trace+by+reflection
61Crystallographic restriction theorem — The crystallographic restriction theorem in its basic form was based on the observation that the rotational symmetries of a crystal are usually limited to 2 fold, 3 fold, 4 fold, and 6 fold. However, quasicrystals can occur with other symmetries …
62France — /frans, frahns/; Fr. /frddahonns/, n. 1. Anatole /ann nann tawl /, (Jacques Anatole Thibault), 1844 1924, French novelist and essayist: Nobel prize 1921. 2. a republic in W Europe. 58,470,421; 212,736 sq. mi. (550,985 sq. km). Cap.: Paris. 3.… …
63optics — /op tiks/, n. (used with a sing. v.) the branch of physical science that deals with the properties and phenomena of both visible and invisible light and with vision. [1605 15; < ML optica < Gk optiká, n. use of neut. pl. of OPTIKÓS; see OPTIC,… …
64Europe, history of — Introduction history of European peoples and cultures from prehistoric times to the present. Europe is a more ambiguous term than most geographic expressions. Its etymology is doubtful, as is the physical extent of the area it designates.… …
65German literature — Introduction German literature comprises the written works of the German speaking peoples of central Europe. It has shared the fate of German politics and history: fragmentation and discontinuity. Germany did not become a modern nation… …
66Hegel, spirit, and politics — Leo Rauch Hegel’s impact on political thought has been immense giving shape to the major political movements of the modern world. Yet the person of average education is hardly familiar with the name, which is usually identified with a small… …
67Obsidian use in Mesoamerica — Obsidian projectile point. Obsidian is a naturally formed volcanic glass that was an important part of the material culture of Pre Columbian Mesoamerica. Obsidian was a highly integrated part of daily and ritual life, and its widespread and… …
68Seifert fiber space — A Seifert fiber space is a 3 manifold together with a nice decomposition as a disjoint union of circles. In other words it is a S^1 bundle (circle bundle) over a 2 dimensional orbifold. Most small 3 manifolds are Seifert fiber spaces, and they… …
69Multiphoton intrapulse interference phase scan — (MIIPS) is a method used in ultrashort laser technology that simultaneously measures (phase characterization), and compensates (phase correction) femtosecond laser pulses using an adaptive pulse shaper. Current ultrashort laser pulse… …
70Electron — For other uses, see Electron (disambiguation). Electron Experiments with a Crookes tube first demonstrated the particle nature of electrons. In this illustration, the profile of the cross shaped target is projected against the tube face at right… …
