TASK DEFINITION: In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.
PROBLEM: The Stratton-Chu model of this phenomenon attempts to improve on earlier scalar models such as the Rayleigh-Sommerfeld theory. The equivalence of complementary arrangements in producing this phenomenon is described by Babinets principle. A simple scalar theory of this phenomenon makes use of an integral named for Kirchhoff and Fresnel, and a simple pictorial model of this phenomenon is given by Huygens principle of wave propagation. FTP name this behavior observed in electrons by Davisson and Germer, the bending of waves as they pass obstacles.

SOLUTION: Science

PROBLEM: The category of these objects has the property that every morphism is a monomorphism. The spectrum of one of these objects contains one point, and the p-adic numbers for a given p form one of these. These objects necessarily have zero Krull dimension. Those with a finite number of elements have order equal to a power of a prime. Their extensions have a one-to-one correspondence with their intermediates according to the fundamental theorem of Galois theory. A division algebra is one of these without multiplicative commutativity, and can be defined as a ring with multiplicative identity, inverse, and commutativity. For 10 points, name these algebriac structures that include the rationals and reals.

SOLUTION: Science

PROBLEM: This country's paluumuuto law has allowed for the repatriation of Ingrians to this nation since the early 1990s. One president of this country was re-elected after his opponent, Honka, withdrew following the "Note Crisis", which was prompted by pressure from the Soviet Union, with whom this country signed the YYA Treaty. An earlier agreement with the Soviets saw this nation lease Porkkala as a military base, thus eliminating Russia's need for this nation's Hanko Peninsula. Prior to leading this country through the Lapland War, Carl Mannerheim negotiated that agreement, the Moscow Armistice. The Winter War was fought between the USSR and, for 10 points, what Scandinavian country with capital at Helsinki.

SOLUTION:
History