This issue of The Caltech Effect features scientists and engineers who have followed unexpected paths, repurposed technology, and responded nimbly to innovative ideas and urgent needs.
Interactive Story
Sense of (Re)Purpose
Caltech researchers have innovated to extend or redirect technologies for vital new uses.
Funding from endowed leadership chairs brings top talent to Caltech and supports researchers who take on pressing problems like COVID-19 or enter high-risk, high-reward areas of discovery.
Caltech community members recount the moments that transformed their careers … and lives.
This summer, I’m working with Professor Yisong Yue as a SURF fellow to devise a new machine learning framework. So far, our model outperforms current models on test functions, and we’re actually starting collaborations with some other research groups to apply our model to their real world datasets. When I arrived at Caltech in the fall, I thought that I would be studying biology. However, I ended up switching to CS and data science, and this transition was only possible because of the freedom that Caltech’s core allowed me to really think about what it is I found interesting. What made the difference, though, is the confidence that people placed in me. My biology lab trusted me to take on bioinformatics projects even though I’d literally learned Python the term before. My current PI trusted me to figure things out for myself, even though I barely knew anything about machine learning when I walked into his office. I’m beyond grateful to be in an environment where people believe by default that you can do things regardless of how conventionally qualified you are to do them.
I remember being in a large room in New Jersey with 100 other managers from a large multinational chemical company. And they asked us to brainstorm ways to increase the profitability of the company by 15 percent over the next year. And I realized that the direction of my career was going to be more than just trying to maximize the profit of a single company. I remembered fondly that as a younger boy, I was enamored with astronomy. I remembered that I was alive during the end of the Apollo program. I had watched live feedback from the surface of Mars through the Viking landers. And of course, Carl Sagan and his cosmos. I realized that I wanted to transform my life and become an astronomer. I wanted to dedicate my life to the expansion of human knowledge even if it was going to be just a little bit. I retook all my undergrad math and physics classes. I applied to a very good graduate program. And 10 years later, I received my degree in astrophysics, and I also started work at the Jet Propulsion Laboratory. I have never regretted this decision. I am very proud that I took the risk. I’m very grateful for all the people that encouraged me and supported me through this process. Life has a funny way of giving people a second chance to chase their dreams.
I graduated from Caltech in 2018 with a bachelor’s degree in computer science, and, soon after that, I joined Salesforce as a software engineer. At the same time, I also began volunteering at the suicide prevention hotline, and I was amazed by the impact that these services had on the people who contacted us. Many of our callers or texters were in distress due to broken relationships or they were suffering from anxiety or depression or bipolar disorder. Some people who contacted us were even actively suicidal in the moment. We were able to talk so many people out of taking their own lives, and we were able to help so many other people feel so much better in the moment and help them realize that they had a lot left to live for. It was by these experiences that I was inspired to apply for the Chang Prize in 2019 because I was hoping to create my own counseling service called Student Counsel, which will be an emotional support text line for college students. I’m really honored and humbled to have been a recipient of the Chang Prize, and we intend to use these resources to build the technical platform for Student Counsel, which we hope to launch in a few months. I’m really grateful to Caltech for the opportunity to make this happen, and I’m really excited to be able to use my experiences to help out others.
From biology to computer science
James Bowden
Rising Sophomore (BS ’23) and Computer Science Major
From astronomy to screenwriting
“I earned my BSc in astrophysics from Caltech and found myself not knowing what I wanted to do next. I talked to a Caltech career counselor who looked over my transcript and noticed my affinity for studying literature and writing. She asked if I had ever considered becoming a writer. I laughed: I wasn’t looking to become unemployed. So, I took the safer path and went to graduate school for astronomy. Just before graduating, I found out that I had stage 3 kidney cancer and would need robotic surgery, which was scheduled for the exact date and time of my PhD defense. I promised myself that if I survived, I would take the leap and follow my passion: to become a screenwriter. After all, what could be scarier than cancer? Three weeks later, I left the ICU, got my PhD, and started my new life doing what I love.”
Dagny Looper (BS ’04)
Filmmaker
From chemistry to exoplanet exploration
Nick Siegler
Astrophysicist and Chief Technologist for NASA’s Exoplanet Exploration Program at JPL
From software engineering to student support
Preethi Periyakoil (BS ’18)
MD/PhD candidate in the Tri-Institutional Program at Weill Cornell Medical College
Recipient of a Caltech Alumni Association Milton and Rosalind Chang Career Exploration Prize, 2019
From improv to astrophysics
I started doing stand-up comedy about 10 years ago. GALEX, the mission for which I was hired as a postdoc at Caltech in 2006, was reaching the end of its mission, and I was at a decision point about where to go with my career. I also was taking improv lessons at Second City in Hollywood. As scientists, we learn a certain approach to solving problems; improv and stand-up present a very different way of approaching life and looking at things. Improv also taught me that a lot of my satisfaction in astronomy comes from working with a team. Before, I was focused on promoting my own reputation as a world-class researcher. It turned out I didn’t feel that comfortable just promoting myself. It was part of the discomfort I felt doing stand-up as well. That was a revelation to me, that I really enjoyed being with a team on stage much more than being there by myself. The experience with improv completely opened up my idea about what my career could be, and I got involved working as part of a group developing software and building instruments for the Palomar and Keck Observatories.
Don Neill
Research Scientist in Space Astrophysics at Caltech
Sense of (Re)Purpose
Caltech researchers have innovated to extend or redirect technologies for vital new uses.
Piggybacking an earthquake-sensing system onto a city’s existing fiber-optic network. Using imaging tech used on the space shuttle to reveal never-before-seen text from priceless manuscripts. Applying an isotopic behavior first discovered in dinosaur teeth to probe what gave rise to life itself. These are a few of the advances made by Caltech researchers who have repurposed their own or others’ technologies to enhance understanding of the world and benefit humanity.
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Repurposed
The isotopic cling factor that could explain the beginnings of life
In 2011, John Eiler, Caltech’s Robert P. Sharp Professor of Geology and Geochemistry, confirmed for the first time that some Jurassic dinosaurs had body temperatures as warm as modern mammals. Using a new form of highly precise mass spectrometer, Eiler examined the distribution of carbon-13 and oxygen-18 isotopes (isotopes are forms of a chemical element that have the same number of protons but a different number of neutrons in their nuclei, resulting in different atomic weights) in a mineral in the tooth enamel of two sauropods, Brachiosaurus and Camarasaurus.
He found that these isotopes bonded, or clumped, to one another in ways that occur only in a warm environment; in this case, in the sauropods’ bodies. “Temperature is the only thing that controls isotopic clumping in the environments where bone, teeth, or eggshells grow,” Eiler says.
Having successfully demonstrated the isotope-clumping technique in samples from dinosaurs, Eiler decided to explore its application in a different area of science: the environments that gave rise to life on Earth or that might have enabled life elsewhere in the solar system. To do this, Eiler focused on the environmental conditions and prebiotic chemistry that sparked amino acids and other biologically useful molecules. First, he studied trace carbonate minerals in a Martian meteorite found in a remote ice field of Antarctica. He and his team were able to determine that the mineralizing fluids of the surface of ancient Mars had temperatures of 64 degrees Fahrenheit, warm enough to support water and well within the “habitable zone” of known life.
Most recently, Eiler took specialized mass spectrometers commonly used to identify trace organic molecules and retooled them to study isotopic distributions within biomolecules and their chemical precursors. He is now using those enhanced instruments to unravel the origins of organic molecules from primitive asteroids, hoping to detail how prebiotic chemistry set a stage for life’s emergence on Earth, and perhaps on Mars and beyond.
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Repurposed
The fiber-optic telecommunications network that captures seismic activity
To run its business and transportation services, the City of Pasadena in the late 1990s installed an underground fiber-optic network, which today stretches for 50 miles. When installing one of these networks, it is common practice to lay additional cable to plan for future growth; the unused portion is called dark fiber.
In 2019, Zhongwen Zhan (MS ’08, PhD ’13), Caltech assistant professor of geophysics, identified an opportunity to give the city’s dark fiber a new purpose, for which city officials granted him access under a five-year agreement. The cables, Zhan noted, could serve as a conduit for the first fiber-based earthquake-monitoring system in the world. The system shoots laser light through the cables and detects when it returns. When seismic waves pass by, the cable expands and contracts enough to affect the time the light takes to travel back to its source, signaling the degree of the seismic activity.
This seismic array is producing data in detail and quantity never before possible because its sensors, which are spaced every 30 feet or so, blanket the city. Previously, the entire metropolitan area had been monitored by only 11 traditional seismometers, leaving large swaths of land unrecorded.
Sensor density is a game-changer, says Zhan. “It will help us start to understand what’s underneath the city much better,” he explains. “The earth is really complicated. Even really soft soil left by an ancient river, for example, may amplify the shake in an earthquake by a factor of three.”
The project is rapidly generating international interest. “We are very excited to move our instruments to different cities,” Zhan says. “The hope is that we are able to ramp up our instrument pool so that we can do that.”
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The planetary-imaging technology that reveals secrets in ancient texts
Greg Bearman, an atomic physicist at the Jet Propulsion Laboratory, developed multispectral imaging to study planetary surfaces in exceptional detail through views captured by spacecraft and satellites. The technology involves bouncing wavelengths of infrared light off what is being imaged, including wavelengths beyond those that the human eye can detect.
In 1993, he began to apply multispectral imaging to the study of ancient scrolls, working with the Israeli Antiquities Authority. Starting in 2008, the now-retired Bearman was the imaging consultant to the Leon Levy Digital Dead Sea Scroll Library, tasked with reimaging the Dead Sea Scrolls for documentation and conservation monitoring.
“It’s like looking for a black cat at midnight,” Bearman says, referring to the lack of contrast between parchment and ink. “But as you move beyond the visible range of light, the parchment gets very bright compared to the ink, and all of a sudden you can read it.”
More recently, the technology helped a team in Italy reveal hidden text on pieces of papyrus charred during the eruption of Mount Vesuvius that destroyed Pompeii in 79 C.E. It also allowed the Museum of the Bible in Washington, D.C., to conduct an independent surface analysis, which determined, in part, that its collection of 16 fragments were forgeries. All but one are made from ancient leather instead of parchment, and, in some cases, ink had visibly pooled in cracks in the aged hide.
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The WWII-era oxygen meter that saved a struggling newborn
In 1940, in need of a way to keep U.S. submarine crews and pilots from losing consciousness or even dying due to oxygen depletion while deep beneath the ocean’s surface, a top-secret military research group tapped Caltech theoretical chemist (and, later, two-time Nobel Prize winner) Linus Pauling for help. Within days, Pauling had developed a design for an instrument that came to be known as the oxygen analyzer.
Pauling knew that, in a magnet’s presence, oxygen molecules line up like obedient elementary school students. Using the principle of torsion balance, he attached two small hollow glass spheres to a metal bar and set this dumbbell-like device between the legs of a horseshoe magnet, then covered it with a bell jar.
Introducing air into the spheres repelled a quartz fiber Pauling placed on the metal bar, causing the dumbbell to rotate and twist the fiber, to which he then attached a mirror, which likewise twisted. The angles at which the mirror sent light to a photocell captured the amount of oxygen present (more oxygen, more twist; less oxygen, less twist) and displayed it on a readout dial.
Military demand soon outstripped Pauling’s production capability, so he turned to fellow Caltech chemist Arnold Beckman to manufacture the oxygen analyzer and expand its market in keeping with what a prescient Pauling had noted at the start: “There are many uses to which the instrument might be adapted other than the original one.”
One of those adaptations, which came about in the 1950s, made Pauling most proud. A Huntington Memorial Hospital anesthesiologist used Pauling’s oxygen analyzer to test the amount of oxygen his failing premature granddaughter was receiving in her incubator and found it insufficient. Adjusting her oxygen supply saved that child and launched the analyzer into the medical field, where it was later used to quell an international epidemic of blindness among preemies caused by a surfeit of oxygen in their incubators.
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The ion-smashing technology that turns comets into oxygen fountains
Caltech’s Konstantinos Giapis studies how colliding high-speed charged ions with semiconductor surfaces can sculpt better-performing chips and memory cards at the nanoscale for computers and phones. At work in this process is the Eley-Rideal mechanism, a class of chemical reactions triggered when ions strike a surface, breaking off atoms and in the process forming new molecules.
A professor of chemical engineering, Giapis shifted his research focus from chips to comets when he came across recent data generated by Rosetta, the European Space Agency’s comet-orbiter probe. The probe showed that molecular oxygen streams off the comet P67/Churyumov-Gerasimenko; finding oxygen was unexpected and mysterious since comets are known to emit mostly water when they get close to the sun. The probe documented how this water becomes ionized and is returned to the comet surface as high-velocity water ions.
“It immediately clicked as to what was going on,” says Giapis, who recognized the same Eley-Rideal mechanism at work 140 million miles from Earth. He halted everything in his lab to use a Caltech accelerator to reproduce how fast-moving water ions would, upon impact, tear oxygen atoms from oxidized minerals to release molecular oxygen. “We accelerated water ions to speeds similar to those measured on the comet and started to see oxygen being produced. This is new and unexpected chemistry.”
Because the P67 comet gives off carbon dioxide as well, Giapis wanted to see if energetic carbon-dioxide ions barreling into oxidized surfaces can also produce oxygen. After finding out that this was the case on oxidized surfaces, he repeated the experiment on a gold foil, which cannot oxidize, and showed that the carbon dioxide molecules dropped their carbon atoms and turned into oxygen.
Giapis is in the early stages of conceiving a device that will be able to turn carbon dioxide into elemental oxygen, and, in doing so, might one day help combat climate change and give astronauts a renewable oxygen source derived from their own exhalations. “It would be very useful on Mars, where the atmosphere consists of 96 percent carbon dioxide,” Giapis says. “Caltech is pursuing a patent for my technology to use energetic carbon dioxide ions to make breathable oxygen. We think big.”
Renee Olson
Writer
Cornelia Li
Illustrator
Pull Up a Chair
Funding from endowed leadership chairs brings top talent to Caltech and supports researchers who take on pressing problems like COVID-19 or enter high-risk, high-reward areas of discovery.
When the COVID-19 pandemic interrupted life around the world, Caltech researchers sprang into action to work on research related to the novel coronavirus. Changing course when a new opportunity or challenge arises is nothing new for Institute scientists. The financial support necessary to execute such a pivot often comes from endowed leadership chairs, which enable the heads of Caltech’s divisions and research institutes to allocate discretionary funds to bolster new priorities and areas of interest.
A Pandemic Pivot
When urgent needs occur, leadership chair support can allow for a rapid response. In the case of COVID-19, Pamela Björkman, David Baltimore Professor of Biology and Bioengineering, and her lab are identifying the antibodies that COVID-19 patients produce in response to the novel coronavirus and studying the degree to which they also react to similar coronaviruses, such as severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS).
Stephen Mayo (PhD ’87), Bren Professor of Biology and Chemistry and William K. Bowes Jr. Leadership Chair in the Division of Biology and Biological Engineering (through August 2020), distributed the discretionary funds from his BBE chair to support Björkman’s research and also pursue a related collaboration, in which he and Björkman are studying the human antibodies that were identified during the SARS outbreak of 2003. In both projects, the researchers are using machine learning to accelerate the understanding of the novel coronavirus and the development of antibodies for passive immunization against COVID-19. Passive immunization occurs when antibodies are directly introduced to an individual. In a vaccine, by contrast, a weakened virus or parts of a virus are injected to spur the patient’s immune system to create antibodies.
A Drone for a Disaster
Flexible funding is also used to nurture innovative ideas, such as one developed at Caltech’s Center for Autonomous Systems and Technologies (CAST).
Atlantic hurricanes have a long history of sweeping through and wreaking havoc upon the archipelago of Turks and Caicos, which makes the islands an ideal place to study how nature repairs itself after a disaster. In previous years, Caltech geology graduate students have traveled to Turks and Caicos in the aftermath of a major storm to study its impact by flying an instrument-laden drone overhead to map changes to the land. The researchers’ ability to gather a complete picture of the islands has been limited, however, by the capabilities of off-the-shelf drones and the restrictive window of time the students could stay on the islands.
Enter Mory Gharib, Hans W. Liepmann Professor of Aeronautics and Bioinspired Engineering, CAST director, and holder of the CAST Booth-Kresa Leadership Chair. Using his CAST chair’s discretionary funds, Gharib partnered with John Grotzinger, Fletcher Jones Professor of Geology and Ted and Ginger Jenkins Leadership Chair for the Division of Geological and Planetary Sciences, to find a better way to study the islands from above.
CAST scientists and engineers, including Nathan Stein (MS ’17, PhD ’20), Reza Nemovi, and Noel Esparza-Duran, designed an autonomous drone for this task. The heavy-lift drone can tote up to 20 pounds, which allows it to carry instruments such as cameras and LIDAR, a technology that bounces lasers off a surface and measures the reflection, which in this case allows the drone to calculate changes in land elevation. The drone also sits in a container equipped with sensors and wind turbines to power the system; this allows the drone to measure a hurricane as it passes. After the storm has subsided, the drone takes off and flies over the island. It scans with multispectral cameras, gathers all the scientific information, lands autonomously in the box, and then relays the information back to Caltech.
Quantum Meets Chemistry
Discretionary funds may also be allocated to support faculty interested in exploring new fields of inquiry.
Scott Cushing, assistant professor of chemistry, recently pivoted his chemistry research to include quantum entanglement, the phenomenon in which a pair or group of particles share a linked quantum state even when they are separated by physical distance. Entanglement not only drives cutting-edge fields within physics such as quantum information and quantum computing, but it also could spark new ways to look at other sciences and techniques. Cushing studies how entanglement might affect spectroscopy, the study of a material’s electromagnetic spectra to understand its makeup. “If you send an entangled photon through a material, do you gain new information that you wouldn’t have gained classically? We’re starting to look at this,” Cushing says.
Cushing’s interests are rooted in instrumentation development, and much of his new research has involved building the equipment needed to understand the complicated signals he receives from entangled photons. “When you see an area where people can’t answer questions and it’s a new thing, it’s fun to dive into it.”
This meeting point of entanglement and chemistry is so new, Cushing says, that only a handful of labs around the country have begun to pursue it, and large grants are hard to find for emerging fields. The support needed to jump-start his dream project upon his arrival at Caltech in 2018 came from David Tirrell’s Carl and Shirley Larson Provostial Chair.
A Cellular Coincidence
Fortuitous collaborations can spark quickly when leadership chair funds provide support.
For years, Angelike Stathopoulos, professor of biology, has investigated how cells send messages to one another. Meanwhile, Kai Zinn, Howard and Gwen Laurie Smits Professor of Biology, has studied the messages certain cells are sending. As it turned out, the two researchers were looking at the very same cells in two different ways but had never made the connection.
This summer, Stathopoulos and colleagues published a study that helps to decipher the language that proteins called ligands use to facilitate cellular communication in many kinds of cells, including, it turns out, the neurons Zinn studies. When Stathopoulos’s group looked at one member of the FGF (fibroblast growth factor) family of proteins in fruit flies, they found a couple of surprises. The ligand (shown above) has a kind of tether that prevents the message from traveling too far from the cell that sent it, and it is capable of reverse signaling, that is, sending a message back to the origin cell. When her team wondered what kind of cells would need to make the precise signaling decisions these newly discovered pathways would allow, they thought of neurons, a fortuitous insight.
“We were working on this FGF-signaling molecule and asked Kai to see where our molecule was expressed,” she says. “It turned out that it was expressed in exactly the cell that he’s studying.” Specifically, Zinn’s lab studies a particular decision-making pathway among neurons in which one cell must send a signal to keep the second cell from dying, and one of the two kinds of cells involved in this process uses the FGF molecule that Stathopoulos investigated.
Now, with support from the Tianqiao and Chrissy Chen Institute for Neuroscience Leadership Chair held by Seymour Benzer Professor of Biology David J. Anderson, the pair has begun a new collaboration. “When we think of reverse signals, it raises all these questions,” Stathopoulos says. She is curious about the biological implications of reverse signaling in the nervous system and what it could mean for understanding of the brain. “Those are the questions we’re asking now with Kai’s lab.”
The New Recruits
Leadership chairs allow Caltech’s division chairs not only to respond quickly to innovative ideas and urgent needs but also to recruit the best and brightest new faculty members and give those researchers the freedom to investigate high-risk, high-reward fields of inquiry.
When Danielle Wiggins (above left), whose research focuses on African American political history and urban political economy, applied for a postdoctoral instructor position at Caltech in 2017, the faculty wanted to offer her a placement as a full professor, but the Institute had no open position in history at that time. Jean-Laurent Rosenthal, Caltech’s Rea A. and Lela G. Axline Professor of Business Economics, used the discretionary funds from the Ronald and Maxine Linde Leadership Chair in the Division of the Humanities and Social Sciences to make this appointment possible. Wiggins joined the faculty as assistant professor of history in the summer of 2019 after a year’s residency at the University of Virginia’s Jefferson Scholars Foundation.
Fiona Harrison, Harold A. Rosen Professor of Physics and Kent and Joyce Kresa Leadership Chair in the Division of Physics, Mathematics and Astronomy, used her chair funding for 2021 to create a start-up package for dark-matter researcher Kathryn Zurek (above right), who recently came to the Institute as professor of theoretical physics. Among her interests is the pursuit of quantum gravity, the field that seeks to unify gravity with the other forces of nature, which are quantum mechanical. Because of the difficulty in studying quantum gravity with observations, the field has remained strictly in the theoretical realm, Zurek says. But now, “a few people are just starting to question that dogma based on a few hints or hooks that we have,” she says.
A decade from now, the notion that quantum gravity has observational signatures may move from being “crazy to mainstream,” says Zurek, similar to the way that her hidden-sector dark-matter observational research has evolved. In the meantime, discretionary funding allows her to pursue high-risk research in a new field in which government funding would be hard to come by.
