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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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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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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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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