2019-2020年高中英语必修4Module4GreatScientists--Backgroundreading.doc

2019-2020年高中英语必修4Module4GreatScientists-Backgroundreading1. cash crop In agriculture, a cash crop is a crop which is sold for money. The term is used to differentiate from subsistence crops, which are those fed to the producers own livestock or grown as food for the producers family. 2. hybrid hybrid , term applied by plant and animal breeders to the offspring of a cross between two different subspecies or species, and by geneticists to the offspring of parents differing in any genetic characteristic. 3. cosmology Cosmology is the study of the universein its totality and by extension mans place in it. Though the word cosmology is itself of fairly recent origin, first used in Christian Wolffs Cosmologia Generalis (1730), the study of the universe has a long history involving science, philosophy, esotericism, and religion. 4. Cambridge The city of Cambridge is an old EnglishUniversitytown and the administrative center of the county of Cambridge shire. It lies approximately 50 miles(80 km) north-northeast of Londonand is surrounded by a number of smaller towns and villages. It is also at the heart of Silicon Fen, which has a reputation as the leading high-technology center of Britain and is one of the major constituent parts of the Oxford-Cambridge Arc. 5. OxfordOxford is a city and local government districtin Oxford shire, England, with a population of 134,248 (xx census). It is home to the University of Oxford, the oldest university in the English-speaking world. 6. relativity relativity, physical theory, introduced by Albert Einstein, that discards the concept of absolute motion and instead treats only relative motion between two systems or frames of reference. One consequence of the theory is that space and time are no longer viewed as separate, independent entities but rather are seen to form a four-dimensional continuum called space-time. 7. Research fields of HawkingHawkings principal fields of research are theoretical cosmology and quantum gravity. In 1971, in collaboration with Roger Penrose, he provided mathematical support for the Big Bang theory of the origin of the universe; if the general theory of relativity was correct, the universe must have a singularity, or starting point, in space-time. Hawking also suggested that, after the Big Bang, primordial or mini black holes were formed. He showed that, neglecting quantum mechanical effects, the surface area of a black hole can increase but never decrease derived a limit to the radiation emitted when black holes collide, and that a single black hole cannot break apart into two separate black holes. In 1974, he calculated that black holes thermally create and emit subatomic particles until they exhaust their energy and explode. Known as Hawking radiation, this theory was first to describe a mathematical link among gravity, quantum mechanics, and thermodynamics. In 1981, Hawking proposed that, although the universe had no boundary, it was finite in space-time; 1983 saw his mathematical proof of this theory.