, and a Consortium for Advanced Science and Engineering (CASE) senior scientist at the University of Chicago’s Pritzker School of Molecular Engineering.
He was elected for “pioneering advancements in materials for energy and environmental applications and for exceptional public engagement efforts, fostering widespread appreciation and understanding of scientific innovation.”
Darling’s research centers around molecular engineering with a current emphasis on advanced materials for cleaning and recovering resources from water, having made previous contributions in fields ranging from self-assembly to advanced lithography to solar energy.
He has published over 150 peer-reviewed scientific articles and holds more than 20 patents. Darling is a dedicated science communicator who has authored three books on energy, water and science policy. He has delivered hundreds of presentations to audiences ranging from elementary school classrooms to TEDx stages to South by Southwest. His work has been featured in the Wall Street Journal, The Economist, NBC News, NPR, CBS’s Innovation Nation and many other outlets, with a video of his Oleo Sponge technology viewed over 100 million times worldwide.
“Being elected an AAAS Fellow is especially meaningful to me because it recognizes not only scientific research, but also the importance of sharing that science broadly,” Darling said. “Throughout my career, I’ve believed that advancing the science of materials for energy and the environment is only half the equation. The other half is ensuring that the public understands why this work matters and how it connects to their lives.”
About the Advanced Photon Source
The U. S. Department of Energy Office of Science’s Advanced Photon Source (APS) at Argonne National Laboratory is one of the world’s most productive X-ray light source facilities. The APS provides high-brightness X-ray beams to a diverse community of researchers in materials science, chemistry, condensed matter physics, the life and environmental sciences, and applied research. These X-rays are ideally suited for explorations of materials and biological structures; elemental distribution; chemical, magnetic, electronic states; and a wide range of technologically important engineering systems from batteries to fuel injector sprays, all of which are the foundations of our nation’s economic, technological, and physical well-being. Each year, more than 5,000 researchers use the APS to produce over 2,000 publications detailing impactful discoveries, and solve more vital biological protein structures than users of any other X-ray light source research facility. APS scientists and engineers innovate technology that is at the heart of advancing accelerator and light-source operations. This includes the insertion devices that produce extreme-brightness X-rays prized by researchers, lenses that focus the X-rays down to a few nanometers, instrumentation that maximizes the way the X-rays interact with samples being studied, and software that gathers and manages the massive quantity of data resulting from discovery research at the APS.
This research used resources of the Advanced Photon Source, a U.S. DOE Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.
Argonne National Laboratory seeks solutions to pressing national problems in science and technology by conducting leading-edge basic and applied research in virtually every scientific discipline. Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science.
The U.S. Department of Energy’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science.
