找回密码
 立即注册
搜索
查看: 346|回复: 0
打印 上一主题 下一主题
收起左侧

[英文] 《Humanity 》作者:- Jerry Oltion 【EPUB】

[复制链接]

管理员 - 管理勋章超级版主 - 超级版主版主勋章 - 版主勋章

灰铜v1_03紫银v2_02绿金v1_01灰金v1_05绿银v1_01绿铜v3_01灵晶土豪紫铜v1_04紫铜v3_01

跳转到指定楼层
楼主
发表于 2013-5-5 20:36 | 只看该作者 回帖奖励 |倒序浏览 |阅读模式
ISAAC ASIMOV’S ROBOT CITY ?? ROBOTS AND ALIENS ?? Book 6 ?? Humanity by Jerry Oltion ?? Copyright ?? 1990 ?? ?? ROBOTS AND EVOLUTION BY ISAAC ASIMOV ?? In general there are two types of change that take place in the Universe: catastrophic andevolutionary. A catastrophic change is characterized by a large alteration of conditions in a short period oftime. An evolutionary change is characterized by slow alterations of conditions over a longperiod of time. Clearly catastrophic change is more dramatic but if we observe the Universe around us it isequally clear that evolutionary change is the rule. A star shines for anywhere from many millions to many billions of years slowly evolving untilit reaches a point where if it is large enough there is an overbalancing so to speak andin the space of a few minutes or a few hours it explodes as a supernova and collapses.Catastrophe But thereafter it exists as a white dwarf neutron star or black hole andreturns to prolonged evolutionary change. Again a huge cloud of dust and gas slowly circling and condensing undergoes evolutionarychange until its center reaches the level of temperature and pressure where nuclear fusion canbegin. There is then ignition and a sun is born. Catastrophe But thereafter a planetarysystem evolves over the space of a few million years achieves equilibrium and continues toevolve over the space of a few billion years. Still again a planet like Earth can evolve geologically over a period of millions of yearsperhaps even billions undergoing slow changes that result in sea-floor spreading movingplates and shifting continents rising and eroding of mountain chains and so on. There arepunctuations in the form of minor catastrophes an earthquake here a volcanic eruption therea sudden flooding yon but beyond and between such events
插件设计:zasq.net

本帖子中包含更多资源

您需要 登录 才可以下载或查看,没有帐号?立即注册

x
您需要登录后才可以回帖 登录 | 立即注册

本版积分规则

QQ|Archiver|手机版|小黑屋| ( Q群816270601 )

GMT+8, 2024-11-29 16:36 , Processed in 1.897947 second(s), 50 queries .

Powered by Discuz! X3.2

© 2001-2013 Comsenz Inc.

快速回复 返回顶部 返回列表