What is DASH?
A central, open-access repository of research by members of the Harvard community.
Featured Works
Why Have Americans Become More Obese?
If you want to understand obesity in America, and how it’s changed in the last few decades, just take a look at the potato.
Americans have always eaten a lot of potatoes, but before the 1950s, people mostly baked, boiled, or mashed their spuds at home. Today the most common way Americans consume their favorite vegetable is the french fry—cut and peeled by a machine, frozen for transport, and then deep fried at a fast food chain.
In their essay, “Why Have Americans Become More Obese,” three economists argue that the nature of obesity in the United States has shifted as a result of changes in how food is prepared: “The switch from individual to mass preparation lowered the time price of food consumption and led to increased quantity and variety of foods consumed.” Faster preparation meant taking in more calories, leading predictably to an ever-expanding waistline.
David Cutler, Otto Eckstein Professor of Applied Economics, and Edward L. Glaeser, the Fred and Eleanor Glimp Professor of Economics, co-authored the study in 2003 with Harvard alumnus Jesse M. Shapiro, now a professor of economics at the University of Chicago Booth School of Business.
Religion, Science, and Anatomy
In his paper, “The Question of Anatomy: Towards a Different Understanding of the Interactions of Religion and Science in the Medieval Middle East,” Prof. Ahmed Ragab explains that in the Middle Ages, anatomy was not, as it is today, a matter of empirical observation. Instead, in the Medieval Middle East, the discourse of anatomy had its foundations in the medical theory of the ancient Greeks and the religious teachings of Islam. Medical scholars had to find creative ways “to deal with the conflicting authorities and sometimes contradicting narratives” of these two traditions.
Prof. Ragab, an affiliate of the FAS department of the history of science, is also the first Richard T. Watson Assistant Professor of Science and Religion in the Faculty of Divinity. He will be delivering a public lecture to mark the inauguration of this new professorship on March 29, 2012, at Andover Hall.
The Robot Swarm
A kilobot is a modular robot about the size of a quarter. It can’t do much on its own, but a collective of several hundred kilobots can work together to form shapes and overcome obstacles in their path.
Together, the robots act like a swarm, maintaining set distances from one other, communicating with neighbors, and coming to collective agreement about the position of each member of the collective.
In their article, “Kilobot: A Robotic Module for Demonstrating Behaviors in a Large Scale (210 Units) Collective”, Michael Rubenstein, a post-doctoral fellow in computer science, and Radhika Nagpal, Thomas D. Cabot Associate Professor of Computer Science, demonstrate how a collective of robots can self-assemble into a desired shape, reforming the shape if it is disrupted or if there is a change in the number of bots.
Advising the Advisors
“Any law professor who does not get asked to sign ‘scholars’ briefs’,” Richard Fallon observes, “is not much of a scholar.” A professor in constitutional law at Harvard Law School, Fallon considers the ethical implications for legal scholars of participating in scholarly briefs in his article, “Scholars’ Briefs and the Vocation of a Law Professor.”
In briefs of this kind, scholars draw on both their legal knowledge and their perceived objectivity to provide support to one side of an argument before a court. Scholars may write the briefs themselves, but often they are sought out by one party or the other to endorse an already-written brief.
In his article, Prof. Fallon suggests that his colleagues ought to consider exercising some restraint when it comes to these documents: “Law professors often should say no, or at least we should say no much more frequently than many of us now do. And when we say yes—as we should sometimes—we should insist that scholars’ briefs reflect higher norms of scholarly integrity than many such briefs now satisfy.”
Global Wind Power
Could the world run on wind power? “Absolutely,” says Michael McElroy, Gilbert Butler Professor of Environmental Studies.
Based on a simulation of global wind fields, McElroy and his colleagues concluded:
“A network of land-based 2.5 MW turbines restricted to non-forested, ice-free, non-urban areas operating as little as 20% of their rated capacity, could supply more than 40 times current worlde consumption of electricity, more than 5 times total global use of energy in all forms.”
The full study, “Global Potential for Wind-Generated Electricity,” was co-authored with Xi Lu, Post-Doctoral Fellow in Atmospheric Chemistry, and Juha Kiviluoma of the VTT Technical Research Centre of Finland.
You can find a complete list of Prof. McElroy’s work in DASH here.
Painting, Pollock, and Fluid Dynamics
In the 1940s, the American artist Jackson Pollock developed a new style of abstract painting. He used common, synthetic paints, dripping or pouring these directly onto the canvas. Pollock described the technique of his “drip paintings” this way: “I continue to get further away from the usual painter’s tools such as easel, palette, brushes, etc. I prefer sticks, trowels, knives and dripping fluid paint or a heavy impasto with sand, broken glass or other foreign matter added.”
In “Painting with Drops, Jets, and Sheets,” Harvard Professor of Physics, Applied Mathematics and Organismic and Evolutionary Biology Lakshminarayanan Mahadevan, along with his colleagues at Boston College, use Pollock’s work to illustrate and reconsider the boundary between art and physics.
The artist is not a slave to the physical properties of her materials; she uses her materials to execute an aesthetic vision which transcends them. The authors argue, however, that Pollock “creatively ceded some of the responsibility for the appearance of his work to natural phenomena, inviting fluid dynamics to coauthor his pieces.” They suggest that “using the tools of physics and art history one may begin to dilineate the intersection of what is aesthetically viable and what is physically possible.”
You can find a complete list of Prof. Mahadevan’s work in DASH here.
