新风尚大学实用英语第四册课后练习答案for_Unit_5..doc

Unit 5 Educational System Passage A On Education Background Knowledge Albert Einstein Albert?Einstein (14 March 1879–18 April 1955) was a theoretical physicist, philosopher and author who is widely regarded as one of the most influential and best known scientists and intellectuals of all time. He is often regarded as the father of modern physics. He received the 1921 Nobel Prize in Physics for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect. (1) Biography Einstein was born in 1879 in Ulm, a city in Germany. His father was Hermann Einstein, a salesman and engineer. His mother was Pauline Einstein. The Einsteins were non-observant Jews. Although Einstein had early speech difficulties, later in his childhood he showed great curiosity about nature and ability to solve difficult mathematical problems. After he left school, he went to Switzerland, where he graduated from the university with a degree in mathematics. Einstein and Mileva Mari? married in January 1903. They had two sons but divorced on 14 February 1919. Einstein married Elsa L?wenthal in the same year and emigrated permanently to the United States in 1933. (2) Major contributions to science In 1905, Einstein began to publish a series of papers which shook the whole scientific and intellectual world. His major contributions to sciences contain two aspects: a. The Special and General Theories of Relativity Einsteins early work on the theory of relativity (1905) dealt only with systems or observers in uniform motion and is referred to as the special theory of relativity; among other results, it demonstrated that two observers moving at great speed will disagree about measurements of length and time intervals made in each others systems, that the speed of light is the limiting speed of all bodies having mass, and that mass and energy are equivalent. In 1911 he asserted the equivalence of gravitation and inertia, and in 1916 he completed his mathemati