D-branes on the Quintic

We study D-branes on the quintic CY by combining results from several directions: general results on holomorphic curves and vector bundles, stringy geometry and mirror symmetry, and the boundary states in Gepner models recently constructed by Recknagel and Schomerus, to begin sketching a picture of D-branes in the stringy regime. We also make first steps towards computing superpotentials on the D-brane world-volumes.Comment: harvmac, 78 pp (v3: notes added and improved discussion of an example

The Submarine and The Washington Conference of 1921

Following the First World War, the tide of public opinion was overwhelmingly against the submarine as a weapon of war. The excesses of the German U-boat had stunned the sensibilities of the world but had, nonetheless, presented new ideas and possibilities of this weapon to the various naval powers of the time, The momentum of these new ideas proved so strong that by the opening of the first major international disarmament conference of the 20th century, practical uses of the submarine had all but smothered the moral indignation of 1918