(measurement of warmth)
61pre-Columbian civilizations — Introduction the aboriginal American Indian (Mesoamerican Indian) cultures that evolved in Meso America (part of Mexico and Central America) and the Andean region (western South America) prior to Spanish exploration and conquest in the 16th …
62Perception — For other uses, see Perception (disambiguation). Perceptual redirects here. For the Brian Blade album, see Perceptual (album). Robert Fludd s depiction of perception (1619) …
63Sunlight — This article is about light emitted by the Sun. For other uses, see Sunlight (disambiguation). Sunshine redirects here. For other uses, see Sunshine (disambiguation). For natural lighting of interior spaces by admitting sunlight, see Daylighting …
64Tornado — This article is about the weather phenomenon. For other uses, see Tornado (disambiguation). For the current tornado season, see Tornadoes of 2011 …
65Marginal utility — In economics, the marginal utility of a good or service is the utility gained (or lost) from an increase (or decrease) in the consumption of that good or service. Economists sometimes speak of a law of diminishing marginal utility, meaning that… …
66W. H. R. Rivers — Photograph of Rivers taken by Henry Maull Born 12 March 1864(1864 03 12) …
67Testicle — Diagram of male (human) testicles …
68Placebo — For other uses, see Placebo (disambiguation) and Placebo effect (disambiguation). Sugar pill redirects here. For Kids of 88 album, see Sugarpills. The placebo effect can be produced by inert tablets, by sham surgery, and by false information,… …
69Heat transfer — is a discipline of thermal engineering that concerns the exchange of thermal energy from one physical system to another. Heat transfer is classified into various mechanisms, such as heat conduction, convection, thermal radiation, and phase change …
70Eritrean Railway — The Eritrean Railway is the only railway system in Eritrea, constructed between 1887 and 1932. The railway is narrow gauge and is slowly being rebuilt after the devastation wreaked upon it by the war of independence. It still manages to operate,… …
