boundary temperature
41Black hole — For other uses, see Black hole (disambiguation). Simulated view of a black hole (center) in front of the Large Magellanic Cloud. Note the gravitat …
42Meteorology — For other uses of the root word meteor , see Meteor (disambiguation). For the work by Aristotle, see Meteorology (Aristotle). Not to be confused with Metrology. Part of the Nature series on Weather   …
43Physical oceanography — World ocean bathymetry. Physical oceanography is the study of physical conditions and physical processes within the ocean, especially the motions and physical properties of ocean waters. Physical oceanography is one of several sub domains into… …
44Heat — In physics, heat, symbolized by Q , is energy transferred from one body or system to another due to a difference in temperature. [cite book|author= Daintith, John |title=Oxford Dictionary of Physics|publisher=Oxford University… …
45United States — a republic in the N Western Hemisphere comprising 48 conterminous states, the District of Columbia, and Alaska in North America, and Hawaii in the N Pacific. 267,954,767; conterminous United States, 3,022,387 sq. mi. (7,827,982 sq. km); with… …
46Life Sciences — ▪ 2009 Introduction Zoology In 2008 several zoological studies provided new insights into how species life history traits (such as the timing of reproduction or the length of life of adult individuals) are derived in part as responses to… …
47industrial glass — Introduction solid material that is normally lustrous and transparent in appearance and that shows great durability under exposure to the natural elements. These three properties lustre, transparency, and durability make glass a favoured… …
48Thermodynamics — Annotated color version of the original 1824 Carnot heat engine showing the hot body (boiler), working body (system, steam), and cold body (water), the letters labeled according to the stopping points in Carnot cycle …
49Cambrian Period — Oldest time division of the Paleozoic Era. During the Cambrian, 543–490 million years ago, there were widespread seas and several scattered landmasses. The largest continent was Gondwana. The average climate was probably warmer than today, with… …
50Holocene Epoch — formerly Recent Epoch Latest interval of the Earth s geologic history, dating from 10,000 years ago to the present. The younger of the two epochs that constitute the Quaternary Period, the Holocene follows the last glacial stage of the… …
