SeanCarroll_2010X[肖恩.卡罗尔][遥远的时间与多元宇宙的迹象].pdf

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1、www.XiYuS锡育软件The universe is really big.宇宙 非常大00:12We live in a galaxy,the Milky Way Galaxy.我们生活在一个名为银河的星系00:16There are about a hundred billion stars in the Milky WayGalaxy.银河系中有约一千亿颗恒星00:19And if you take a camera and you point it at a random partof the sky,and you just keep the shutter open,as lo

2、ng asyour camera is attached to the Hubble Space Telescope,itwill see something like this.如果你拿起相机 并把它指向空中的任何一处 打开快门并让它开在那里 只要你的相机接通着哈勃天文望远镜 这就是它会看到的00:22Every one of these little blobs is a galaxy roughly the size ofour Milky Way-a hundred billion stars in each of thoseblobs.这里的每一小点 都是与我们的银河系大小相当的星系

3、 每一小点中都有一千亿颗恒星00:33There are approximately a hundred billion galaxies in theobservable universe.而在整个可见宇宙中 约有一千亿个星系00:41100 billion is the only number you need to know.所以你记住一千亿这个数字就行了00:46The age of the universe,between now and the Big Bang,is ahundred billion in dog years.宇宙的年龄 自大爆炸以来 在狗看来已过了一千亿年00:

4、48(Laughter)Which tells you something about our place in theuniverse.（笑）这就告诉了你 我们在这宇宙中的位置00:53One thing you can do with a picture like this is simply admireit.面对这样的画面 你可以做的一件事便是欣赏00:58Milky:adj.乳白色的;牛奶的;乳状的;柔和的;混浊不清的 shutter:n.快门;百叶窗;关闭物;遮板/vt.为装百叶窗;以百叶窗遮闭blobs:n.斑点(blob的复数)/v.溅污(blob的三单形式)approxima

5、tely:adv.大约,近似地;近于 observable:adj.显著的;觉察得到的;看得见的/n.物可观察量;感觉到的事物Its extremely beautiful.它极其美丽01:00Ive often wondered,what is the evolutionary pressure thatmade our ancestors in the Veldt adapt and evolve to reallyenjoy pictures of galaxies when they didnt have any.我常想 在星系的照片还不存在的时候 究竟是什么推动了我们远在非洲大草原的

6、祖先 让他们适应 进化 并欣赏这些星系的呢？01:02But we would also like to understand it.但除了欣赏 我们也想要了解它们01:12As a cosmologist,I want to ask,why is the universe like this?作为一个宇宙学家 我想问问 宇宙为什么是这样的呢？01:14One big clue we have is that the universe is changing withtime.宇宙随着时间流逝的演变 是一条重要的线索01:18If you looked at one of these gala

7、xies and measured itsvelocity,it would be moving away from you.如果你选中一个星系并测量它的速度 你会发现它正离你远去01:21And if you look at a galaxy even farther away,it would bemoving away faster.而如果你选中的是一个更远的星系 你会发现它正以更快的速度离你远去01:26So we say the universe is expanding.所以说 宇宙正在膨胀01:30What that means,of course,is that,in the

8、past,things werecloser together.当然 这就意味着过去所有的一切 彼此之间都比较接近01:32In the past,the universe was more dense,and it was alsohotter.曾经的宇宙密度比现在高 它也比现在热01:36If you squeeze things together,the temperature goes up.如果你把东西紧捏在一切 温度便会上升01:40evolutionary:adj.进化的;发展的;渐进的 Veldt:n.(南非洲的)草原 cosmologist:n.宇宙论者,宇宙学家 veloc

9、ity:n.【物】速度 squeeze:vt.挤;紧握;勒索/vi.压榨/n.压榨;紧握;拥挤;佣金That kind of makes sense to us.听起来有道理吧01:42The thing that doesnt make sense to us as much is that theuniverse,at early times,near the Big Bang,was also very,verysmooth.而让我们觉得没道理的 是宇宙初期 大爆炸之后那个 极度光滑的宇宙01:44You might think that thats not a surprise.你或许

10、觉得这并不值得惊讶01:51The air in this room is very smooth.这房间里的空气便十分光滑01:53You might say,Well,maybe things just smoothedthemselves out.你也许会说“大概这些东西就是会自己慢慢平滑掉的”01:55TED演讲者：Sean Carroll|肖恩.卡罗尔演讲标题：Sean Carroll:Distant time and the hint of a multiverse|遥远的时间与多元宇宙的迹象内容概要：A physicist,cosmologist and gifted scien

11、ce communicator,Sean Carroll is askinghimself-and asking us to consider-questions that get at the fundamental nature of theuniverse.在TEDx加州理工学院，宇宙学家肖恩.卡罗尔把我们带入一段娱乐性强且发人深省的，穿梭于时间与宇宙之间的旅程，目的是探究一个貌似简单的问题:为什么存在着时间?潜在的答案指向的对于整个宇宙以及宇宙中的我们的见解足以令人称奇。But the conditions near the Big Bang are very,very differe

12、ntthan the conditions of the air in this room.但大爆炸不久之后的环境 与这房间里的空气相比十分 十分的不同01:58In particular,things were a lot denser.特别是一切的密度02:03The gravitational pull of things was a lot stronger near theBig Bang.当时的地心引力 比现在强很多02:05What you have to think about is we have a universe with ahundred billion galaxi

13、es,a hundred billion stars each.我们不得不想想 这个宇宙里有一千亿个星系 而每个星系里都有一千亿颗恒星02:09At early times,those hundred billion galaxies were squeezedinto a region about this big-literally,at early times.在宇宙初期 那一千亿个星系 被挤压到这么小的空间 毫不夸张 当初就这么小02:15make sense:有意义;讲得通;言之有理 smoothed:adj.平滑的;平滑后的/v.弄平滑;使顺利;缓和(smooth的过去分词)dif

14、ferent than:不同于 In particular:尤其,特别 gravitational:adj.力重力的,力引力的 squeezed:挤压/塞进/压榨/设法腾出And you have to imagine doing that squeezing without anyimperfections,without any little spots where there were afew more atoms than somewhere else.我们得想象一下这个挤压过程 这个完美的过程 毫无瑕疵 这里比那里多一两个原子也不行02:23Because if there had

15、 been,they would have collapsed underthe gravitational pull into a huge black hole.如果真有任何瑕疵 地心引力也会把它们 压成一个巨大的黑洞02:31Keeping the universe very,very smooth at early times is noteasy,its a delicate arrangement.让初期的宇宙保持在极度光滑的状态并非易事 这是个极为精细的布置02:36Its a clue that the early universe is not chosen randomly

16、.这条线索意味着初期宇宙 并非任意选择的产物02:41There is something that made it that way.是某些东西把它造就成那样的02:45We would like to know what.而我们想知道那是什么02:47So part of our understanding of this was given to us byLudwig Boltzmann,an Austrian physicist in the 19th century.19世纪的奥地利物理学家路德维希玻尔兹曼 给予了我们不少对此的了解02:49And Boltzmanns contr

17、ibution was that he helped usunderstand entropy.玻尔兹曼的贡献在于他帮助我们理解了熵02:55Youve heard of entropy.你们听见过熵02:58Its the randomness,the disorder,the chaoticness of somesystems.在某些系统中 它是随意性 是不规则 是混乱03:00squeezing:n.压榨;推挤;挤出酌;轧水/v.挤压;握住;硬塞进;紧抱;敲诈(squeeze的ing形式)/adj.挤压的;压榨的 imperfections:n.不合格折贴(imperfection的复

18、数)atoms:n.物原子(atom的复数)collapsed:adj.倒塌的;暴跌的;收缩的;倾陷了的/v.倒塌;崩溃(collapse的过去分词);价格暴跌 pull into:(车)进站 randomly:adv.随便地,任意地;无目的,胡乱地;未加计划地 entropy:n.热熵(热力学函数)Boltzmann gave us a formula-engraved on his tombstonenow-that really quantifies what entropy is.玻尔兹曼给了我们一条 被刻在了他墓碑上的公式让我们得以在数量上解释熵03:03And its basica

19、lly just saying that entropy is the number ofways we can rearrange the constituents of a system so thatyou dont notice,so that macroscopically it looks the same.这条公式所说的 不过是 我们可以重新组合 构成一个系统的各个要素 而在宏观上 你看不出任何变化03:09If you have the air in this room,you dont notice eachindividual atom.在感受这房间里的空气时 你不可能注意

20、每一个原子吧03:18A low entropy configuration is one in which theres only afew arrangements that look that way.如果能够组合出某个布局的方式屈指可数 那这个布局的熵值就会很小03:23A high entropy arrangement is one that there are manyarrangements that look that way.反之 若能组合出某个布局的方式很多 这个布局的熵值就会很大03:27This is a crucially important insight,bec

21、ause it helps usexplain the second law of thermodynamics-the law thatsays that entropy increases in the universe,or in isolated bitof the universe.对这一点的领悟极其关键 因为它帮助我们解释 热力学第二定律 在整个宇宙 或是被隔离开的部分宇宙中 熵值只可增大03:31The reason why entropy increases is simply because there aremany more ways to be high entropy

22、 than to be low entropy.熵值增大的原因很简单 只因呈现出对应于大熵值的布局 比呈现出对应于小熵值的布局的方式多得多03:42engraved:adj.被牢记的;被深深印入的/v.雕刻(engrave的过去式)tombstone:n.墓碑;墓石 quantifies:vt.量化;为定量;确定数量/vi.量化;定量 rearrange:vt.重新排列;重新整理 constituents:n.成分(constituent的复数)configuration:n.配置;结构;外形 crucially:adv.关键地;至关重要地 thermodynamics:n.热力学Thats

23、a wonderful insight,but it leaves something out.虽说领会到这些很奇妙 但还有被遗漏的部分03:49This insight that entropy increases,by the way,is whatsbehind what we call the arrow of time,the differencebetween the past and the future.值得提及的是 正是熵值的增大 推动着我们的时间之箭 造就着过去与未来的不同03:53www.XiYuS锡育软件Every difference that there is be

24、tween the past and the futureis because entropy is increasing-the fact that you can过去与未来 它们之间的所有区别 都呈现于熵值的增大 正如你能记得往事 却无法去记住将来所要发生的04:00is because entropy is increasing-the fact that you canremember the past,but not the future.生的04:00The fact that you are born,and then you live,and then youdie,alway

25、s in that order,thats because entropy is increasing.又如你出生 成长 死亡的过程 这些不变的顺序 都源于熵值的增大04:09Boltzmann explained that if you start with low entropy,itsvery natural for it to increase,because theres more ways tobe high entropy.玻尔兹曼解释道 如果你从小熵值出发 它会很自然的增大 因为处于大熵值状态的途径更多04:16What he didnt explain was why the

26、 entropy was ever low inthe first place.但他并没有解释 为什么最初的熵值那么小04:23The fact that the entropy of the universe was low was areflection of the fact that the early universe was very,verysmooth.宇宙初期的小熵值 意味着的莫过于 初期的宇宙非常非常的光滑04:28Wed like to understand that.而我们想要理解它的原由04:34Thats our job as cosmologists.那便是作为宇

27、宙学家的我们的任务04:36in the first place:首先;起初 cosmologists:n.宇宙论者,宇宙学家Unfortunately,its actually not a problem that weve beengiving enough attention to.遗憾的是 我们并没有 给予这个问题多大的关注04:38Its not one of the first things people would say,if you askeda modern cosmologist,What are the problems were tryingto address?如果

28、你问一个现代宇宙学家“我们正研究着的问题有哪些？”这不会是回答中你最先听到的问题之一04:42One of the people who did understand that this was aproblem was Richard Feynman.认识到这个问题的重要性的其中一人 便是理查德费曼04:4850 years ago,he gave a series of a bunch of differentlectures.50年前 他给了一系列的演讲04:52He gave the popular lectures that became The Character ofPhysic

29、al Law.他面向大众的讲座 成了物理之美04:54He gave lectures to Caltech undergrads that became TheFeynman Lectures on Physics.他面向加州理工学院本科生的讲课 成了费曼物理学讲义04:58He gave lectures to Caltech graduate students that becameThe Feynman Lectures on Gravitation.他面向加州理工学院研究生的讲课 成了费曼引力学讲义05:02In everyone of these books,everyone of

30、 these sets of lectures,he emphasized this puzzle:Why did the early universe havesuch a small entropy?在上述的每本书 费曼的每个讲座中 他都强调了这个难题 为什么初期的宇宙有着那么小的熵值？05:06So he says-Im not going to do the accent-he says,Forsome reason,the universe,at one time,had a very lowentropy for its energy content,and since then

31、the entropyhas increased.我就不模仿他的口音了 他说：“虽说宇宙中包含着的能量巨大 某些原因使它曾一度拥有小熵值 而从那以后 熵值不断增大05:14a bunch of:一群;一束;一堆 undergrads:n.大学肄业生/adj.大学生的(等于undergraduate)Gravitation:n.重力；万有引力；地心吸力 emphasized:v.强调,着重(emphasize的过去式)at one time:曾经,一度;同时The arrow of time cannot be completely understood until themystery of

32、the beginnings of the history of the universe arereduced still further from speculation to understanding.直至我们能够真正理解 而非单单推测 整个宇宙历史的 开端的秘密 时间之箭 便无法被完全理解”05:24So thats our job.这就是我们的使命05:34We want to know-this is 50 years ago,Surely,yourethinking,weve figured it out by now.这是费曼50年前说的 你也许在想：“那么久了 我们现在弄清

33、了吧”05:36Its not true that weve figured it out by now.错了 我们到现在也没弄清05:40The reason the problem has gotten worse,rather than better,is because in 1998 we learned something crucial about theuniverse we didnt know before.非但没把问题弄清 它还变得更糟糕了 因为在1998年 一个关于宇宙的新发型展现在了我们面前05:42We learned that its accelerating.宇

34、宙不仅在膨胀05:51The universe is not only expanding.而且在加速膨胀05:53If you look at the galaxy,its moving away.如果你看见一个星系正离你远去05:55If you come back a billion years later and look at it again,itwill be moving away faster.十亿年后再回来看它时 你会发现它远去的速度加快了05:57Individual galaxies are speeding away from us faster andfaster.

35、各个星系离我们远去的速度都在不断加快着06:02So we say the universe is accelerating.所以我们说这个宇宙正在加速膨胀06:05beginnings:n.开始,开端(beginning的复数);早期 speculation:n.投机;推测;思索;投机买卖 accelerating:adj.促进的,物加速的;催化的Unlike the low entropy of the early universe,even though wedont know the answer for this,we at least have a goodtheory that

36、can explain it,if that theory is right,and thatsthe theory of dark energy.与宇宙初期的小熵值不同 虽然我们没有答案 但要解释这现象 我们至少还有一套不错的理论 如果那理论是正确的 我是在说暗能量理论06:07Its just the idea that empty space itself has energy.它说 真空区自身便有能量06:17In every little cubic centimeter of space,whether or nottheres stuff,whether or not there

37、s particles,matter,radiation or whatever,theres still energy,even in the spaceitself.这空间中的任何一立方厘米中 无论那里有没有东西 无论那里有没有粒子 物质 辐射 或任何别的什么 那里仍有能量 就这空间中便有06:20And this energy,according to Einstein,exerts a push on theuniverse.在爱因斯坦看来 这能量推动着宇宙06:30It is a perpetual impulse that pushed galaxies apart fromeac

38、h other.这是一股永恒的冲量 使各星系之间的距离越来越大06:35Because dark energy,unlike matter or radiation,does notdilute away as the universe expands.因为暗能量 与物质和辐射不同 它不会因为宇宙的膨胀而被稀释06:39The amount of energy in each cubic centimeter remains thesame,even as the universe gets bigger and bigger.即便宇宙越来越大 每立方厘米中的能量 都将保持不变06:45cub

39、ic:adj.立方体的,立方的 exerts:v.发挥(exert的三单形式);运用;表现出 push on:推进;推动;努力向前 perpetual:adj.永久的；不断的；四季开花的；无期限的 impulse:n.冲动;电子脉冲;刺激;神经冲动;推动力/vt.推动 apart from:除之外;且不说;并且 dilute:adj.稀释的;淡的/vt.稀释;冲淡;削弱/vi.变稀薄;变淡This has crucial implications for what the universe is going todo in the future.这对宇宙未来的发展 有着关键的影响06:51Fo

40、r one thing,the universe will expand forever.其中之一 便是宇宙会永远膨胀下去06:57Back when I was your age,we didnt know what the universewas going to do.当我像你们那么小的时候 我们并不知道宇宙是否会膨胀下去06:59Some people thought that the universe would recollapse inthe future.某些人认为 宇宙将会再坍缩07:03Einstein was fond of this idea.爱因斯坦就很喜欢这想法07

41、:06But if theres dark energy,and the dark energy does not goaway,the universe is just going to keep expanding foreverand ever and ever.但如果有暗能量 而暗能量又会永远留在那里 宇宙便会永不停息的 这样膨胀下去07:0814 billion years in the past,100 billion dog years,but aninfinite number of years into the future.从140亿年前 狗的一千亿年前 直至无数年以后 直

42、至永恒的未来07:14Meanwhile,for all intents and purposes,space looks finite tous.在此期间 不论我们有什么意图或目的 宇宙空间在我们看来都是有限的07:21Space may be finite or infinite,but because the universe isaccelerating,there are parts of it we cannot see and neverwill see.宇宙或许有限 或许无限 但因为它正在膨胀 我们看不到它的某些部分 也将永远无法看到07:26Theres a finite r

43、egion of space that we have access to,surrounded by a horizon.能让我们获取信息的宇宙空间非常有限 它被边界包围着07:34implications:n.蕴涵式;暗指,暗示;含蓄,含意;卷入(implication的复数)For one thing:首先;一则 intents:n.意图;目的;意向(intent的复数)finite:adj.有限的；限定的/n.有限之物So even though time goes on forever,space is limited to us.所以即便时间不停下它的脚步 宇宙空间对我们来说还是有

44、限的07:38Finally,empty space has a temperature.最后 真空区有它的温度07:42In the 1970s,Stephen Hawking told us that a black hole,even though you think its black,it actually emits radiation,when you take into account quantum mechanics.在70年代 斯蒂芬霍金告诉我们 虽然你认为黑洞是黑的 它其实会辐射 如果把量子力学考虑进去的话07:45The curvature of space-time

45、 around the black hole brings tolife the quantum mechanical fluctuation,and the black holeradiates.黑洞周围的空间曲率 是会导致真空量子涨落的 黑洞也就会辐射07:53A precisely similar calculation by Hawking and Gary Gibbonsshowed that,if you have dark energy in empty space,thenthe whole universe radiates.根据霍金与加利基本斯的 一个类似的精确计算 如果真

46、空区里有暗能量 整个宇宙便会辐射08:01The energy of empty space brings to life quantumfluctuations.真空区的能量 带来量子涨落08:10And so even though the universe will last forever,andordinary matter and radiation will dilute away,there willalways be some radiation,some thermal fluctuations,even inempty space.所以虽然宇宙是永恒的 而且一般的物质和辐

47、射会被稀释 但某些辐射会永远留下 某些热涨落 即便那是真空区08:14Hawking:n.利用鹰行猎/v.袭击;翱翔;攫取(hawk的现在分词)emits:发出/放射/发行(emit的动词单数第三人称形式)takeinto account:考虑;重视;体谅 curvature:n.弯曲,数曲率 space-time:adj.时空的/n.时空(等于spacetime)fluctuation:n.起伏,波动 radiates:vt.辐射;传播;流露;发射;广播/vi.辐射;流露;发光;从中心向各方伸展/adj.辐射状的,有射线的 Gibbons:吉本斯(Gibbons姓氏)/脊椎长臂猿(gibbo

48、n的名词复数)fluctuations:n.物波动(fluctuation的复数);变动;起伏现象 thermal:adj.热的;热量的;保热的/n.上升的热气流So what this means is that the universe is like a box of gasthat lasts forever.这也就是说 宇宙好比一盒气体 永恒的气体08:25Well what is the implication of that?这又意味着什么呢？08:31That implication was studied by Boltzmann back in the 19thcentur

49、y.玻尔兹曼在19世纪对此进行了研究08:33He said,well,entropy increases because there are many,many more ways for the universe to be high entropy,ratherthan low entropy.他说 熵值只会增大 因为让宇宙处于大熵值状态的方式 比让它处于小熵值状态的方式 多得多08:36But thats a probabilistic statement.但那是一个概率性的称述08:44It will probably increase,and the probability is

50、enormouslyhuge.它可能会增大 而且这可能性奇大无比08:47Its not something you have to worry about-the air in thisroom all gathering over one part of this room andsuffocating us.我们不需要担心 这房间里的空气不会挤到一处 并让我们窒息08:51Its very,very unlikely.这可能性极小极小08:57Except if they locked the doors and kept us here literallyforever,that wo