internal symmetry
51Diamond cut — This article is about diamond cut styles. For a broader discussion of decorative diamonds, see Diamond (gemstone). Part of a series on Diamonds Material …
52subatomic particle — or elementary particle Any of various self contained units of matter or energy. Discovery of the electron in 1897 and of the atomic nucleus in 1911 established that the atom is actually a composite of a cloud of electrons surrounding a tiny but… …
53Stress (mechanics) — Continuum mechanics …
54Feynman diagram — The Wick s expansion of the integrand gives (among others) the following termNarpsi(x)gamma^mupsi(x)arpsi(x )gamma^ upsi(x )underline{A mu(x)A u(x )};,whereunderline{A mu(x)A u(x )}=int{d^4pover(2pi)^4}{ig {mu u}over k^2+i0}e^{ k(x x )}is the… …
55Hooke's law — models the properties of springs for small changes in length Prof. Walter Lewin explains Hooke s law, in …
56Pythagoreans and Eleatics — Edward Hussey PYTHAGORAS AND THE EARLY PYTHAGOREANS Pythagoras, a native of Samos, emigrated to southern Italy around 520, and seems to have established himself in the city of Croton. There he founded a society of people sharing his beliefs and… …
57physical science, principles of — Introduction the procedures and concepts employed by those who study the inorganic world. physical science, like all the natural sciences, is concerned with describing and relating to one another those experiences of the surrounding… …
59Molecular vibration — A molecular vibration occurs when atoms in a molecule are in periodic motion while the molecule as a whole has constant translational and rotational motion. The frequency of the periodic motion is known as a vibration frequency, and the typical… …
60Starfish — For other uses, see Starfish (disambiguation). Asteroidea redirects here. For the Asteraceae subfamily, see Asteroideae. Sea Stars Temporal range: Ordovician–Recent …
