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PatriciaBurchat_2008-_解释暗物质_
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As a particle physicist , I study the elementary particles and how they interact on the most fundamental level. |
作为一名粒子物理学家,我研究基本粒子 以及它们如何在微观上如何相互作用 |
physicist:n.物理学家;物理学研究者; elementary:adj.基本的;初级的;[化学]元素的; particles:n.微粒,粒子;粒子系统;碎木料(particle的复数形式); interact:v.互相影响;互相作用;n.幕间剧;幕间休息; fundamental:n.基础; adj.十分重大的;
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For most of my research career I've been using accelerators , such as the electron accelerator at Stanford University, just up the road, to study things on the smallest scale . |
对于我大部分的研究,我一直在使用加速器, 例如在斯坦福大学路边的电子加速器 去在微观上研究物质。 |
career:n.职业;事业;生涯;经历; accelerators:n.[核]加速器(accelerator的复数形式); electron:n.电子; scale:n.规模;比例;鳞;刻度;天平;数值范围;v.衡量;攀登;剥落;生水垢;
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But more recently , I've been turning my attention to the universe on the largest scale. |
但是最近,我的注意力转向了 宏观上整个宇宙。 |
recently:adv.最近;新近;
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Because, as I'll explain to you, the questions on the smallest and the largest scale are actually very connected. |
因为,正如我将要对你们解释的, 宏观和微观上的问题其实是非常相关的。 |
So I'm going to tell you about our 21st-century view of the universe, what it's made of and what the big questions in the physical sciences are -- at least some of the big questions. |
所以我将要告诉你们关于我们21世纪的宇宙观, 它是由什么构成的,以及什么是物理学中的一些大问题--- 至少是它们中的一些大问题。 |
physical:adj.[物]物理的;身体的;物质的;符合自然法则的;n.体格检查;
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So recently, we have realized that the ordinary matter in the universe -- and by ordinary matter I mean you, OK, me, the planets, the stars, the galaxies -- the ordinary matter makes up only a few percent of the content of the universe. |
最近,我们意识到 宇宙中的普通物质--- 我指的普通物质,我的意思是你,我 行星,横星,银河系--- 普通物质仅仅占据 宇宙组成的一小部分。 |
galaxies:n.银河; (galaxy的复数) content:n.内容,目录;满足;容量;adj.满意的;vt.使满足;
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Almost a quarter, or approximately a quarter of the matter in the universe, is stuff that's invisible . |
近乎四分之一,或者大约四分之一 的宇宙组成是一些不可见的东西。 |
approximately:adv.大约,近似地;近于; stuff:n.东西:物品:基本特征:v.填满:装满:标本: invisible:adj.看不见的;n.看不见的人或物;
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By invisible I mean it doesn't absorb in the electromagnetic spectrum . |
不可见,我指的是它不吸收地磁波谱。 |
absorb:v.吸收;使并入;吞并;同化;理解;吸收;耗费;承受; electromagnetic:adj.电磁的; spectrum:n.光谱;频谱;范围;余象;
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It doesn't emit in the electromagnetic spectrum. It doesn't reflect . |
在光谱中不放射电磁波。它不反射电磁波。 |
emit:v.发出,射出,散发(光、热、声音、气等); reflect:v.反映;映出(影像);反射;表明,表达;
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It doesn't interact with the electromagnetic spectrum, which is what we use to detect things. |
它在电磁波谱照射下不发生反应, 而这却是我们如何用来检测物质的方法。 |
detect:vt.察觉;发现;探测;
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It doesn't interact at all. So how do we know it's there? |
它根本不反应。所以我们如何知道它们在那? |
We know it's there by its gravitational effects. |
我的得知它们存在通过引力效应。 |
gravitational:adj.[力]重力的,[力]引力的;
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In fact, this dark matter dominates the gravitational effects in the universe on a large scale, and I'll be telling you about the evidence for that. |
实际上,这种暗物质 宏观上统治宇宙中的引力效应, 我将会告诉你们它的证据。 |
dark matter:n.暗物质(根据一些理论,指太空中不反射光的物质); dominates:v.支配;控制;左右;影响;(dominate的第三人称单数) evidence:n.证据,证明;迹象;明显;v.证明;
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What about the rest of the pie? |
派的其它部分是什么呢? |
The rest of the pie is a very mysterious substance called dark energy. |
这个派的其它部分是一种十分神秘的物质,叫做暗能量。 |
mysterious:adj.神秘的;不可思议的;难解的; substance:n.物质;实质;主旨;物品;
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More about that later, OK. |
一会再讨论它。 |
So for now, let's turn to the evidence for dark matter. |
所以现在,我们来谈谈暗物质存在的证据。 |
In these galaxies, especially in a spiral galaxy like this, most of the mass of the stars is concentrated in the middle of the galaxy. |
在这些星系中,尤其是在一个像这样的螺旋星系中, 大部分的质量集中在星系的中央。 |
especially:adv.尤其;特别;格外;十分; spiral:n.螺旋;旋涡;螺旋形之物;adj.螺旋形的;v.使成螺旋形;vi.盘旋;螺旋形上升; galaxy:n.银河;[天]星系;银河系;一群显赫的人; mass:n.块,团; adj.群众的,民众的; v.聚集起来,聚集; concentrated:adj.决心要做的; v.集中(注意力); (concentrate的过去式和过去分词)
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This huge mass of all these stars keeps stars in circular orbits in the galaxy. |
这些恒星巨大的质量使得这些星星在星系中沿圆周运动轨道运动。 |
circular:adj.圆形的; n.(同时送达很多人的)印刷信函(或通知、广告); orbits:n.[天][航]轨道(orbit的复数); v.环绕…的轨道运行;
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So we have these stars going around in circles like this. |
所以我们看到这些恒星沿圆圈这样运动。 |
As you can imagine, even if you know physics -- this should be intuitive , OK -- that stars that are closer to the mass in the middle will be rotating at a higher speed than those that are further out here, OK. |
如你所想,即使你不知道物理----这应该是很直观的, 这些靠近中心的恒星将会以更高的速度旋转, 相比于在外面的这些。 |
intuitive:adj.直觉的;凭直觉获知的; rotating:v.(使)旋转,转动;(工作)由…轮值;(rotate的现在分词)
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So what you would expect is that if you measured the orbital speed of the stars, that they should be slower on the edges than on the inside. |
所以,你所期待的也许是如果你测量这些恒星运动的轨道速度, 它们(速度)应该是边缘的比里面的慢。 |
measured:adj.缓慢谨慎的; v.测量; (measure的过去分词和过去式) orbital:adj.轨道的;眼窝的;
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In other words, if we measured speed as a function of distance -- this is the only time I'm going to show a graph, OK -- we would expect that it goes down as the distance increases from the center of the galaxy. |
换言之,如果我们测量速度作为距离的函数--- 这是我唯一一次展示图表,好吗? 我们会期待它(速度)会减小 随着距离星系中央的路程增加。 |
When those measurements are made, instead what we find is that the speed is basically constant, as a function of distance. |
当这些被测量, 反而,我们发现这个速度基本上是一个常数, 作为距离的函数。 |
measurements:n.测量值,尺寸(measurement的复数); basically:adv.主要地,基本上;
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If it's constant, that means that the stars out here are feeling the gravitational effects of matter that we do not see. |
如果它(速度)是一个常数,这意味着外面的恒星 正在感受到一些我们看不到物质所施加的引力效应。 |
In fact, this galaxy and every other galaxy appears to be embedded in a cloud of this invisible dark matter. |
事实上,这个星系以及每一个其它的星系 似乎被内嵌在一团我们看不到的暗物质中。 |
embedded:adj.嵌入式的;植入的;内含的;v.嵌入(embed的过去式和过去分词形式);
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And this cloud of matter is much more spherical than the galaxy themselves, and it extends over a much wider range than the galaxy. |
这团物质比星系本身更加类似于球形, 而且它们(暗物质)比星系本身延伸至更广的范围。 |
spherical:adj.球形的,球面的;天体的; extends:v.使伸长;扩大;扩展;延长;使延期;(extend的第三人称单数)
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So we see the galaxy and fixate on that, but it's actually a cloud of dark matter that's dominating the structure and the dynamics of this galaxy. |
所以,我们注视着这个星系,但是它其实实在一团 决定它们结构与动态的暗物质中。 |
fixate:v.(使)固定,注视; dominating:adj.个性强势的; v.支配; (dominate的现在分词) structure:n.结构;构造;建筑物;vt.组织;构成;建造; dynamics:n.动力学,力学;
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Galaxies themselves are not strewn randomly in space; they tend to cluster . |
星系本身并不是任意地散布在空间中; 它们趋向于聚集在一起。 |
strewn:v.撒;散播(strew的过去分词);adj.撒满的;散播的; randomly:adv.随便地,任意地;无目的,胡乱地;未加计划地; cluster:n.群;簇;丛;串;vi.群聚;丛生;vt.使聚集;聚集在某人的周围;
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And this is an example of a very, actually, famous cluster: the Coma cluster. |
这是一个实际上非常著名的星系团:后发座(Coma)星系团。 |
Coma:n.[医]昏迷;[天]彗形像差;
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And there are thousands of galaxies in this cluster. |
而且这个星系团中有数以千计的星系。 |
They're the white, fuzzy , elliptical things here. |
它们是这些白色的,模糊的,椭圆的东西。 |
fuzzy:adj.模糊的;失真的;有绒毛的; elliptical:adj.椭圆的;省略的;
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So these galaxy clusters -- we take a snapshot now, we take a snapshot in a decade -- it'll look identical . |
所以,这些星系团——我们现在拍一张照, 十年后我们拍一张照——它们将会看起来一模一样。 |
clusters:n.[植]簇;丛(cluster的复数形式);[计]群集; snapshot:n.快照,快相;急射,速射;简单印象;vt.给…拍快照;vi.拍快照; identical:adj.同一的;完全相同的;n.完全相同的事物;
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But these galaxies are actually moving at extremely high speeds. |
但是这些星系团其实在以极高的速度运动。 |
extremely:adv.非常,极其;极端地;
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They're moving around in this gravitational potential well of this cluster, OK. |
它们其实在这个星系团的引力势阱中运动。 |
potential:n.潜能;可能性;[电]电势;adj.潜在的;可能的;势的;
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So all of these galaxies are moving. |
所以,这些星系在运动。 |
We can measure the speeds of these galaxies, their orbital velocities , and figure out how much mass is in this cluster. |
我们可以测量这些星系的速率,它们的轨道速度, 并算出星系团中有多少质量。 |
velocities:n.[力]速度(velocity的复数);
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And again, what we find is that there is much more mass there than can be accounted for by the galaxies that we see. |
并且再一次,我们发现的这里有更多的质量 相比于我们实际看到的星系所能证明的。 |
Or if we look in other parts of the electromagnetic spectrum, we see that there's a lot of gas in this cluster, as well. |
或者我们看其它部分的电磁波谱, 我们看到这里也有很多气体。 |
But that cannot account for the mass either. |
但是那也不能解释这些质量。 |
account for:对…负有责任;对…做出解释;说明…的原因;导致;(比例)占;
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In fact, there appears to be about ten times as much mass here in the form of this invisible or dark matter as there is in the ordinary matter, OK. |
事实上,这里有大约10倍多的质量 以暗物质存在 相比于普通物质。 |
It would be nice if we could see this dark matter a little bit more directly . |
如果我们能更直接地看到暗物质,那会更好 |
directly:adv.直接地;立即;马上;正好地;坦率地;conj.一…就;
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I'm just putting this big, blue blob on there, OK, to try to remind you that it's there. |
我只放一个大的蓝色的水泡在这里, 试图提醒你它们(暗物质)在这里。 |
blob:n.一滴;一抹;v.弄脏;把…做错;得零分; remind:v.提醒;使想起;
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Can we see it more visually ? Yes, we can. |
我们能更形象地看到它们嘛?是的,我们可以。 |
visually:adv.形象化地;外表上;看得见地;
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And so let me lead you through how we can do this. |
那么让我帮助你们了解如何这样做。 |
So here's an observer : it could be an eye; it could be a telescope . |
那么这里是一个观察器: 它可以是一只眼睛;它可以是一个望远镜。 |
observer:n.观察员;观察者;观察家;观测者; telescope:n.望远镜;v.(使)叠套缩短;精简;
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And suppose there's a galaxy out here in the universe. |
假设在宇宙中有一个星系。 |
suppose:v.推断:假定:假设:设想:
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How do we see that galaxy? |
我们如何能看到那个星系? |
A ray of light leaves the galaxy and travels through the universe for perhaps billions of years before it enters the telescope or your eye. |
一束光离开星系并穿过宇宙 经过了也许几十亿年 在它进入望远镜或者你的眼睛之前。 |
Now, how do we deduce where the galaxy is? |
现在,你如何猜测星系的位置? |
deduce:v.推论;推断;演绎;
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Well, we deduce it by the direction that the ray is traveling as it enters our eye, right? |
嗯,我们猜测它的位置根据光线传播 进入我们眼睛的方向? |
We say, the ray of light came this way; the galaxy must be there, OK. |
例如,这束光这样出来, 星系一定在那。 |
Now, suppose I put in the middle a cluster of galaxies -- and don't forget the dark matter, OK. |
现在,假设我在屏幕中央放一个星系团--- 别忘了还有暗物质,好吗? |
Now, if we consider a different ray of light, one going off like this, we now need to take into account what Einstein predicted when he developed general relativity . |
现在,如果我们考虑另外一束像这样离开的光线, 我们现在需要考虑 爱因斯坦当他发展广义相对论的时候,曾经预言过的(现象)。 |
take into account:考虑;重视;体谅; predicted:v.预言;预告;预报;(predict的过去分词和过去式) relativity:n.相对论;相关性;相对性;
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And that was that the gravitational field, due to mass, will deflect not only the trajectory of particles, but will deflect light itself. |
那就是由于有质量,引力场 不仅会使粒子的运动轨迹偏转, 而且会使光本身偏转。 |
deflect:v.偏转,转移;偏斜,转向;引开;阻止; trajectory:n.[物]轨道,轨线;[航][军]弹道;
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So this light ray will not continue in a straight line, but would rather bend and could end up going into our eye. |
所以这束光不会沿直线行进, 相反会弯曲然后最终进入我们的眼睛 |
would rather:宁愿,宁可;
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Where will this observer see the galaxy? |
这个观察器会在哪里看到星系呢? |
You can respond . Up, right? |
你们可以回答我。上面,对吗? |
respond:vi.回答;作出反应;承担责任;n.应答;唱和;
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We extrapolate backwards and say the galaxy is up here. |
我们倒推然后确定星系在这里。 |
extrapolate:vt.外推;推断;vi.外推;进行推断;
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Is there any other ray of light that could make into the observer's eye from that galaxy? |
这里还有其它的 可以进入观察者眼睛的光线嘛? |
Yes, great. I see people going down like this. |
是的,非常好。我看到人们做向下的姿势。 |
So a ray of light could go down, be bent up into the observer's eye, and the observer sees a ray of light here. |
一束光也可以往下走,然后弯曲 进入观察者的眼睛, 这个观察着便会在这里看到一束光。 |
Now, take into account the fact that we live in a three-dimensional universe, OK, a three-dimensional space. |
现在,考虑我们生活在 三维宇宙的事实 一个三维空间。 |
three-dimensional:adj.三维的;立体的;真实的;
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Are there any other rays of light that could make it into the eye? |
还有其它光线可以进入我们的眼睛嘛? |
Yes! The rays would lie on a -- I'd like to see -- yeah, on a cone . |
是的,光线可以排列在一个---我希望看到---对了,一个圆锥形 |
cone:n.圆锥体,圆锥形;[植]球果;v.使成锥形;
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So there's a whole ray of light -- rays of light on a cone -- that will all be bent by that cluster and make it into the observer's eye. |
所以,许多束光会在一个圆锥上--- 它们都被弯曲过 然后进入观察者的眼睛。 |
If there is a cone of light coming into my eye, what do I see? |
如果有锥形的光进入我的眼睛,我看到了什么? |
A circle, a ring. It's called an Einstein ring -- Einstein predicted that, OK. |
一个圆圈,一个环形。它被称作一个爱因斯坦环---爱因斯坦预言了它 |
Now, it will only be a perfect ring if the source , the deflector , and the eyeball , in this case, are all in a perfectly straight line. |
那么,它仅仅会是一个完美的环形如果它的源,这个偏导物质 以及我们的眼球,在这个情况下,恰好在一条直线上。 |
source:n.来源;水源;原始资料; deflector:n.导向装置;偏针仪,导流板; eyeball:n.眼球;眼珠;v.瞪着;逼视;盯住
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If they're slightly skewed , we'll see a different image. |
如果它们被略微偏转,我们将会看到一个不同的图像 |
slightly:adv.些微地,轻微地;纤细地; skewed:adj.歪斜的;曲解的;
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Now, you can do an experiment tonight over the reception, OK, to figure out what that image will look like. |
你们今晚在招待会后可以做一个试验, 去看到这个图像会是什么样子。 |
Because it turns out that there is a kind of lens that we can devise , that has the right shape to produce this kind of effect. |
因为我们可以设计一种透镜, 它(透镜)有产生这种现象的合适的形状。 |
lens:n.透镜,镜头;晶状体;隐形眼镜;汽车的灯玻璃;v.给…摄影; devise:v.设计; n.[法]遗赠财产的遗嘱(或其中的条款);
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We call this gravitational lensing . |
我们称它为引力透镜。 |
lensing:adj.透镜状(lense的现在分词);
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And so, this is your instrument , OK. |
所以,这是你们的仪器 |
instrument:n.仪器;工具;乐器;手段;器械;
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(Laughter). |
(笑声) |
But ignore the top part. |
但是忽略上部。 |
ignore:v.驳回诉讼;忽视;不理睬;
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It's the base that I want you to concentrate, OK. |
我希望你们关注它的底座。 |
So actually, at home, whenever we break a wineglass , |
所以实际上,在家里,不管何时我们打碎一个玻璃酒杯, |
wineglass:n.玻璃酒杯;葡萄酒杯;
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I save the bottom, take it over to the machine shop. |
我保留它的底部,把它送去机械修理店。 |
We shave it off, and I have a little gravitational lens, OK. |
我们把它剃掉,然后我就有了一个引力透镜。 |
shave:v.刮胡子;(尤指)刮脸;(少量地)削减;n.修面;刮脸;剃须;
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So it's got the right shape to produce the lensing. |
所以,它有合适产生透镜效果的形状。 |
And so the next thing you need to do in your experiment, is grab a napkin . I grabbed a piece of graph paper; I'm a physicist. (Laughter) |
所以,你在实验中需要做的下一件事情, 就是找来一张餐巾纸。我找来了一张坐标纸;我是一个物理学家。(笑声) |
napkin:n.餐巾;餐巾纸;尿布; grabbed:v.抓住;攫取;抓住,夺得;(grab的过去分词和过去式)
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So, a napkin. Draw a little model galaxy in the middle. |
那么,一张餐巾纸。在中间画一个小小的星系模型。 |
And now put the lens over the galaxy, and what you'll find is that you'll see a ring, an Einstein ring. |
然后现在把透镜放到星系上, 你将看到的是,一个爱因斯坦环。 |
Now, move the base off to the side, and the ring will split up into arcs , OK. |
现在,把底座移到另一边, 然后,这个圆环会分裂成一些弧形。 |
split:v.分离;使分离;劈开;离开;分解;n.劈开;裂缝;adj.劈开的; arcs:n.弧光灯,[数]弧(arc的复数);
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And you can put it on top of any image. |
你可以把它放到任何图像上。 |
On the graph paper you can see how all the lines on the graph paper have been distorted . |
在坐标纸上你可以看到 这些线是如何被扭曲的。 |
graph paper:n.方格纸;坐标纸;标绘纸; distorted:adj.歪曲的;受到曲解的;v.扭曲(distort的过去式和过去分词);
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And again, this is a, a kind of an accurate model of what happens with the gravitational lensing. |
再一次说明,这是一种非常精确的模型 去解释引力透镜产生的现象。 |
accurate:adj.精确的;
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OK, so the question is: do we see this in the sky? |
那么,问题是:我们在天空中看到这个吗? |
Do we see arcs in the sky when we look at, say, a cluster of galaxies? |
当我们看一个星系团的时候,我们能看到弧形吗? |
And the answer is: yes. |
答案是:是的。 |
And so, here's an image from the Hubble space telescope. |
这是来自哈勃望远镜的图像。 |
Many of the images you are seeing are earlier from the Hubble space telescope. |
你看到的许多图像 来自早期的哈勃望远镜。 |
images:n.印象;声誉;形象;画像;雕像;(image的第三人称单数和复数)
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Well, first of all , for the golden shape galaxies -- those are the galaxies in the cluster. |
嗯,首先,关于这些金色的星系--- 它们是在星系团中的一些星系。 |
first of all:adv.首先;
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They're the ones that are embedded in that sea of dark matter that are causing the bending of the light to cause these optical illusions , or mirages , practically , of the background galaxies. |
它们嵌在一团暗物质中 因而引起了光的弯曲 引起了这些视错觉,或者差不多,蜃景, 来自后面的星系。 |
optical:adj.光学的;眼睛的,视觉的; illusions:n.幻想;错觉;幻觉;幻影(illusion的复数) mirages:n.[气象]海市蜃楼(mirage复数); practically:adv.实际地;几乎;事实上;
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So the streaks that you see, all these streaks, are actually distorted images of galaxies that are much further away. |
所以你看到条纹,所有这些条纹, 其实都是更远出的扭曲的星系的图像。 |
streaks:n.[地质]条痕; v.形成条纹;
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So what we can do, then, is based on how much distortion we see in those images, we can calculate how much mass there must be in this cluster. |
那么我们能做的,就是根据扭曲程度的大小 来自这些图像,我们可以计算出 在这团星系中一定有多少质量。 |
distortion:n.变形;[物]失真;扭曲;曲解;
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And it's an enormous amount of mass. |
质量的总额是十分庞大的。 |
enormous:adj.庞大的,巨大的;凶暴的,极恶的;
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And also, you can tell by eye, by looking at this, that these arcs are not centered on individual galaxies; they are centered on some more spread out structure. |
所以,你可以通过观察它(图像),辨别 这些弧线的中心不是某一个星系; 它们(弧线)以一个更加扩散的的结构为中心。 |
individual:n.个人;有个性的人;adj.单独的;个别的; spread out:冒火;喷火;
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And that is the dark matter in which the cluster is embedded, OK. |
这就是暗物质 星系嵌入其中。 |
So this is the closest you can get to kind of seeing at least the effects of the dark matter with your naked eye. |
这是最接近于看到 至少通过肉眼看到暗物质的影响。 |
naked:adj.裸体的;无装饰的;无证据的;直率的;
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OK, so, a quick review then, to see that you're following. |
那么,一个非常快的回顾,以知道你们正在跟随。 |
So the evidence that we have that a quarter of the universe is dark matter -- this gravitationally attracting stuff -- is that galaxies, the speeds with which stars orbiting galaxies is much too large; it must be embedded in dark matter. |
我们有的证据 证明这?是暗物质--- 这些以引力作用吸引的东西--- (证据)是这些行星围绕星系运动的速率 (速率)过大;它(行星)一定嵌在暗物质中 |
gravitationally:adv.gravitational的变形adj.[物理学]万有引力的; orbiting:v.[航][天]轨道运行;轨道运动;转圈(orbit的ing形式);
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The speed with which galaxies within clusters are orbiting is much too large; it must be embedded in dark matter. |
星系在星系团中的圆周运动速度太大了; 它(星系)一定嵌在暗物质中 |
And we see these gravitational lensing effects, these distortions that say that, again, clusters are embedded in dark matter. |
我们看到了这些引力透镜的效应。这些扭曲(的现象) 再次证明,星系团嵌在暗物质中。 |
distortions:n.[物]畸变,[力]扭曲(distortion的复数);
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OK. So now, let's turn to dark energy. |
好。现在我们转向暗能量。 |
So to understand the evidence for dark energy, we need to discuss something that Stephen Hawking referred to in the previous session . |
所以为了了解暗能量的证据,我们需要讨论一些 史蒂芬霍金前一段谈到的现象。 |
Hawking:n.利用鹰行猎;v.袭击;翱翔;攫取(hawk的现在分词); referred:v.提到;引用;认为;指示;涉及;(refer的过去式和过去分词) previous:adj.以前的;早先的;过早的;adv.在先;在…以前; session:n.会议;(法庭的)开庭;(议会等的)开会;学期;讲习会;
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And that is the fact that space itself is expanding . |
那就是宇宙正在扩张的事实。 |
expanding:v.扩大,增加,增强细谈;详述;(expand的现在分词)
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So if we imagine a section of our infinite universe, OK, and so I've put down four spiral galaxies, OK. |
所以如果我们想象无限宇宙中一小部分, 然后我放4个漩涡星系, |
infinite:adj.无限的,无穷的; n.无限;
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And imagine that you put down a set of tape measures, so every line on here corresponds to a tape measure -- horizontal or vertical -- for measuring where things are. |
假设你放一套卷尺, 这里的每一条线对以一个卷尺--- 水平的或垂直的---用来测量东西的位置。 |
corresponds:v.相一致;符合;类似于;相当于;通信;(correspond的第三人称单数) tape measure:n.卷尺;皮尺; horizontal:n.水平线;水平面;横线;水平位置;adj.水平的;与地面平行的;横的; vertical:n.垂直线;垂直位置;adj.竖的;垂直的;直立的;纵向的;
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If you could do this, what you would find that with each passing day, each passing year, each passing billions of years, OK, the distance between galaxies is getting greater. |
如果你可以这样做,你将发现的是 每过去一天,每过去一年, 每过去几十亿年 星系间的距离正在变得更大。 |
And it's not because galaxies are moving away from each other through space; they're not necessarily moving through space. |
然而这并不是因为星系在运动 在空间中互相远离; 他们不一定在动。 |
necessarily:adv.必要地;必定地,必然地;
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They're moving away from each other because space itself is getting bigger, OK. |
他们正在远离对方 因为空间本身正在扩张。 |
That's what the expansion of the universe or space means. |
这是宇宙或者空间扩张的意思。 |
expansion:n.扩张;膨胀;扩展;扩大;
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So they're moving further apart. |
所以他们正运动地越来越远。 |
Now, what Stephen Hawking mentioned, as well, is that after the Big Bang , space expanded at a very rapid rate. |
史蒂芬霍金也提到的, 在大爆炸之后,宇宙空间以非常快的速率扩张。 |
Bang:n.猛敲; v.猛敲; v.正好; expanded:adj.扩充的;展开的;vt.扩大(expand的过去式);
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But because gravitationally attracting matter is embedded in this space, it tends to slow down the expansion of the space, OK. |
但是因为制造引力的物质 嵌在这个空间中, 它(暗物质)倾向于减慢空间扩张的速率。 |
So the expansion slows down with time. |
所以扩张的速率随着时间减慢。 |
So, in the last century, OK, people debated about whether this expansion of space would continue forever, whether it would slow down, you know, will be slowing down, but continue forever. |
所以,上个世纪,人们辩论 宇宙是否会永远扩张, 是否会减慢, 或者是否会减慢,但是永远进行。 |
debated:v.讨论,辩论;思考;盘算;(debate的过去分词和过去式)
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Slow down and stop, asymptotically stop, or slow down, stop, and then reverse , so it starts to contract again. |
或者减慢并停止,接近停止。 或者减慢,停止,然后在颠倒,再重新收缩。 |
asymptotically:adv.渐近地; reverse:n.反面; v.颠倒; adj.相反的; contract:v.收缩;感染;订约;n.合同;婚约;
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So a little over a decade ago, two groups of physicists and astronomers set out to measure the rate at which the expansion of space was slowing down, OK. |
所以十多年后, 两组物理学家和天文学家 着手测量 宇宙减速扩张的速率。 |
physicists:n.物理学家;机械唯物论者(physicist的复数); astronomers:天文学家;
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By how much less is it expanding today, compared to, say, a couple of billion years ago? |
通过它今天少扩张了多少, 用于和几十亿年前比较。 |
compared:adj.比较的,对照的; v.相比; (compare的过去式和过去分词)
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The startling answer to this question, OK, from these experiments, was that space is expanding at a faster rate today, than it was a few billion years ago, OK. |
这个问题的令人吃惊的答案是,根据这些实验, 宇宙本身今天正在以更快的速率扩张, 相比于几十亿年前。 |
startling:adj.惊人的;让人震惊的;极鲜亮的;v.使惊吓;使吓一跳;(startle的现在分词)
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So the expansion of space is actually speeding up. |
所以宇宙空间的扩张正在加速。 |
This was a completely surprising result. |
这是完全令人惊讶的结果。 |
There is no persuasive theoretical argument for why this should happen, OK. |
没有令人信服的理论依据解释为什么这会发生。 |
persuasive:adj.有说服力的;劝诱的,劝说的; theoretical:adj.理论的;理论上的;假设的;推理的;
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No one was predicting ahead of time this is what's going to be found. |
没有人事先预言了什么将会被发现。 |
predicting:v.预言;预告;预报;(predict的现在分词)
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It was the opposite of what was expected. |
它(实验结果)和我们的期望是相反的。 |
So we need something to be able to explain that. |
所以我们需要一些东西去解释它。 |
Now it turns out, in the mathematics , you can put it in as a term that's an energy. |
现在,在数学中, 你可以放入一项成为能量。 |
mathematics:n.数学;数学运算;
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But it's completely different type of energy from anything we've ever seen before. |
但是它是一种不同的能量 和我们见过的都不一样。 |
We call it dark energy, and it has this effect of causing space to expand. |
我们叫它暗能量, 而且它有使宇宙扩张的影响。 |
But we don't have a good motivation for putting it in there at this point, OK. |
但是我们现在还没有很好的动机 去(在数学中)放入这样一项。 |
motivation:n.动机;积极性;推动;
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So it's really unexplained as to why we need to put it in. |
所以,无法解释为什么我们需要放入这样一项。 |
unexplained:adj.未经解释的;未经说明的;不清楚的;
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Now, so at this point, then, what I want to really emphasize to you, is that first of all, dark matter and dark energy are completely different things, OK. |
现在,这个时候,我想强调的是, 首先,暗物质和暗能量 是完全不同的东西。 |
emphasize:v.强调;重视;着重;使突出;
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There are really two mysteries out there as to what makes up most of the universe, and they have very different effects. |
它们是宇宙中关于组成成分的两个谜题, 而且它们影响不同。 |
Dark matter, because it gravitationally attracts, it tends to encourage the growth of structure, OK. |
暗物质,因为它的引力效应, 它倾向于促成固定结构的形成。 |
So clusters of galaxies will tend to form, because of all this gravitational attraction. |
所以这些星系构成的星系团会形成, 原因是引力作用。 |
Dark energy, on the other hand , is putting more and more space between the galaxies. |
暗能量,另一方面, 在星系之间产生越来越多的空间。 |
on the other hand:另一方面;
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Makes it -- the gravitational attraction between them -- decrease , and so it impedes the growth of structure. |
使它们之间的引力作用减小, 因为它(暗能量)阻碍了固定结构的形成。 |
decrease:v.降低;减少;缩小;减弱;n.减少;减小量;所减少的总量;减缩位置; impedes:vt.阻碍;妨碍;阻止;
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So by looking at things like clusters of galaxies, and how they -- their number density , how many there are as a function of time -- we can learn about how dark matter and dark energy compete against each other in structure forming. |
通过看这些星系的星系团, 以及它们如何----它们的数密度--- ---它们的数量以时间为函数, 我们可以了解暗物质、暗能量 如何在结构的形成上互相竞争。 |
density:n.密度; compete:v.竞争;对抗;参加比赛(或竞赛);
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In terms of dark matter, I said that we don't have any, you know, really persuasive argument for dark energy. |
在暗物质方面,我说过我们没有任何 真正有说服力的论据来解释暗能量。 |
Do we have anything for dark matter? And the answer is: yes. |
我们有暗物质的证据嘛?答案是:是的。 |
We have well-motivated candidates for the dark matter. |
我们有非常好的动机给暗能量指定一个候选人。 |
Now, what do I mean by well-motivated? |
现在,我指的“好动机”是什么? |
I mean that we have mathematically consistent theories that were actually introduced to explain a completely different phenomena , OK, things that I haven't even talked about, that each predict the existence of a very weakly interacting new particle. |
我的意思是说我们有数学上统一的理论 被引入 去解释一个完全不同的现象 一些我还没有讨论到的现象, (现象)每个预言了 新的弱作用粒子。。 |
mathematically:adv.算术地,数学上地; consistent:adj.始终如一的,一致的;坚持的; phenomena:n.现象(phenomenon的复数); weakly:adv.虚弱地;无力地;软弱地;有病地;adj.虚弱的;软弱的; interacting:v.交流;沟通;合作;相互影响;(interact的现在分词)
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So, this is exactly what you want in physics: where a prediction comes out of a mathematically consistent theory that was actually developed for something else. |
这正是在物理中你想要的: 当一个预言从相容的数学理论中推断出来 然后实际上被发展用以解释其它东西。 |
prediction:n.预报;预言;
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But we don't know if either of those are actually the dark matter candidate, OK. |
但是我们不知道是否他们中的一个 其实是暗物质的候选者。 |
One or both, who knows? Or it could be something completely different. |
一个或者两个都是,谁知道呢?或者它可以使一些完全不同的东西。 |
Now, we look for these dark matter particles because after all, they are here in the room, OK, and they didn't come in the door. |
现在,我们寻找这些暗物质粒子 因为毕竟它们在这里,在这个房间里, 而且它们不进门。 |
They just pass through anything. |
它们仅仅穿越一切。 |
pass through:穿过;经历;经验;遭受;
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They can come through the building, through the earth; they're so non-interacting. |
它们穿过建筑,穿过地球; 它们如此不活泼。 |
So one way to look for them is to build detectors that are extremely sensitive to a dark matter particle coming through and bumping it. |
所以一种寻找它们的方式是修建探测器 对于暗物质粒子穿过碰撞它极度敏感的探测器。 |
detectors:n.探测器;侦测设备(detector的复数); sensitive:adj.敏感的;感觉的;易受影响的;n.敏感的人;有灵异能力的人; bumping:v.碰上,撞上;颠簸行进(bump的现在分词)
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So a crystal that will ring if that happens. |
一种晶体振子在它发生时会振动。 |
crystal:n.水晶; adj.晶莹的;
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So one of my colleagues up the road and his collaborators have built such a detector. |
我的一个同事和他的合作者在路边 已经修建了一个这样的探测器。 |
colleagues:n.同事;同行(colleague的复数); collaborators:n.[劳经]合作者;投敌者(collaborator的复数);
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And they've put it deep down in an iron mine in Minnesota , |
他们把它(探测器)深深地放在明尼苏达州的底下铁矿中, |
Minnesota:n.明尼苏达州(美国中北部洲);
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OK? -- deep under the ground -- and in fact, in the last couple of days announced the most sensitive results so far. |
底下非常深的地方。实际上,在过去的几天里 至今所公布过的最敏锐的结果显示。 |
They haven't seen anything, OK, but it puts limits on what the mass and the interaction strength of these dark matter particles are. |
他们没有看到任何东西,但是这给暗物质的质量 以及相互酌强度作了限制。 |
interaction:n.[计]交互,相互作用;相互交流;干扰;
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There's going to be a satellite telescope launch later this year. |
今年将会有卫星望远镜发射。 |
launch:v.发射(导弹,火箭等); n.发射;
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And it will look towards the middle of the galaxy, to see if we can see dark matter particles annihilating and producing gamma rays that could be detected with this. |
它将会关注星系中心, 以观测是否我们可以看到暗物质湮灭 并产生可以用这种方式检测到的γ射线。 |
annihilating:v.消灭;歼灭;毁灭;彻底击败;(annihilate的现在分词) gamma:n.微克;希腊语的第三个字母; detected:v.发现;查明;侦察出;(detect的过去分词和过去式)
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The large hadron collider , a particle physics accelerator, that we'll be turning on later this year. |
那个大的强子碰撞器,一个粒子物理加速器, 今年将会开启。 |
hadron:n.[高能]强子(参与强相互作用的基本粒子); collider:n.对撞机;碰撞机;
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It is possible that dark matter particles might be produced at the large hadron collider. |
很可能暗物质离子会产生于 大的强子碰撞机。 |
Now, because they are so non-interactive, they will actually escape the detector, so their signature will be missing energy, OK. |
现在,因为它们如此不活泼, 他们其实将会逃离探测器, 所以,它们的署名将会是丢失的能量。 |
signature:n.署名;签名;信号;
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Now unfortunately , there is a lot of new physics whose signature could be missing energy, so it will be hard to tell the difference. |
不幸的是,很多新的物理量 它们(物理量)可以代表能量损失, 所以,很难辨别它们(代表能量损失的物理量)。 |
unfortunately:adv.不幸地;
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And finally , for future endeavors , there are telescopes being designed specifically to address the questions of dark matter and dark energy: ground-based telescopes. And there are three space-based telescopes that are in competition right now to be launched to investig ate dark matter and dark energy. |
最终,关于未来的努力,现在有设计的望远镜 专门研究暗物质和暗能量: 一些地面望远镜。而且现在又3架以空间为基地的望远镜 现在正在竞争 被发射以研究暗物质和暗能量。 |
finally:adv.终于;最终;(用于列举)最后;彻底地; endeavors:尽力; telescopes:n.望远镜; v.套叠; (telescope的第三人称单数) specifically:adv.特别地;明确地; ground-based:adj.陆基的;以地面为基础的; space-based:天基,天基式; competition:n.竞争;比赛,竞赛;
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So in terms of the big questions: |
所以,关于这些大问题: |
What is dark matter? What is dark energy? |
什么是暗物质?什么是暗能量? |
The big questions facing physics. |
是物理学面对的大问题。 |
And I'm sure you have lots of questions. |
而且,我确定你们有很多问题。 |
Which I very much look forward to addressing over the next 72 hours while I'm here, OK. Thank you. |
我期待着在接下来的 我在这里的72小时讨论它们(问题)。好的。谢谢。 |
look forward to:盼望,期待;
|
(Applause) |
(掌声) |