Useful News for You

Through his close relationship with the woods of Walden Pond in Concord, Massachusetts, Henry David Thoreau observed the ebb and flow of the natural world first-hand. Prolific in his practice of collecting botanical samples, Thoreau’s journals reveal detailed observations on local flora.

Six hundred forty-eight specimens, long preserved in the Harvard University Herbaria, now serve as the foundation of a new exhibition, “In Search of Thoreau’s Flowers: An Exploration of Change and Loss,” at the Harvard Museum of Natural History.

The exhibition is an immersive multidisciplinary experience that marries art and science through a modern artistic interpretation of Thoreau’s preserved plants. It invites visitors to ask, “What do Thoreau’s findings tell us about what plants are winning, and what plants are losing, in the face of climate change today?”

Wondering is a series of random questions answered by Harvard experts. For the latest installment, we asked Deirdre Leigh Barrett, a psychology lecturer at Harvard Medical School and the author of “The Committee of Sleep,” what language a bilingual or multilingual person is most likely to dream in and why.

There have been very few studies on bilingualism and multilingualism and how they affect dreams. These are small studies, but they certainly find that people who speak any second language, even without good proficiency, at least occasionally dream in the second language. One study asked the subjects what they thought made the difference, and they said that it was determined by the people and or the setting that was being dreamed about. If you thought of your family back in your country of origin, it’d likely be in that language regardless of whether it was now your dominant language. And if you were dreaming about people you’ve known as a young adult, living in another setting where you spoke a different language, you’d be dreaming in that language. It was combination of where the dream was set, what language was associated with that, and what people were in the dream — that’s what they said determined it.

But I’ve heard others say that if they were dreaming about important emotional issues, they would dream in their original language, and if they were dreaming about practical, abstract, or work-related things, they would dream in their newer language. I heard something different from the most multilingual person I’ve ever talked to. He was a high-level Swedish economist, and he said that he was fluent in about 15 languages. He said that he dreamed in whatever language he was speaking that day, even if the dreams were about his family of origin in Sweden.

There is something that I have never seen mentioned in any of the published studies on this, which is that there are some people who say they are never aware of language in dreams — that they don’t dream in any particular language. I very much identify with that. Most of the time, I don’t hear language in my dreams. I have only a handful of times dreamed in a language other than English, which fits the findings of some studies that say that your degree of proficiency in a second language determines how often you will dream in it. I studied French in school, but I am not a proficient speaker. I’ve dreamed in French at least twice.

People who are not proficient in a foreign language sometimes say that they have once or more dreamed in the rudimentary second language, and in the dream, they believed they were very proficient in it. When people discuss it, it’s usually along the lines of “Why is it that we can be so much more fluent in our dreams?” Dream psychologists, especially neuroscientists, say that it’s likely because the prefrontal area that is responsible for reality checks is shut down. It is possible that they are more proficient in the dream, but it’s also possible that they feel more proficient in the dream because they’re not doing the usual self-judgment.

I think that dreams are best thought of as just thinking in a different biological state, where areas associated with visualization and emotion are more active than usual intuition, and that is why we’re less verbal and less logical when we dream. There are a few theories that say dreams are there for memory consolidation, for threat simulation, and for wish fulfillment. And yes, they’re for all of that, and a million other things, just like our waking thought.

Harvard faculty and students are advancing solutions to climate change and its wide-ranging impacts through new scientific, technological, legal, behavioral, public health, policy, and artistic innovations. Ten research teams will share $1.3 million in the eighth round of the Climate Change Solutions Fund (CCSF) awards. Aiming for impact at both the local and global level, these projects will seek to reduce the risks of climate change, hasten the transition to renewable energy, diminish the impact of existing fossil fuels on the climate, understand and prepare for the effects of climate change, and propel innovations needed to accelerate progress toward a healthier, more sustainable future.

“Full engagement in the critical work of confronting climate change requires that Harvard advance on as many fronts as we have at our disposal,” said Harvard President Larry Bacow. “The Climate Change Solutions Fund is one of the ways in which we support faculty and students in their important work, and the diversity of this year’s projects is a testament to the variety of tools we have at our disposal to address humanity’s greatest challenge.”

The fund review committee, chaired by Vice Provost for Climate and Sustainability James Stock, selected research projects from across the University’s 12 Schools. Proposals that demonstrated imaginative and promising collaboration among faculty and students received special consideration, as did projects designed to use the campus as a testbed to study climate change solutions at an institutional scale, which connects with the priorities of the Presidential Committee on Sustainability. As of 2022, nearly 70 CCSF projects have received more than $8 million in funding.

“We had a very strong set of proposals this year. The breadth across Schools and the substantive strength of the proposals illustrates how so many Harvard scholars are engaging in climate-related research,” said Stock. “I’m also grateful to the members of the proposal review committee for the time and thought that they put into selecting the winning proposals.”

This year’s projects range from designing strategies for extreme heat adaptation and helping students explore the consequences of their consumption on Harvard’s campus, to studying the health impacts of wildfires on vulnerable populations and building data infrastructure to understand climate change migration around the world.

The fund was established in 2014 by President Emerita Drew Faust and is supported by the Office of the President and donations from alumni and others. CCSF is managed by the Office of the Vice Provost for Climate and Sustainability at Harvard.

This year’s winning projects:

Dryscreen: Creating Human-Centered Comfort in Buildings

 Joanna Aizenberg, Amy Smith Berylson Professor of Materials Science and Professor of Chemistry and Chemical Biology, Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS); Jonathan Grinham, Assistant Professor of Architecture, Harvard Graduate School of Design (GSD) and Harvard Center for Green Buildings and Cities

This project seeks to reduce the energy consumption and the use of harmful refrigerants in air conditioning by using a technology that decouples air cooling from humidity reduction — two functions performed simultaneously by conventional air conditioners in buildings. Doing so can lead to significant energy savings by separately tuning dehumidification and cooling to reflect ambient conditions. The new technology — Dryscreen — is a water-selective membrane vacuum system that has been designed and fabricated with support from the U.S. Department of Energy. Funding through the CCSF will enable the on-campus field testing of the Dryscreen prototype, using the Center for Green Buildings and Cities’ HouseZero LiveLab.

Realizing Low-Cost Direct Air CO₂ Capture Using Oxygen Resistant Proton-Coupled Electrochemistry

Michael Aziz, Gene and Tracy Sykes Professor of Materials and Energy Technologies, SEAS

Aziz and his team are developing a new way to remove carbon dioxide from the air through the use of electrochemistry. So-called direct air carbon dioxide (DAC) capture represents a crucial solution if the world is to limit global warming to within to 2° Celsius. But conventional DAC technologies are both energy intensive and expensive. Using electrochemistry of water-soluble organic molecules allows for a scalable, low energy cost, and safe way to capture carbon. In the current electrochemical system developed in the PI’s lab, however, atmospheric oxygen (O₂) renders the system inoperable. Funding will help the researchers develop a new electrochemical cell structure, with distinct compartments for electrochemistry and carbon capture, which would make the carbon capture process resistant to oxygen or any harmful component in the inlet gas.

Using Satellite Observations of Atmospheric Methane to Support Effective Global Climate Policy

Daniel Jacob, Vasco McCoy Family Professor of Atmospheric Chemistry and Environmental Engineering, SEAS, Faculty of Arts and Sciences (FAS) Department of Earth and Planetary Sciences; Robert Stavins, A. J. Meyer Professor of Energy & Economic Development, Harvard Kennedy School (HKS)

Methane is a potent greenhouse gas. Decreasing methane emissions represents a significant way to mitigate climate change and is an essential element of achieving the objectives of the Paris Agreement. However, the national accounting of methane can be inaccurate because of the variety of methane sources and the complexity associated with them. Using high-resolution satellite observations, this project will deploy a new, publicly accessible system for quantifying methane emissions from top-emitting countries. The project will engage stakeholders to validate and to improve national emissions inventories in support of the Paris Agreement and the Global Methane Pledge.

Building Data Infrastructure to Understand Climate Change Migration

Tarun Khanna, Jorge Paulo Lemann Professor, Harvard Business School (HBS), Faculty Director of The Lakshmi Mittal and Family South Asia Institute; Satchit Balsari, Assistant Professor in Emergency Medicine, Harvard Medical School (HMS) and Beth Israel Deaconess Medical Center; Caroline Buckee, Professor of Epidemiology, Harvard T.H. Chan School of Public Health; Jennifer Leaning, Senior Research Fellow, FXB Center for Health and Human Rights; Professor of the Practice, Harvard T.H Chan School of Public Health; Rahul Mehrotra, John T. Dunlop Professor in Housing and Urbanization, GSD; Neha B. Joseph, Research Fellow, The Lakshmi Mittal and Family South Asia Institute at Harvard

The aim of this project is to develop a transformative, open-access climate and population health data-monitoring ecosystem in South Asia. More than 700 million people in South Asia have been affected by at least one climate-related disaster in the last decade. Yet, there is only a vague understanding of how climate change affects who moves, when, and why; how such distress migration in South Asia affects host communities; and the impact that large population fluxes have on access to food, shelter, jobs, and population health. Understanding these forces requires micro data on individual mobility, health, and related measures. Funding will allow the researchers to develop a prototype open-source data repository of traditional and novel data streams from public and private datasets, and invite interdisciplinary teams of stakeholders — including communities, scientists, and policymakers — to explore and apply the datasets to advance adaptation measures.

Climate Change and Mental Health in Madagascar: A Health Systems Ecological Approach

Karestan Koenen, Professor of Psychiatric Epidemiology, Harvard T.H. Chan School of Public Health; Christopher Golden, Assistant Professor of Nutrition and Planetary Health, Harvard T.H. Chan School of Public Health

Research will focus on developing and piloting the use of mental health assessment instruments for identifying and measuring the impact of priority mental health and psychosocial problems associated with climate change. The project will center around the population of Malagasy, Madagascar, an island nation experiencing a famine attributed to climate change. The adverse effects of climate change on human physical and mental health remains largely understudied. Of the few empirical studies that exist, most are limited almost exclusively to high-income countries, and none has taken place in Madagascar. In developing reliable mental health assessment instruments, validated in the Malagasy context, the project promises to provide proof of concept that could be used in other settings facing climate-driven crises.

Mather as a Living Lab

L Mahadevan, de Valpine Professor of Applied Mathematics, Physics, Organismic and Evolutionary Biology; Faculty Dean of Mather House; Vijay Reddi, Associate Professor, SEAS; Anas Chalah, Assistant Dean for Teaching and Learning, Active Learning Labs, SEAS

The goal of this project is to help residents of Mather, one of Harvard University’s undergraduate student houses, to quantify and deliberate on the consequences of their consumption in the broader context of climate and environmental change. Using miniature sensors, students will measure the use of energy and water, food consumption and waste, along with indoor and outdoor variations in the ambient conditions, such as temperature, carbon dioxide and humidity through the seasons and semesters. The anonymized data will be analyzed using statistical tools combined with mathematical models to ultimately stimulate debate about policy changes and inform choices and decisions associated with sustainable approaches to community living and learning.

Barocaloric Materials for Sustainable Cooling Technologies

Jarad A. Mason, Assistant Professor of Chemistry and Chemical Biology, FAS; Joost J. Vlassak, Abbott and James Lawrence Professor of Materials Engineering, SEAS

This project is aimed at advancing the basic science of solid-state barocaloric cooling, a technology that promises to reduce energy consumption and the use of harmful refrigerants in cooling buildings and removing heat from data centers. Cooling accounts for more than 20 percent of the world’s electricity consumption, and, therefore, better understanding barocaloric materials could ultimately yield a significant climate benefit. Funding will support a research collaboration between the Department of Chemistry and Chemical Biology and the School of Engineering and Applied Sciences, which will allow for the researchers to bridge the gap between materials discovery and prototype development, with a particular focus on discovering novel materials and mechanisms critical to realizing solid-state cooling at scale.

Belief Formation and Adaptation to Climate Change

Dev Patel, Graduate Student in Economics, FAS

Climate change poses an existential threat for hundreds of millions of people across developing countries. In the absence of severe mitigation measures by the rest of the world, these households must take steps themselves to address the dramatic shifts already occurring in their local environments. The project asks how households learn about and adapt to climate change. This research dives into the underlying mental models guiding farmers’ decisions in agricultural production to understand how the relatively slow, incremental environmental changes characteristic of climate change can often fail to prompt appropriate reactions. The focus is then on the critical issue of rising soil salinity in rural Bangladesh, which drastically reduces rice yields under status quo production. Combining new satellite-based measures of flooding with experimental variation in information and technology access, the research team estimates how households react to the changes in salinity brought on by flooding events and how these beliefs shape climate change adaptation.

Characterizing Wildfire Smoke Health Impacts and Identifying Vulnerable Populations: A 10-year Study of the Western U.S.

Rachel Nethery, Assistant Professor of Biostatistics, Harvard T.H. Chan School of Public Health

With wildfire severity in the Western U.S. projected to continue increasing over the coming decades, wildfire smoke exposure presents an escalating threat to human health. Implementing resilience building programs in high-risk communities is one of the most effective tactics for minimizing climate change-related health burdens. The aim of this project is to study past wildfire smoke exposure in order to inform resilience-building efforts. Specifically, the project will examine the impacts of exposure on more than 100 health outcomes over a 10-year period to identify drivers of vulnerability and create county-level wildfire smoke risk profiles.

Digital Interactivity and Bioclimatic Comfort: Design Strategies for Extreme Heat Adaptation

Belinda Tato, Associate Professor in Practice of Landscape Architecture, GSD

Extreme heat is a critical climate challenge threatening human health, causing economic stress, and driving greenhouse gas emissions. Higher temperatures and longer and more intense heat waves will continue to impact cities. The organization and structure of the urban built environment is critical in responding to this threat as heat islands in cities intensify negative effects of extreme heat. This project will focus on developing an interactive bioclimatic comfort application and data collection platform for community participation and empowerment with an off-grid temporary installation exhibit. Beyond the typical data focused optimization that is common in a “smart cities” approach, this project focuses on utilizing sensors to allow individuals to experience a new level of interactivity and access to real time bioclimatic information. The project acts on two levels: 1) A temporary physical installation on campus that will serve as a living laboratory and testing ground for sensors and climate-sensitive urban design elements 2) Development of a bioclimatic data collection and sharing platform for community participation in climate-sensitive urban design projects.

Not long ago, the idea of photographing a black hole was as quixotic as photographing a unicorn. Now, scientists have not one but two images of two different supermassive black holes — and they both look as magical as flaming doughnuts.

“I remember when black holes were purely theoretical,” said Ellen Stofan, under secretary for science and research at the Smithsonian and former chief scientist at NASA, during a post-reveal panel on Thursday. Moderated by Stofan, the conversation brought together four members of the Harvard-led team of scientists that in 2019 revealed to the world the first image of a black hole — a behemoth dubbed M87 after its galaxy, Messier 87. Hours before the panel discussion, the team shared a second image — a close-up of Sagittarius A-star (or Sgr A*), the black hole snacking on light and cosmic debris at the center of our very own Milky Way galaxy.

“There can be no doubt now that we’ve seen black holes for the first time,” said Shep Doeleman, founding director of the Event Horizon Telescope collaboration, an international team of more than 100 scientists led by the Center for Astrophysics | Harvard & Smithsonian. “It’s the dawn of a new era in astronomy.”

In this new era, scientists could prove — or disprove — Einstein’s long-held theories of gravity and relativity, find Earth 2.0, or discover a wormhole to another universe. (The latter won’t be so hard for Doeleman, who said, cheekily, that he comes from another universe.)

Photographing a black hole is even harder than it sounds. To capture images of objects so far away, “You’d need a telescope the size of the Earth,” said Kari Haworth, an engineer and the chief technology officer for the EHT. “We didn’t do that because that’s impossible, and it would ruin a lot of people’s views,” she said.

Instead, the researchers turned the Earth into a giant telescope by coordinating individual machines positioned in Hawaii, Chile, Mexico, Spain, France, and other locations. Each team had to snap a photo at the exact same time. Because black holes gobble up everything that gets too close — even light — they cannot be seen. But their massive gravity pulls in and compresses nearby light and debris, creating a spinning gaseous eddy that’s teeming with energy. “Turning falling matter into luminosity,” was how Doeleman put it.

That luminosity can be seen and photographed. Some of the light that gets pulled into the black hole’s gravitational field makes a U-turn or a loop-de-loop before escaping and shooting off in the direction of Earth, carrying an image of where it came from. The EHT team’s final photograph is a composite of pictures taken by each telescope and stacked one on top of each other. To combine all that data — which is light, captured at a very precise moment in time — the team needed to achieve one more strange feat. Each telescope team froze their light, stored it on hard disks (it’s too massive to send across the internet), and flew it, by airplane, to one central location.

An international team of astronomers led by scientists at the Center for Astrophysics | Harvard & Smithsonian who produced the first direct image of a black hole three years ago have now produced a portrait of a second, this time a much-anticipated glimpse of one at the heart of the Milky Way.

The new picture was captured by researchers from the Event Horizon Telescope (EHT) Collaboration who unveiled their first image in 2019. The group targeted both black holes at the outset but focused their attention on one at a time, owing to a difference in the complexity of the two projects.

“This is our supermassive black hole,” said Peter Galison, director of Harvard’s Black Hole Initiative, a member of the EHT team, and the Joseph Pellegrino University Professor in the History of Science and Physics. “This is at the center of where we live.”

This is a coming-of-age story — involving your brain.

That’s how W.A. Harris opened his virtual Harvard Science Book Talk on Monday. The talk, presented by the University’s Division of Science, Cabot Science Library, and Harvard Book Store, brought Harris together with old friend Joshua Sanes, the Jeff C. Tarr Professor of Molecular and Cellular Biology at Harvard and director of the Center for Brain Science. The neuroscientists discussed Harris’ new book, “Zero to Birth: How the Human Brain Is Built,” which elucidates how one cell develops into the complex operational centers that not only make us human, but also individuals, with entirely unique traits, behaviors, and, yes, malfunctions.

Harris presented the relevant evolutionary history, crediting the many pioneering neuroscientists who uncovered how the “Adams and Eves of our brains” were born. One, Santiago Ramón y Cajal, created the first drawings of intricate neuron trees, which are still widely studied. Another, Conrad Hal Waddington, likened the development of different neuron types to a ball rolling down an uneven hill.

“The neural stem cells are a bit unpredictable,” Harris explained. “We can’t predict exactly where they’ll land, but they will create the right amount of neuron types.”

Other 20th-century neuroscientists, including Roger Sperry, took a more hands-on approach, Harris said. Sperry removed, flipped, and reinserted a frog’s eye, leaving the amphibian with an upside-down world. And while the neurons adapted, rewiring to restore vision, the eye was not so nimble. To look up, the frog looked down — for the rest of its life.

Moving from amphibian to mammal, David Hubel and Torsten Wiesel deprived a kitten of vision in one eye to see how the limitation might affect a growing brain. When they restored vision after the kitten reached 3 months old, the duo discovered that the animal never gained sight in the closed eye.

Soyeon Yi beat out 36,000 contestants to become South Korea’s first — and so far only — astronaut to fly into space. In 2008, she lifted off with a crew of Russia cosmonauts on a nine-day mission to the International Space Station (ISS), where she conducted 18 experiments and medical tests for the Korea Aerospace Research Institute.

Yi, who has a doctorate in biosystems, recently attended Space Week, an event hosted by the Space Consortium at Harvard & MIT and started by Alissa Haddaji, a lecturer in space law, policy, and ethics. This year’s event is dedicated to sustainability in space, including mission debris and national security.

Yi spoke with the Gazette about what the war in Ukraine could mean for American and Russian astronauts at the ISS. After the interview the head of Russia’s space agency announced the nation would pull out of the ISS due to economic sanctions over the war but did not set a date for the action. The interview was edited for clarity and length.

Q&A

Soyeon Yi

GAZETTE: There’s been growing tension between Russia and the West, especially regarding the International Space Station. How important is the war in Ukraine to the continuation of the ISS?

YI: The first idea that comes to my mind is how awkward the relationship is in the space station between Russian and U.S. astronauts because they cannot go anywhere. Maybe they might not have a strong opinion on the war or maybe they would love to avoid talking about that also, because they are not the person who can control or change something. Maybe some of them don’t agree with their own government. If I were either a Russian cosmonaut or American astronaut, I might do my best to not ruin our relationship as a friend or “comrade” because of this uncomfortable situation.

GAZETTE: You were at the International Space Station for about nine days. Could you provide some insight of the relationships between American and Russian astronauts?

YI: All those astronauts are selected from their countries after careful and sincere consideration. They are representatives of their own countries and not as politicians, but as heroes. We know what causes diplomatic problems with huge consequences, so we always do our best not to make a conflict among us. We can hate some country, but we know it doesn’t mean we hate every single citizen of that country. As astronauts, we are always doing our best to distinguish between those two. That’s the kind of essence of the collaboration at the ISS.

GAZETTE: As South Korea’s first and only astronaut, how important is it for you to be an inspiration for other Koreans who want to reach space?

YI: When I came to the U.S. for the very first time as an exchange student in 2003, it was a huge culture shock. A lot of my friends and colleagues, especially in the STEM field, were either “Star Trek” fans or “Star Wars” fans. I didn’t have any resources to think about sci-fi or STEM. When I came here, I felt a little bit jealous, because many friends of mine in the U.S. during their childhood daydreamed about space, watched crazy sci-fi movies, and dreamed about being an astronaut. During my childhood, I didn’t even know the vocabulary attributed to all that. Those movies and then real-life astronauts and space activities work together to inspire kids. Hopefully, I can inspire them to look up to the night sky and to dream about their future in space.

GAZETTE: Why is it so important to you to help nurture the next generation of women in STEM?

YI:  When I looked down to the Earth from space, it made me wonder: “Why on earth I was born in Korea?” There’s no specific reason, and there’s no specific effort I made to be born in that country and in that timeline. I was the first kid in my family to go to college full time, and until I went to the Space Station, I thought life was unfair because some kids had a much better situation than me. But once I got on the ISS, I realized that maybe someone feels jealous of me. Because I was lucky to be born in Korea. I think it’s really important to consider our next generation’s future. It’s in our hands; it’s our responsibility. I’m so honored to be the first, but I don’t want to be the last.

GAZETTE: What are some important conversations we should be having about space sustainability?

YI: ISS is the best test site to practice sustainability and a great example of how we can make sustainability work on Earth. Sometimes sustainability happens not because we really want to do it, but because of the situation. If you don’t have any clean water, you might be forced to recycle your urine. We definitely don’t want to make a situation like that on our Earth; we should be prepared before. We should preserve everything before we run out.

Scientists have long understood that plate tectonics, the drift of separate, rigid plates that make up the Earth’s crust, formed continents and mountains and was crucial to the evolution of the planet’s surface from one of molten lava and rock to an environment hospitable to life.

What’s been less clear is when it began.

A team of Harvard-led researchers have analyzed some very rare, ancient, and nearly indestructible crystals the size of small grains of sand called zircons for chemical clues about the onset of plate tectonics. The study, published in AGU Advances, suggests that 3.8 billion years ago there was a major transition in the geochemistry of these zircons that make them look much more like the zircons that are formed today in the red-hot environments where plate tectonics happen.

“Prior to 3.8 billion years ago, the planet doesn’t seem to be as dynamic,” said Nadja Drabon, a Harvard assistant professor of Earth and Planetary Sciences and the paper’s first author. “Today, there’s lots of crust that gets constantly destroyed in what are called subduction zones and new crust is created. Many [previous] zircons showed that back then once the early crust formed, it lived for a really long time — about 600 million years in this case. While there was some internal reworking, we never created new granitic crust. … Then 3.8 billion years ago, everything changes.”

Think of zircons as tiny time capsules that retain chemical clues of the Earth’s first 500 million years. Some were formed in the magma of the planet more than 4 billion years ago when the Earth, geologically speaking, was still in its infancy. It makes them the oldest known materials on Earth. Their secrets can be understood by zapping them with lasers, which is what the researchers did for their analysis.

The scientists saw that 3.8 billion years ago as the planet was cooling, a lot of new crust was suddenly being formed and that the geochemical signatures of zircons began to look like those generated in subduction zones, the places where two colliding tectonic plates meet and one slides under the other and into the mantle where it is recycled (code word for burned to a crisp).

The researchers say it’s not clear whether there were subduction zones 3.8 billion years ago, but what is known is that the new crust being formed was likely a result of some type of plate tectonics.

The study adds to growing research that tectonic movement occurred relatively early in Earth’s 4.5 billion-year history. It offers hints about how the planet became habitable and the conditions under which the earliest forms of life developed.

Today, the Earth’s outer shell consists of about 15 shifting blocks of crust, which hold the planet’s continents and oceans. The process was key to the evolution of life and the development of the planet because the process exposed new rocks to the atmosphere, which led to chemical reactions that stabilized Earth’s surface temperature over billions of years.

Evidence of when the change began is hard to come by because it’s so scarce. Only 5 percent of all rocks on Earth are older than 2.5 billion years old, and no rock is older than about 4 billion years.

This is where the zircons come in.

The team of researchers, which included geologists from Stanford and Louisiana State University, gathered 3,936 new zircons from a 2017 expedition in South Africa. Thirty-three of them were at least 4 billion years old. It was quite the haul, because zircons from that time period are difficult to find because of their size.

Researchers essentially have to get lucky after grinding down rocks they’ve collected into sand and separating the resulting finds. The South Africa zircons ranged from 4.1 billion to 3.3 billion years old. The team looked at three different geochemical features of the zircon crystals they found: the hafnium isotope, oxygen isotope, and trace element compositions. Each gave them a different piece of the puzzle.

For instance, the hafnium isotope offered hints about the formation and evolution of the Earth’s crust; the oxygen isotopes about whether there were oceans; and the trace elements about the composition of the crust. The data suggested that the rate of crust formation started picking up almost 4 billion years ago.

The researchers also looked at data from other studies on ancient zircons that have been found around the world to see whether there was evidence of a similar shift. They found it in the data on hafnium isotopes.

“All of them show this shift between 3.8 and 3.6 billion years ago,” Drabon said.

Drabon says there wasn’t much data on the other two geochemical features, and she hopes to focus on those next, including looking at when oceans started forming.

There’s so much to do, Drabon said. “I don’t even know where to start.”

Peter B. Kilian remembers leaving Logan Airport with Brittany Walsh in mid-February and having a single thought as he looked left and right at other drivers: “They don’t know our car is filled with piranhas.”

Known for their fearsome teeth and bloody B-movie feasts, the fish are illegal to own in Massachusetts. Kilian wasn’t aware of that when he decided that studying their predation behavior would be a “cool” project for the Bellono Lab, which investigates how molecular and cellular adaptations lead to unique behavioral functions in organisms.

But he didn’t let it stop him. And before too long, with the necessary local approvals and a piranha permit for the lab in hand, he and Walsh, a fellow research technician in the lab, found themselves scrambling on short notice to meet a freight plane at Logan. After they loaded multiple boxes containing 20 caribe piranha into Walsh’s Honda CR-V, it was time to plan the actual science.

Researchers will study the temperaments of two species native to the Amazon — caribe and red-bellied piranha, which the lab plans to add later this year. The group want to determine if one species is more aggressive than the other and if they can parse out this behavioral difference by looking at blood, hormone levels, and gene expression.

The work is just starting, but already, Kilian, who’s leading the research, can tell you that the fish aren’t as terrifying as their reputation.

“They’re not apex predators,” he said. “They’re not regularly hunting in packs taking down healthy large animals. They’re very skittish when we have to put our hands into the tanks. In terms of where they lie in the wild, they’re relatively low on the totem pole. They’re prey species.”

As far as memos go, this one may go down as one of the most consequential of Amir Siraj’s career.

U.S. Space Command released a communication last month that confirmed earlier findings from Siraj ’22, a Harvard astrophysics concentrator, and Avi Loeb, Frank B. Baird Jr. Professor of Science, that a meteor from another solar system hit Earth in 2014.

“I’m not sure I’ve heard of many other scientific discoveries that have had to be confirmed by the U.S. Department of Defense, but that’s how this unusual story played out,” Siraj said.

The discovery predates Oumuamua, the oblong space rock that was until now considered the first-known interstellar meteor by three years.

Known as CNEOS 2014-01-08, the meteor measured only 1.5 feet wide and was hurtling toward Earth at about 45 kilometers per second, well over 100,000 mph, which is a clue that it’s not from this solar system. The meteor ignited into a fireball on Jan. 8, 2014, when it entered Earth’s atmosphere off the coast of Papua, New Guinea, with the energy equivalent to about 110 metric tons of TNT. It may have sprinkled fragments into the Pacific Ocean. CNEOS 2014-01-08 is now the third interstellar object that has been confirmed, along with Oumuamua and the comet 2I/Borisov.

The 2014 meteor was originally identified as an interstellar object by Siraj in 2019 when he and Loeb were studying Oumuamua. The pair posted their findings as a preprint and submitted their results to an astronomy journal, but the paper was not accepted for publication because they used data from a NASA database that used classified information that could not be verified.

The memo was signed by U.S. Space Force Lt. Gen. John Shaw and sent out in a tweet. It provides official verification of their findings. It states that Joel Mozer, chief scientist of Space Operations Command, reviewed the Siraj and Loeb’s analysis and confirmed the findings to NASA.

Siraj found the meteor as he combed through a database of fireballs kept by NASA’s Center for Near Earth Object Studies (CNEOS) on Loeb’s suggestion. He saw something that immediately grabbed his attention.

“It’s not that meteors of this size are unusual,” he said. “We actually get a couple dozen each year. But what was unusual about this meteor was that this object had a very high impact speed and the unusual direction at which it encountered our planet.”

At Earth’s distance from the sun, any object moving faster than about 42 kilometers per second is too fast to be captured by the sun’s gravity, Siraj explained. Anything traveling over this speed limit likely comes from interstellar space because the gravity from our sun acts as a celestial speed bump to stop more local meteors from gaining that kind of speed. The 2014 meteor must have been ejected from another neighboring star and sent our way if it was traveling with such velocity.

Siraj and Loeb ran many calculations and found that the meteor had caught up to Earth from behind its orbit before entering the atmosphere and likely had a speed closer to 60 kilometers per second relative to the average velocity of nearby stars, or about 134,000 miles per hour at some point.

The problem that snarled the paper’s acceptance at peer review was that they couldn’t directly confirm the margin of error on the fireball’s velocity because the CNEOS database doesn’t have the information needed to confirm it.

The snag started a three-year process as Siraj and Loeb worked through a bureaucratic logjam to receive government confirmation on their findings, working with scientists and officials at NASA, Los Alamos National Laboratory, and other offices. They eventually connected with Matt Daniels, assistant director for space security at the White House’s Office of Science and Technology Policy, to get an analysis from Shaw and Mozer.

Siraj said the hard part is over, but there’s a lot more to do now, like getting the paper published in a peer-reviewed journal and doing follow-ups. For instance, the researchers are currently looking into an ocean expedition to search the ocean floor off the coast of Papua New Guinea for pieces of the 2014 meteor.

“If we were able to recover any fragments from this meteor, it would represent the first time that humanity has ever touched a rock from beyond our solar system,” Siraj said.

Building a plane while flying it isn’t typically a goal for most, but for a team of Harvard-led physicists that general idea might be a key to finally building large-scale quantum computers.

Described in a new paper in Nature, the research team, which includes collaborators from QuEra Computing, MIT, and the University of Innsbruck, developed a new approach for processing quantum information that allows them to dynamically change the layout of atoms in their system by moving and connecting them with each other in the midst of computation.

This ability to shuffle the qubits (the fundamental building blocks of quantum computers and the source of their massive processing power) during the computation process while preserving their quantum state dramatically expands processing capabilities and allows for self-correction of errors. Clearing this hurdle marks a major step toward building large-scale machines that leverage the bizarre characteristics of quantum mechanics and promise to bring about real-world breakthroughs in material science, communication technologies, finance, and many other fields.

“The reason why building large-scale quantum computers is hard is because eventually you have errors,” said Mikhail Lukin, the George Vasmer Leverett Professor of Physics, co-director of the Harvard Quantum Initiative, and one of the senior authors of the study. “One way to reduce these errors is to just make your qubits better and better, but another more systematic and ultimately practical way is to do something which is called quantum error correction. That means that even if you have some errors, you can correct these errors during your computation process with redundancy.”