Research at Princeton 2018-2019

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Princeton University 91 Prospect Avenue Princeton, New Jersey 08540 Discovery Research at Princeton 2018-2019 A major new exhibition, Nature’s Nation: American Art and Environment, explores how American artists of different traditions and backgrounds have reflected and shaped environmental understanding and our changing relationship with the natural world. See page 26.

Below: Thomas Moran, American, 1837–1926, Lower Falls, Yellowstone Park (Grand Canyon of the Yellowstone), 1893. Oil on canvas. Gilcrease Museum, Tulsa, Oklahoma.

After its premiere at the Princeton University Art Museum (Oct. 13, 2018– Jan. 6, 2019), the exhibition travels to the Peabody Essex Museum in Salem, Massachusetts (Feb. 2–May 5, 2019), and to the Crystal Bridges Museum of American Art in Bentonville, Arkansas (May 25–Sept. 9, 2019). Dean’s For corporations and To learn more about Princeton For inquiries regarding note foundations looking for University inventions and sponsored research opportunities to collaborate: licensing opportunities: administration: PHOTO BY DAVID KELLY CROW Connect with Corporate Engagement and Technology Licensing Research and Project Princeton Foundation Relations John Ritter Administration Coleen Burrus Director Elizabeth Adams Follow Director patents.princeton.edu Director cefr.princeton.edu T 609-258-1001 orpa.princeton.edu the data T 609-258-5954 [email protected] T 609-258-3091 [email protected] [email protected]

PHOTO BY DAVID KELLY CROW

Pablo Debenedetti Dean for Research Class of 1950 Professor in Engineering and Nondiscrimination Statement In compliance with Title IX of the Applied Science Education Amendments of 1972, Professor of Chemical and Section 504 of the Rehabilitation Biological Engineering Act of 1973, Title VI of the Civil Rights Act of 1964, and other federal, state, and local laws, Princeton University does not discriminate on the basis of age, race, color, sex, sexual orien- tation, gender identity, religion, national or ethnic origin, disabil- ity, or veteran status in any phase of its employment process, in any If there is a theme to this year’s Discovery: to grow at different times of the year, and phase of its admission or financial Research at Princeton, it is the ascendancy that such “vernalized” plants would produce aid programs, or other aspects of data science in aiding our quest for deeper offspring that would inherit their growth habits. of its educational programs or understanding. We now have the computing With Stalin’s backing, Lysenko deployed these activities. The vice provost for institutional equity and diversity power and resources to collect, combine and ideas on a massive scale, setting back Soviet is the individual designated by query data in ways not before possible, and this genetics research by decades. the University to coordinate its Jennifer Rexford is the chair of Princeton’s Department of Computer Science and the power is growing daily. And with this capability Whatever the controversy of the day, the efforts to comply with Title IX, Gordon Y.S. Wu Professor in Engineering. “Princeton computer science faculty members comes the potential to accelerate the pace of way forward in science relies on following the Section 504 and other equal are pushing the envelope on scientific discovery by combining a deep understanding of discovery and push the limits of knowledge to evidence, wherever it may lead. Princeton opportunity and affirmative the underlying science with innovation in algorithms and computer systems. Better yet, action regulations and laws. benefit humanity. researchers are at the forefront of this path, this is only the beginning, with the opportunity to transform scholarship in a wide range Questions or concerns regarding of disciplines across campus.” New discoveries also have the potential both through theoretical advances in artificial Title IX, Section 504 or other to contradict what we thought we knew. intelligence and machine learning (page 20), aspects of Princeton’s equal Research can push us into contentious terri- and through innovations in data science that opportunity or affirmative action tory and threaten our deeply held convictions. are helping to address societal challenges, such programs should be directed to the Office of the Vice Provost for New ideas should not be rejected just because as eviction and its impacts (page 5), energy- Institutional Equity and Diversity, they challenge existing paradigms. Rather, efficient transportation (page 7), marine “dead Princeton University, 205 Nassau Discovery: Research at every new theory, and even many old ones, zones” (page 12), attitudes on immigration Hall, Princeton, NJ 08544 or At Princeton’s Office of the Dean for Research, we help faculty, staff and students connect Princeton is online at must be tested against hard facts and data, (page 36), and many more. 609-258-6110. with external and internal resources to create knowledge, make discoveries, and address discovery.princeton.edu. and through the open exchange of ideas. The search for understanding is at the heart scientific and technical challenges. When the interpretation of data is influ- of University research, whether the quest leads Subscribe to receive our Office of the Dean for Research Assistant Director for Finance Director of Research Integrity enced by political motives, the results are to beautiful theorems, practical inventions or a monthly newsletter at 91 Prospect Ave. and Administration and Assurance research.princeton.edu/ often detrimental. An example comes from new interpretation of art (page 26). Princeton is Princeton, New Jersey 08540 Annette Tate Stuart Leland subscribe. the former Soviet Union, when Stalin endorsed a place where all of these aspects of research research.princeton.edu Director of Corporate Director of Research and the theories of agronomist and biologist Trofim coexist, cross-fertilize and intermingle. But why T 609-258-5500 Discovery: Research at Engagement and Foundation Project Administration Lysenko, who rejected Mendelian genetics. take my word for it? Let the pages of Discovery [email protected] Princeton is published Relations Elizabeth Adams Lysenko believed that the right environmental be the data that convince you. Dean for Research Coleen Burrus annually by the Office Director of Technology cues by themselves sufficed to train plants Pablo Debenedetti of the Dean for Research Copyright © 2018 by The Trustees Executive Director of Licensing and the Office of of Princeton University Associate Dean Laboratory Animal Resources John Ritter Communications. In the Nation’s Service and Karla Ewalt Laura Conour the Service of Humanity Editor and Producer Catherine Zandonella 950008 Copy Editor Explore ResearchWith.Princeton.edu, a public, searchable database of Liz Fuller-Wright select Princeton University research. Designer Matilda Luk Research Discovery at Princeton 2018-2019

ILLUSTRATION BY DANIEL HERTZBERG 20 From Math 2 to Meaning Research News

Artificial intelligence blends algorithms and applications 40 Books

PAINTING BY THOMAS COLE 42 26 Nature’s Nation Selected Faculty How American art shaped our Honors environmental perspectives

48 Innovation Indicators

ILLUSTRATION BY J.F. PODEVIN 30 Beyond Einstein Physicists find surprising connections in the cosmos

PHOTO FROM THINKSTOCK BY GETTY IMAGES 36 Fact-checking Immigration

Professor Leah Boustan uses big data to explore myths about the past Cover: Through advances in artificial intelligence and machine learning, Princeton researchers are building technologies in health care, transportation, energy and many other areas. See our cover story, From Math to Meaning, on page 20. Illustration by Daniel Hertzberg.

discovery.princeton.edu 1 Research News

IMAGE BY ALEX NORTON, EYEWIRE

Crowdsourced brain mapping

These neurons, mapped With the help of a quarter-million video game players, Princeton researchers by Eyewire gamers, created and shared detailed maps of more than 1,000 neurons — and they’re just include ganglion cell getting started. types in blue and green By playing Eyewire, an online platform that turns a time-intensive research and inhibitory neurons in yellow and red. problem into an interactive game, the gamers built an unprecedented data set of neurons. Since Eyewire’s launch in 2012, more than 265,000 people have signed onto the game, which asks them to trace the twisting and branching paths of each neuron. “We’ve made a digital museum that shows off the intricate beauty of the reti- na’s neural circuits,” said H. Sebastian Seung, the Evnin Professor in Neuroscience and a professor of computer science and the Princeton Neuroscience Institute. The research was published in May 2018 in the journal Cell. The new Eyewire Museum is an interactive archive of neurons available to the general public and neuroscientists around the world, including the hundreds of researchers involved with Seung in the federal Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative. Explore the neurons at museum.eyewire.org. –By Liz Fuller-Wright

2 Discovery: Research at Princeton 2018-2019 Incubator for startups opens near campus

In May 2018, Princeton officials and local representatives cut the ribbon on the Princeton Innovation Center BioLabs, a 31,000-square-foot co-working lab and office space for high-tech startup companies formed by Princeton faculty, students and alumni as well as members of the wider New Jersey community. “Increasingly, our students, faculty and researchers seek to make a difference in the world through innovative entrepreneurial ventures that address societal needs,” said Princeton President Christopher L. Eisgruber. “Princeton Innovation Center BioLabs is one of several initiatives designed to strengthen the innovation ecosystem in central New Jersey and thereby expand the impact of Princeton’s teaching and research.” –By Liz Fuller-Wright

New supercomputer bolsters research

Princeton’s newest supercomputer, known as TIGER after the University’s mascot, began operating this May with nearly six times the computing power of its predecessor. Mental health declining The TIGER computing cluster, located in Princeton’s 47,000-square-foot data center, among disadvantaged adults provides high-performance computing capabilities for research in numerous disciplines. “A wide range of research crucial to American adults of low socioeconomic status humanity, from investigations of fusion energy report increasing mental distress and worsening to new frontiers in genomics, is now dependent well-being, according to a study by Princeton on computers to analyze huge complex data University and Georgetown University. sets and turn predictions into testable hypo- Between the mid-1990s and early 2010s, theses,” said Jeroen Tromp, the Blair Professor mental health declined among disadvantaged of Geology and director of the Princeton Americans ages 24 to 76, according to self- Institute for Computational Science and reports. As individuals’ socioeconomic status Engineering. –By Melissa Moss increased, their mental health deterioration lessened or, in some cases, even improved. The findings were highlighted in theProceedings of the National Academy of Sciences in June 2018. “The findings are consistent with drug overdose death rates and underscore the dire need for improved access to, and affordability of, mental health services for low-income and less-educated American adults of all ages,” said Noreen Goldman, the Hughes-Rogers Professor of Demography and Public Affairs at Princeton’s Woodrow Wilson School of Public and International Affairs. –By B. Rose Kelly

PHOTO BY MA. FLOREVEL C. FUSIN-WISCHUSEN

discovery.princeton.edu 3 PHOTO BY SAMEER A. KHAN/FOTOBUDDY Focus on Undergraduate Research

Campus as Lab: Tracking campus ecology

As a junior, Artemis Artemis Eyster spends more time than Eyster designed and most students on the wooded paths led a class for fellow near campus where Albert Einstein undergraduates to study the ecology once cleared his mind. of Princeton’s Lake The Class of 2019 undergraduate, Carnegie through the named after the Greek goddess of University’s Campus as the wilderness, created a new environ- Lab program. mental research course for fellow students in which she and her classmates analyzed the ecology of local areas. They explored areas vulnerable to ecological harm as part of Princeton’s Campus as Lab program, which helps faculty and students study real-world environmental issues with the University as a testing ground. tree counts, plant and animal diversity, and the Central New Jersey’s mix of small towns, amount of developed land. They connected suburbs, farms and nature preserves makes those metrics to the health of the University’s it an ideal place to explore the impact of human century-old Lake Carnegie, a popular re- activity on the environment. creation area. “If the University wants to make informed Eyster’s class is one of several projects for decisions based on the natural environment,” the Campus as Lab initiative, which is orga- Eyster said, “it’s important that they have a nized through the Office of Sustainability and system of monitoring these areas.” supported by the High Meadows Foundation Adam Maloof, an associate professor of Sustainability Fund. geosciences, advised the class on an array Eyster ultimately used what she learned of sensors and techniques. From aerial pho- to inform her junior-year independent work, tos taken over the past century, the students and this past summer, she traveled to Panama tracked Princeton’s environmental conditions to study the role of woody vines in forest over time. They measured traffic, light pollution, succession. –By Kevin McElwee

4 Discovery: Research at Princeton 2018-2019 PHOTO BY DENISE APPLEWHITE

Eviction Lab examines the intersection of poverty and housing

How many Americans are forced to leave their homes each year? When Matthew Desmond began investigating evictions in America, it was impossible to answer that question. “Imagine if we didn’t know how many people got cancer every year, or graduated from high school,” said Desmond, Princeton’s “Seeing the map, you are struck by how Matthew Desmond Maurice P. During Professor of Sociology. many families are experiencing housing insta- (second from right), bility every day, every month, every year,” said author of the Pulitzer “This is a major American problem.” Prize-winning 2016 His initial deep dive into evictions in Lillian Leung, a research specialist with the bestseller Evicted, and Milwaukee led to a 2016 bestseller, the Pulitzer Eviction Lab. “It’s easy to think, ‘Oh, this is a his team created a Prize-winning Evicted, in which he illustrated problem far away from me,’ but the map shows national database of the profound connections between landlords, that it’s happening everywhere — to people eviction records, where near us. If it’s local, it’s something you can take visitors can see how their tenants, sheriffs and judges. In the years since, region stacks up against Desmond and the researchers in his Eviction action on.” others, look at maps of Lab have gathered more than 80 million court “If you want to take data to your elected eviction rates, and more. records from across the country, painstakingly officials, our website will automatically create assembling, cleaning and processing data to a report on counties you’ve been evaluating,” create the first-ever national database of said James Hendrickson, a senior research eviction records. specialist. “You can get your county’s eviction They found that about 2.3 million Americans rate, statistics, demographic characteristics. lived in a home that received an eviction judg- That’s something you can directly take to your ment in 2016, the most recent year for which city council members, your U.S. representa- they have complete data. And in Virginia that tives, your state senators.” year, one in 10 evictions were for delinquencies For their “bread-and-butter work,” the lab less than $340, statistics that Desmond rattled relies on the computers in the Office of Popu- off without notes. lation Research (OPR), and they use the super- “In 2016 we heard a lot about the opioid computing clusters at the Princeton Institute crisis, and rightfully so — there were about for Computational Science and Engineering 65,000 people that overdosed that year,” said (PICSciE) for bigger projects, said Hendrickson. Desmond, who joined Princeton’s faculty in “If it weren’t for the computing resources summer 2017. “But that means that for every Princeton makes available to us through OPR tragic overdose death, there were 36 people and PICSciE, this work wouldn’t be possible,” put out on the street. And that’s not ‘probably’ said Adam Porton, a research specialist. an underestimate, that’s absolutely an underes- Understanding eviction data is an essential timate, because we still have holes in our data.” step in figuring out which policies can alleviate In April 2018, the team went public with poverty in America, said Desmond. “We can’t evictionlab.org, where visitors can search for ask those questions if we don’t have the data.” data on almost any city or state, see how their Learn more at evictionlab.org. region stacks up against others, look at maps of –By Liz Fuller-Wright eviction rates and much more.

discovery.princeton.edu 5 PHOTO BY LARRY LEVANTI Focus on Undergraduate Research

An overdue spotlight on an avant-garde playwright

Students performed a play A symposium and performances inspired by the late María held in April 2018 at Princeton Irene Fornés called The focused an overdue spotlight Book of Miaou-Wow-Wow: Don’t Drink Everything Your on one of the most influential Mother Pours You. The cast but perhaps least-known included Haydon John, American theater-makers Class of 2021 (foreground); of the 20th century, María and (left to right) E. Harper Irene Fornés. Nora Jeremijenko-Conley, Class of 2020; Julia Yu, Born in Cuba in 1930, Class of 2019; and Tamia Fornés is regarded as a defining Goodman, Class of 2019. force within the off-off- Broadway movement of the 1960s and 1970s. As a playwright, director, designer and teacher, she Then-seniors Alex Vogelsang and Lydia Watt, became a guiding presence for emerging Class of 2018, were featured in Fornés’ theater artists of the 1980s and 1990s, espe- landmark play, Fefu and Her Friends, directed cially those invested in staging feminist, queer by R.N. Sandberg, a lecturer in English, and Latinx aesthetics and experiences. theater and the Lewis Center for the Arts, Associate Professor of Theater Brian Herrera in the historic Maclean House on the Princeton hosted the Latinx Theatre Commons’ María campus. The students participated as part of Irene Fornés Institute Symposium at Prince- their senior theses, which are independent ton, a national, intergenerational community projects required of graduating students. gathering of more than 100 artists, academics, More than 60 Princeton students were students and others. The symposium featured involved in the performance and production performances, conversations and workshops of the three plays. The symposium, perfor- guided by some of Fornés’ most eminent mances and many other events across the former students. country focused on Fornés in the context of The Program in Theater at the Lewis Center the playwright’s decline in recent years due for the Arts also dedicated its main 2017-18 to Alzheimer’s disease. At the symposium, production to Fornés with an evening of two participants pledged to preserve and advance one-act plays: FNU LNU by Mac Wellman, a the artist’s legacy and visibility in the 2019-20 fellow avant-garde playwright, and the world theatrical season and beyond. Fornés passed premiere of The Book of Miaou-Wow-Wow: away on Oct. 30, 2018, with this promise of Don’t Drink Everything Your Mother Pours You by her work and influence living on through a Migdalia Cruz, a student and longtime friend of new generation.–By Steve Runk Fornés. Faculty member Elena Araoz directed both plays, and Cruz’s play was commissioned through the Lewis Center’s Roger S. Berlind ’52 Playwright in Residence program.

6 Discovery: Research at Princeton 2018-2019 PHOTO BY SAMEER A. KHAN/FOTOBUDDY

When driverless ride-hailing services come to a curb near you

When requesting a ride-hailing service, you may soon notice something missing: the driver. Fleets of autonomous electric vehicles could someday replace human-powered ride-sharing. Programming obstacles still stand in the way of this happening on a large scale, but associate research scholar Lina Al-Kanj is tackling These considerations are hard enough Associate research scholar Lina Al-Kanj the unique challenges with Warren Powell, a to calculate on a case-by-case basis, but when expanded to thousands of cars, the designs algorithms professor of operations research and financial for optimizing engineering. decision-making becomes quite complicated. driverless ride- “Driverless cars are becoming a reality, and To handle this complexity, Al-Kanj and hailing services. we already have electric cars on the market,” Powell developed a framework that scales Al-Kanj said. Uber and Google’s Waymo each along with the number of cars in the fleet. have deals in place for 20,000 or more auton- Al-Kanj’s model allows companies to identify omous cars to hit the roads over the next few the best locations for recharging facilities, years. the value of faster charging devices, and the Al-Kanj has adapted an algorithm, originally optimal size of batteries for fleet operators. developed by Powell for the trucking indus- Al-Kanj hopes that ride-hailing companies try, to coordinate the actions of thousands will take note of her research, which is of driverless electric cars. One challenge she funded by the Andlinger Center for Energy and addressed is the need for autonomous cars the Environment, so that her logic as well as to make forward-looking decisions. Currently, her strategic simulator can assist fleet opera- ride-hailing apps are nearsighted — they con- tors in real-time dispatch. –By Kevin McElwee nect the user to the closest car. Al-Kanj’s system takes into consideration the charge level of the battery, the length and destination of the trip, when best to recharge the car, and where to position cars to optimize use of the fleet. Consider a car near Philadelphia with a battery at half charge that gets pinged for a trip to New York City, roughly 100 miles away. Al-Kanj’s approach, based on Powell’s research on making decisions in the presence of uncer- tainty, calculates the downstream value of each car based on the projected charge level of the battery after the trip. Because the vehicles are electric and autonomous, the algorithm must address many other factors that a human driver normally handles: Should the car park and wait for more customers? Should it move to a location with many potential customers? Should it take time to recharge? discovery.princeton.edu 7 PHOTO BY SAMEER A. KHAN/FOTOBUDDY

Turning up the heat on the search for better plastics

Graduate student Dane If you have ever poured hot coffee into a cheap after mechanical injury and being simultane- Christie is exploring plastic cup, you may recall that sinking feeling ously stiff and tough. materials that could lead as the cup seems to wilt. Not quite solid, not “When you think about anything from to applications such as self-repairing plastic, quite liquid, the cup totters between two states telescopes probing space to fiber optic cables high-efficiency solar cells of matter. under the oceans, all of it relies on glass,” and better batteries. This shift from a hard, glass-like state to said Dane Christie, a graduate student in a soft and rubbery state is called the glass the Department of Chemical and Biological transition, and understanding it could lead Engineering (CBE) and the first author of a to applications such as self-repairing plastic, recent paper published in the journal ACS high-efficiency solar cells and better batteries. Central Science. A research team at Princeton has turned “For most polymers, the glass transition up the heat on the search for a more detailed temperature is probably the single most understanding of plastics by studying the tem- important material parameter,” said Richard perature at which materials undergo the glass Register, the Eugene Higgins Professor of transition. Chemical and Biological Engineering, who The team performed highly precise mea- co-led the study with Rodney Priestley, an surements of the glass transition temperature associate professor of CBE. “It’s what makes in plastics known as block copolymers, which a tire rubber rubber and a soda bottle a are chains of at least two repeating polymer relatively stiff plastic.” units. What they found could help scientists But measuring the exact glass transition create new polymers that, like window glass, temperature of these materials, which self- have an underlying disordered structure that assemble into shapes that bring various lends strength and durability. sections of the polymer chains into contact Block copolymers are an active area of with each other, is not easy. To do so, Christie research because they can be made to have attached fluorescent labels that allowed him highly desirable properties, such as healing to track the precise movement of the parts of the chain as he raised the temperature. This allowed him to observe how the materials change during the transition from a liquid to a glass state. The results showed a dramatic and asymmetric change in the intrinsic values of the glass transition temperature within each piece of the chain, especially near the interfaces, Christie attached facts missed by previous studies. fluorescent labels to The study was funded by the U.S. Air Force the ends of polymer Office of Scientific Research and the National chains to study the Science Foundation through the Princeton transition from a glass Center for Complex Materials. –By Scott Lyon to a liquid state.

8 Discovery: Research at Princeton 2018-2019 PHOTO BY SAMEER A. KHAN/FOTOBUDDY

Finding meaning among the junk

Genes make up only about 10 percent of the human genome. The other 90 percent? Once called “junk DNA,” researchers now know that this genetic material contains on-off switches that can activate genes. But how these segments, called enhancers, find and activate a a separate fluorescent tagging system to the Thomas Gregor and his target gene in the crowded environment of a target gene that lights up when the gene is team are exploring how pieces of DNA once cell’s nucleus is not well understood. activated. thought of as junk are Researchers have now filmed the enhancers Video of the cells let researchers observe involved in the regulation as they find, connect and activate genes in how two regions of DNA interact with each of other genes. From living cells. The study was published in the other, said Michal Levo, a postdoctoral left: Hongtao Chen, Lev journal Nature Genetics in July 2018 by an in- research fellow. “We can monitor in real time Barinov, Michal Levo and Thomas Gregor. ternational team led by Thomas Gregor, where the enhancer and the gene are physically an associate professor of physics and the located and simultaneously measure the Lewis-Sigler Institute for Integrative Genomics. gene’s activity in an attempt to relate these The malfunction of gene activation causes processes,” she said. the development of many diseases, including The researchers found that physical contact cancer. between the enhancer and gene is neces- “The key to curing such conditions is our sary to activate transcription, the first step in ability to elucidate underlying mechanisms,” reading the genetic instructions. The enhancers Gregor said. “The goal is to use these rules to stay connected to the gene the entire time it is regulate and re-engineer the programs under- active. When the enhancer disconnects, gene lying development and disease processes.” activity stops. Since enhancers are sometimes located far Their observations contradict a favored from the gene they regulate, researchers have hypothesis known as the “hit-and-run model,” been puzzled by how the two segments find which suggested that the enhancer does not each other. Previous studies conducted on need to stay attached to the gene during non-living cells provided only snapshots that transcription. omitted important details. The team discovered that sometimes the In the new study, researchers used imaging enhancer and gene met and connected but techniques developed at Princeton to track gene activation did not occur, a finding they the position of an enhancer and its target gene plan to explore further. while simultaneously monitoring the gene’s The study, which included work by Princeton activity in living fly embryos. Hongtao Chen, graduate student Lev Barinov and collaborators an associate research scholar and lead author at Thomas Jefferson University, was funded on the study, attached fluorescent tags to the by the National Institutes of Health and the enhancer and its target gene. He also attached National Science Foundation. –By Kevin McElwee

discovery.princeton.edu 9 Bold and cold: A new faculty member and a new microscope explore life’s essential molecules

By Kevin McElwee

At the end of a long underground hallway on That discovery followed another 2017 the edge of campus, a door leads to a brightly publication from Yan’s team that illustrated the lit room. Within looms an imposing 12-foot-tall structure of the vital calcium channel known as machine, whose array of wires and tubes can Cav1.1. Calcium channels are involved in neuro- only be seen through a tinted window. logical, cardiovascular and muscular disorders. At a table nearby, two researchers pre- The year before, Yan and her team worked pare the latest sample. They huddle over a out the structure of proteins that control the bowl from which billows a cool white cloud of flux of glucose, the blood sugar that fuels our liquid nitrogen. The machine behind them is a bodies. Faulty glucose transporters play a role cryo-electron microscope, one of the world’s in diabetes. Learning how to shut them off most sensitive microscopes. It is capable of could also be key to starving cancer cells. capturing crisp, three-dimensional images of At its simplest level, cryo-EM shoots elec- individual proteins, molecules essential for trons at frozen substances to capture pictures regulating human health. of their atomic structures. As the “cryo” part Professor Nieng Yan is a leading expert in of the name suggests, each sample needs to using cryo-electron microscopy, or cryo-EM, be flash-frozen to about minus 180 degrees to obtain detailed images of proteins, the Celsius to quell its normal movement and building blocks for our muscles, skin, blood, harden it against the electron beam. hormones and more. A sample contains several billion copies of Last fall Yan returned to Princeton — she’d the protein under study, and the device col- earned her Ph.D. here in 2004 — as the first lects thousands of two-dimensional images of Shirley M. Tilghman Professor of Molecular each sample. Then a computer identifies each Biology, to lead the University’s efforts in protein, matches like perspectives, and recom- cryo-EM — a technology so influential that its bines the images together to construct a 3-D development was awarded the 2017 Nobel Prize volume. By capturing images during different in Chemistry. stages of activity, the technique can reveal how “The future of biology is mapping individual the protein functions. proteins within the cell, or even an entire cell, Preparing a sample to go into the cryo-EM at atomic scale,” Yan said. takes care, but it is much easier than its main Yan was already something of a celebrity rival technology, X-ray crystallography, which before coming to Princeton. While a profes- involves laboriously solidifying proteins into sor at Tsinghua University, one of China’s top crystals. For decades, biologists considered research institutions, she garnered more than cryo-EM to be crystallography’s poor cousin 450,000 followers on Weibo, a social media because its images looked more like blobs platform similar to Twitter. She has published than like intricately folded chains of atoms. numerous groundbreaking papers on the That changed in 2013 with the invention structures of some of the body’s most of a new detector technology that yields important proteins, the ones that form near-atomic-resolution images. channels through the outer membrane of Paul Shao is Princeton’s resident expert in the cell and dictate what comes in and out. cryo-EM and the specialist responsible for One of these proteins is the sodium channel, running the machine, a Titan Krios made by a molecule essential to the healthy functioning Thermo Fisher Scientific. The machine is of the heart and brain. Defective sodium chan- housed in the Princeton Institute for the nels are linked to epilepsy, heart arrhythmias, Science and Technology of Materials’ Imaging paralysis and chronic pain. In 2017, Yan and her and Analysis Center, located in the Andlinger research team published the most detailed Center for Energy and the Environment. picture ever taken of the sodium channel. That “High-end instrumentation like this is very image and others like it give biologists a 3-D sensitive to its environment. Fortunately, map through the sodium channel — a guide to one of the most structurally sound places in help them understand what goes wrong when it Princeton just happens to be out that door,” fails, and how to design drugs to fix it. said Shao, gesturing past the whirring microscope toward the room’s entryway. “It’s solid bedrock.” 10 Discovery: Research at Princeton 2018-2019 PHOTO BY SAMEER A. KHAN/FOTOBUDDY

Imaging and Analysis “The future of biology Specialist Paul Shao prepares a sample for imaging using cryo- is mapping individual electron microscopy, which Xuelan Wu (center), a graduate student in proteins within the cell, chemistry, and Nikita Dutta (right), a graduate student or even an entire cell, in mechanical and aerospace engineering, use for at atomic scale.” their research.

Nieng Yan Shirley M. Tilghman Professor of Molecular Biology

PHOTO BY DENISE APPLEWHITE

Nieng Yan is a global leader in cryo-electron microscopy.

discovery.princeton.edu 11 IMAGE COURTESY OF NASA

“With advanced Swirls of algae in the western Indian Ocean’s Gulf of Aden indicate computing techniques, the presence of ocean eddies. Laure Resplandy researchers will soon includes eddies in computer models that aim to predict ocean be able to predict dead zones. adverse events before they occur, allowing PHOTO BY CHRIS FASCENELLI governments to warn Aided by supercomputers, Laure

Resplandy models communities.” how the oceans, atmosphere and climate interact. Laure Resplandy Assistant Professor of Geosciences and the Princeton Environmental Institute

12 Discovery: Research at Princeton 2018-2019 Breathing life into the Indian Ocean by predicting ‘dead zones’ By Kevin McElwee

In 2001, off India’s coastal state of Goa, the system that dictates almost all weather shrimp catch dropped by 80 percent in just a patterns in South Asia. few years. The die-off was later traced to a dip Her models don’t have enough computing in the ocean’s oxygen level. power to track every single wave and eddy in “It was a massive event that almost col- the ocean, but with informed estimations, she lapsed the fisheries on the western Indian can create a model that approximates what to coast,” said Laure Resplandy, an assistant expect. She and her collaborators run these professor of geosciences and the Princeton models on supercomputers in Princeton’s TIGER Environmental Institute, who studies how our research computing cluster and at Oak Ridge oceans, atmosphere and climate interact. National Laboratory. They then compare their “One of the Indian fishing industry’s biggest models’ predictions to the measurements of sources of income is the export of shrimp to oxygen levels, water temperatures and algae the United States.” growth collected over the past century. If a Resplandy believes that researchers, aided model draws an accurate picture for recent by advanced computing techniques, will soon events, its predictions for the future are more be able to predict events such as these before trustworthy. they occur, allowing governments to warn John Dunne is a research oceanographer communities or to prevent such occurrences at GFDL who collaborates with Resplandy. He altogether. She and her collaborators, including heads GFDL’s Biogeochemistry, Ecosystems, scientists at the Geophysical Fluid Dynamics and Climate Group and has over 20 years of Laboratory (GFDL), a division of the U.S. experience in collecting field observations, National Oceanic and Atmospheric Admini- analyzing data and performing modeling. stration located about 3 miles from Princeton’s Dunne was impressed with Resplandy’s campus, are developing computer models breadth of research. “She now has many aimed at making this goal a reality. examples of research in which she has become Tropical regions in the Indian Ocean are engaged and advanced the understanding of predisposed to low oxygen levels because the topic,” he said. “She’s a person that Prince- exchanges with the atmosphere are limited and ton is lucky to have in their arsenal of scientific the water is warm. In higher latitudes, rough innovators.” seas can take in and dissolve more oxygen from Resplandy was drawn to the Indian Ocean the atmosphere, and colder oceans can contain when writing her doctoral dissertation while at more oxygen. the Laboratoire d’Océanographie et du Climat “If you leave your Coke in the sun, it’ll in France, where she developed a model for lose most of its fizz fast,” Resplandy explained. addressing similar biogeochemical questions “Warmer liquids hold less gas than colder that is still used by the Indian government. ones.” More recently, her models offered ocean- Although low-oxygen regions occur natu- ographers a detailed picture of how oceans rally, human activity is the likely culprit when and rivers carry the Earth’s carbon and impact oxygen levels plummet so far that ocean life the storage of carbon on land, research that starts to die. In many coastal areas, agricultural was published in June 2018 in Nature Geo- fertilizers spur the growth of algae, which in science. She has also received funding from turn become food for microbes that consume NASA to collaborate with colleagues at the Jet the oxygen, creating massive “dead zones” de- Propulsion Laboratory and the Scripps Insti- void of aquatic life. Because India’s agriculture tution of Oceanography on a study of carbon is growing along with its booming population, fluxes during El Niño events. the Indian Ocean is particularly susceptible. Resplandy hopes that her new project on To learn more about how and when these oxygen levels in the Indian Ocean, which is coastal dead zones can arise, Resplandy funded through the Princeton Environmental and her colleagues developed models with Institute’s Grand Challenges program, can also hundreds of factors, including algal production aid Indian officials. She doesn’t see herself as of oxygen, the mixing of fresh and salt a policy advocate, but she expects her models water, and the ocean eddies that promote to lead to preventative measures, such as algae growth and oxygen exchanges between safeguards to reduce fertilizer runoff. surface and deeper waters. She also includes She recognizes the magnitude of the ques- variables controlling the monsoon, the massive tions she is trying to answer. “It’s challenging,” she said. “I’d do something else if it weren’t.” discovery.princeton.edu 13 Treasure in ancient trash By Kevin McElwee

Thomas Conlan fiddled with a strange, Conlan’s collaborators on the project are brownish-black rock on his desk. For Howard Stone, the Donald R. Dixon ’69 and centuries, people had considered the piece Elizabeth W. Dixon Professor of Mechanical of rubble worthless, but it is priceless to and Aerospace Engineering; Nan Yao, a senior Conlan’s research. research scholar with the Princeton Institute The lumpy rock is a sample of slag, the for the Science and Technology of Materials material left over after heating ore to extract (PRISM) and director of the Imaging and Anal- valuable metals. With researchers from art, ysis Center; and Rachel Selinsky, an associate engineering and materials science, Conlan is research scholar in mechanical and aerospace exploring whether these discarded scraps engineering. Conlan was also advised by Craig can fill gaps in early Japanese history. Arnold, a professor of mechanical and aero- Conlan, a professor of East Asian studies space engineering and the director of PRISM, and history, hopes to use the mining waste to and Bruce Koel, a professor of chemical and learn about the political and cultural climate biological engineering. of Japan in the eighth to 18th century CE, a At a recent meeting to discuss the project, period for which written records are sparse. the researchers huddled around a desk in Much of Conlan’s slag comes from the Conlan’s book-lined office, far from the sterile smelting of copper, a metal that played an labs and whirring machines in the imaging important role in historical trade, monuments center. and coinage. “We know there was an incredibly Material scientists have analyzed slag in the vibrant process of metallurgy in the past,” Con- past, but the researchers think this is the first lan said. “They were mining tons of this stuff, time that slag has been used to investigate a but there’s nothing really written about it.” region’s history. Some products of these early copper mines “There’s a kind of detective problem here,” can still be seen today. The world’s largest Stone said. bronze Buddha, located in Nara, Japan, dates “It’s like trying to figure out a puzzle without from 745. Its construction required nearly having all the pieces,” Nan said. 490 tons of copper from a nearby mine, as “It’s like figuring out what a forest looked described in documents from that period. But like from 30 leaves,” Conlan said. from the 10th to the 16th century, very few Selinksy is in charge of conducting the records discuss mining, leading researchers to experiments, which include identifying a wonder whether metallurgy declined or was sample’s constituent elements by shooting simply not documented. X-rays at it and measuring what is emitted This lack of textual records can sometimes in response. So far, the data suggest that skew historians’ perspectives, Conlan said. Japanese metallurgists did not add any in- “Historians have overestimated the importance gredients, such as calcium, to improve the of rice and agriculture,” he said. “And they have extraction of copper. underestimated the importance of mining and The team has now turned their attention to trade.” the slag’s crystallographic composition, using Conlan hopes to correct this imbalance by different tools to see if the material’s history is probing the microscopic structure of slag. He locked in its structure. obtained 30 or so samples, dating from 700 to If their work does identify improvements in 1700, from colleagues in Japan. Using state- metallurgy through time, the research could of-the-art methods with support from the fundamentally change the way historians not David A. Gardiner ’69 Magic Project fund for only look at early Japan, but how they view the innovation in the humanities, his team wants to historical role of copper worldwide. Many early learn the techniques of medieval metallurgists, economies depended on copper production, including what additives were mixed in the and these techniques may well shine light on metals, what temperatures were used and how other ancient civilizations that left few written the materials were refined. records.

14 Discovery: Research at Princeton 2018-2019 Researchers are using modern materials analyses to learn about medieval metallurgical practices, depicted here in the book Kodō zuroku by the Sumitomo Family. The

IMAGE COURTESY OF THE EAST ASIAN LIBRARY AND THE GEST COLLECTION, PRINCETON UNIVERSITY LIBRARY book dates to 1795 and describes how to extract copper from ore.

discovery.princeton.edu 15 PHOTO BY SAMEER A. KHAN/FOTOBUDDY

Are the quantum laws “There’s an ongoing of nature the secret to plants’ efficiency at harnessing energy from quest to find new, sunlight? A team led by Gregory Scholes (right), plans to find out. The team compelling examples includes graduate student Ben Xinzi Zhang (left) and postdoctoral research of the use of quantum associate Kyra Schwarz. mechanics in biology.”

Gregory Scholes William S. Tod Professor of Chemistry

16 Discovery: Research at Princeton 2018-2019 Going quantum to unlock plants’ secrets By Kevin McElwee

When it comes to green living, nobody does both the left and the right reaction will occur in it better than plants. When plants convert light a quantum superposition. into fuel through photosynthesis, not a single To find out if this is happening, Scholes’ particle of light is wasted. If we could unlock team set up an experiment to take snap- plants’ secrets, we might be able to perfect the shots of molecules during the reaction. With design of light harvesting in solar cells. funding from the W.M. Keck Foundation, Gregory Scholes, Princeton’s William S. Tod the researchers bombard the molecules with Professor of Chemistry, suspects that the key pulses of laser light, which place the nor- to plants’ efficiency stems from their ability mally chaotic molecules into the same quantum to harness quantum physics, the unintuitive rhythm. “We use light to synchronize molecules behaviors of very small particles. In 2010, he led so that they all dance to the same beat,” said a team that demonstrated quantum effects in graduate student Ben Xinzi Zhang. marine algae. Next, to see if the molecules are indeed in But the finding was not without controversy. a superposition, researchers use a second Quantum behaviors usually reveal themselves laser pulse. It monitors the state of the at extremely low temperatures isolated from molecule using rapid bursts that light up the real-world disturbances, raising questions as to positions of the atoms like a strobe light whether these quantum states can survive the illuminating a dancer. warm and wet conditions of life. The researchers then look for patterns from So Scholes and his team decided to probe reaction pathways that add and cancel, just like quantum behavior in one of the simplest known in the double-slit experiment. “The signatures chemical reactions, the transfer of a hydrogen will tell us how these two sides are interacting,” atom from one part of a molecule to another. said Kyra Schwarz, a postdoctoral research If their experiments work out, the researchers associate on the team. could rewrite our understanding of how The results of the experiment are not yet in, chemical reactions occur. but if quantum superposition plays a role in a At the heart of quantum theory is the idea reaction as ubiquitous as the transfer of hydro- that matter can behave both like particles gen, it could underlie many processes in nature. and like waves. If we fire particles at a barrier The result could also reshape how chemical containing two slits, classical physics predicts reactions are conceptualized and understood that the particles will land in two piles, one across disciplines, making it possible to lever- behind either slit. In contrast, quantum age quantum properties to control and create mechanics predicts that each particle will new reactions. act like spread-out waves and pass through Scholes will also lead a new Energy Frontier both slits (see figure), where the intensity at Research Center, announced in July 2018 any point can either add together or cancel and funded by the U.S. Department of Energy, itself out. to study how light harvesting and solar photo- This quantum nature of matter, known as chemistry can make new molecules and fuels. a superposition, has been predicted and The center includes faculty members at observed since the 1920s, and has helped us Princeton as well as national laboratories and comprehend the microscopic world. However, leading universities. these quantum ideas have not yet shaped the understanding of chemical reactions. Quantum mechanics “That’s the big question we’re trying to an- predicts that each swer,” Scholes said. “Can we harness quantum particle will act like mechanics to work for us in chemistry?” spread-out waves and pass through both slits. The researchers addressed the question by studying what happens when light hits a molecule that can undergo two separate hydrogen transfer reactions, one on the left and one on the right side of the molecule. If classical rules prevail, then each reaction will proceed one step at a time. If quantum rules are involved,

discovery.princeton.edu 17 Engine of cosmic evolution Eve Ostriker looks under the hood

By Catherine Zandonella

Outside Eve Ostriker’s office door Modeling the various parts of the picture — stretches the universe, dotted with orange star formation, galactic winds and the rest of galaxies against the black backdrop of space. the interstellar ecosystem — requires bringing The mural lines the hallway in Princeton’s together a number of astrophysical concepts. astrophysical sciences building, where it The timescales over which things happen can inspires Ostriker to explore what lies beyond be very long — billions of years — or very short, our own galaxy, the Milky Way. How did those on the order of days. far-flung galaxies grow and evolve? After identifying the crucial physical details, “It is the story of ‘How did we get here?’ but researchers create a computer model in which it is not just us, it is all of the galaxies,” Ostriker a galactic region is divided into a grid consisting said. “I’m motivated by wanting to understand of hundreds of millions of cells. If the models, how the universe works. And the fact that we as they run forward in time, give results that now have the tools to do this just makes it all look similar to actual astronomical observa- the more exciting.” tions, then the researchers are on the right The tools she uses are powerful super- track. computers and algorithms capable of simu- lating the birth, life, death and reincarnation Bubbles and clouds of stars in their galactic homes. Ostriker, a One area Ostriker explored with her team was professor of astrophysical sciences, and her the formation of superbubbles, giant fronts of collaborators and students build computer hot gas that billow out from a cluster of super- models using fundamental physical laws — nova explosions. The spreading bubble drives ones that govern gravity, fluid dynamics and heat and turbulent gas out into the interstellar electromagnetic radiation — to follow the medium, fueling the cosmic engine. The project evolution of conditions found in deep space. included work by then-undergraduate Roberta Raileanu of the Class of 2016 and Chang-Goo Interstellar ecosystem Kim, an associate research scholar jointly Beyond the edges of our solar system lies the appointed at Princeton and the Simons interstellar medium, the space between stars. Foundation’s Flatiron Institute. This is the “engine of cosmic evolution,” More recently, Ostriker and her colleagues Ostriker said, where gases — mostly hydrogen turned their focus toward interstellar clouds. and some helium — coalesce to form new stars, Jeong-Gyu Kim, a Lyman Spitzer, Jr. post- which grow, burn brighter and eventually die. doctoral fellow at Princeton, developed a Fueling this engine are massive stars — those way to track how light moves through, 10 times the mass of our sun. They pour out and ultimately disperses, the clouds of gas particles of ultraviolet light that ionize the gas surrounding nascent star clusters. Alwin Mao, around them and keep even distant parts of a graduate student, explores how dust and galaxies warm. When they die, these stars gases collapse to form stars. Munan Gong, who explode as supernovae that rapidly expel gas earned her Ph.D. at Princeton in 2017, studies into the interstellar medium. molecules and dust in the clouds. “Without massive stars to return energy to The research team uses computing re- the system and keep the interstellar medium sources through the Princeton Institute for warm and stirred up, everything would be kind Computational Science and Engineering and of dead,” Ostriker said. its TIGER and Perseus research computing A big puzzle is what causes the torrent of clusters, as well as supercomputers adminis- gas flowing out of galaxies, particularly at early tered through NASA. “It is fantastic that the stages of cosmic evolution. Telescope obser- University offers high-performance com- vations show outpourings of gas called galactic puting resources,” Ostriker said. “It means winds. Ostriker and her team are modeling how that a student working on a new project supernovae can spur formation of these winds, can do cutting-edge research right away.” as well as galactic fountains of gas in the Milky Way.

18 Discovery: Research at Princeton 2018-2019 PHOTO BY SAMEER A. KHAN/FOTOBUDDY

Astrophysicist “It is the story of ‘How Eve Ostriker investigates the evolution of stars J.-G. KIM, W.-T. KIM, AND E.C. OSTRIKER did we get here?’ but it is 2018, THE ASTROPHYSICAL JOURNAL and galaxies. not just us, it is all of Interstellar clouds form star clusters that ionize and the galaxies.” disperse gas.

Eve Ostriker Professor of Astrophysical Sciences

discovery.princeton.edu 19 From Math Artificial intelligence blends algorithms to Meaning and applications By Kevin McElwee ILLUSTRATION BY DANIEL HERTZBERG

Artificial intelligence is already a part of from a ventilator, because if they are wrong, everyday life. It helps us answer questions like they could complicate the patient’s health “Is this email spam?” It identifies friends in further. online photographs, selects news stories based In partnership with researchers at the on our politics and helps us deposit checks via University of Pennsylvania’s hospital system, our phones — if all somewhat imperfectly. Engelhardt and her team aim to move patient But these applications are just the begin- care away from a one-size-fits-all approach to ning. Through advances in computer science, one that is tailored to individual patients. Their researchers are creating new capabilities algorithm considers many patient factors and that have the potential to improve our lives then calculates when and how to remove the in ways we have yet to imagine. Princeton patient from the ventilator. It makes numerous researchers are at the forefront of this decisions, including how much sedative to give research, from the theoretical underpinnings prior to the procedure and how to test whether to the new apps and devices to the ethical the patient can breathe unassisted. considerations. Machine learning could also help in situa- Attempts at building intelligent systems are tions where high-quality human healthcare is as old as computers themselves. Early efforts not immediately available, such as with patients often involved directly programming rules of in palliative care, who could be monitored behavior into a system. For example, research- around the clock as if by a specialist. ers might input the laws of motion to control a robotic arm. But the resulting behaviors usually Reinforcement learning fell short. Engelhardt uses a machine-learning approach With artificial intelligence, computers learn called reinforcement learning, a departure from from experience. Through “machine learning,” the older but still widely used practice of a subfield of artificial intelligence, computers “supervised learning,” where programmers are programmed to make choices, learn from provide computers with training sets of data the outcomes, and adjust to feedback from the and ask the machines to generalize to new environment. situations. For example, to teach a computer to Machine learning is transforming scholarship identify dogs in photos, programmers provide across campus, said Jennifer Rexford, Prince- tens of thousands of images, from which the ton’s Gordon Y.S. Wu Professor in Engineering computer develops its own rules to figure out and chair of the computer science department. whether new photos contain a dog. “Princeton has a very long tradition of Reinforcement learning, by contrast, is more strong work in computer science and mathe- like the trial-and-error learning that young matics, and we have many departments that children use. A toddler who tries to pet the are just top notch, combined with an emphasis family cat and receives a sharp swipe will learn on serving humanity,” Rexford said. “You just to stay away from cats. Similarly, the computers don’t get that everywhere.” try things and interpret the results. Mengdi Wang, an assistant professor of Positive outcomes operations research and financial engineering, One societal challenge that artificially intelli- studies this approach. She has used reinforce- gent machines are addressing is how to make ment learning to limit risk in financial portfolios, better health care decisions. Barbara Engel- help a local hospital predict complications in hardt, an associate professor of computer knee replacement surgery, and partner with science, is creating algorithms to help doctors Microsoft Research to produce story-quality adopt practices most likely to have positive dialogue. patient outcomes. One challenge when implementing rein- For example, when should a patient be forcement learning is data overload. Computers weaned from a ventilator? Used by one in don’t have the advantage of human forgetful- three patients in intensive care units, a venti- ness, so they must process all incoming data. lator is a life-saving device, but is invasive, In practice, experts often have to step in to costly and can spread infection. Doctors often put some bounds on the number of items that wait longer than necessary to remove a patient need to be considered.

discovery.princeton.edu 21 PHOTO BY SAMEER A. KHAN/FOTOBUDDY A. SAMEER BY PHOTO

Barbara Engelhardt, “Having too many variables is the bottleneck radioactivity-damaged Fukushima Daiichi associate professor of of reinforcement learning,” Wang said. “Even if power station in Japan, presents challenges. computer science, you have all the information in the world, you Autonomous aerial vehicles could aid explores how a have a limited amount of processing power.” search-and-rescue efforts in tight spaces technique called Wang developed a method for helping where the risk of human error is great. reinforcement learning can guide physicians computers figure out what is and what is Majumdar is exploring how to apply a set through difficult not important. It’s an algorithm that reduces of tools from machine learning known as decisions such as complexity by mathematically compressing a “generalization theory” to guarantee drone when to remove a large collection of possible states into a small safety in new environments. Roughly speaking, patient from a number of possible clusters. The approach, generalization theory provides ways to narrow ventilator. which she developed with Anru Zhang of the the difference between performance on the University of Wisconsin-Madison, uses statistics training data and performance on new data. and optimization to group the likely scenarios for each stage of a decision-making process. Language learning Teaching computers to recognize shapes is AI to the rescue one thing, but teaching them to understand Although reinforcement learning is powerful, everyday language is quite another. To get it offers no guarantees when an algorithm at the question of how the brain processes confronts a new environment. For example, language, Princeton researchers scanned the an autonomous aerial vehicle (drone) trained brains of volunteers who watched episodes of to perform search-and-rescue missions in a the BBC television series Sherlock to see what certain set of environments may fail the brain is doing while its owner is taking in dramatically when deployed in a new one. new information. Developing approaches to guarantee drone The challenge was how to aggregate results safety and performance is the goal of Anirudha from several brains to identify trends. Each Majumdar, an assistant professor of mechanical brain is shaped slightly differently, leading to and aerospace engineering. Due to safety and slight differences in their functional magnetic technological limitations, most drones today resonance imaging (fMRI) scans. “It is as if you require a human to control the craft using send a thousand tourists to take a photo of its cameras and sensors. But steering drones the Eiffel Tower. Each photo will be slightly through destroyed buildings, like those in the different depending on the camera, the spot

22 Discovery: Research at Princeton 2018-2019 where the tourist stood to take the picture, and in June 2017, the researchers demonstrated so forth,” said Peter Ramadge, the Gordon Y.S. that they could determine from looking at the Wu Professor of Engineering and director fMRI scans which scene was being watched of the Center for Statistics and Machine with about 72 percent accuracy. Learning. “You need machine learning to understand what is common to the response Into the black box of all the subjects,” he said. Machine learning has the potential to unlock Ramadge and other computer scientists, questions that humans find difficult or including then-undergraduate Kiran Vodrahalli impossible to answer, especially ones involving of the Class of 2016, worked with researchers large data sets. For really complex questions, at the Princeton Neuroscience Institute to researchers have developed a method called aggregate brain scans using a method for deep learning, inspired by the human brain. finding commonalities called a “shared This method relies on artificial neural networks, response model.” They then mapped brain collections of artificial neurons that, like real activity to the dialogue in the episodes using brain cells, can receive a signal, process it, a natural language processing technique — and produce an output to hand off to the next which extracts meaning from speech — neuron. developed by Sanjeev Arora, Princeton’s While deep learning has been successful, Charles C. Fitzmorris Professor in Computer researchers are still discovering what tasks it Anirudha Majumdar, Science, and his team. is best suited for, said Arora, who recently assistant professor While a typical speech recognition method founded a program in theoretical machine of mechanical and aerospace engineering, learning at the nearby Institute for Advanced needs huge numbers of examples, the new uses machine learning method is capable of drawing meaning from a Study. “The field has derived a lot of use from to control autonomous relatively small collection of words, such as the treating deep learning as a black box,” he said. aircraft, which can be few hundred found in the script of the TV show. “The question is what will we see when we deployed for search-and- In a paper published in the journal NeuroImage open the black box.” rescue operations.

PHOTO BY SAMEER A. KHAN/FOTOBUDDY

discovery.princeton.edu 23 Unintended consequences In addition to broad ethical questions about the use of AI and the implications of intelligent machines in society, near-term worries about AI systems taking jobs from people are becoming more common. Enter Ed Felten, who is researching policies to curb the unintended consequences of AI. Felten, the Robert E. Kahn Professor of Computer Science and Public Affairs and Efficient fusion reactions director of Princeton’s Center for Information To harness fusion — the same process Technology Policy, served as deputy U.S. chief that powers the sun — for our energy technology officer in the Obama White House, needs here on Earth, researchers at where he led federal policy initiatives on AI and the U.S. Department of Energy’s machine learning. Princeton Plasma Physics Laboratory With researchers at New York University, (PPPL) are using deep learning to predict Felten has explored whether concerns about factors that can halt fusion reactions AI’s impact on jobs and the economy can be and damage the walls of the con- supported by data. The researchers used stan- tainment vessel. William Tang, a PPPL dard benchmarks published by AI researchers. Will AI disrupt low-skill physicist and a lecturer with the rank For visual recognition, for example, the team workers? Not as much as you might think, of professor in astrophysical sciences evaluated how many images an AI algorithm according to Ed Felten, at Princeton, leads a team of research- correctly categorized. Felten and his col- the Robert E. Kahn ers who are developing code for the leagues paired this estimation with data sets Professor of Computer massive international fusion experiment provided by the Bureau of Labor Statistics. Science and Public known as ITER (Latin for “the way”), The question is whether AI will replace Affairs and director of the Center for under construction in France. workers, or complement their efforts and lead Information Technology –By John Greenwald to even greater opportunities? History shows Policy. that new technologies often prove beneficial for workers in the long term, but not without

PHOTO BY SAMEER A. KHAN/FOTOBUDDY

24 Discovery: Research at Princeton 2018-2019 Mengdi Wang, assistant professor of operations research and financial engineering, applies machine learning to subjects ranging from financial portfolios to storytelling. PHOTO BY SAMEER A. KHAN/FOTOBUDDY A. SAMEER BY PHOTO

short-term pains for workers replaced by technology. The future of chemistry While some researchers think that low- skill jobs will experience the greatest threat Machine learning can predict the from artificially intelligent machines, Felten’s outcomes of chemical reactions. numbers suggest otherwise. Airline pilots Abigail Doyle, the A. Barton Hepburn and lawyers may be at least as threatened by Professor of Chemistry, and her team automation as the person behind the counter used a machine-learning technique at the local 7-Eleven, he said. called random forest analysis to obtain “Things like house cleaning are very difficult surprisingly accurate predictions of to automate,” Felten said. “The person doing the yields of chemical reactions. A that job needs to make a lot of contextual random forest model works by ran- decisions. Which objects on the floor are trash domly selecting small samples from the and which objects on the floor are valued training data set and using that sample objects that have fallen on the floor?” to build a decision tree. Each individual Felten and his team plan to pair their find- decision tree then predicts the yield for ings with geographic information, giving a kind a given reaction, and then the result is of heat map on what regions of the country will averaged across the trees to generate be most affected, to allow companies and gov- an overall yield prediction. The study ernments to prepare for the coming changes. was published in the journal Science “I’m an optimist in that I think there’s huge in February 2018. –By Liz Fuller-Wright opportunity,” Felten said. “AI is going to lead to tremendous progress in a lot of different areas. But it does come with risks, and we could easily do it badly.” discovery.princeton.edu 25 Nature’s Nation How American art shaped our environmental perspectives

By Catherine Zandonella

OIL ON CANVAS, NATIONAL GALLERY OF ART, WASHINGTON

26 Discovery: Research at Princeton 2018-2019 When landscape artist Thomas Cole visited New Hampshire’s White Mountains in the summer of 1839, he sketched the telling signs of deforestation and human encroachment on a once pristine wilderness. But his final painting depicted a relatively unspoiled tableau, featuring rich forests and weather-blasted trunks. Cole employed a bit of 19th-century photoshopping to edit out signs of development. He dialed up the scenic foliage and blurred the signs of human habitation — houses, barns, roads. His paintings spoke of a world where humans and nature could coexist. Artists do more than reproduce the world around us. They also, for reasons from artistic to commercial to ideological, shape our perspective on the environment and our relationship with it. The power of art to influence our understanding of the environment is the focus of a major new exhibition, Nature’s Nation: American Art and Environment, which opened at the Princeton University Art Museum on Oct. 13, 2018. The exhibition brings together more than 100 pieces of American art to tell the story of ecological change in North America over 300 years of history. Through the selection of works on display and an accompanying book, the exhibition addresses how artists in America have inter- preted the environment over the centuries — from the era of exploration and colonialism through U.S. nationhood and expansion to the growing awareness of profound human impact on a global scale. The show also features recent artists whose work exposes environmental injustice and environmental change. “We wanted to create an exhibition that would tell an alternative history of American art and chart the development of modern ecological consciousness — the understanding that nature is neither preordained nor immutable, but interconnected and fluid,” said Karl Kusserow, the John Wilmerding Curator of American Art at the Princeton University Art Museum.

American landscape painter Thomas Cole covered up signs of development in his 1839 painting, A View of the Mountain Pass Called the Notch of the White Mountains (Crawford Notch), as seen in comparison to a sketch he CRAWFORD NOTCH, GRAPHITE ON CREAM WOVE PAPER, PRINCETON UNIVERSITY made earlier that year. ART MUSEUM discovery.princeton.edu 27 28

Discovery: Research Princeton at 2018-2019 indigenous presence. presence. indigenous reasserts the nation’s and Kootenai Tribes, Confederated Salish Smith, amember of the Jaune Quick-to-See America, In The Browning of

OIL AND MIXED MEDIA ON CANVAS, CROCKER ART MUSEUM, SACRAMENTO

©JAUNE QUICK-TO-SEE SMITH 2000, artist

Princeton Environmental Institute’s Currie C. History and American Studies. He was also the the Ralph H.Wark Associate Professor of Art theat College of William and Mary, where he is appeared as the backgrounds of wealthy works of art. Landscapes, when they did exist, aboriginal population was rarely portrayed in the subjugation of the environment and its colonized. Throughout the colonial period, a peaceful and orderly land just waiting to be colonists,attract depicted the continent as timber. and continent was also bountiful with fish,game to conflicts with indigenous peoples. Yet the abounded, from swamps and new diseases America, massive trees covered the land. Risks When European colonists arrived in North Marketing colonialism in the same way.” not everyone perceives places and conditions mental justice and ecological inequity, since decisions. It also alerts us to issues of environ these issues and inform our ethical and moral of expression. significance of art, literature and other forms as ecocriticism, the study of the ecological Braddock, who is apioneer in the field known significant and even unprecedented ways,” said realized that humans are changing the world in world, but only in the last 300 years have we the Humanities Council in fall 2014. well as aPrinceton Belknap Visiting Fellow in Environment and the Humanities in 2016-17, as and Thomas A. Barron Visiting Professor in the The exhibition’s co-curator is Alan Braddock Early works, published in the late 1500s to “Art has the power to help us understand “Artists have always made pictures of their

works of American artists, including in Western depiction of nature —it continued in the Europe —replaced by amore realistic Long after the style grew out of fashion in upstate New York, embraced the picturesque. School because of their style and focus on those in the group known as the Hudson River and mountains stretching into the distance. progression, with water bodies, promontories depth. The vistas unfurled in alogical, stepwise foreground of the painting to asense give of beauty. Artists rocks placed and trees in the order on wild nature while preserving its then popular in Europe and America, imposed novel, novels such as James Fenimore Cooper’s 1826 loss of wilderness, as documented in popular largely in based the Northeast, lamented the was changing. Many in the U.S. population, gardens and serene vistas. colonists’ portraits and consisted of manicured recover some of this lost history,” Igoe said. and through this analysis we were able to peoples and environments all over the globe, to clear forests and build sugar plantations. when European colonists used enslaved labor comehad from Jamaica in the mid-1700s, and varnish from North Africa. American tulip poplar and white cedar framing, Jamaica, brass drawer pulls from England, regal, the chest is made of mahogany from of drawers crafted in Philadelphia. Ornate and materials scientists, was an 18th-century chest a postdoctoral researcher Princeton. at as part of the an art historian who conducted investigations conditions of the past, said Laura Turner Igoe, of art can reveal the ecological and societal embody environments. The material origins Through their materials, very artistic works Embodying the environment tractable and accessible to development.” century, it was necessary to picture land as facilitate nation building in the 18th and 19th threatening and scary,” Kusserow said. “To touristsused to attract and settlers. nation’s first nationalpark in 1872 and was later Yellowstone whose painting landscapes such as those by Thomas Moran, American landscape painters, especially A painting style known as “picturesque,” By the 1800s, however, American sentiment “The construction of the chest implicates The team determined that the mahogany One item Igoe examined, with help from “Wilderness was as overwhelming, seen The Last of the Mohicans (see back cover)(see celebrated the Nature’s Nation Nature’s The Grand Canyon of the exhibition while .

New beginnings ULTRACHROME INKJET PRINT. COLLECTION OF THE NEVADA MUSEUM OF ART. ©CHRIS JORDAN Art has the power to help us understand the environment — to take scientific data and turn it into “emotional data,” said Rob Nixon, the Thomas A. and Currie C. Barron Family Professor in Humanities and the Environment and a professor of English and the Princeton Environmental Institute. For Nature’s Nation, Nixon explored a work by American photographer Chris Jordan, from the series Midway: Message from the Gyre, 2009. It is a photo of a decaying corpse of a baby albatross, its insides stuffed full with plastic bottle caps that its mother scooped up from the miles of floating detritus in the Great Pacific Garbage Patch and ladled into its hungry chick’s beak. The image contrasts the revered values of nourishment and procreation against the practices of today’s throwaway society. Nixon said that images like these help the public make sense of complex issues like pollution, climate change, habitat loss and food “This exhibition asks museum visitors to In the photo series security. “We constantly are faced with rethink some basic assumptions about who Midway: Message from a cascade of data and metrics about the we are in the world,” Kusserow said, “in a way the Gyre, 2009, Chris Jordan reveals the that is designed to prompt conjecture and urgency of these issues,” Nixon said, “but outcomes of today’s how do we translate and reconfigure these data inspire, as well as teach.” He realizes what throwaway society. in ways that reach people emotionally? a momentous task this is, and how high the I see that as very much germane to the spirit stakes are. of this project.” “If you don’t get them engaged, you’ve lost — we’ve lost.” Not just a nation Nature’s Nation, while set in the realm of American art, is not a uniquely American story. After its premiere at Princeton (Oct. 13, 2018–Jan. 6, 2019), the exhibition The United States is itself a planetary creation: travels to the Peabody Essex Museum in Salem, Massachusetts (Feb. 2– Built with labor shipped across the sea, its May 5, 2019), and to the Crystal Bridges Museum of American Art in Bentonville, colonies founded to supply natural resources, Arkansas (May 25–Sept. 9, 2019). the country later became the world’s consumer and continues to draw people from around the world. Borders cannot constrain the spread of pollution, climate change or endangered Nature’s Nation: American Art and Environment has been made possible species. with leadership support from Shelly Malkin, Class of 1986, and Tony Nor can borders contain human popula- Malkin; Annette Merle-Smith; the Henry Luce Foundation; the Princeton tions. The Browning of America is a work that Environmental Institute; and the Barr Ferree Foundation Fund for illustrates the porosity of borders and reas- Publications, Department of Art and Archaeology, Princeton University. serts the nation’s indigenous presence through Generous support has been provided by the National Endowment for a mixed-media assemblage of symbols and the Arts Humanities Council, the Dean for Research Innovation Fund, and collaged newspaper clippings covered with the Humanities Council’s David A. Gardner ’69 Magic Grant. Further brownish-red stains. The work was created in support has been provided by Susan and John Diekman, Class of 1965; 2000 by the artist Jaune Quick-to-See Smith, Gail and Peter Ochs, Class of 1965; the PSEG Foundation; the Kathleen C. a member of the Confederated Salish and Sherrerd Program Fund for American Art; Stacey Roth Goergen, Class of Kootenai Tribes. 1990, and Robert B. Goergen; the High Meadows Foundation Sustainability Artists’ interpretations of nature and nation Fund; the New Jersey State Council on the Arts, a partner agency of the have evolved since the days when Thomas Cole National Endowment for the Arts; the Program in American Studies, covered up human impacts on the environ- Princeton University; and the Partners and Friends of the Princeton ment. Kusserow and Braddock hope that by University Art Museum. This exhibition is supported by an indemnity from exposing the historical and present-day ways the Federal Council on the Arts and the Humanities. in which art imagines the environment, they can encourage the public conversation around issues of environmental preservation and justice.

discovery.princeton.edu 29 ILLUSTRATION BY J.F. PODEVIN 30 Discovery: Research at Princeton 2018-2019 Beyond Einstein

Physicists find surprising connections in the cosmos

By Catherine Zandonella

Albert Einstein’s desk can still be found on The key insight is that gravity, the force that the second floor of Princeton’s physics depart- brings baseballs back to Earth and governs the ment. Positioned in front of a floor-to-ceiling growth of black holes, is mathematically re- blackboard covered with equations, the desk latable to the peculiar antics of the subatomic seems to embody the spirit of the frizzy-haired particles that make up all the matter around us. genius as he asks the department’s current This revelation allows scientists to use one occupants, “So, have you solved it yet?” branch of physics to understand other seem- Einstein never achieved his goal of a unified ingly unrelated areas of physics. So far, this theory to explain the natural world in a single, concept has been applied to topics ranging coherent framework. Over the last century, re- from why black holes run a temperature to how searchers have pieced together links between a butterfly’s beating wings can cause a storm three of the four known physical forces in a on the other side of the world. “standard model,” but the fourth force, gravity, This relatability between gravity and sub- has always stood alone. atomic particles provides a sort of Rosetta No longer. Thanks to insights made by stone for physics. Ask a question about gravity, Princeton faculty members and others who and you’ll get an explanation couched in the trained here, gravity is being brought in from terms of subatomic particles. And vice versa. the cold — although in a manner not remotely “This has turned out to be an incredibly rich close to how Einstein had imagined it. area,” said Igor Klebanov, Princeton’s Eugene Though not yet a “theory of everything,” Higgins Professor of Physics, who generated this framework, laid down over 20 years ago some of the initial inklings in this field in the and still being filled in, reveals surprising ways 1990s. “It lies at the intersection of many fields in which Einstein’s theory of gravity relates to of physics.” other areas of physics, giving researchers new tools with which to tackle elusive questions.

discovery.princeton.edu 31 From tiny bits of string One of Polyakov’s colleagues was Klebanov, The seeds of this correspondence were who in 1996 was an associate professor sprinkled in the 1970s, when researchers at Princeton, having earned his Ph.D. at were exploring tiny subatomic particles called Princeton a decade earlier. That year, quarks. These entities nest like Russian dolls Klebanov, with graduate student Steven inside protons, which in turn occupy the atoms Gubser and postdoctoral research associate that make up all matter. At the time, physi- Amanda Peet, used string theory to make cists found it odd that no matter how hard calculations about gluons, and then compared you smash two protons together, you cannot their findings to a string-theory approach release the quarks — they stay confined inside to understanding a black hole. They were the protons. surprised to find that both approaches yielded One person working on quark confinement a very similar answer. A year later, Klebanov was Alexander Polyakov, Princeton’s Joseph studied absorption rates by black holes and Henry Professor of Physics. It turns out that found that this time they agreed exactly. quarks are “glued together” by other particles, That work was limited to the example of called gluons. For a while, researchers thought gluons and black holes. It took an insight by gluons could assemble into strings that tie Juan Maldacena in 1997 to pull the pieces into quarks to each other. Polyakov glimpsed a more general relationship. At that time, Mal- a link between the theory of particles and dacena, who had earned his Ph.D. at Princeton the theory of strings, but the work was, in one year earlier, was an assistant professor at Polyakov’s words, “hand-wavy” and he didn’t Harvard. He detected a correspondence behave precise examples. tween a special form of gravity and the theory Meanwhile, the idea that fundamental that describes particles. Seeing the importance particles are actually tiny bits of vibrating string of Maldacena’s conjecture, a Princeton team was taking off, and by the mid-1980s, “string consisting of Gubser, Klebanov and Polyakov theory” had lassoed the imaginations of many followed up with a related paper formulating leading physicists. The idea is simple: just as the idea in more precise terms. a vibrating violin string gives rise to different Another physicist who was immediately notes, each string’s vibration foretells a par- taken with the idea was Edward Witten of ticle’s mass and behavior. The mathematical the Institute for Advanced Study (IAS), an beauty was irresistible and led to a swell of independent research center located about a enthusiasm for string theory as a way to explain mile from the University campus. He wrote a not only particles but the universe itself. paper that further formulated the idea, and the combination of the three papers in late 1997 and early 1998 opened the floodgates. “It was a fundamentally new kind of connec- A high standard tion,” said Witten, a leader in the field of string The standard model accounts for three theory who had earned his Ph.D. at Princeton of the four forces of nature: electro- in 1976 and is a visiting lecturer with the rank of magnetism, which governs electricity, professor in physics at Princeton. “Twenty years magnets and light; the strong force, later, we haven’t fully come to grips with it.” which holds particles together inside the atomic nucleus;and the weak force, Two sides of the same coin which acts over short distances and This relationship means that gravity and governs some forms of radioactivity. subatomic particle interactions are like At the atomic scale, objects follow two sides of the same coin. On one side is a different set of physical laws from an extended version of gravity derived from those that govern baseballs and cars. Einstein’s 1915 theory of general relativity. The laws of quantum mechanics lead to On the other side is the theory that roughly some quite odd behaviors. For example, describes the behavior of subatomic particles two particles can have a long-distance and their interactions. connection such that measuring one The latter theory includes the catalogue of affects its partner instantaneously, particles and forces in the “standard model” a state called “entanglement” that (see sidebar), a framework to explain matter Einstein reluctantly embraced, calling it and its interactions that has survived rigorous “spooky action at a distance.” testing in numerous experiments, including at the Large Hadron Collider.

32 Discovery: Research at Princeton 2018-2019 The relationship between gravity and strings “was a fundamentally new kind of connection. Twenty years later, we haven’t fully come to grips with it.”

Edward Witten Charles Simonyi Professor at the Institute for Advanced Study and Visiting Lecturer with the Rank of Professor in Physics at Princeton

ILLUSTRATION BY J.F. PODEVIN

discovery.princeton.edu 33 ILLUSTRATION BY J.F. PODEVIN

“It is a tremendously successful idea. It compels one’s attention. It ropes you in, it ropes in other fields, and it gives you a vantage point on theoretical physics that is very compelling.”

Steven Gubser Professor of Physics

34 Discovery: Research at Princeton 2018-2019 In the standard model, quantum behaviors calculate chaos, but black holes — which are baked in. Our world, when we get down to are some of the most chaotic quantum sys- the level of particles, is a quantum world. tems possible — could help. Work by Stephen Notably absent from the standard model is Shenker and Douglas Stanford at Stanford gravity. Yet quantum behavior is at the basis of University, along with Maldacena, demonstrates the other three forces, so why should gravity how, through AdS/CFT, black holes can model be immune? quantum chaos. The new framework brings gravity into the One open question Maldacena hopes the discussion. It is not exactly the gravity we know, AdS/CFT correspondence will answer is the but a slightly warped version that includes an question of what it is like inside a black hole, extra dimension. The universe we know has where an infinitely dense region called a sin- four dimensions, the three that pinpoint an gularity resides. So far, the relationship gives object in space — the height, width and depth us a picture of the black hole as seen from the of Einstein’s desk, for example — plus the outside, said Maldacena, who is now the Carl P. fourth dimension of time. The gravitational Feinberg Professor at IAS. description adds a fifth dimension that “We hope to understand the singularity causes spacetime to curve into a universe that inside the black hole,” Maldacena said. “Under- includes copies of familiar four-dimensional standing this would probably lead to interesting flat space rescaled according to where they lessons for the Big Bang.” are found in the fifth dimension. This strange, The relationship between gravity and strings curved spacetime is called anti-de Sitter (AdS) has also shed new light on quark confinement, space after Einstein’s collaborator, Dutch initially through work by Polyakov and Witten, astronomer Willem de Sitter. and later by Klebanov and Matt Strassler, who The breakthrough in the late 1990s was was then at IAS. that mathematical calculations of the edge, Those are just a few examples of how or boundary, of this anti-de Sitter space can the relationship can be used. “It is a tremen- be applied to problems involving quantum dously successful idea,” said Steven Gubser, behaviors of subatomic particles described by who today is a professor of physics at a mathematical relationship called conformal Princeton. “It compels one’s attention. It ropes field theory (CFT). This relationship provides you in, it ropes in other fields, and it gives you a the link, which Polyakov had glimpsed earlier, vantage point on theoretical physics that is between the theory of particles in four space- very compelling.” time dimensions and string theory in five di- The relationship may even unlock the mensions. The relationship now goes by several quantum nature of gravity. “It is among our best names that relate gravity to particles, but most clues to understand gravity from a quantum researchers call it the AdS/CFT (pronounced perspective,” said Witten. “Since we don’t A-D-S-C-F-T) correspondence. know what is still missing, I cannot tell you how big a piece of the picture it ultimately will be.” Tackling the big questions Still, the AdS/CFT correspondence, while This correspondence, it turns out, has many powerful, relies on a simplified version of practical uses. Take black holes, for example. spacetime that is not exactly like the real uni- The late physicist Stephen Hawking startled the verse. Researchers are working to find ways to physics community by discovering that black make the theory more broadly applicable to the holes have a temperature that arises because everyday world, including Gubser’s research on each particle that falls into a black hole has an modeling the collisions of heavy ions, as well as entangled particle that can escape as heat. high-temperature superconductors. Using AdS/CFT, Tadashi Takayanagi and Shinsei Also on the to-do list is developing a proof Ryu, then at the University of California-Santa of this correspondence that draws on under- Barbara, discovered a new way to study lying physical principles. It is unlikely that entanglement in terms of geometry, extending Einstein would be satisfied without a proof, said Hawking’s insights in a fashion that experts Herman Verlinde, Princeton’s Class of 1909 consider quite remarkable. Professor of Physics, the chair of the Depart- In another example, researchers are using ment of Physics and an expert in string theory, AdS/CFT to pin down chaos theory, which says who shares office space with Einstein’s desk. that a random and insignificant event such as “Sometimes I imagine he is still sitting the flapping of a butterfly’s wings could result there,” Verlinde said, “and I wonder what he in massive changes to a large-scale system would think of our progress.” such as a faraway hurricane. It is difficult to

discovery.princeton.edu 35 Fact-checking Immigration

Professor Leah Boustan uses big data to explore myths about the past

By Kevin McElwee

PHOTO FROM THINKSTOCK BY GETTY IMAGES

36 Discovery: Research at Princeton 2018-2019 PHOTO BY EDWIN LEVICK COURTESY OF THE LIBRARY OF CONGRESS. PHOTOS BY SAMEER A. KHAN/FOTOBUDDY Leah Boustan, professor of economics, uses digitized historical records and other sources — like this 1906 photograph of immigrants on an Atlantic liner — to give researchers a statistical footing for studies on immigration, past and present.

“When the horns started to blow and anecdotes. We rarely test our beliefs we saw the Statue of Liberty, I thought I was with thousands of cases.” Boustan tries in heaven. Really. She’s up there and saying, to rediscover that lost nuance, giving econo- ‘Come on in. From now on you are a free mists and historians a statistical footing person.’” for their research. These are the words of Turkish immigrant One of the questions Boustan has tackled John Alabilikian, who came to the United is the issue of “white flight.” Between 1940 States in 1922, collected by the Ellis Island and 1970, white Americans left cities in large Foundation in 1985 as part of its oral history numbers, but historians have debated whe- library. In his interview, Alabilikian described ther this exodus was motivated by the desire escaping the Armenian genocide and jour- to pursue opportunities in suburbs or because neying to America. of an influx of black Americans. Boustan’s Personal anecdotes like these serve as a analysis, published in the Quarterly Journal of rich source of data for economist Leah Platt Economics in 2010 when she was on the faculty Boustan, who brings modern statistical analysis at the University of California-Los Angeles, and big-data tools to the study of historical suggests that both were true. events and trends. With the recent digitization Another of Boustan’s recent projects is of first-person accounts and other documents, on the age of mass migration, a period from Boustan can uncover insights from people’s around 1850 to about 1920, when more than personal experiences in ways previously not 30 million Europeans moved to the United possible. “It’s almost as if we can conduct sur- States. Working with longtime collaborators veys of people who lived in the past,” she said. Ran Abramitzky at Stanford University and Boustan, who joined Princeton as a pro- Katherine Eriksson at the University of fessor in economics in 2017, has an impressive California-Davis, and with support from the record of proving and disproving ideas that National Science Foundation, Boustan people believe based on anecdotes or “gut compared historical data to today’s records, feelings.” In the past, economists and his- asking: Are immigrants today assimilating torians had few data tools, but with today’s more slowly than they did in the past? powerful computers and mathematical “Many people imagine that immigrants from approaches, historical perspectives can be Europe very quickly climbed the economic tested against hard numbers. ladder and adopted U.S. behavior norms, and “Often what we think we know, we don’t that immigrants today are slower to do so,” really know,” Boustan said. “If you start to Boustan said. “That’s not the case.” introspect, and ask, ‘Where do my beliefs Prior work suggested that European immi- come from?’ you might realize they come from grants during the age of mass migration were your family’s experience or from relatively few paid less than native-born workers upon first discovery.princeton.edu 37 arrival, but then quickly caught up. Boustan cally male-dominated discipline. When a and her collaborators tracked the occupations leading journal recently asked her how the field of 21,000 natives and immigrants over two might attract and train more women, she was decades, and, in work published in 2014 in the caught off guard. “I realized that I didn’t know Journal of Political Economy, showed that this much about the overall situation of women in common wisdom does not fit the facts in two economics — I only knew anecdotes from my different ways. Many recently arrived immigrant personal experiences,” Boustan said. groups did not have lower earnings than natives So she began investigating the problem with and, overall, the income of immigrants and her characteristic big-data approach. “It is a natives rose at close to the same rate. very important question, and the best way to Slow rates of economic assimilation are work on big questions is to take a look at the consistent with the experiences of recent data,” she said. immigrants, according to studies by other She paired with graduate student Andrew researchers, Boustan said. “There is nothing Langan to collect data on the male-female special — or necessarily alarming — about graduate student ratios in economics economic convergence that takes more than departments at leading research universities one generation,” Boustan said. “We have been and learn more about why some programs have there before.” more success than others in training women. One measure of cultural assimilation that Graduate programs in economics are on aver- Boustan looked at was how immigrants named age 30 percent female across the nation, with their children. Because selecting a child’s some as low as 10 percent female and others name costs nothing, and thus is independent achieving a 50-50 balance, Boustan and her of socio-economic status, Boustan argued that team found. names indicate a family’s eagerness to adopt “The average picture looks gloomy, but American culture. In work supported by a grant there are some bright rays,” Boustan said. For from the Russell Sage Foundation, she and example, even departments with high numbers her colleagues used millions of entries from of male students and faculty can serve female recently digitized census records to calculate a students well if they provide opportunities for “foreignness index” for each name in the early training and mentoring, they found. 1900s. She conducted a similar exercise using Boustan keeps this in mind as she mentors birth certificate records from California today. and advises students in Princeton’s economics In both cases, she found that immigrants shift department. One advisee, Ji Won Choi, said, “I away from foreign-sounding names as they hope I can be an example, like Leah, for others spend more time in their adopted nation, and in the future.” at the same rate. Until recently, Princeton’s Department of “What was striking about those two sets of Economics had few women in senior faculty analyses — the past and present — is that the positions, but the department has doubled speed of cultural assimilation, by this measure, its number of female faculty members over is almost identical in the past and present,” the past four years, said Janet Currie, the Boustan said. The study is detailed in an NBER Henry Putnam Professor of Economics and Working Paper posted in July 2016. Public Affairs at the Woodrow Wilson School, Boustan’s work is part of a growing trend in who was department chair until June 2018. economics toward harnessing large data sets “Nevertheless,” Currie said, “we are not where to explain historical observations, said her we would like to be, and we’ll need continuous colleague and former mentor, Henry Farber, effort not to lose the gains we have made Princeton’s Hughes-Rogers Professor of and to diversify the faculty and student body Economics. Farber met Boustan when she in other dimensions.” was an undergraduate at Princeton in the late With so many charged topics facing society 1990s. Boustan later earned a Ph.D. at Harvard today, from the equitable treatment of University in 2006 and then became a profes- women in the workplace to the role of sor at the University of California-Los Angeles. immigrants in building the nation, Boustan’s Today, Boustan’s office is only a few doors data-driven approach to controversial issues down from Farber, who is next door to his is more relevant than ever. To explain the own dissertation adviser, Orley Ashenfelter, importance of this work, Boustan quotes the Joseph Douglas Green 1895 Professor of her former mentor, the Harvard economic Economics — three generations of empirical historian and labor economist Claudia Goldin: economics in one hallway. “Princeton is lucky “The best historical questions are the ones to have her on the faculty,” Farber said. that speak to the world we live in today.” Boustan is also part of the trend toward increasing female participation in a histori-

38 Discovery: Research at Princeton 2018-2019 “Many people imagine that [19th-century] immigrants from Europe very quickly climbed the economic ladder and adopted U.S. behavior norms, and that immigrants today are slower

to do so. That’s not the case.”

Leah Boustan Professor of Economics

PHOTO BY DAVID KELLY CROW

discovery.princeton.edu 39 Islam in Pakistan: A History Books Princeton University Press, May 2018

Muhammad Qasim Zaman, the Robert H. Niehaus ’77 Professor of Near Eastern Studies and Religion The first modern state to be founded in the name of Islam, Pakistan was the largest Muslim country in the world at the time of its establishment in 1947. Islam in Pakistan is the first comprehensive book to explore Islam’s evolution in this region over the past century and a half, from the British colonial era to the present day. Muhammad Qasim Zaman presents a rich historical account of this major Muslim nation, insights into the rise and gradual decline of Islamic modernist thought in the South Asian region, and an understanding of how Islam has fared in the contemporary world. Examining how facets of Islam have been pivotal in Pakistani history, Islam in Pakistan offers sweeping perspectives on what constitutes an Islamic state. The Dancing Lares and the Serpent in the Garden: Religion at the Roman Street Corner Street Players: Princeton University Press, September 2017 Black Pulp Fiction and the Making of a Literary Harriet Flower, the Andrew Fleming West Underground Professor in Classics University of Chicago Press, The most pervasive gods in ancient Rome had no November 2018 traditional mythology attached to them, nor was Kinohi Nishikawa, assistant their worship organized by elites. Throughout the professor of English and African Roman world, neighborhood street corners, farm American studies boundaries and household hearths featured small shrines to the beloved lares, a pair of cheerful The uncontested center of the little dancing gods. These shrines were maintained black pulp fiction universe for more primarily by ordinary Romans, and often by slaves than four decades was Los Angeles and freedmen, for whom the lares’ cult provided publisher Holloway House. From a unique public leadership role. In this compre- the late 1960s until it closed in hensive and richly illustrated book, the first to 2008, Holloway House specialized focus on the lares, Harriet Flower offers a striking- in cheap paperbacks with page- ly original account of these gods and a new way turning narratives featuring black of understanding the lived experience of protagonists in crime stories, conspiracy thrillers, prison everyday Roman religion. novels and Westerns. A reconsideration Kinohi Nishikawa contends that black pulp fiction was of seemingly humble built on white readers’ fears of the feminization of society gods that were — and the appeal of black masculinity as a way to counter central to the it. In essence, it was the original blaxploitation: mass- religious world of marketing race to suit the reactionary fantasies of a white the Romans, this is audience. But while chauvinism and misogyny remained also the first major troubling yet constitutive aspects of this literature, after account of the full 1972 Holloway House moved away from publishing sleaze for range of lares a white audience to publishing solely for black readers. worship in the homes, When it closed, Holloway House was synonymous with neighborhoods and genre fiction written by black authors for black readers — a temples of ancient field of cultural production that Nishikawa terms “the black Rome. literary underground.” But as Street Players demonstrates, this cultural authenticity had to be promoted and in some cases made up — and there is a story of exploitation at the heart of black pulp fiction’s origins that cannot be ignored.

40 Discovery: Research at Princeton 2018-2019 The Discrete Charm of the Machine: Why the World Became Digital Princeton University Press, forthcoming February 2019

Ken Steiglitz, the Eugene Higgins Professor of Computer Science, Emeritus, and senior scholar A few short decades ago, we were informed by the smooth signals of analog television, radio and vinyl discs; communi- cated with our analog telephones; and even computed with analog computers. Today our world is digital, built with zeros and ones. Why did this revolution occur? The Discrete Charm of the Machine explains, in an engaging and accessible manner, the varied physical and logical reasons behind this radical transformation. The spark of individual genius shines through this story of innovation: the stored program of Jacquard’s loom, the logical branching of Charles Babbage, Alan Turing’s brilliant abstraction of the discrete machine. Steiglitz follows the progression of these ideas in the building of our digital world, from the internet and artificial intelligence to the edge of the unknown.

The Chinese Must Go: Violence, Exclusion, and the Making of the Small Wars, Big Data: Alien in America The Information Revolution Harvard University Press, February 2018 in Modern Conflict Beth Lew-Williams, assistant professor of history Princeton University Press, June 2018 The American West erupted in anti-Chinese Eli Berman, chair of economics at the violence in 1885. Following the massacre of University of California-San Diego Chinese miners in Wyoming Territory, commu- Joseph Felter, deputy assistant secretary nities throughout California and the Pacific of defense for South and Southeast Asia Northwest harassed, assaulted and expelled Jacob Shapiro, professor of politics and thousands of Chinese immigrants. Beth Lew- international affairs at Princeton’s Williams shows how American immigration Woodrow Wilson School of Public and policies incited this violence and how the International Affairs violence, in turn, provoked new exclusionary with Vestal McIntyre, staff writer at the policies. Ultimately, Lew-Williams argues, Harvard Kennedy School Chinese expulsion and exclusion produced the concept of the “alien” in modern America. The way wars are fought has changed starkly over the past 60 years. As The Chinese Must Go makes clear, anti- International military campaigns used to play out between large Chinese law and violence continues to have armies at central fronts. Today’s conflicts find major powers facing consequences rebel insurgencies that deploy elusive methods, from improvised for today’s immi- explosives to terrorist attacks. Small Wars, Big Data presents a grants. The transformative understanding of these contemporary confron- present resur- tations and how they should be fought. The authors show that gence of xeno- a revolution in the study of conflict — enabled by vast data, rich phobia builds qualitative evidence and modern methods — yields new insights into mightily upon terrorism, civil wars and foreign interventions. past fears of Modern warfare is not about struggles over territory but over the “heathen people. Civilians — and the information they might choose to pro- Chinaman.” vide — can turn the tide at critical junctures. Small Wars, Big Data provides groundbreaking perspectives for how small wars can be better strategized and won to the benefit of the local population.

ALL TEXT AND IMAGES COURTESY OF THE PUBLISHER discovery.princeton.edu 41 Selected Faculty Honors Memberships and Fellowships

American Academy of Arts and Association for Computing Irvin Glassman, Robert H. Letters: Member Machinery: Fellow Goddard Professor of Jeffrey Eugenides, professor of Aarti Gupta, professor of Mechanical and Aerospace creative writing in the Lewis computer science (2017) Engineering, Emeritus (2018) Center for the Arts (2018) Yiguang Ju, Robert Porter Combustion Institute: Fellow Patterson Professor of American Academy of Arts and Frederick Dryer, professor of Mechanical and Aerospace Sciences: Member mechanical and aerospace Engineering (2018) Simon Gikandi, Robert engineering, emeritus; senior Chung Law, Robert H. Goddard Schirmer Professor of English; scholar (2018) Professor of Mechanical and chair, Department of English Aerospace Engineering (2018) (2018) Daniel Heller-Roazen, Arthur Engineering professors named W. Marks ’19 Professor of fellows of National Academy of Inventors Comparative Literature (2018) Tali Mendelberg, John Work Two engineering faculty members, Paul Prucnal and Jennifer Garrett Professor in Politics Rexford, have been named as fellows of the National Academy (2018) of Inventors, an honor that recognizes contributions that have Jacqueline Stone, professor of an impact on quality of life, economic development and societal religion (2018) welfare. Prucnal, a professor of electrical engineering, is recognized American Council of Learned as the inventor of an ultra-fast switch called the Terahertz Opti- Societies: Fellow cal Asymmetric Demultiplexer. Prucnal’s research concentrates on optical communications and signal processing. His research Thomas Conlan, professor of into optical networks in the 1980s generated new disciplines in East Asian studies and history the field and has resulted in over 1,000 scholarly papers. Prucnal (2018) is the holder of 27 patents. Katja Guenther, associate Rexford, chair of computer science and the Gordon Y.S. professor of history (2018) Wu Professor in Engineering, is an expert on large computer networks and internet routing. She has made several contribu- American Mathematical tions to the development of the Border Gateway Protocol, which Society: Fellow allows for communications among the many networks that form Fernando Codá Marques, pro- the internet. A 1991 alumna, Rexford holds 22 patents. fessor of mathematics (2018) –By John Sullivan Alexandru Ionescu, professor PHOTOS BY DAVID KELLY CROW of mathematics (2018) Sergiu Klainerman, Eugene Higgins Professor of Mathe- matics (2018) John Pardon, professor of mathematics (2018) Peter Sarnak, Eugene Higgins Professor of Mathematics (2018)

Paul Prucnal Jennifer Rexford

42 Discovery: Research at Princeton 2018-2019 Clifford Brangwynne selected as Howard Hughes PHOTO BY LAURA PEDRICK FOR HHMI Medical Institute Investigator

Dorothy and Lewis B. Cullman Clifford Brangwynne, whose research explores the hidden order Center for Scholars and within cellular liquid, has been named a Howard Hughes Medical Writers: Fellow Institute Investigator. Brangwynne, an associate professor of chemical and biologi- Brooke Holmes, Robert F. cal engineering at Princeton University, is one of 19 new investi- Goheen Professor in the gators named by the institute this year. The distinction is one of Humanities, professor of the most sought-after awards in biomedical research. classics (2018) A nonprofit medical research organization headquartered in Chevy Chase, Maryland, HHMI provides roughly $8 million over Dorothy and Lewis B. a seven-year period for researchers, who remain based at their Cullman Center for Scholars home institutions, pursuing cutting-edge science. This innova- and Writers: John and tive approach affords researchers time to concentrate on their Constance Birkelund Fellow work and not have to continually seek short-term grants. David Bell, Sidney and Ruth –By Adam Hadhazy Clifford Brangwynne Lapidus Professor in the Era of North Atlantic Revolutions, professor of history (2018) National Academy of Medicine: National Distinctions for Early Career Econometric Society: Fellow Member Researchers Esteban Rossi-Hansberg, Anne Case, Alexander Stewart Theodore A. Wells ’29 1886 Professor of Economics Professor of Economics and and Public Affairs, Emeritus Alfred P. Sloan Foundation: Nathalie de Leon, assistant International Affairs (2017) (2017) Research Fellowship professor of electrical , Uwe Reinhardt Leeat Yariv Todd Hyster, assistant engineering (2018) Professor of Economics (2017) National Academy of professor of chemistry (2018) Kaushik Sengupta, assistant Sciences: Member Mary Caswell Stoddard, professor of electrical ITER: Science Fellow Sanjeev Arora, Charles C. assistant professor of ecology engineering (2018) David Johnson, principal Fitzmorris Professor in and evolutionary biology (2018) research physicist, Princeton Computer Science (2018) National Science Foundation: Plasma Physics Laboratory Orley Ashenfelter, Joseph Camille and Henry Dreyfus Early Career Development (2018) Douglas Green 1895 Professor Foundation: Camille Dreyfus (CAREER) Award Francesca Poli, research of Economics (2018) Teacher-Scholar José Avalos, assistant profes- physicist, Princeton Plasma Dalton Conley, Henry Putnam Mohammad Seyedsayamdost, sor of chemical and biological Physics Laboratory (2017) University Professor in assistant professor of engineering and the Andlinger Charles Skinner, principal Sociology (2018) chemistry (2018) Center for Energy and the Environment (2018) research physicist, Princeton David MacMillan, James S. Plasma Physics Laboratory McDonnell Distinguished David and Lucile Packard Ian Bourg, assistant professor (2018) University Professor of Foundation: Packard Fellowship of civil and environmental Chemistry (2018) for Science and Engineering engineering and the Princeton John D. and Catherine T. Environmental Institute (2018) Peter Ozsváth, professor of John Pardon, professor of MacArthur Foundation: Fellow mathematics (2018) mathematics (2017) Nathalie de Leon, assistant Elizabeth Paluck, professor of professor of electrical Virginia Zakian, Harry C. Wiess psychology and public affairs engineering (2018) Professor in the Life Sciences, Defense Advanced Research (2017) professor of molecular biology Projects Agency: Young Barbara Engelhardt, associate (2018) Faculty Award professor of computer science National Academy of Design: Amir Ali Ahmadi, assistant pro- (2018) National Academician fessor of operations research Gillat Kol, assistant professor Eve Aschheim, lecturer in visual and financial engineering of computer science (2018) arts and the Lewis Center for (2017) the Arts (2017)

discovery.princeton.edu 43 PHOTO COURTESY OF THE DEPARTMENT OF Andrej Kosmrlj, assistant Tera Hunter earns awards AFRICAN AMERICAN STUDIES professor of mechanical and for scholarship on slave marriage aerospace engineering (2017) Wyatt Lloyd, assistant Tera Hunter, the Edwards Professor of American History and professor of computer a professor of history and African American studies, received science (2017) three prizes for her 2017 book, Bound in Wedlock: Slave and Free Black Marriage in the Nineteenth Century. Jared Toettcher, assistant professor of molecular bio- The Organization of American Historians awarded her the logy, James A. Elkins, Jr. ’41 Mary Nickliss Prize in U.S. Women’s and/or Gender History, and Preceptor in Molecular Biology the American Historical Association gave her two awards, the (2018) Joan Kelly Memorial Prize (for women’s history and/or feminist theory) and the Littleton-Griswold Prize (in U.S. law and society). , assistant Mark Zhandry Hunter researched court records, legal documents and professor of computer personal diaries to illustrate the constraints that slavery placed science (2018) on intimate relationships. Her own great-great-grandparents, Ellen and Moses Hunter, were enslaved, freed and then married U.S. Air Force Office of during Reconstruction. –By Denise Valenti Scientific Research: Young Tera Hunter Investigator Research Program Award Prizes and Distinctions Jeffrey Thompson, assistant professor of electrical engineering (2017) American Astronomical American Historical Association Alisha Holland, assistant Society’s Division on Matthew Karp, assistant professor of politics: 2018 U.S. Department of Energy Dynamical Astronomy professor of history, Elias Giovanni Sartori Book Award Office of Science: Early Career James Stone, Lyman Spitzer Boudinot Bicentennial Research Program Award Jr., Professor of Theoretical Preceptor: 2017 John H. American Society for Matrix Nathalie de Leon, assistant Astrophysics; professor of Dunning Prize Biology professor of electrical engi- astrophysical sciences and Jean Schwarzbauer, Eugene neering (2018) applied and computational American Philosophical Higgins Professor of Molecular Nathaniel Ferraro, theoretical/ mathematics; chair, Society Biology: 2018 Senior Investi- computational research Department of Astrophysical Angela Creager, Thomas M. gator Award physicist, Princeton Plasma Sciences: 2018 Brouwer Award Siebel Professor in the History Physics Laboratory (2018) of Science, professor of American Society of Civil American Chemical Society Engineers Samuel Lazerson, research history: 2018 Patrick Suppes physicist, Princeton Plasma Emily Carter, dean, School Prize in the History of Science Sigrid Adriaenssens, associate Physics Laboratory (2018) of Engineering and Applied Douglas Massey, Henry G. professor of civil and envi- Science; Gerhard R. Andlinger Bryant Professor of Sociology ronmental engineering: 2018 U.S. Office of Naval Research: Professor in Energy and the and Public Affairs, Woodrow George Winter Award Young Investigator Program Environment; professor of Wilson School: 2017 Henry Award mechanical and aerospace Allen Moe Prize in the American Statistical engineering and applied and Association Prateek Mittal, associate Humanities computational mathemat- professor of electrical Jianqing Fan, Frederick L. ics: engineering (2018) 2018 Award in Theoretical American Physical Society Moore, Class of 1918, Chemistry William Bialek, John Archibald Professor in Finance; David MacMillan, James S. Wheeler/Battelle Professor in professor of operations McDonnell Distinguished Physics and the Lewis-Sigler research and financial University Professor of Institute for Integrative engineering: 2018 Noether Chemistry: 2018 Gabor A. Genomics: 2018 Max Delbrück Senior Scholar Award Somorjai Award for Creative Prize in Biological Physics Research in Catalysis Association for Computer American Political Science Aided Design in Architecture American Geophysical Union Association Mónica Ponce de León, dean, Eric Wood, Susan Dod Brown Paul Frymer, professor of School of Architecture; Professor of Civil and Envi- politics: 2018 J. David professor of architecture: ronmental Engineering: 2017 Greenstone Book Prize 2018 Teaching Award of Robert E. Horton Medal Excellence

44 Discovery: Research at Princeton 2018-2019 Association for Computing David Spergel, Charles A. Young Four Princeton faculty members win Machinery Professor of Astronomy on Guggenheim Fellowships Kyle Jamieson, associate the Class of 1897 Foundation, professor of computer professor of astrophysical Four Princeton faculty members, representing a range of science: 2018 SIGMOBILE sciences: 2018 Breakthrough subjects in the humanities, have received Guggenheim RockStar Award Prize in Fundamental Physics Fellowships. Brooke Holmes, the Robert F. Goheen Professor in the Stephen Lyon, professor of Econometric Society Humanities and professor of classics, explores the Greco- electrical engineering: 2017 Roman roots of Western ideas about the physical body, the SenSys Test of Time Award Stephen Redding, Harold T. Shapiro ’64 Professor in natural world, matter and the non-human. Margaret Martonosi, Hugh Economics; professor of Martin Kern, the Greg (’84) and Joanna (P13) Zeluck Professor Trumbull Adams ’35 Professor economics and inter- in Asian Studies and chair of the East Asian studies department, of Computer Science: 2017 national affairs, Woodrow was awarded the Guggenheim for his project Performance, SenSys Test of Time Award Wilson School: 2018 Memory and Authorship in Ancient China: The Formation of the Jennifer Rexford, Gordon Y.S. Frisch Medal Poetic Tradition. Wu Professor in Engineer- Ekaterina Pravilova, professor of history, specializes in ing; professor of computer Fusion Power Associates 19th-century Imperial Russia, and was awarded the Guggenheim science; chair, Department for her project Political Money: A History of the Russian Ruble, Steven Cowley, director, of Computer Science: 2018 Princeton Plasma Physics 1768-1917. SIGCOMM Award Laboratory, professor of Monica Youn, a lecturer in creative writing and the Lewis Center for the Arts, is the author of three books of poetry, astrophysical sciences: 2017 Association for Psychological most recently Blackacre (2016), which won the William Carlos Distinguished Career Award Science Williams Award of the Poetry Society of America. Her 2010 Nathaniel Fisch, professor of Jonathan Cohen, Robert book, Ignatz, was a finalist for the National Book Award. astrophysical sciences: 2018 Bendheim and Lynn Bendheim –By the Office of Communications Distinguished Career Award Thoman Professor in PHOTO COURTESY OF THE Neuroscience; professor of Stewart Prager, professor PHOTO BY DENISE APPLEWHITE OFFICE OF ADMISSION psychology and the Princeton of astrophysical sciences: 2017 Neuroscience Institute: 2018 Distinguished Career Award William James Fellow Award Gruber Foundation Brain & Behavior Research Jo Dunkley, professor of Foundation physics and astrophysical Ilana Witten, associate sciences: 2018 Cosmology professor of psychology and Prize as part of the Planck Team the Princeton Neuroscience William Jones, associate Institute: 2017 Freedman Prize professor of physics: 2018 for Exceptional Basic Research Cosmology Prize as part of the Planck Team Breakthrough Prize Ekaterina Pravilova Brooke Holmes Foundation IEEE PHOTO BY ADENA STEVENS PHOTO COURTESY OF MONICA YOUN Jo Dunkley, professor of Bede Liu, professor of physics and astrophysical electrical engineering, sciences: 2018 Breakthrough emeritus: 2018 Jack S. Kilby Prize in Fundamental Physics, Signal Processing Medal as part of the WMAP Science Margaret Martonosi, Hugh Team Trumbull Adams ’35 Professor Norman Jarosik, senior of Computer Science: 2018 research physicist, lecturer Technical Achievement Award in physics: 2018 Breakthrough Prize in Fundamental Physics INFORMS Optimization Society Lyman Page Jr., James S. Robert Vanderbei, professor McDonnell Distinguished of operations research and University Professor in financial engineering:2017 Martin Kern Monica Youn Physics: 2018 Breakthrough Khachiyan Prize Prize in Fundamental Physics

discovery.princeton.edu 45 Jewish Book Council Materials Research Society Phi Beta Kappa Society Eve Krakowski, assistant Sigurd Wagner, professor of Nancy Weiss Malkiel, professor professor of Near Eastern electrical engineering, of history, emeritus: 2018 studies and Program in Judaic emeritus; senior scholar: Sidney Hook Memorial Award Studies, Christian Gauss Fund 2017 David Turnbull Lectureship University Preceptor: 2017 Award Pulitzer Prize Board National Jewish Book Award Matthew Desmond, Maurice P. Yair Mintzker, professor of Modern Language Association During Professor of Sociology: history: 2017 National Jewish Christy Wampole, associate 2017 Pulitzer Prize in General Book Award professor of French and Nonfiction Italian: 2017 Prize for a Journal of Africana Religions First Book Research & Development Judith Weisenfeld, Agate Council of New Jersey Brown and George L. Collord National Book Critics Circle Craig Arnold, professor of Professor of Religion: 2017 John McPhee, Ferris Professor mechanical and aerospace Albert J. Raboteau Prize for the of Journalism in Residence: engineering: 2017 Edison Best Book in Africana Religions 2018 Sandhof Award for Patent Award, Technology Lifetime Achievement Transfer PHOTO BY DENISE APPLEWHITE Manfred Bitter, principal National Endowment for the research physicist, Princeton Humanities Plasma Physics Laboratory: Judith Weisenfeld, Agate 2017 Edison Patent Award, Brown and George L. Collord Imaging Systems Professor of Religion: 2017 Philip Efthimion, head, Fellowship plasma science and technology, Princeton Plasma New York State Physics Laboratory; lecturer Alicia Ostriker, lecturer with in astrophysical sciences: the rank of professor in 2017 Edison Patent Award, creative writing and the Lewis Imaging Systems Center for the Arts: 2018 New Kenneth Hill, principal York State Poet, New York State research physicist, Princeton Walt Whitman Citation of Merit Plasma Physics Laboratory: for Poets 2017 Edison Patent Award, Imaging Systems Paul Muldoon Nokia Corporation Paul Muldoon receives Kaushik Sengupta, assistant Simons Foundation Her Majesty’s Gold Medal for Poetry professor of electrical engi- Steven Gubser, professor from Queen Elizabeth neering: 2017 Bell Labs Prize of physics: 2017 Simons Investigator Award, Physics Northwestern University Paul Muldoon, the Howard G.B. Clark ’21 Uni- Eve Ostriker, professor of versity Professor in the Humanities, professor Assaf Naor, professor of astrophysical sciences: 2017 of creative writing in the Lewis Center for the mathematics: 2018 Frederic Simons Investigator Award, Arts and director of the Princeton Atelier, has Esser Nemmers Prize in Astrophysics received Her Majesty’s Gold Medal for Poetry. Mathematics Ran Raz, professor of Muldoon, a native of Ireland, is the second computer science: 2018 Irish poet to receive the award in its 83-year PEN America Center Simons Investigator Award, history, after Michael Longley in 2001. The Po- Edmund White, professor of Theoretical Computer Science etry Medal Committee recommended Muldoon creative writing in the Lewis on the basis of the body of his work. Dame Center for the Arts, emeritus: Igor Rodnianski, professor Carol Ann Duffy, Britain’s poet laureate, de- 2018 PEN/Saul Bellow Award of mathematics: 2017 Simons scribed his work as ”ambitious, erudite, witty for Achievement in American Investigator Award, and musical.” –By Jamie Saxon Fiction Mathematics

46 Discovery: Research at Princeton 2018-2019 PHOTO BY DENISE APPLEWHITE Amit Singer, professor of Gillian Knapp receives mathematics and the Program presidential award in Applied and Computa- for STEM mentorship tional Mathematics: 2017 Simons Investigator Award, Gillian Knapp, an emeritus professor of Math+X astrophysical sciences and senior scholar, Allan Sly, Henry Burchard Fine has received the National Science Foundation’s Professor of Mathematics: Presidential Award for Excellence in Science, 2017 Simons Investigator Award, Mathematics and Engineering Mentoring. Mathematics Knapp taught at Princeton for 34 years and was one of the first women to join the science Society for Developmental faculty. In 2005, she founded the Princeton Biology Prison Teaching Initiative (PTI), a leader in Eric Wieschaus, Squibb providing college-accredited classes to Gillian Knapp Professor in Molecular Biology, incarcerated individuals. The Presidential Award professor of molecular biology recognizes Knapp’s work in founding PTI, as and the Lewis-Sigler Institute well as her role in developing and expanding for Integrative Genomics: 2018 mentorship opportunities for undergraduate Lifetime Achievement Award and graduate students in the Department of Astrophysical Sciences, where she helped Society for Ethnomusicology foster a diverse and inclusive student and faculty community. Gavin Steingo, assistant –By Emily Aronson professor of music: 2017 Alan Merriam Prize

Society of Labor Economists International Prizes and Distinctions Henry Farber, Hughes-Rogers Professor of Economics: 2018 Jacob Mincer Award BBVA Foundation International Association of Royal College of Music B. Rosemary Grant, senior Mathematical Physics Michael Pratt, conductor, U.S. Department of Energy’s research biologist, emeritus; Michael Aizenman, professor Princeton University Office of Science senior biologist, ecology and of physics and mathematics: Orchestra; director, Program Nathaniel Fisch, professor of evolutionary biology: 2018 2018 Henri Poincaré Prize in Musical Performance: astrophysical sciences: 2017 Frontiers of Knowledge Award 2018 Honorary Member One of 40 Research Milestones Peter Grant, Class of 1877 King’s College, University of over the Past 40 Years Professor of Zoology, Emeri- Cambridge Royal Spanish Mathematical tus; professor of ecology and Michael Cook, Class of 1943 Society University of California- evolutionary biology, emeritus: University Professor of Near Javier Gómez-Serrano, Berkeley Center for Buddhist 2018 Frontiers of Knowledge Eastern Studies: 2018 Honorary assistant professor of math- Studies Award Fellow ematics: 2017 Vicent Caselles Jacqueline Stone, professor of Mathematical Research Award religion: 2017 Toshihide Numata Chinese Academy of Sciences National Economics Book Award H. Vincent Poor, Michael Henry Foundation, China Royal Swedish Academy of Strater University Professor Gregory Chow, Class of 1913 Sciences and the Crafoord University of Pittsburgh School of Electrical Engineering: 2017 Professor of Political Foundation of Medicine Foreign Member Economy, Emeritus; professor Syukuro Manabe, senior Bonnie Bassler, Squibb of economics, emeritus: 2017 meteorologist, atmospheric Professor in Molecular Hungarian Academy China Economics Prize and oceanic sciences: 2018 Biology; chair, Department of Sciences Crafoord Prize in Geosciences of Molecular Biology: 2018 Gáspár Bakos, professor of Queen Elizabeth II Dickson Prize in Medicine astrophysical sciences: 2017 Steven Cowley, director, Wissenschaftskolleg zu Berlin Dénes Gábor Award Princeton Plasma Physics Beatriz Colomina, professor of Laboratory; professor of architecture: 2018 Fellow astrophysical sciences: 2018 Knighthood

discovery.princeton.edu 47 Innovation Indicators Fiscal year 2018 Sponsored Research Projects

$358.5 M Total funding

1,459 69 Total $137.2 M Projects sponsored supported by research industry funding projects $221.3 M Princeton University U.S. Department of 270 campus expenditures1 Energy’s Princeton Projects Plasma Physics supported by Laboratory (PPPL) foundation funding allocation2

1Expenditures for fiscal year July 1-June 30. 2Amount allocated for fiscal year Oct. 1-Sept. 30. Funding does not include pass-through procurements related to ITER, an international fusion experiment.

Funding Sources for Sponsored Research Activities (Campus) Technology Licensing Activities 1% Other 118

5% Invention disclosures received

Industry 201 12% U.S. Department National 28% of Defense Science Patent applications filed Foundation 32 58 18% Other government (including State Patents Technologies of New Jersey) National issued licensed Institutes of Health Foundations $ M 24% 12.8 12%

Gross royalty proceeds

48 Discovery: Research at Princeton 2018-2019 Dean’s For corporations and To learn more about Princeton For inquiries regarding note foundations looking for University inventions and sponsored research opportunities to collaborate: licensing opportunities: administration: PHOTO BY DAVID KELLY CROW Connect with Corporate Engagement and Technology Licensing Research and Project Princeton Foundation Relations John Ritter Administration Coleen Burrus Director Elizabeth Adams Follow Director patents.princeton.edu Director cefr.princeton.edu T 609-258-1001 orpa.princeton.edu the data T 609-258-5954 [email protected] T 609-258-3091 [email protected] [email protected]

PHOTO BY DAVID KELLY CROW

Below: Thomas Moran, American, 1837–1926, Lower Falls, Yellowstone Park (Grand Canyon of the Yellowstone), 1893. Oil on canvas. Gilcrease Museum, Tulsa, Oklahoma.