geometrical object
61Lens (optics) — For other uses, see Lens. A lens. Lenses can be used to focus light. A lens is an optical device with perfect or approximate axial symmetry which tra …
62Group theory — is a mathematical discipline, the part of abstract algebra that studies the algebraic structures known as groups. The development of group theory sprang from three main sources: number theory, theory of algebraic equations, and geometry. The… …
63Whewell’s philosophy of science and ethics — Struan Jacobs ON SCIENCE Introduction Among the most prodigious of English minds of the nineteenth century, William Whewell (1794–1866) was at various times, and among other things, philosopher, intellectual historian, scientist, educationist,… …
64KABBALAH — This entry is arranged according to the following outline: introduction general notes terms used for kabbalah the historical development of the kabbalah the early beginnings of mysticism and esotericism apocalyptic esotericism and merkabah… …
65History of geometry — Geometry (Greek γεωμετρία ; geo = earth, metria = measure) arose as the field of knowledge dealing with spatial relationships. Geometry was one of the two fields of pre modern mathematics, the other being the study of numbers. Classic geometry… …
66History of mathematics — A proof from Euclid s Elements, widely considered the most influential textbook of all time.[1] …
67Isaac Newton — Sir Isaac Newton …
68Tensor — For other uses, see Tensor (disambiguation). Note that in common usage, the term tensor is also used to refer to a tensor field. Stress, a second order tensor. The tensor s components, in a three dimensional Cartesian coordinate system, form the… …
69Mathematics of general relativity — For a generally accessible and less technical introduction to the topic, see Introduction to mathematics of general relativity. General relativity Introduction Mathematical formulation Resources …
70William Delbert Gann — (June 6, 1878 ndash; June 14, 1955), also W. D. Gann, was a trader recognized not only for his trading abilities, but also for his financial market forecasts. The accuracy of his forecasts is still the subject of substantial debate. Gann s son… …
