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Thursday, August 7th, 2014

    Time Event
    12:00a
    The history man

    In the early 1960s, the United States had 350,000 military troops in West Germany. At a glance, this fact might not seem relevant to international monetary policy. But as Francis Gavin pointed out in a 2004 book on the subject, it mattered to U.S. policymakers: Dollars were being sent overseas and staying there.

    “One of the largest burdens on U.S. accounts abroad that put pressure on the currency was military spending,” says Gavin, who is now a political science professor at MIT. “And one of the largest parts of military spending was having people, and their families, abroad.”

    Indeed, as Gavin asserted in that book, “Gold, Dollars, and Power,” four consecutive presidential administrations in the U.S., from Dwight Eisenhower’s through Richard Nixon’s, were “obsessed with trying to end the U.S. payments imbalance and gold outflow without jeopardizing America’s vast political and military commitments around the world.” This tension was a major reason the gold system got scrapped in 1971, in Gavin’s view.

    This helps explain another thing that might not be obvious at a glance: how a scholar writing about monetary policy early in his career would evolve into a leading expert on nuclear weapons policy, as Gavin has. Earlier this year, he joined MIT (from the University of Texas at Austin) as the first Frank Stanton Professor in Nuclear Security Policy Studies. He has since written a second historically grounded book, “Nuclear Statecraft” (Cornell University Press, 2012), an analysis of nuclear weapons policy, as well as numerous articles on the subject.

    As Gavin sees it, studying nuclear policy followed naturally from studying monetary policy.

    “It turns out there was a security story in that,” he explains. In the 1950s and 1960s, as U.S. leaders start talking about troop reductions abroad, “they realize they can’t pull these troops back. Why can’t they? Well, because they’re serving a purpose: to reassure the West Germans, so they don’t develop their own nuclear weapons.” That scenario, from the U.S. point of view, could have been far more fraught than simply dealing with one opposing nuclear superpower.

    In Gavin’s reassessment of the Cold War, then, economics and geopolitics are deeply intertwined: U.S. and Soviet leaders set nuclear and other military policies not so much through abstract game-theory maneuvers, but by constantly facing economic and military constraints. Moreover, Cold War statecraft was not a bilateral standoff, but a multilateral affair in which the superpowers were also trying to limit the nuclear capabilities of their allies. And only by thinking historically do we get this full picture, Gavin believes.

    “You get a better sense of those constraints and risks by going into the historical documents,” Gavin says. “It doesn’t look the way some of the models would show you it looks.” He adds: “There is no replacement for a deep, substantive knowledge of a particular country, a time, a language, a culture, the larger historical forces.”

    “Then 1989 happened”

    Indeed, the newest faculty member in MIT’s Department of Political Science and its Security Studies Program is actually a historian by training — albeit one who embraces multiple disciplines at once. Gavin received his BA in political science from the University of Chicago, but his graduate degrees, from Oxford University and the University of Pennsylvania, are in history.

    Gavin’s road to success started, as many do, with close scholarly mentorship. At Chicago he studied with the prominent political scientist John Mearsheimer, who was, Gavin says, “The first professor I got to know up close. And he’s been a role model my whole life, just seeing how hard he worked, how smart he was, how passionate he was about ideas.”

    Gavin might have been inclined to continue within political science, except for world events: The Berlin Wall fell and the Soviet Union’s hold over Eastern Europe shattered. To better grasp those changes, Gavin felt he needed to learn more history.

    “I graduated in 1988, and then 1989 happened, and the world turned upside down,” Gavin says. “It was kind of like ‘The Wizard of Oz,’ when it goes from black and white to color. And everything we’d assumed changed in the most amazing and dramatic ways. I wanted to learn more about that.”

    So Gavin moved away from the political models he had learned — for a while, anyway — and began studying Cold War history, working with the scholar Marc Trachtenberg at Penn.

    “My whole career has been trying to marry the deep, substantive, specific knowledge that I’ve tried to learn as a historian with the powerful analytical tools that social scientists develop,” Gavin explains, adding: “I have extraordinary respect for both disciplines.”

    Moving into the public sphere

    As Gavin continues to work on his own research, meanwhile, he has taken a keen interest in engaging with policymakers and global leaders, and impressing the uses of history upon them, too. History, as Gavin sees it, does not offer easy lessons from the past that can be plugged into present-day questions; rather, it demands rigorous critical thinking that lets us think about the constellation of forces at work when politics or society shifts.

    “There are a lot of people who say: ‘Does history provide lessons?’” Gavin observes. “I want to be very cautious about saying you can mine the past for specific lessons.”

    Instead, he adds, “It’s a way of thinking about things and understanding causality and change over time and developing a sensibility. Social scientists hate terms like ‘sensibility,’ but I can’t think of a better one for understanding things like unintended consequences. Having a deep historical sensibility gives you a sensitivity to those sorts of things.”

    As part of this outreach, Gavin helped lead the Next Generation Project, centered at Columbia University, which connected scholars and policymakers, including some from the current administration, in dialogue about global policy. One aim, Gavin says, has been to let politicians see “how applied history can be used to help make us better understand international relations and make better policy decisions.”

    In the meantime, Gavin’s scholarly research continues apace. He has been producing new papers about contemporary nuclear policy — and emphasizing the ways U.S. policy priorities have remained surprisingly intact over the decades.

    “The U.S. [has] always used its alliances not just to protect its friends, but to suppress its friends’ desires to get nuclear weapons,” Gavin says. Recognizing that this remains true, he thinks, “explains a lot of continuities between the Cold War and post-Cold War eras.”

    And for all his diverse disciplinary interests, Gavin is sure he is now in the right institutional location for his work: Moving to MIT, he says, represents a kind of intellectual homecoming, since his colleagues include historically engaged political scientists like Stephen Van Evera.

    “I consider MIT really the premier place to study these things, and it’s like a dream come true,” Gavin says. “The graduate students are amazing, the faculty are incredible. … I couldn’t imagine a better place.”

    2:00p
    Origami robot folds itself up, crawls away

    For years, a team of researchers at MIT and Harvard University has been working on origami robots — reconfigurable robots that would be able to fold themselves into arbitrary shapes.

    In today’s issue of Science, they report their latest milestone: a robot, made almost entirely from parts produced by a laser cutter, that folds itself up and crawls away as soon as batteries are attached to it.

    “The exciting thing here is that you create this device that has computation embedded in the flat, printed version,” says Daniela Rus, the Andrew and Erna Viterbi Professor of Electrical Engineering and Computer Science at MIT and one of the Science paper’s co-authors. “And when these devices lift up from the ground into the third dimension, they do it in a thoughtful way.”

    Rus is joined on the paper by Erik Demaine, an MIT professor of computer science and engineering, and by three researchers at Harvard’s Wyss Institute for Biologically Inspired Engineering and School of Engineering and Applied Sciences: Sam Felton, Michael Tolley, and Rob Wood.

    At the IEEE International Conference on Robotics and Automation this spring, Rus, Demaine, Wood, and five other researchers at MIT and Harvard presented a paper on bakable robots, which would self-assemble from laser-cut materials when uniformly heated. The new work is similar, but a network of electrical leads, rather than an oven or hot plate, delivers heat to the robot’s joints to initiate folding.

    “That’s exciting from a geometry standpoint,” Demaine says, “because it lets us fold more things. Because we can do the sequencing, we have a lot more control. And it lets us make active folding structures. Instead of just self-assembly, you can then make it walk.”

    The robot is built from five layers of materials, all cut according to digital specifications by a laser cutter. The middle layer is copper, etched into an intricate network of electrical leads. It’s sandwiched between two structural layers of paper; the outer layers are composed of a shape-memory polymer that folds when heated.

    After the laser-cut materials are layered together, a microprocessor and one or more small motors are attached to the top surface. In the prototype, that attachment was done manually, but it could instead be performed by a robotic “pick and place” system.

    “There is a magic sauce in the mechanical design that forms the leg system that can be actuated with one motor,” Rus says.

    In fact, while the researchers experimented with both single-motor and four-motor designs, the Science paper reports a design that uses two motors. Each motor controls two of the robot’s legs; the motors are synchronized by the microprocessor. Each leg, in turn, has eight mechanical “linkages,” and the dynamics of the linkages convert the force exerted by the motor into movement.

    “It’s called a one-degree-of-freedom structure, in which you just need to turn one crank and the whole thing moves in the way that you want,” Demaine explains. “It lets you transfer just one degree of freedom into a whole complicated motion, all through the mechanics of the structure.”

    In prior work, Rus, Demaine, and Wood developed an algorithm that could automatically convert any digitally specified 3-D shape into an origami folding pattern. The design of the new robot was intended to demonstrate not only the possibility of motion generation, but also the ability to perform the two folds necessary to produce arbitrary shapes. “You need to be able to do a single fold, ideally all the way to 180 degrees, in both directions,” Demaine says. “Then the next level of challenge is to do what’s called a cyclic fold, where you have a bunch of panels connected together in a cycle, and they can all fold simultaneously. That’s demonstrated in one component of the system.”

    The sharpest fold that the prototype system can execute is 150 degrees, not 180. But as Demaine explains, in origami, 180-degree folds are generally used to join panels together. With 150-degree folds, the panels won’t quite touch, but that’s probably tolerable for many applications.

    In the meantime, Demaine is planning to revisit the theoretical analysis that was the basis of the researchers’ original folding algorithm, to determine whether it’s still possible to produce arbitrary three-dimensional shapes with folds no sharper than 150 degrees.

    “It’s very exciting because there is always work to be done between theory and devices,” Rus says. “I make robots and love theory, and Erik proves theorems and loves mechanisms. In order for this research to work, you need people who are of the same mind about what is important.”

    “This is the first time where they’ve self-folded such a complicated robotic structure,” says Ronald Fearing, a professor of electrical engineering and computer science at the University of California at Berkeley, who has been following the MIT and Harvard researchers’ work. “Because they build it with the electronics on first, you can now choose which folds occur when. If you don’t have the electronics, then you’re limited to patterns where you heat up the whole thing and everything folds at once. So being able to do the timed sequence is a nice capability.”

    Origami robotics is “a pretty powerful concept, because cutting planar things and folding is an inherently very low-cost process,” Fearing says. “If you have a hollow-shell structure, then you have something that is very strong and very lightweight. If you put motors on there, you end up with a robot that is very powerful for its weight, so you start to be able to take advantage of things like you see with insects carrying so many times their weight. Folding, I think, is a good way to get to the smaller robots.”

    The work was funded by the National Science Foundation, the Wyss Institute for Biologically Inspired Research at Harvard, and the Air Force Office of Scientific Research.

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