Diana Davis

Power, Knowledge, and Environmental History in the Middle East and North Africa

To consider in what ways incorporating the emerging field of environmental history into studies of the Middle East challenges our views of the past and/or present, it is necessary first to take stock of our mainstream notions of the environment in the Middle East and North Africa (MENA) and how we think it has changed over the last several thousand years. The most common received wisdom about the environment in the MENA is that it is an arid, marginal environment, in many places a wasteland degraded by overgrazing and deforestation for hundreds if not thousands of years. The local populations, especially nomads and small farmers, are frequently blamed for the alleged environmental ruin. Born in large part of Western imperialism in the region, this environmental imaginary of the MENA has been uncritically adopted by the majority of postindependence ruling elites as well as development agencies.

Deserts and Drylands Before the Age of Desertification

This chapter analyses the deep and complex history of western thinking about deserts and desertification in the centuries before the word desertification was coined in 1927 by a French colonial forester. It shows that a relatively benign view of the drylands dominated in western thinking until the early colonial period when notions of deforestation causing desiccation began to take shape. During the period of 19th century colonialism, particularly British and French colonialism in Africa, deserts, drylands, and their degradation became a particular focus of colonial scientific research as well as practical policy formulation. It was during this period that indigenous peoples, primarily but not only nomads, were blamed most often for what later came to be called desertification. French colonial experiences, first in North Africa, and later in West Africa were especially influential in the formation of much of our contemporary mainstream understandings of desertification, and thus our management of the drylands, today. A great deal of our thinking about drylands, as well as many policies for developing them, derive from the colonial period and were carried into the contemporary mainstream in large part by several UN agencies. The chapter concludes by suggesting that desertification is a (neo)colonial concept that would benefit from careful reconsideration.

Negative refraction and tiling billiards

Abstract We introduce a new dynamical system that we call tiling billiards, where trajectories refract through planar tilings. This system is motivated by a recent discovery of physical substances with negative indices of refraction. We investigate several special cases where the planar tiling is created by dividing the plane by lines, and we describe the results of computer experiments.

Inquiry-Based Learning in a First-Year Honors Course.

Abstract We describe a case study of a problem-solving section, using the “Harkness” discussion method, of an honors multivariable calculus course. Students in the problem-solving section had equivalent outcomes on exams, reported higher ratings in self-assessments of skills, and took more math classes in the following year, compared with students in the lecture-based sections.

Between Sand and Sea: Constructing Mediterranean Plant Ecology

The iconic landscapes of the Mediterranean Basin have long stimulated the imaginations of artists, writers, and scientists. They have primarily been portrayed as degraded, an interpretation absorbed into the developing discipline of ecology. The core concepts of Mediterranean vegetation ecology, though, are based largely on the work of Louis Emberger, a French colonial botanist. This chapter analyzes Emberger’s problematic approach and its use as the foundation of a great deal of scientific work on the ecology of the Basin. It concludes that Mediterranean vegetation ecology would benefit from “knowledge decolonization” that demonstrates the complex messiness of knowledge politics, material landscape change, and social dynamics together in order to avoid the ecologically and socially problematic outcomes that have been common in the Basin for a century.

Average Pace and Horizontal Chords

We are motivated by a problem about running: If a race was completed in an average pace of P minutes per mile, is there necessarily some mile of the race that was run in exactly P minutes? The answer is no. We explain why, and describe the history of this celebrated problem, known as the Universal Chord Theorem. We also clarify and streamline the proof of a more powerful result by Heinz Hopf from 1937.

Geodesics on the regular tetrahedron and the cube

Consider all geodesics between two given points on a polyhedron. On the regular tetrahedron, we describe all the geodesics from a vertex to a point, which could be another vertex. Using the SternBrocot tree to explore the recursive structure of geodesics between vertices on a cube, we prove, in some precise sense, that there are twice as many geodesics between certain pairs of vertices than other pairs. We also obtain the fact that there are no geodesics that start and end at the same vertex on the regular tetrahedron or the cube.