Railroads, Cases and Selections

Railroads and American Law

Railroads and American Economic Growth : A

This paper examines the historical impact of railroads on the American economy, with a focus on quantifying the aggregate impact in the agricultural sector in 1890. Expansion of the railroad network may have affected all counties directly or indirectly — an econometric challenge that arises in many empirical settings. However, the total impact on each county is captured by changes in that count...

Selections

It was not until the sixteenth century that dead bodies were submitted to medico-legal investigation. The horror which human dissections inspired in the ancients, and the religious awe with which they beheld the mortal wreck of their fellows, not only retarded the progress of anatomy and physiology, but excluded the light of medicine from the researches of the forum. The Jewish law, indeed, con...

Zigzags, Railroads, and Knots in Fullerenes

Two connections between fullerene structures and alternating knots are established. Knots may appear in two ways: from zigzags, i.e., circuits (possibly self-intersecting) of edges running alternately left and right at successive vertices, and from railroads, i.e., circuits (possibly self-intersecting) of edge-sharing hexagonal faces, such that the shared edges occur in opposite pairs. A z-knot...

Selections Reprinted

MR1631259 (2000d:11019) 11B25; 11N13 Gowers, W. T. A new proof of Szemerédi’s theorem for arithmetic progressions of length four. Geometric and Functional Analysis 8 (1998), no. 3, 529–551. This remarkable paper gives a new proof that every subset of the integers with positive density must contain arithmetic progressions of length four. This was conjectured by P. Erdős and P. Turán [J. London M...