heat erosion
61Hutton, James — born June 3, 1726, Edinburgh, Scot. died March 26, 1797, Edinburgh Scottish geologist, chemist, and naturalist. After short careers in law and medicine, he followed his interest in chemistry and developed an inexpensive manufacturing process for… …
62Precambrian time — Interval of geologic time from с 3. 8 billion years ago, the age of the oldest known rocks, to 544 million years ago, the beginning of the Cambrian Period. This interval represents more than 80% of the geologic record and thus provides important… …
63Oxygen — This article is about the chemical element and its most stable form, O2 or dioxygen. For other forms of this element, see Allotropes of oxygen. For other uses, see Oxygen (disambiguation). nitrogen ← oxygen → fluorine ↑ O ↓ …
64Grand Canyon — This article is about the canyon in the southwestern United States. For other Grand Canyons, see Grand Canyon (disambiguation). Grand Canyon …
65Climate Change Science Program — The Climate Change Science Program (CCSP) was the program responsible for coordinating and integrating research on global warming by U.S. government agencies from February 2002 to June 2009.[1] Toward the end of that period, CCSP issued 21… …
66Deforestation during the Roman period — The rise and fall of the Roman Empire encompasses the time when Rome was the leading contributor to deforestation in the Mediterranean. Whereas the Mediterranean was largely prehistoric in 1000 BC, it was definitely historic by 500 AD.[1] Roman… …
67biosphere — biospheric /buy euh sfer ik/, adj. /buy euh sfear /, n. 1. the part of the earth s crust, waters, and atmosphere that supports life. 2. the ecosystem comprising the entire earth and the living organisms that inhabit it. [1895 1900; < G Biosphäre; …
68Physical Sciences — ▪ 2009 Introduction Scientists discovered a new family of superconducting materials and obtained unique images of individual hydrogen atoms and of a multiple exoplanet system. Europe completed the Large Hadron Collider, and China and India took… …
69Electrical discharge machining — An electrical discharge machine Electric discharge machining (EDM), sometimes colloquially also referred to as spark machining, spark eroding, burning, die sinking or wire erosion,[1] is a manufacturing process whereby a desired shape is obtained …
70horticulture — horticultural, adj. horticulturist, n. /hawr ti kul cheuhr/, n. 1. the cultivation of a garden, orchard, or nursery; the cultivation of flowers, fruits, vegetables, or ornamental plants. 2. the science and art of cultivating such plants. [1670… …
