Relativity theory has had a profound influence on our picture of matter by forcing us to modify our concept of a particle in an essential way. (47)In classical physics, the mass of an object had always been associated with an indestructible material substance, with some “stuff” of which all things were thought to be made. Relativity theory showed that mass has nothing to do with any substance, but is a form energy. Energy, however, is a dynamic quantity associated with activity, or with processes.(48)The fact that the mass of a particle is equivalent to a certain of energy means that the particle can no longer be seen as a static object, but has to be conceived as a dynamic pattern, a process involving the energy which manifest itself as the particle’s mass.

　　(49)This new view of particles was initiated by Dirac when he formulated a relativistic equation describing the behavior of electrons. Dirac’s theory was not only extremely successful in accounting for the fine details of atomic structure, but also revealed a fundamental symmetry between matter and anti-matter. It predicted the existence of an anti-matter with the same mass as the electron but with an opposite charge. This positively charged particle, now called the positron, was indeed discovered two years after Dirac had predicted it. The symmetry between matter and anti-matter implies that for every particle there exists an antiparticles with equal mass and opposite charge. Pairs of particles and antiparticles can be created if enough energy is available and can be made to turn into pure energy in the reverse process of destruction.(50)These processes of particle creation and destruction had been predicted from Dirac’s theory before they were actually discovered in nature, and since then they have been observed millions of times.

　　The creation of material particles from pure energy is certainly the most spectacular effect of relativity theory, and it can only be understood in terms of the view of particles outlined above.(51)Before relativistic particle physics, the constituents of matter had always been considered as being either elementary units which were indestructible and unchangeable, or as composite objects which could be broken up into their constituent parts; and the basic question was whether one could divide matter again and again, or whether one would finally arrive at some smallest indivisible units.

　　答案

　　47.在古典物理中，某一物體的質(zhì)量總是與一種不可毀滅的物質(zhì)相關(guān)聯(lián)。這是一種構(gòu)成一切物質(zhì)的“東西”。

　　48.某一粒子的質(zhì)量相當(dāng)于一定的能量，這一事實(shí)意味著該粒子不再被看作是一個(gè)靜態(tài)的物體，而應(yīng)該被看成是一種動(dòng)態(tài)的形式，一種與能量表現(xiàn)為粒子質(zhì)量相關(guān)的過(guò)程。

　　49.這一新的粒子觀是由迪拉克首創(chuàng)的，他列出了描述電子運(yùn)動(dòng)行為的相對(duì)論方程。

　　50.粒子生成和毀滅的過(guò)程在真正被發(fā)現(xiàn)之前，迪拉克的理論已經(jīng)對(duì)它們作出了預(yù)測(cè)，從那時(shí)起人們對(duì)此做過(guò)數(shù)百萬(wàn)次的觀測(cè)。

　　51.在相對(duì)論粒子物理學(xué)誕生之前，人們一直以為物質(zhì)的構(gòu)成成分要么是不可毀滅和不可改變的基本單位，要么是可以分解為其構(gòu)成部分的合成物。

　　總體分析

　　本文是一篇關(guān)于粒子物理理論的文章。

　　第一段：指出相對(duì)論改變了我們的粒子概念，從而影響了我們對(duì)物質(zhì)的理解。

　　第二段：指出這一粒子觀點(diǎn)是由迪拉克首創(chuàng)的，他的理論揭示了物質(zhì)和反物質(zhì)的基本對(duì)稱。該理論已經(jīng)得到了證實(shí)。

　　第三段：純能量創(chuàng)造物質(zhì)粒子是相對(duì)論最驚人的影響。相對(duì)論觀點(diǎn)的粒子物理學(xué)改變了人們對(duì)于物質(zhì)的看法和理解。

　　本文是一篇科普性說(shuō)明文，屬于正式文體�？忌�首要的任務(wù)是清楚地分析句子結(jié)構(gòu)，并結(jié)合自己的物理常識(shí)準(zhǔn)確把握生疏詞匯，在此基礎(chǔ)上完成翻譯。本題考核的知識(shí)點(diǎn)：(一)被動(dòng)語(yǔ)態(tài)。(二)定語(yǔ)，包括定語(yǔ)從句，分詞作定語(yǔ)。(三)狀語(yǔ)從句。