miércoles, 30 de noviembre de 2016

Steppe by steppe

Anthropologists often work best with one foot inside a society and one foot outside it: They are steeped in a culture, but detached enough to analyze it. For Manduhai Buyandelger, this vantage point is part of life itself. She is a Mongolian anthropologist at MIT, whose work illuminates her home society and very much derives from her own insider-outsider relationship to it.

Consider: In a nation whose self-image glorifies nomads on the rural steppes, Buyandelger is a city dweller raised in downtown Ulan Bator, the capital. Growing up in Mongolia during the Cold War, she attended Russian schools, giving her an uncommon perspective on both her own nation and the Soviet regime that was controlling it. Indeed, studying politics, propaganda, and the country’s shift to a post-Soviet society has been essential to her research. And for all of Buyandelger’s deep roots in Mongolia, she has lived in the U.S. for years, returning home periodically for intensive research.

“All these things gave me ways of thinking about diversity and cultural differences,” Buyandelger says. “There were hidden parts of life I found intriguing, such as religion, which people practiced every day in secret. I lived with those contradictions from very early on.”

Her work reflects this. Buyandelger’s first book, “Tragic Spirits,” about the surprising return of shamanism to post-Soviet Mongolia, concluded the return of older religious practices was a way for Mongolians to re-establish their national identity. Her current book project examines women in Mongolian politics, as they establish themselves in the rapidly changing, free-market culture that has altered their social roles.

Or, as Buyandelger puts it, she tries to make sense of the “change, discord, propaganda, and inconsistencies in everyday life,” having experienced plenty of these things herself.  

“Socialism collapsed, right in front of my eyes”

Growing up in Ulan Bator, Buyandelger found herself attending rigorous Russian schools that were built mainly for the children of Soviet expats; the U.S.S.R. controlled Mongolia as a satellite country during the Cold War.

“I think that going to a Russian school gave me some dual background and some way of comparing things, and being able to associate myself with not only one culture, but multiple cultures,” Buyandelger recounts.

In the meantime, she also witnessed some of the splits within Mongolian culture. For instance, her mother’s parents recoiled from living in the family’s apartment in the middle of Ulan Bator. Instead, they remained in the outskirts of the city, a place where “they had to bring in their own water and firewood. … They didn’t care about about modern amenities. For them it was important to have access to the outdoors and have their own little plot of land.” As Buyandelger noticed, some Mongolians retained private traditions and older values even given an opportunity for change.

By the time she started college, Buyandelger wanted to become a fiction writer. But then events overtook things: The Soviet Union and its whole socialist system starting breaking up, and she wanted to analyze it.

“Right when I entered college, in 1989, socialism collapsed, right in front of my eyes,” Buyandelger says. “It was the time of the democratic movement, the demonstrations. My walk from my home to the university went through the main square, and that’s where everything was taking place. … I really wanted to write about those transformations that took place: What did they mean for a country that was so consistently and neatly packaged as socialist, as it burst into complete chaos and embraced change so eagerly, and tried to build everything anew?”

Buyandelger’s career path took shape when she received a Fulbright scholarship to study in the U.S. This allowed her to start graduate school at Harvard University, where scholars such as Nicola di Cosmo and Michael Herzfeld took note of her remarkable linguistic range — Buyandelger could then do research in traditional and contemporary Mongolian, Russian, English, and ancient Tibetan, and read French — and encouraged her to continue.

After receiving her PhD from Harvard in 2004, Buyandelger spent three years in the Harvard Society of Fellows and then joined the MIT faculty in 2008. She is the Class of 1956 Career Development Professor and was awarded tenure in 2016.

“There’s no easy solution”

Both of Buyandelger’s books lie at the junction of culture and the market. In “Tragic Spirits,” which she researched mostly in remote rural areas, the end of communism led to a new breed of shamans — storefront entrepreneurs offering their services as seers. This helped them make money and survive in the new economy, and in the process, helped people re-assert a form of Mongolian identity after the Soviets shuttered religious expression.

Her ongoing book project, titled “A Thousand Steps to Parliament: Elections, Women’s Participation, and Gendered Transformation in Postsocialist Mongolia,” similarly finds unanticipated developments after the end of socialism. The book is about female parliamentary candidates running for office in increasingly commercialized election campaigns. In this case, while Mongolians enjoy far more freedom than they once had, commercial culture has also changed Mongolia’s gender dynamics, Buyandelger thinks, in a way that affects politics.  

“During socialism, the state purposefully, with the help of women’s organizations, propagated images of working women and women heroes and professionals,” Buyandleger observes. “So there were not sexualized images of women. They were presented as model citizens, in medicine or as teachers, or women workers laying bricks. That disappeared. With the commercialization [of the market economy], the images of women switched, from idealized workers to [those of] beauty pageants, trophy wives, entertainment. That’s the transformation of state-sanctioned gender ideas to market-dominated ones.”

Women face multiple new challenges as a result, from finding political funding in a campaign-intensive culture, to presenting themselves in ways that are professional yet nonthreatening, Buyandelger believes.

“The double bind is they have to meet the requirements of [a] sexism that allocates feminine and masculine features in a very distinct way,” Buyandelger says. “They have to be feminine enough to be accepted by gender norms … but if they are [too] feminine, that prescribes them into a lower stratum.” As she sees it, some women in politics have made strides by presenting themselves as being professionally successful in ways that register well with voters, but others have struggled. Many female candidates, in Buyandelger’s view, present themselves as being “intellectful” — a word from the taken from the Mongolian term “oyunlag,” which translates as “with intellect.”

So as with religion, in politics there are problematic social fractures and tensions that have developed, almost inevitably, as an old culture has collided with radical political and economic changes. But these struggles are exactly what makes Buyandelger want to study her home country in unique detail.

“That’s what the country is struggling with, and there’s no easy solution,” Buyandelger says — partly as an insider, partly as an outsider, and always as an observer.



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Commercializing integrated photonics

Leaders from industry, state government, and higher education focused on the best ways to create a robust, integrated-photonics manufacturing corridor along Interstate 90 from Boston to Rochester, New York, on the final day of the American Institute for Manufacturing Integrated Photonics (AIM Photonics) fall meeting held at MIT Oct. 31 through Nov. 2.

“The meeting’s presenters showed that Massachusetts has strong capability in integrated photonics today, and that community colleges, manufacturing extension partnership programs, and small and medium enterprises can provide robust support to achieve the I-90 corridor for excellence in integrated photonics,” says Julie Diop, program manager for the AIM Photonics Academy at MIT. Integrated photonic systems use light pulses (photons) as well as electrical signals to process and communicate data within the same integrated circuit.

The AIM Photonics Academy, a part of AIM Photonics, has received $800,000 in state funding from the Massachusetts Executive Office of Housing and Economic Development for equipment to prototype integrated photonic devices on the MIT campus. “AIM Academy is creating a facility where professors, students, and industry can meet, design projects, and roll those projects into the curriculum. It’s one way to help foster the I-90 integrated photonics corridor,” Diop says.

Drawing about 145 participants, the first two days of the meeting focused on developing a technical roadmap for chip-making and photonic sensors, connectors, assembly, testing and systems packaging, as well as design automation. This Integrated Photonic Systems Roadmap, directed by Robert C. Pfahl Jr., will eventually align the integrated photonics supply chain for industry success.

The AIM Photonics fall meeting was a collaborative effort of AIM Photonics Academy, the Microphotonics Center at MIT, and iNEMI. About two dozen attendees joined the Massachusetts Integrated Photonics Manufacturing Supply Chain meeting on the final day. The meeting concluded with the first meeting of the AIM Academy Advisory Council.



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Wiesner Gallery relaunched

It’s a hard slog in the studio, battling with materials, suppressing self-doubts, cultivating a vision, destroying false starts, and ultimately creating something new. To emerging artists, seeing work outside the confines of one's studios and in a gallery setting is no mere frivolity; it is formative. Exhibitions change relationships to both one's work and audience.

MIT students have a space dedicated to this invaluable function: the Jerome B. Wiesner Student Art Gallery. The Wiesner Gallery was established by a gift from the Class of 1983 and dedicated to Jerome B. Wiesner, MIT president from 1971 to 1980, who championed the arts as an essential part of MIT education and campus life. According to Wiesner, “Taken together, the arts, science and technology form a triple anvil on which to forge a new kind of apprenticeship for a complex world — an education in which the search for beauty is made real enough to take its place beside the university’s ancient mission, the search for truth.”

The Wiesner Gallery, located on the second floor in the Student Center (Building W20), exclusively exhibits the work of student artists, including those enrolled in classes at the Student Art Association (SAA) and those supported by the grants program of the Council for the Arts at MIT (CAMIT). The space also hosts the annual Harold and Arlene Schnitzer Prize exhibition and shows works by numerous student groups and initiatives, such as the MIT Origami club and the Trashion Show. It was designed to be flexible enough to accommodate all artistic modes of expression, with adaptable walls and lights and a raised stage suitable for performances.

Over the years there have been several attempts to revitalize the Wiesner Gallery. Now, an extensive renovation funded through the generous support of the Schnitzer Family Foundation, sponsors of the Eugene McDermott Award in the Arts at MIT gala, and the office of associate provosts Karen Gleason and Philip S. Khoury will upgrade the space to meet changing needs of MIT student artists.

The space has been reconfigured to increase the footprint of the gallery by 25 percent and to expand the usable wallspace. Four high-definition monitors, an extensive new hanging system for two-dimensional work, and an integrated shelving system for displaying three-dimensional work have been added. A new glass wall maintains openness while allowing sound to be controlled for audio and video works and performances. Other improvements include new hardwood floors and modular furniture. Beyond being an exhibition venue, the renovated Wiesner Gallery will accommodate a broad range of programs and events and become a hub for student arts programs, including the SAA, the START studio (a 24-hour makerspace for arts focused entrepreneurial projects) and the Arts Scholars.     

Hyun-A Park ’83 recalls how the idea to create a gallery as the 1983 senior class gift came about: “There was no formal space for student exhibition opportunities. We had the notion that if the space were there in a visible location, it would create the energy to coalesce the arts for the students. We were being proactive about it, rather than meeting an existing demand.” When she approached Paul and Priscilla Gray, then-MIT president and his wife and co-founder of the MIT Public Service Center, about the prospect of creating a student exhibition venue, Park suggested dedicating it to former President Jerome Wiesner. “Jerry Wiesner had always been such an advocate for the arts at MIT, and pretty much created the Council for the Arts, and was really the force who brought to the Institute the contemporary art features that we still enjoy today.”

As an urban planning student, Park had taken classes in the School of Architecture and Planning in glass blowing and life drawing, had worked at the Hayden Gallery, and in her senior year had become involved with the Council for the Arts at MIT. Now a member of the council, she looks forward to being actively involved in the gallery’s relaunch: “I hope the grants programs and the council can be an integral part of the success of the gallery in the future.”

The inaugural exhibition, on view now through Dec. 31 in the newly renovated space, features work from 20 Arts Scholars that were made at MIT — including video, sound art, photography, painting, drawing, and performance. The renovation is evidence of the value placed on student art work at MIT, and the students whose work will be on view at the Wiesner Gallery’s grand reopening represent the many vibrant student communities on campus — from researchers in the MIT Media Lab and the School of Engineering to residents in Senior House to varsity athletes.



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School of Architecture and Planning receives $1.5 million grant from Mellon Foundation

The Andrew W. Mellon Foundation has awarded MIT’s School of Architecture and Planning (SA+P) a $1.5 million grant in continued support for the Global Architectural History Teaching Collaborative (GAHTC).

Aimed at expanding the coverage of global history in architecture education, the collaborative includes scholars who are producing classroom materials for those teaching architectural history at the undergraduate or survey level. In 2013, the foundation made an initial grant of $1 million to SA+P toward the creation of the collaborative.

The new grant supplements the original funding, extending the activities of GAHTC for another three years. The goal of the collaborative is not only to promote the development of survey course material in the history of architecture, but also to advance teacher-to-teacher conversations to support pedagogy with a global perspective.

Teaching a survey of architecture’s history featuring material from around the globe requires a great deal of preparation and learning on the part of the teacher. But because there is no specialized preparation for teaching such courses or funding for course development, the survey course is under increasing threat and fewer schools of architecture now offer it.

GAHTC is designed as a rapid-response mechanism to deal with this problem, given that the survey course is an important tool in building global awareness.

The collaborative holds annual teaching conferences and award grants of various types to groups of faculty to create high-quality teaching material that will be made available to teachers and professors worldwide and free of cost through a website, beginning in early 2017.

MIT Professor Mark Jarzombek and Vikramaditya Prakāsh of the University of Washington are co-principal investigators. The board is composed of Jarzombek, Prakāsh, Robert Cowherd of the Wentworth Institute of Technology, Gail Fenske of Roger Williams University, Suzanne Marchand of Louisiana State University, and Adnan Morshed of Catholic University of America.



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LIGO back online, ready for more discoveries

Today, scientists restarted the twin detectors of LIGO, the Laser Interferometer Gravitational-wave Observatory, after making several improvements to the system. Over the last year, they have made enhancements to LIGO’s lasers, electronics, and optics that have increased the observatory’s sensitivity by 10 to 25 percent. The detectors, scientists hope, will now be able to tune in to gravitational waves — and the extreme events from which they arise — that emanate from farther out in the universe.  

On Sept. 14, 2015, LIGO’s detectors made the very first direct detection of gravitational waves, just two days after scientists restarted the observatory as Advanced LIGO — an upgraded version of LIGO’s two large interferometers, one located at Hanford, Washington, and the other 3,000 kilometers away in Livingston, Lousiana. After analyzing the signal, scientists determined that it was indeed a gravitational wave, which arose from the merger of two massive black holes 1.3 billion light years away.

Three months later, on Dec. 26, 2015, the detectors picked up another signal, which scientists decoded as a second gravitational wave, rippling out from yet another black hole merger, slightly farther out in the universe, 1.4 billion light years away.

Now with LIGO’s latest upgrades, members of the LIGO Scientific Collaboration are hoping to detect more frequent signals of gravitational waves, arising from colliding black holes and other extreme cosmic phenomena. MIT News spoke with Peter Fritschel, the associate director for LIGO at MIT, and LIGO’s chief detector scientist, about LIGO’s new view.

Q: What sort of changes have been made to the detectors since they went offline?

A: There were different sorts of activities at the two observatories. With the detector in Livingston, Louisiana, we did a lot of work inside the vacuum system, replacing or adding new components. As an example, each detector contains four test masses that respond to a passing gravitational wave. These test masses are mounted in complex suspension systems that isolate them from the local environment. Previous testing had shown that two of the vibrational modes of these suspensions could oscillate to a degree that would prevent the detector from operating with its best sensitivity. So, we designed and installed some tuned, passive dampers to reduce the oscillation amplitude of these modes. This will help the Livingston detector operate at its peak sensitivity for a greater fraction of the data run duration.

On the Hanford, Washington, detector, most of the effort was geared toward increasing the laser power stored in the interferometer. During the first observing run, we had about 100 kilowatts of laser power in each long arm of the interferometer. Since then we worked on increasing this by a factor of two, to achieve 200 kilowatts of power in each arm. This can be quite difficult because there are thermal effects and optical-mechanical interactions that occur as the power is increased, and some of these can produce instabilities that must be tamed. We actually succeeded in solving these types of problems and were able to operate the detector with 200 kilowatts in the arms. However, there were other problems that cost sensitivity, and we didn’t have time to solve these, so we are now operating with 20 to 30 percent higher power than we had in the first observing run. This modest power increase gives a small but noticeable increase in sensitivity to gravitational wave frequencies higher than about 100 hertz.

We also gathered a lot of important information that will be used to plan out the next detector commissioning period, which will commence at the end of this six-month observation period. We still have a lot of challenging work ahead of us to get to our final design sensitivity.

Q: How sensitive is LIGO with these new improvements? 

A: The metric we most commonly use is the sensitivity to gravitational waves produced by the merger of two neutron stars, because we can easily calculate what we should see from such a system — but note we have not yet detected gravitational waves from a neutron star-neutron star merger. The Livingston detector is now sensitive enough to detect a merger from as far away as 200 million parsecs (660 million light years). This is about 25 percent farther than it could “see” in the first observing run. For the Hanford detector the corresponding sensitivity range is pretty much on par with what it was during the first run and is about 15 percent lower than these figures.

Of course in the first observing run we detected the merger of two black holes, not neutron stars. The sensitivity comparison for black hole mergers is nonetheless about the same: Compared to last year’s observing run, the Livingston detector is around 25 percent more sensitive and the Hanford detector is about the same. But even small improvements in sensitivity can help, since the volume of space being probed, and thus the rate of gravitational-wave detections, grows as the cube of these distances.

Q: What do you hope to “hear” and detect, now that LIGO is back online?

A: We definitely expect to detect more black hole mergers, which is still a very exciting prospect. Recall that in the first run we detected two such black hole binary mergers and saw strong evidence for a third merger. With the modest improvement in sensitivity and the plan to collect more data than we did before, we should add to our knowledge of the black hole population in the universe.

We would also love to detect gravitational waves from the merger of two neutron stars. We know these systems exist, but we don’t know how prevalent they are, so we can’t be sure how sensitivity we need to start seeing them. Binary neutron star mergers are interesting because (among other things) they are thought to be the producers and distributers of the heavy elements, such as the precious metals, that exist in our galaxy.



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martes, 29 de noviembre de 2016

Harder, better, faster, stronger

Imagine if you and a group of students were tasked with designing, building, testing, and driving a Formula-style electric race car from the ground up. Every year.

For students who are members of MIT Motorsports — a.k.a. the MIT Formula SAE (FSAE) team, originally founded in 2001 — that task determines how they spend their free time, on weekends, evenings, and often, January Independent Activities Period as well as summer.

On a recent Saturday in the Edgerton Center’s Area 51 Student Shop (Room N51), about two dozen students on the FSAE team were sitting at large work tables, huddled over their laptops, designing components for their 2017 vehicle using the Solidworks design software. Friendly banter, shared jokes, and periods of serious focus characterized the day. One student, senior Brian Wanek, sat wearing a helmet inside a prototype of what would be the driver’s seat, while sophomore Wasay Anwer measured the frame.

The task for this year — borrowing from a Daft Punk song — is building a harder, better, faster, stronger car for the June 2017 Collegiate Design Series hosted by the Society of Automotive Engineers in Lincoln, Nebraska.

Last year’s performance was nothing to shrug at. MIT's team passed all inspections, placed fourth in vehicle cost (spending the least amount of money to construct the car), placed fourth overall in design, and sixth overall in a field of 21 teams from around the globe.

“Our previous car was an evolutionary step in our team’s history,” says team captain and MIT junior Luis Alberto Mora, who joined FSAE as a freshman. “We kept the working components the same and made minor improvements on previous designs. This year’s car is a revolutionary step; brand new electric powertrain and batteries, new tire size, giving us the freedom to make no compromises in performance.”

The team operates on a tight budget, just over $100,000, and they actively raise funds from sponsors inside and outside of MIT. The Edgerton Center, the Department of Mechanical Engineering, Ford Motor Company, and General Motors provide the bulk of funding necessary to keep the team running year after year.

More than 1,000 parts go into the construction of their car, most of which is fabricated in the shop using a mix of manual and computer numeric control (CNC) machines, rapid prototyping machines, and water jet cutters. The team typically purchases all the raw materials needed to build their new car, as well as high-cost items such as battery cells, electric motors, and motor controllers. 

This year the team is designing their own battery pack based off of high-discharge lithium-ion cy­lindrical cells. “Our previous battery pack [used on last year’s car] was purchased by a company that later went out of business and needed lots of repairs. We gained a lot of knowledge from having to fix it,” says Elliot Owen, a junior in mechanical engineering and battery lead for MIT FSAE. “This year’s battery pack will have a different chemistry in a different format. Previously we had big floppy sheets, now we have little canisters, similar to what is used in Tesla. We can make a 25 percent weight reduction, we have more energy, and it’s safer,” Owen says.

The lighter car weighs in at 215 kilograms without a driver, 30 kg lighter than last year’s vehicle. The new car will have a chassis and suspension of a hybrid design: a primary steel tube structure with stressed carbon fiber panels.

Last year’s car also serves a purpose for this year’s build. “We can try out new software on the old car, we can debug it, and by the time the new car is built, the software, the mechanical parts, are already worked out,” Mora says.

To sustain a team that, without fail, loses a number of valuable team members each year to graduation is no small task — and recruiting new members is essential. Tianye Chen, a junior in electrical engineering and computer science who is the low voltage electrical systems lead, says: “We try to give new members meaningful things to do, teach them how to use the tools, and give them projects to keep them engaged.”

Patrick McAtamney, technical instructor and master machinist in Area 51, works closely with the FSAE team and sees multiple benefits being on an Edgerton Center team. “One thing that students get are social skills, how to work with other team members on sub teams, a mechanical engineering student will work with an aero-astro student to solve engineering problems together.”

“FSAE provides one of the most real-world engineering experiences offered on campus,” says assistant professor of mechanical engineering Amos Winter, the team’s faculty advisor who meets with them regularly to go over design specifications. “As an educator, it makes me very happy to see the students absorb, synthesize, and apply the theory we teach in classes into practical engineering solutions.”

While the June competition is still a ways off, for the FSAE students it will mark the culmination of a year-long project of long hours, hard work, and fun — a noteworthy accomplishment for all.



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Creating videos of the future

Living in a dynamic physical world, it’s easy to forget how effortlessly we understand our surroundings. With minimal thought, we can figure out how scenes change and objects interact.

But what’s second nature for us is still a huge problem for machines. With the limitless number of ways that objects can move, teaching computers to predict future actions can be difficult.

Recently, researchers from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) have moved a step closer, developing a deep-learning algorithm that, given a still image from a scene, can create a brief video that simulates the future of that scene.

Trained on 2 million unlabeled videos that include a year’s worth of footage, the algorithm generated videos that human subjects deemed to be realistic 20 percent more often than a baseline model.

The team says that future versions could be used for everything from improved security tactics and safer self-driving cars. According to CSAIL PhD student and first author Carl Vondrick, the algorithm can also help machines recognize people’s activities without expensive human annotations.

“These videos show us what computers think can happen in a scene,” says Vondrick. “If you can predict the future, you must have understood something about the present.”

Vondrick wrote the paper with MIT professor Antonio Torralba and Hamed Pirsiavash, a former CSAIL postdoc who is now a professor at the University of Maryland Baltimore County (UMBC). The work will be presented at next week’s Neural Information Processing Systems (NIPS) conference in Barcelona.

How it works

Multiple researchers have tackled similar topics in computer vision, including MIT Professor Bill Freeman, whose new work on “visual dynamics” also creates future frames in a scene. But where his model focuses on extrapolating videos into the future, Torralba’s model can also generate completely new videos that haven’t been seen before.

Previous systems build up scenes frame by frame, which creates a large margin for error. In contrast, this work focuses on processing the entire scene at once, with the algorithm generating as many as 32 frames from scratch per second.

“Building up a scene frame-by-frame is like a big game of ‘Telephone,’ which means that the message falls apart by the time you go around the whole room,” says Vondrick. “By instead trying to predict all frames simultaneously, it’s as if you’re talking to everyone in the room at once.”

Of course, there’s a trade-off to generating all frames simultaneously: While it becomes more accurate, the computer model also becomes more complex for longer videos. Nevertheless, this complexity may be worth it for sharper predictions.

To create multiple frames, researchers taught the model to generate the foreground separate from the background, and to then place the objects in the scene to let the model learn which objects move and which objects don’t.

The team used a deep-learning method called “adversarial learning” that involves training two competing neural networks. One network generates video, and the other discriminates between the real and generated videos. Over time, the generator learns to fool the discriminator.

From that, the model can create videos resembling scenes from beaches, train stations, hospitals, and golf courses.  For example, the beach model produces beaches with crashing waves, and the golf model has people walking on grass.

Testing the scene

The team compared the videos against a baseline of generated videos and asked subjects which they thought were more realistic. From over 13,000 opinions of 150 users, subjects chose the generative model videos 20 percent more often than the baseline.
 
Vondrick stresses that the model still lacks some fairly simple common-sense principles. For example, it often doesn’t understand that objects are still there when they move, like when a train passes through a scene. The model also tends to make humans and objects look much larger in size than reality.

Another limitation is that the generated videos are just one and a half seconds long, which the team hopes to be able to increase in future work. The challenge is that this requires tracking longer dependencies to ensure that the scene still makes sense over longer time periods. One way to do this would be to add human supervision.

“It’s difficult to aggregate accurate information across long time periods in videos,” says Vondrick. “If the video has both cooking and eating activities, you have to be able to link those two together to make sense of the scene.”

These types of models aren’t limited to predicting the future. Generative videos can be used for adding animation to still images, like the animated newspaper from the Harry Potter books. They could also help detect anomalies in security footage and compress data for storing and sending longer videos.

“In the future, this will let us scale up vision systems to recognize objects and scenes without any supervision, simply by training them on video,” says Vondrick.

This work was supported by the National Science Foundation, the START program at UMBC, and a Google PhD fellowship.



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How online tools and open innovation can support implementation of Paris Agreement goals

An MIT research initiative is harnessing the power of crowds and online collaborative tools in support of fulfilling global Paris Agreement climate goals.

MIT’s Climate CoLab, founded and directed by Professor Thomas Malone of the MIT Center for Collective Intelligence, presented its work and innovative approach in a series of events earlier this month at the United Nations Framework Convention on Climate Change (UNFCCC) Conference of the Parties in Marrakech, Morocco (COP22). Climate CoLab’s team was on the ground in Marrakech to strengthen and build new collaborations with the international community in support of the 2015 Paris international climate agreement, and to showcase the role crowds and online collaborative tools can play in supporting implementation of the Paris Agreement goals. Of the project, Malone said: “It’s now possible to harness the collective intelligence of thousands of people, all over the world, at a scale, and with a degree of collaboration, that was never possible before in human history."

Amid notable milestones in international climate cooperation this fall — including the early legal entry into force of the Paris Agreement, a recent international accord on reducing global hydrofluorocarbons (HFCs), and another on reducing emissions from the aviation sector, COP22 was still awash with reminders of the stark scientific realities that further near-term action is needed to combat the most dangerous impacts of climate change. Among them, a new United Nations' Environmental Program 2016 Emissions Gap Report, released immediately prior to COP22, projected that 25 percent greater global emissions cuts are needed prior to 2030. UN Secretary-General Ban Ki-moon recently urged the global community, “We are still in a race against time. We need to transition to a low-emissions and climate-resilient future.”

Climate CoLab is pioneering a crowd-based methodology to help meet this challenge. The project was highlighted during several events at COP22, including two official UN side events, and a featured interview with the UNFCCC Climate Change Studio. What if we could harness all of the ingenuity and intelligence of everybody that’s [at COP22], and also everybody that couldn’t be here today, to continuously work together on climate change solutions? What could be possible?” said Laur Hesse Fisher, Climate CoLab project manager, during the interview. “New digital collaboration tools enable that,” she continued.

On Monday, Nov. 14, Climate CoLab co-hosted an official side event with collaborator Climate Interactive and the Abibimman Foundation, entitled “Meeting the Paris Goals through Decision-Maker Tools and Climate Education.” Panelist Andrew Jones, Climate Interactive’s co-director, started the session with the premise that we need large-scale engagement in order to adequately address this challenge: We don’t need 10,000 experts, we need 1 billion amateurs doing all they can, effectively, to make change.”

The role of non-state actors and open transparent stakeholder engagement processes were featured throughout COP22. On Nov. 15, Hesse Fisher joined a panel of collaborators from various international organizations, including Climate Policy Institute, Climate-KIC, the Global Environmental Facility, ICLEI, and many others, organized by the Cities Climate Finance Leadership Alliance. Addressing an audience of government officials, academics, non-profit advocates, and others, the panelists discussed the role of innovation platforms and tools in helping finance climate action.

Additionally, building on last year’s launch of a partnership with the UN Secretary-General’s Climate Resilience Initiative: Absorb, Anticipate, Reshape (A2R), Climate CoLab was featured in an A2R brochure distributed at A2R Initiative COP22 events, for its new contest on “Anticipating Climate Hazards,” which seeks proposals on early warning systems and climate preparedness responses. Of the collaboration, Malone said, “To contend with the most pressing impacts of climate change, it is clear that now more than ever before, we need ideas and contributions of as many people as possible to address climate change.”

As focus turns to accelerating countries’ implementation of their emissions reductions targets and adaptation strategies put forward under the Paris Agreement — also known as “nationally-determined contributions” or “NDCs” — Climate CoLab is exploring how this online collaborative approach of stakeholder engagement and expert-validated climate planning including assessment could prove valuable to countries. Building on themes of open engagement and enhancing transparency, Malone remarked, “We believe it’s possible to open up the national and international climate planning processes to anyone around the world who wants to participate.” As Fisher said, this approach provides “new ways that the world can work together.”



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Climate models may be overestimating the cooling effect of wildfire aerosols

Whether intentionally set to consume agricultural waste or naturally ignited in forests or peatlands, open-burning fires impact the global climate system in two ways which, to some extent, cancel each other out. On one hand, they generate a significant fraction of the world’s carbon dioxide emissions, which drive up the average global surface temperature. On the other hand, they produce atmospheric aerosols, organic carbon, black carbon, and sulfate-bearing particulates that can lower that temperature either directly, by reflecting sunlight skyward, or indirectly, by increasing the reflectivity of clouds. Because wildfire aerosols play a key role in determining the future of the planet’s temperature and precipitation patterns, it’s crucial that today’s climate models — upon which energy and climate policymaking depend — accurately represent their impact on the climate system.

But a new study in Atmospheric Chemistry and Physics by researchers at the MIT Joint Program on the Science and Policy of Global Change shows that at least one widely-used climate model is overestimating the cooling effect of these aerosol emissions by as much as 23 percent.

“This overestimation could lead to errors in projections of surface temperature and rainfall, both globally and regionally,“ says Chien Wang, a senior research scientist at MIT’s Department of Earth, Atmospheric and Planetary Sciences and the Joint Program, who co-authored the paper with two members of his group: lead author and research scientist Benjamin S. Grandey and postdoc Hsiang-He Lee of the Center for Environmental Sensing and Modeling at the Singapore-MIT Alliance for Research and Technology. “We hope our findings will reduce such errors in climate modeling.”

To make long-term global projections, most climate models represent atmospheric wildfire aerosol emissions by using monthly measures of emissions at different locations around the globe, and then averaging those emissions over multiple years — before estimating their effect on solar radiation at each location over the multi-year period. Questioning the accuracy of this conventional approach, the researchers proposed a revised representation of wildfire aerosol emissions in which the radiative effect associated with each monthly measure of emissions is first calculated, before averaging over the multi-year period. The revised approach would account for year-to-year variability in the aerosols’ radiative effect, which is missing in the conventional representation.

Using a global aerosol-climate model — the Community Earth System Model (CESM) — and the Global Fire Emissions Database (GFED4.0s), the researchers compared both modeling approaches over a 10-year period. The comparison showed that wildfire emissions are responsible for a global mean net radiative effect of about -1.26 watts per square meter for the conventional approach, and about -1.02 watts per square meter for the revised approach. The conventional climate modeling approach systematically overestimated the strength of the net radiative effect of wildfire aerosols — by 23 percent globally and by higher levels (58 percent over Australia and New Zealand; 43 percent over Boreal Asia, where wildfires are commonplace) regionally.

The researchers attribute this systematic overestimation to the non-linear influence of the aerosols on clouds, due largely to interactions between organic carbon aerosols and clouds. Organic carbon aerosols initially boost the reflectivity (and thus cooling effect) of clouds, but as concentrations increase over a particular geographic location, the rate of increase in cloud reflectivity (and cooling effect) slows down considerably. By incorrectly assuming that the indirect cooling effect of aerosol emissions increases linearly with their concentration, conventional approaches overestimate that effect in climate models.

Representing the year-to-year variability in the cooling effect of wildfire aerosols in climate models could improve our understanding of the climate system and the overall accuracy of global and regional climate projections.

“Hopefully what we’ve found here will be taken into account in future climate modeling studies, which could help improve decision-making regarding climate mitigation and adaptation,” says Grandey.

The research team recommends further research to test the robustness of their method by using different climate models and wildfire emissions data sets, improve the scientific understanding of the mechanisms behind the results, and explore in greater depth the impact of year-to-year variation in aerosol emissions on different aspects of climate change.

The research was funded by the Singapore National Research Foundation through the Singapore-MIT Alliance for Research and Technology's Center for Environmental Sensing and Modeling, as well as by grants from the National Science Foundation, the Department of Energy, and the Environmental Protection Agency.



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Professor Hung Cheng pledges $1 million for a new MIT scholarship

MIT professor of applied mathematics Hung Cheng has pledged $1 million to establish a new scholarship for MIT students. The Hung and Jill Cheng Scholarship Fund will fully support undergraduates beginning this academic year.

Cheng was inspired to establish the scholarship through writing his novel, "Nanjing Never Cries" (MIT Press, 2016), which follows four people as they survive the 1937 Nanjing massacre and cope with its aftermath during the Sino-Japanese War. The scholarship will give first preference to students from Nanjing, China, and then to students from China and to students of Chinese descent.

MIT plays a special role in the lives of the characters of Cheng’s novel. John Winthrop, an American, and Calvin Ren, a Nanjing native, meet at MIT, where they build a close friendship as they study, physics, aeronautical engineering, and mechanical engineering. When Winthrop accepts Ren’s invitation to work with him on designing and building airplanes in China on the eve of the Sino-Japanese War, they discover that their strong bond and strong education in science and technology have given them the means to make a significant practical contribution to the Chinese war effort.

Cheng believes that MIT is uniquely qualified to prepare students to do the kind of world-changing work accomplished by the characters in his novel, and hopes that his new scholarship will enable more students access the valuable education and supportive community that MIT offers.

“You have a lot of very smart and hardworking people here, talking to each other and being friends, and they all benefit from each other,” Cheng says. “To be nurtured by this environment helps us grow and to become a more useful person. MIT students can do a lot of good — to help wipe out poverty, develop energy, and to help implement medical sciences. If you learn a science or technology background very well from MIT, you can turn it into a very valuable experience and do something useful for humanity.”

Although Cheng’s book is fictional, its characters and events of the book draw in part on Cheng’s own experience growing up in China and as a professor. Born in China in 1937, just a few months after the beginning of the Sino-Japanese War, Cheng moved to Taiwan as a teenager and then moved to the United States to pursue undergraduate studies at Caltech. After earning his BS in 1959, he stayed at Caltech, earning his PhD in in only two years. After postdoctoral appointments at Caltech, Princeton University, and Harvard University, he came to MIT as an assistant professor in 1965 and rose to the rank of full professor four years later. Since then, he has made significant contributions to gauge-field theory, working with Harvard’s T. T. Wu to formulate an unexpected prediction that the cross-section of colliding protons increases with energy, which The New York Times announced was experimentally confirmed at CERN in 1973. He has also worked on problems in unified field theory related to scale invariance and general relativity.

“I am delighted that my friends Hung Cheng and Jill Tsui have made this gift to MIT,” said Michael Sipser, dean of the MIT School of Science. “Professor Cheng has been my colleague at MIT for many years, and we both know that to solve our most difficult and important problems, MIT needs motivated and creative students. Endowed scholarships make it possible for all brilliant students — even those with limited financial resources — to join our community.”



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MIT Skoltech Seed Fund issues call for proposals

The MIT Skoltech Seed Fund Program is calling for proposals, now through Dec. 23, from MIT faculty and researchers with principal investigator status for innovative projects that have the potential to benefit the development of the MIT Skoltech Program or the mission of the Skolkovo Foundation. The program strongly encourages proposals that involve collaborative research with Skoltech or other Russian academic and research institutions.  

Interested researchers are encouraged to submit proposals in the following three main categories:

  • research projects in science and engineering (biomedicine, energy, information technology, data science and computational modeling, product design and manufacturing, and space);

  • research projects in the areas of policy, economics, humanities, arts and social sciences (especially innovation and entrepreneurship, international collaborative programs, technology and policy, and general Russian studies, including Russian history, Russian art and Russian economy); and

  • non-research projects to promote engagement and collaboration on topics and activities that may impact Russia, Skoltech, or other Russian institutions — such as course development, course teaching, student exchange, event organization (e.g., a hackathon or other application-type activity), etc.

The MIT Skoltech Seed Fund will award grants in amounts up to $75,000, for one year.

The application deadline is Friday Dec. 23. For more information and to apply, visit the Skoltech Seed Fund page



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MIT Reads hosts author Janet Mock

MIT Reads, an Institute-wide reading and discussion program, welcomed author, editor, and media professional Janet Mock to a full Kirsch Auditorium Nov. 15 for a conversation about her memoir, "Redefining Realness."

Seated in easy chairs on the stage just one week after the presidential election, Mock and moderator / MIT junior Syn Odu started a timely discussion with Odu’s own questions and then took more from the audience.

As a mixed-race trans woman of color, Mock spoke openly about the fears that the 2016 election results have provoked, in her words, in “brown folk, undocumented folk, black folk, queer folk, trans folk, and disabled people [who] are now having to fight even more to say that we deserve to be here.”

But Mock’s message was not one of fear or defeat. In the election, Mock said she supported Hillary Clinton, but now, “We have a better option, and it’s us. We have to do the work now.” She urged those gathered to deepen their communities, get involved in grassroots organizations that support marginalized populations, and seek out safe places where they can process and heal.

The timing of this author event could not have been more perfect, said PhD student Danielle Olson. “I am a woman of color at MIT and a strong ally of the LBGTQ+ community,” she said. “Last Wednesday I came to campus feeling hyper visible as a black woman on campus — not because MIT isn’t diverse, but [because of] this past election cycle.” Olson, an undergraduate alumna of MIT who returned as a graduate student in electrical engineering and computer science, says MIT Reads is one of several new opportunities she’s found across campus to support students and give them safe spaces to connect with one another. The program’s inaugural reading selection was also a pleasant surprise. “I am so happy we chose this author,” she said.

“We had a wonderful cross section of the MIT community attend,” said Nina Davis-Millis, who coordinates MIT Reads as part of her role as the director of Community Support and Staff Development at MIT Libraries. “It was a wonderful example of [Director Chris Bourg’s] vision of the libraries being a place on campus where people can have difficult discussions.”

During the question-and-answer portion of the evening, the audience wanted to know how Mock worked through the difficulties of her young life growing up poor and transgender. As an adult, Mock said, she has relied on community and self-care: “Finding spaces in which I can show up and not have to perform or be some kind of leader or figurehead. Where I just show up and be empty and not have to give anyone anything. That helps me process. Writing has always helped me process. Reading has always helped me process.”

The conversational format and intimacy of the discussion struck Dan Calacci, a first-year master’s student in media arts and sciences. “It was unique because it was really just two people who cared quite a bit about intersectional issues having a conversation — and a very personal conversation at that,” he said. “As a white person somewhere between queer and cis, it was super nice to be able to drop in on a conversation like that and hear from people who have thought deeply about these issues.”

The timing was necessary given the events of the prior week, according to Julio Oyola, assistant director of LBGTQ Services at MIT’s Rainbow Lounge. Mock met with a small group of invited students before the public event. Oyola said it was an opportunity to “express their gratitude for her serving as a role model for them as trans folk and queer students of color. It was moving and remarkable especially in light of how some folks are feeling.”

The conversation with Mock was co-sponsored by the Division of Student Life, the Office of the Dean for Graduate Education, the Sloan School Student Life Office, and the Program in Media Arts and Sciences. The author event is one of several community events facilitated by MIT Reads this fall, including smaller group discussions scheduled to accommodate not only students and faculty but also staff and other MIT affiliates.  

MIT Reads’ launch comes at a time when community dialogue is more important than ever. Its enthusiastic response across MIT has heartened Davis-Millis: “The thing that really made my heart sing was the idea of the MIT community getting excited about a book and coming together around the act of reading.”



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lunes, 28 de noviembre de 2016

3Q: Dennis Frenchman on the rise of innovation districts in Cambridge and beyond

Cities around the world are redeveloping industrial areas, downtown districts, and exurban office parks with a mix of retail, housing, and the anchors of the new digital economy: startup incubators and co-working spaces. But beyond these basic ingredients, what makes a 21st-century urban neighborhood both a productive and an enriching place to live and work?

Dennis Frenchman, the Class of 1922 Professor of Urban Design and Planning in the School of Architecture and Planning (SA+P), has played a leading role in the design and development of innovation districts around the world, from Medellín, Colombia, to Seoul, South Korea. He has analyzed the technological, social, and economic factors of their evolution, and the planning and policy strategies that encourage the growth of these “productive neighborhoods.” Frenchman is currently leading SA+P’s DesignX program to accelerate innovation and entrepreneurship in design and the built environment.  

SA+P asked Frenchman to share what he’s learned about what makes a successful innovation district, and to offer his perspective on what needs to happen to ensure that its economic and social benefits are widely distributed. He also weighed in on the innovation ecosystems of Cambridge and Boston, including The Engine, the new enterprise recently launched by MIT to support startup companies working on scientific and technological innovation with the potential for transformative societal impact.

The Engine will host a community forum — attended by President L. Rafael Reif, Provost Martin Schmidt, Executive Vice President and Treasurer Israel Ruiz, and Professor Anantha Chandrakasan, head of the Department of Electrical Engineering and Computer Science — on Wednesday, Nov. 30, at 5:30 p.m. in Room 32-123.

Q: What is an innovation district? What would a visitor typically find there?

A: To understand innovation districts, we need to look back at the way we have organized ourselves in the past, and the ways in which cities have been formed by both economic and social forces, all wrapped up together.

In the 19th century, the neighborhoods where people lived and their places of work — factories, docks, shipyards — were very close to each other. That created a certain kind of city form. I’ve done a lot of work on Lowell, Massachusetts, and industrial mill towns, where you see this strong pattern. In the 20th century, with the advent of the automobile and other technologies, city planners advocated moving factories to the periphery of the city. We spent the whole 20th century separating places to live from places to work.

With the arrival of digital technology, all of those older systems are changing. The nature of work is changing. The first generation of digital natives is now entering the workforce. They are very entrepreneurial, and they have at their fingertips the means of production: With a laptop and a skilled person, you can produce enormous value. So what is the factory? Where is this value being produced, and how? The factories are now the urban places in which these folks socialize, live, and produce — make things. And that really is what a “productive neighborhood,” as I like to call it, or an innovation district, is all about.

So what do you see there? You definitely see housing and places for people to live. You see 21st-century industries clustering there, because they are following the talent. You see social spaces: a huge resurgence in restaurants, markets, and cafés. And you see laboratories, startup accelerators, and shared work space. Don’t think of this as an industrial district — it’s not an office park. It’s really a neighborhood in which a culture has emerged around this new kind of production and lifestyle. People are globally connected and producing very high-value products, and the production and the living are both occurring 24 hours a day.

Q: Are innovation districts emerging organically, or are they the product of active planning and specific policies?

A: It’s an emerging phenomenon, but planning can make it more inclusive, diverse, functional, and productive. We are just now inventing the public policy to take advantage of these trends. There’s a lot of existing policy that does not make innovation in the city very easy to do.

I’m an urban designer. Most of our current land-use regulation is built around zoning, which at its base is about separation of different uses. We have residential districts, commercial districts, industrial districts. But that isn’t the way cities are being formed now in these innovation districts. They are mixed-use in a fine-grained way. You have living space mixed with industry, as in the Brooklyn Navy Yard, for example. A lot of these things were not allowed in the past. The old regulations were all made for the 20th-century city. The main function of cities in the last century was consumption, and the suburbs were for living. Now people are moving back to the city to produce, and we have to think about how to do that in an inclusive way. Cities have to transform their public policy for the built environment to enable inclusivity to happen, starting with mixed-use zones.

Another core issue is diversity. One of the things that we’ve found here at MIT is that diversity — cross-currents of people, ideas, and experiences — is an essential ingredient in creation and innovation. But achieving that diversity won’t happen on its own. We need policy for inclusionary housing and working. We need to be pulling folks into this new economy who wouldn’t normally get into it. At MIT, it’s up to us to make sure that we’re engaging high school students, for example, and bringing people from disadvantaged backgrounds into this system.

In some places, this will take a long time to take hold. Other places provide opportunities because of their location and context, but may need a push. It took a long time to get the innovation district going on the waterfront in South Boston. The original vision was to simply have a lot of high-tech companies based there. But it needed more social life, more excitement. New housing is coming, and shopping is being built. It’s beginning to take on the characteristics of a productive neighborhood. But we have to be sure that all folks in South Boston are able to get jobs in this new economy. It has to be inclusive. Social values are also economic imperatives now.

Q: How will The Engine — MIT’s new venture to support transformative innovation — contribute to the growth of this kind of “productive neighborhood” in the city of Cambridge?

A: The Engine makes a lot of sense for MIT, but also for the innovation ecosystem developing in Boston and Cambridge. It’s a great move to put its headquarters in Central Square. MIT could play an incredible role in the transformation of that neighborhood. There is an intention in the forming of The Engine to try to do that, which is extremely positive.

Where you have schools surrounded by new investment these days, we’re seeing that the campus and neighborhood are merging together and becoming one thing. The campus is diffusing into the wider neighborhood as research and industry are attracted to the area. That’s why I think of it as a new form. The fact that The Engine is off-campus fits exactly the theory that the campus is beginning to dissolve into the city of Cambridge, socially if not legally. This is a cultural change. The new economy is beginning to take root.

Another thing that’s great about The Engine is that it’s providing a place for students to land and continue their innovation after they graduate. This aligns with what we are trying to promote in DesignX. Just as the physical campus is dissolving, so is the boundary of graduation. It offers a way for students to continue on with the innovation and entrepreneurship adventure. Increasingly we’re going to have to see education as a continuous platform at MIT and outside of MIT in different neighborhoods. Increasingly the campus will become part of its neighborhood. That's what I predict. And this is a way of remaking cities.



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Inside tiny tubes, water turns solid when it should be boiling

It’s a well-known fact that water, at sea level, starts to boil at a temperature of 212 degrees Fahrenheit, or 100 degrees Celsius. And scientists have long observed that when water is confined in very small spaces, its boiling and freezing points can change a bit, usually dropping by around 10 C or so.

But now, a team at MIT has found a completely unexpected set of changes: Inside the tiniest of spaces — in carbon nanotubes whose inner dimensions are not much bigger than a few water molecules — water can freeze solid even at high temperatures that  would normally set it boiling.

The discovery illustrates how even very familiar materials can drastically change their behavior when trapped inside structures measured in nanometers, or billionths of a meter. And the finding might lead to new applications — such as, essentially, ice-filled wires — that take advantage of the unique electrical and thermal properties of ice while remaining stable at room temperature.

The results are being reported today in the journal Nature Nanotechnology, in a paper by Michael Strano, the Carbon P. Dubbs Professor in Chemical Engineering at MIT; postdoc Kumar Agrawal; and three others.

“If you confine a fluid to a nanocavity, you can actually distort its phase behavior,” Strano says, referring to how and when the substance changes between solid, liquid, and gas phases. Such effects were expected, but the enormous magnitude of the change, and its direction (raising rather than lowering the freezing point), were a complete surprise: In one of the team’s tests, the water solidified at a temperature of 105 C or more. (The exact temperature is hard to determine, but 105 C was considered the minimum value in this test; the actual temperature could have been as high as 151 C.)

“The effect is much greater than anyone had anticipated,” Strano says.

It turns out that the way water’s behavior changes inside the tiny carbon nanotubes — structures the shape of a soda straw, made entirely of carbon atoms but only a few nanometers in diameter — depends crucially on the exact diameter of the tubes. “These are really the smallest pipes you could think of,” Strano says. In the experiments, the nanotubes were left open at both ends, with reservoirs of water at each opening.

Even the difference between nanotubes 1.05 nanometers and 1.06 nanometers across made a difference of tens of degrees in the apparent freezing point, the researchers found. Such extreme differences were completely unexpected. “All bets are off when you get really small,” Strano says. “It’s really an unexplored space.”

In earlier efforts to understand how water and other fluids would behave when confined to such small spaces, “there were some simulations that showed really contradictory results,” he says. Part of the reason for that is many teams weren’t able to measure the exact sizes of their carbon nanotubes so precisely, not realizing that such small differences could produce such different outcomes.

In fact, it’s surprising that water even enters into these tiny tubes in the first place, Strano says: Carbon nanotubes are thought to be hydrophobic, or water-repelling, so water molecules should have a hard time getting inside. The fact that they do gain entry remains a bit of a mystery, he says.

Strano and his team used highly sensitive imaging systems, using a technique called vibrational spectroscopy, that could track the movement of water inside the nanotubes, thus making its behavior subject to detailed measurement for the first time.

The team can detect not only the presence of water in the tube, but also its phase, he says: “We can tell if it’s vapor or liquid, and we can tell if it’s in a stiff phase.” While the water definitely goes into a solid phase, the team avoids calling it “ice” because that term implies a certain kind of crystalline structure, which they haven’t yet been able to show conclusively exists in these confined spaces. “It’s not necessarily ice, but it’s an ice-like phase,” Strano says.

Because this solid water doesn’t melt until well above the normal boiling point of water, it should remain perfectly stable indefinitely under room-temperature conditions. That makes it potentially a useful material for a variety of possible applications, he says. For example, it should be possible to make “ice wires” that would be among the best carriers known for protons, because water conducts protons at least 10 times more readily than typical conductive materials. “This gives us very stable water wires, at room temperature,” he says.

The research team also included MT graduate students Steven Shimizu and Lee Drahushuk, and undergraduate Daniel Kilcoyne. The work was supported by the U.S. Army Research Laboratory and the U.S. Army Research Office through the MIT Institute for Soldier Nanotechnologies, and Shell-MIT Energy Initiative Energy Research Fund.



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New Kendall Wi-Fi supports Kendall Square and nearby residential areas

Through a unique collaboration among MIT, Google, Boston Properties, the City of Cambridge, and the Cambridge Housing Authority (CHA), an open and free-of-charge Wi-Fi network is now available in the Kendall Square area and the Newtowne Court and Washington Elms public housing neighborhoods.

The idea, originally brought to MIT and others by Google, took three years to execute because of the intricate work involved in building out fiber networks to provide connectivity to outdoor wireless access points. MIT took on the infrastructure challenge and spearheaded the project. The MIT-led team worked cooperatively with the City of Cambridge, the Cambridge Housing Authority, Boston Properties, Alexandria Real Estate Equities, and others to take advantage of ongoing construction activity so that multiple duct banks could be built over time to connect properties in the Wi-Fi coverage areas. Ultimately, MIT will host and maintain Kendall Wi-Fi within its existing network system.

“The effort required patience,” reflects Israel Ruiz, MIT’s executive vice president and treasurer. “Our Information Systems and Technology team worked carefully and diligently to put the necessary pieces in place. I am grateful for their steady work and for our strong partnership with Google, Boston Properties, and Cambridge. That collaboration, including with the Cambridge Housing Authority, has created a vital amenity for Kendall Square and nearby residents.”

From the outset, the coverage was designed to extend to outdoor areas of the Newtowne Court and Washington Elms neighborhoods. "According to city data from 2014, 30 percent of CHA residents don't have internet access,” observes Liz Schwab, head of external affairs for Google Cambridge. “Projects like this can help fill that need. Access to the internet is critical, whether it's to complete homework, search for a job, or get important municipal updates. We're happy to support installation of a Wi-Fi network that will significantly increase internet access for our neighbors here in Cambridge." In conjunction with the outdoor Wi-Fi coverage, connectivity will also be made available at the Pisani Center, which is the community facility in the Washington Elms neighborhood.

The initial phase of the Kendall Wi-Fi network also covers the newly created Grand Junction Park at the corner of Main Street and Galileo Galilei Way, to which MIT contributed $500,000 in conjunction with its Kendall Square Initiative zoning agreement. Phase 2 of Kendall Wi-Fi, which is expected to be completed in 2018, will further connect areas within Kendall Square between Main Street and Broadway, and will reach out to the One Broadway vicinity including the Broad Canal recreational area.

“Kendall Square is one of the most connected neighborhoods on the planet,” remarks Bryan Koop, Boston Properties’ executive vice president for the Boston region. “Boston Properties is thrilled to be partnering with Google, MIT, and the City of Cambridge to provide access and extend connectivity to all residents in the area.”

Since the network investment was a truly collaborative venture, residents and city leaders will join with MIT, Google, and Boston Properties to celebrate Kendall Wi-Fi at a Nov. 29 dinner event hosted by the Cambridge Housing Authority at the Pisani Center. Greg Russ, executive director of the CHA, helped to plan the festivities. “We have invited all residents from Washington Elms and Newtowne Court to attend the event so they can be aware of the new service and celebrate its creation, along with all the sponsors. On behalf of our community, I am thankful for the addition of this critically important service. It will make a big difference in the lives of our residents.”

At the event, Mayor E. Denise Simmons will officially announce the launch of Kendall Wi-Fi. “It’s heartening to see our business and institutional partners coming together to support the residential community in this manner,” the mayor says. “This collaboration will bring a high-impact benefit for our families in the Washington Elms and Newtowne Court neighborhoods. More and more, we are seeing just how truly critical it is for people to have reliable internet access, which is why I am so pleased to see this service being implemented.”



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domingo, 27 de noviembre de 2016

Four MIT students named 2017 Marshall Scholars

Four MIT students — Matthew Cavuto, Zachary Hulcher, Kevin Zhou, and Daniel Zuo — are winners in this year’s prestigious Marshall Scholarship competition. Another student, Charlie Andrews-Jubelt, was named an alternate. The newest Marshall Scholars come from the MIT departments of Mechanical Engineering, Physics, Mathematics, and Electrical Engineering and Computer Science.

Funded by the British government, the Marshall Scholarships provide exceptional young Americans the opportunity for two years of graduate study in any field at a U.K. institution. Up to 40 scholarships are awarded each year in the rigorous nationwide competition. Scholars are selected on the basis of academic merit, leadership potential, and ambassadorial potential.

“The Presidential Committee on Distinguished Fellowships is so proud — as am I, personally — to have had the opportunity to help all the nominated MIT students through the Marshall Scholarship process,” says Kim Benard, assistant dean of distinguished fellowships and academic excellence. “Matthew, Zach, Kevin, and Daniel represent the very best of MIT. We have also had the great pleasure to work with students who ultimately didn’t win, but who will have extraordinary careers that will increase the reputation of MIT.”

Matthew Cavuto

Matthew Cavuto, from Skillman, New Jersey, is an MIT senior majoring in mechanical engineering with a concentration in biomechanics and biomedical devices. As a Marshall Scholar, Cavuto will engage in advanced prosthetic and assistive technology research over the course of two years of study in the U.K. at Imperial College London and Cambridge University.

In his first year, Cavuto will pursue an MS in biomedical engineering (concentrating in neurotechnology) at Imperial College London, working with Tim Constandinou on the SenseBack Project, an initiative aimed at allowing amputees to feel through their prostheses. In his second year, he will earn an MPhil in Engineering at Cambridge University, under the supervision of Fumiya Iida in the Bio-Inspired Robotics Laboratory, designing assistive technologies and exoskeletons through imitating nature. Cavuto plans to eventually earn a PhD in biomechatronics with the goal of revolutionizing accessible mobility for the paralyzed by designing the world’s first successful robotic exoskeleton.

Cavuto became interested in creating the next generation of prostheses and assistive devices while volunteering at New Jersey’s Kessler Institute for Rehabilitation, where he observed firsthand the challenges faced by amputees. During a summer internship at Germany’s Technical University of Berlin, Cavuto investigated the development of a prosthetic exoskeleton to rehabilitate stroke patients. As a researcher at the MIT Global Engineering and Research (GEAR) Lab, Cavuto has investigated and prototyped new designs for prosthetic knees tailored for people living in developing countries. He currently leads a team that, with nongovernmental organizations in India, has developed and field-tested a low-cost device that allows above-knee amputees to cross their legs. With a patent pending, he hopes to soon transition to manufacturing and distribution of the device to the millions of amputees living in the developing world. 

In extracurricular activities, Cavuto participates in varsity fencing and is an award-winning ballroom dancer and woodworker. Amos Winter, assistant professor in the Department of Mechanical Engineering and the director of GEAR, says, “Matt represents the finest of our students at MIT. He has taken just about every hands-on engineering design course offered at MIT, and he is a prolific carpenter, designer, and artist. Matt exemplifies MIT’s motto of ‘mens et manus,’ or, mind and hand.”

Zachary Hulcher

Zachary Hulcher, from Montgomery, Alabama, is pursuing a dual major in electrical engineering and computer science and physics, with a minor in mathematics. As a Marshall Scholar, he will study and perform research in high-energy physics at Cambridge University, following in the footsteps of such luminary physicists as Newton, Maxwell, and Hawking. Hulcher plans to earn a PhD and, as a professor of physics, make contributions to expand the field of high energy physics.

Hulcher spent his sophomore summer conducting research with Professor Yen-Jie Lee at the Compact Muon Solenoid (CMS) Experiment at CERN’s Large Hadron Collider in Geneva, Switzerland. He returned to CERN his junior summer to continue with and present on his research. Since the fall of 2015, he has been a research assistant in the group of physics professor Krishna Rajagopal at the Center for Theoretical Physics at MIT. Hulcher has been improving the analysis and modeling of how CMS measurements can be used to probe quark-gluon plasma, a substance connected to the Big Bang that may lead to greater understanding of the formation of the universe. "Zach took on, mastered, and then drove a theoretical physics research project,” observes Rajagopal. “He will be the principal author of a paper describing an important advance, and he showed fearless confidence in giving a talk at an international workshop in which he showed new results (some only hours old) that garnered much attention. All the while, he is both well-grounded and well-rounded.”

Hulcher is also motivated by a desire to teach others. He has been a teaching assistant for the physics department at MIT, a grader in the mathematics department, and a tutor for MIT’s chapter of Eta Kappa Nu, the national honor society for electrical engineering and computer science. Through the MIT International Science and Technology Initiatives’ Global Teaching Labs, he traveled to Xalapa, Mexico, to assist with courses focused on mobile and internet technologies, and he taught courses on physics to high school students in Italy and Israel.

Since his freshman year, Hulcher has been an offensive lineman with MIT’s varsity football team and was named this year to the NEWMAC all-academic team for his outstanding scholarly and athletic performance. Hulcher also serves on the executive board for the MIT chapter of the Tau Beta Pi engineering honor society.

Kevin Zhou

Kevin Zhou, from Carlsbad, California, will graduate next June with dual bachelor’s degrees in physics and mathematics. He will then embark on a two-year course of study at Cambridge University and the University of Durham. In his first year, Zhou will acquire an MAst in Cambridge’s department of applied mathematics and theoretical physics by completing part III of the Mathematical Tripos course. In his second year, he will earn an MS at Durham’s Institute for Particle Physics Phenomenology. When he returns to the U.S., Zhou will pursue a PhD in particle physics. He ultimately plans to be a research professor in theoretical physics and contribute to new methods to teach physics.

Zhou is currently involved in two MIT physics research groups. In the Physics of Living Systems Group, led by Jeremy England, the Thomas D. and Virginia W. Cabot Career Development Associate Professor of Physics, Zhou is researching the thermodynamics of DNA damage and repair, and has co-authored a paper on nonequilibrium states that has been submitted to Physical Review Letters. “Kevin has a polyglot sort of fluency in different idea-spaces that makes him able to see where the math might be applicable in ways that very few people can,” says England. Zhou is also working with associate professor of physics Jesse Thaler, whose research group at the Center for Theoretical Physics uses quantum chromodynamics to analyze the structure of jets, the sprays of particles produced in high-energy collisions. Zhou has been developing cutting-edge analytic techniques for determining the problem of quark/gluon discrimination; his efforts will be applied in the search for new physics at the Large Hadron Collider at CERN.

Zhou received honorable mention at this year’s prestigious Putnam Mathematical Competition for college students. In addition to his passion for pure mathematics, Zhou is intrigued by computer science and has interned as a software engineer at Dropbox and Facebook.

Zhou is committed to helping the next generation of physics students and researchers. As vice president of the Society of Physics Students, he directed a summer reading group for his peers on advanced mathematical methods and taught STEM classes to middle school students through the MIT Splash program. He is a junior coach for the U.S. Physics Olympiad where he has developed and taught classes on physics concepts and mentored students at yearly training camps. Zhou also enjoys singing and has performed with the MIT Concert Choir and MIT Centrifugues.

Daniel Zuo

Daniel Zuo, from Memphis, Tennessee, is graduating next June with a bachelor’s degree in electrical engineering and computer science, an MEng in electrical engineering and computer science, and a minor in creative writing. At Cambridge University, Zuo will do two consecutive one-year master’s degree programs: an MPhil in advanced computer science and an MPhil in machine learning, speech, and language technology. After completing his studies in the U.K., Zuo will pursue a PhD and hopes to develop a startup venture that will advance internet connectivity in the developing world. He ultimately plans to teach and conduct research as a professor of computer science.

Zuo is particularly interested in lossless datacenter architectures and their potential to help people interact more effectively with massive amounts of data. He is currently a research assistant for TIBCO Career Development Assistant Professor Mohammad Alizadeh in the Networks and Mobile Systems group at MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL). Alizadeh’s group works to improve the performance, usability, and robustness of networks and cloud services; Zuo has been investigating algorithms that provide scheduling and congestion control to enhance network performance. “Daniel is brilliant,” Alizadeh says. “It’s been a joy to work with him. He is one of those rare students that can jump into an unfamiliar area and quickly figure out exactly the right way to think about the hard technical problems.”

Zuo has also conducted research in Professor Manolis Kellis’ group at CSAIL, which focuses on computational methods for accessing large data sets for the analysis of human disease. He developed “greedy” algorithms to produce a comprehensive set of overlapping enhancers across cell types for a specific gene. He has also worked as a software engineer at several technology and finance companies, including Electronic Arts, Arcadia Funds, and Complete Solar Solutions. Zuo’s own projects include Fold, a mobile payment service to allow easy and secure peer-to-peer Bitcoin transactions over Bluetooth technology.

In his freshman year, Zuo helped launch MakeMIT, the largest hardware hackathon in the nation, and has continued his involvement with the project as a committee member with the MIT student organization TechX. Zuo is also active in public service in the Boston community through his leadership roles with the Phi Kappa Theta fraternity.



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viernes, 25 de noviembre de 2016

New method for analyzing crystal structure

A new technique developed by MIT researchers reveals the inner details of photonic crystals, synthetic materials whose exotic optical properties are the subject of widespread research.

Photonic crystals are generally made by drilling millions of closely spaced, minuscule holes in a slab of transparent material, using variations of microchip-fabrication methods. Depending on the exact orientation, size, and spacing of these holes, these materials can exhibit a variety of peculiar optical properties, including “superlensing,” which allows for magnification that pushes beyond the normal theoretical limits, and “negative refraction,” in which light is bent in a direction opposite to its path through normal transparent materials.

But to understand exactly how light of various colors and from various directions moves through photonic crystals requires extremely complex calculations. Researchers often use highly simplified approaches; for example they may only calculate the behavior of light along a single direction or for a single color.

Instead, the new technique makes the full range of information directly visible. Researchers can use a straightforward laboratory setup to display the information — a pattern of so-called “iso-frequency contours” — in a graphical form that can be simply photographed and examined, in many cases eliminating the need for calculations. The method is described this week in the journal Science Advances, in a paper by MIT postdoc Bo Zhen, recent Wellesley College graduate and MIT affiliate Emma Regan, MIT professors of physics Marin Soljačić and John Joannopoulos, and four others.

The discovery of this new technique, Zhen explains, came about by looking closely at a phenomenon that the researchers had noticed and even made use of for years, but whose origins they hadn’t previously understood. Patterns of scattered light seemed to fan out from samples of photonic materials when the samples were illuminated by laser light. The scattering was surprising, since the underlying crystalline structure was fabricated to be almost perfect in these materials.

“When we would try to do a lasing measurement, we would always see this pattern,” Zhen says. “We saw this shape, but we didn’t know what was happening.” But it did help them to get their experimental setup properly aligned, because the scattered light pattern would appear as soon as the laser beam was properly lined up with the crystal. Upon careful analysis, they realized the scattering patterns were generated by tiny defects in the crystal — holes that were not perfectly round in shape or that were slightly tapered from one end to the other.

“There is fabrication disorder even in the best samples that can be made,” Regan says. “People think that the scattering would be very weak, because the sample is nearly perfect,” but it turns out that at certain angles and frequencies, the light scatters very strongly; as much as 50 percent of the incoming light can be scattered. By illuminating the sample in turn with a sequence of different colors, it is possible to build up a full display of the relative paths light beams take, all across the visible spectrum. The scattered light produces a direct view of the iso-frequency contours — a sort of topographic map of the way light beams of different colors bend as they pass through the photonic crystal.

“This is a very beautiful, very direct way to observe the iso-frequency contours,” Soljačić says. “You just shine light at the sample, with the right direction and frequency,” and what comes out is a direct image of the needed information, he says.

The finding could potentially be useful for a number of different applications, the team says. For example, it could lead to a way of making large, transparent display screens, where most light would pass straight through as if through a window, but light of specific frequencies would be scattered to produce a clear image on the screen. Or, the method could be used to make private displays that would only be visible to the person directly in front of the screen.

Because it relies on imperfections in the fabrication of the crystal, this method could also be used as a quality-control measure for manufacturing of such materials; the images provide an indication of not only the total amount of imperfections, but also their specific nature — that is, whether the dominant disorder in the sample comes from noncircular holes or etches that aren’t straight — so that the process can be tuned and improved.

“Using a clever trick, the Soljačić group turned what is ordinarily a nuisance (i.e., unavoidable disorder in nanofabrication) to their advantage,” says Mikael Rechtsman, an assistant professor of physics at Pennsylvania State University who was not involved in this work. “The random scattering caused by the disorder allowed them to directly image the iso-frequency contours of the photonic crystal slab structure. Since any nanofabricated structure always has some degree of disorder, and since disorder is invariably difficult to model a priori in simulations, their method provides an extremely convenient characterization tool for photonic crystal resonant mode band structures.”

Rechtsman adds, “This could become an essential tool in the hunt for high-power single-mode semiconductor lasers (in particular, photonic crystal surface emitting lasers), with wide-ranging applications including telecommunications and manufacturing.”

The team also included researchers at MIT Research Laboratory of Electronics, including Yuichi Igarashi (now at NEC Corporation in Japan), Ido Kaminer, Chia Wei Hsu (now at Yale University), and Yichen Shen. The work was supported by the Army Research Office through the Institute for Soldier Nanotechnologies at MIT, and by the U.S. Department of Energy through S3TEC, an Energy Frontier Center.



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miércoles, 23 de noviembre de 2016

Enhancing education from pre-K to MIT and beyond

To improve education — whether pK-12, college, professional training, or online courses — one must first gain an understanding of how people learn. Applying that learning on a large scale requires a forward-thinking focus on expanding the reach of high-quality education for learners of all ages, all across the globe. 

These are the challenges that drive two Institute-wide initiatives announced by President L. Rafael Reif earlier this year: the MIT Integrated Learning Initiative (MITili) and the pK-12 Action Group

The integrated sciences of learning, now emerging as a significant field of research, is at the core of MITili (pronounced “mightily”). By applying scientific rigor to investigate the methods that lead to effective learning, MITili aims to enhance the educational experience at all perspectives — from improving education at MIT to inspiring lifelong learning online to advancing the Institute’s campaign to promote STEM understanding within elementary, middle, and high schools.

Fueled by MIT’s residential education and global online efforts, MITili pulls together resources from across campus to integrate faculty insights and foster rigorous quantitative and qualitative research in education. The initiative leverages expertise in cognitive psychology, neuroscience, economics, engineering, public policy, and other fields. 

It is this cross-discipline thinking that led to the recent appointment of Parag Pathak, professor of economics and a founder of the School Effectiveness and Inequality Initiative (SEII), as MITili deputy director. Pathak, who has worked extensively with the Boston school system to make it easier to navigate school assignment systems and level the playing field for city families, will join MITili Director John Gabrieli, a professor in the Department of Brain and Cognitive Sciences, in guiding the group’s vision. Based on Pathak’s background, the new position is a natural fit.

“MIT is known for solving problems, so if we can improve how people learn then we can improve how much education they get,” Pathak explains. “Individuals who have more access to education not only learn more but live longer and are better citizens.” 

Supported by two new staff members, Associate Director Jeff Dieffenbach and Program Coordinator Steve Nelson, Pathak and MITili are off and running on several projects, including continued exploration into Boston’s school assignments, an in-depth analysis of charter schools and their effectiveness for special education students, and an upcoming study on the impact of affirmative action policies in education. Says Pathak: “A lot of our work is very fresh and new. By taking a scientific perspective to solve problems, we are breaking free of the old way of thinking.”

The Office of Digital Learning has also established a separate, though related, initiative called the pK-12 Action Group, which enables a diverse MIT community to collaborate on STEM projects for pre-kindergarten through 12th grade students and teachers. By working together, MIT faculty, staff, and students amplify their impact on existing efforts — studies, classroom technologies, curriculum, teacher professional development — while driving new work and outreach, all with the goal of understanding how learning happens and transforming how students learn. 

Professor Eric Klopfer, director of both the MIT Scheller Teacher Education Program and MIT Education Arcade, has been involved with the pK-12 Action Group since its early stages. Recently named co-chair of the pK-12 advisory group, Klopfer joins Professor Angela Belcher and provides breadth to the leadership team. Associate Director Claudia Urrea brings over 20 years of experience in the field of education and technology. She works together with the faculty to coordinate direction and vision and to engage the larger pK-12 community at MIT.   

“We come at this from different perspectives,” Klopfer says. “Angie is passionate about science and engineering and making them accessible to all, while I come from a more established learning and education focus. Both angles are important to tackle these global challenges and make a significant impact on pk-12 education. We’re thinking big.”

Collaboration with the community is key. For this reason, the effort is led by practicing educators, not administrators. And it’s why the work is already making a big difference, with the following initiatives:

  • Connected Learning Initiative (CLIx), a cross-unit project with MIT’s Office of Digital Learning, gives thousands of young people from under-served communities in India an opportunity for quality education through the meaningful integration of technology;
  • Teaching Systems Lab (TSL), working in partnership with the Woodrow Wilson National Fellowship Foundation, examines what it takes to prepare new teachers for today’s classrooms and the systems needed to help these teachers transform learning through tomorrow’s learning environments; and
  • on-campus workshops, which leverage many existing pK-12 efforts at MIT, are designed to provide professional teacher development, advance STEM curricula, and explore new ways to enhance educational experiences.

The goal of influencing how people around the world get educated is big, bold — and shared by both MITili and the pK-12 Action Group. But that doesn’t mean the goal is out of reach. As Pathak says: “It all starts with the science of learning.”



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Saharan dust in the wind

Every year, trade winds over the Sahara Desert sweep up huge plumes of mineral dust, transporting hundreds of teragrams — enough to fill 10 million dump trucks — across North Africa and over the Atlantic Ocean. This dust can be blown for thousands of kilometers and settle in places as far away as Florida and the Bahamas.

The Sahara is the largest source of windblown dust to the Earth’s atmosphere. But researchers from MIT, Yale University, and elsewhere now report that the African plume was far less dusty between 5,000 and 11,000 years ago, containing only half the amount of dust that is transported today.

In a paper published today in Science Advances, the researchers have reconstructed the African dust plume over the last 23,000 years and observed a dramatic reduction in dust beginning around 11,000 years ago. They say this weakened plume may have allowed more sunlight to reach the ocean, increasing its temperature by 0.15 degrees Celsius — a small but significant spike that likely helped whip up monsoons over North Africa, where climate at the time was far more temperate and hospitable than it is today.

“In the tropical ocean, fractions of a degree can cause big differences in precipitation patterns and winds,” says co-author David McGee, the Kerr-McGee Career Development Assistant Professor in MIT’s Department of Earth, Atmospheric and Planetary Sciences. “It does seem like dust variations may have large enough effects that it’s important to know how big those impacts were in past and future climates.”

McGee’s co-authors include lead author Ross Williams, a former graduate student at MIT; along with Christopher Kinsley, Irit Tal, and David Ridley from MIT; Shineng Hu and Alexey Fedorov from Yale University; Richard Murray from Boston University; and Peter deMenocal from Columbia University.

A wet Sahara

Around 11,000 years ago, the Earth had just emerged from the last ice age and was beginning a new, interglacial epoch known as the Holocene. Geologists and archaeologists have found evidence that during this period the Sahara was much greener, wetter, and more livable than it is today.

“There was also extensive human settlement throughout the Sahara, with lifestyles that would never be possible today,” McGee says. “Researchers at archaeological sites have found fish hooks and spears in the middle of the Sahara, in places that would be completely uninhabitable today. So there was clearly much more water and precipitation over the Sahara.”

This evidence of wet conditions shows that the region experienced regular monsoon rains during the early Holocene. This was primarily due to the slow wobbling of Earth’s axis, which exposed the Northern Hemisphere to more sunlight during summer; this, in turn, warmed the land and ocean and drew more water vapor — and precipitation — over North Africa. Increased vegetation in the Sahara may have also played a role, absorbing sunlight and heating the surface, drawing more moisture over the land. 

“The mysterious thing is, if you try to simulate all these changes in these early and mid-Holocene climates, the models intensify the monsoons, but nowhere near the amounts suggested by the paleodata,” McGee says. “One of the things not factored into these simulations is changes in windblown dust.”

Tracking a dust plume

In their results published today, McGee and colleagues propose a reduction in African dust may indeed have contributed to increasing monsoon rains in the region. The researchers came to their conclusion after estimating the amount of long-range windblown dust emitted from Africa over the last 23,000 years, from the end of the last ice age to today.

They focused on dust transported long distances, as these particles are small and light enough to be lifted and carried through the atmosphere for days before settling thousands of kilometers away from their source. This fine-grained dust scatters incoming solar radiation, cooling the ocean’s surface and potentially affecting precipitation patterns, depending on how much dust is in the air.

To estimate how the African dust plume has changed over thousands of years, the team looked for places where dust should accumulate rapidly. Dust can sink to the floor of open ocean, but there layers of sediment build up very slowly, at a rate of 1 centimeter every 1,000 years.

Places like the Bahamas, by contrast, accumulate sediment much more quickly, making it easier for scientists to determine the ages of particular sediment layers. What’s more, it’s been shown that most of the windblown dust that has accumulated in the Bahamas originated not from local regions such as the U.S., but from the Sahara.

Dust’s climate role

McGee and his colleagues obtained sediment core samples from the Bahamas that were collected in the 1980s by scientists from the Woods Hole Oceanographic Institution. They brought the samples back to the lab and analyzed their chemical composition, including isotopes of thorium — an element that exists in windblown dust worldwide, at known concentrations.

They determined how much dust was in each sediment layer by measuring the primary isotope of thorium, and determined how fast it was accumulating by measuring the amount of a rare thorium isotope in each layer.

In this way, the team analyzed sediment layers from the last 23,000 years, and showed that around 16,000 years ago, toward the end of the last ice age, the dust plume was at its highest, lofting at least twice the amount of dust over the Atlantic, compared to today. However, between 5,000 and 11,000 years ago, this plume weakened significantly, with just half the amount of today’s windblown dust.

Colleagues at Yale University then plugged their estimates into a climate model to see how such changes in the African dust plume would affect both ocean temperatures in the North Atlantic and overall climate in North Africa. The simulations showed that a drop in long-range windblown dust would raise sea surface temperatures by 0.15 degrees Celsius, drawing more water vapor over the Sahara, which would have helped to drive more intense monsoon rains in the region.

“The modeling showed that if dust had even relatively small impacts on sea surface temperatures, this could have pronounced impacts on precipitation and winds both in the north Atlantic and over North Africa,” McGee says. Noting that the next key step is to reduce uncertainties in the modeling of dust’s climate impacts, he adds: “We’re not saying, the expansion of monsoon rains into the Sahara was caused solely by dust impacts. We’re saying we need to figure out how big those dust impacts are, to understand both past and future climates.”

Ina Tegen, a professor at the Leibniz Institute for Tropospheric Research in Germany, says the group’s results suggest that “dust effects today may be considerable as well.”

“Dust loads vary with changing climate, and due to the effects of dust on [solar] radiation, ice formation in clouds, and the carbon cycle, this may cause important climate  feedbacks,” says Tegen, who was not involved in the research. “The changing climate since the last ice age can be considered a ‘natural laboratory’ to study such effects. Understanding the past is the basis for predicting future changes with any confidence.”

This research was supported, in part, by the National Science Foundation.



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