So in 1781, an English composer, technologist and astronomer called William Herschel noticed an object on the sky that didn't quite move the way the rest of the stars did. And Herschel's recognition that something was different, that something wasn't quite right, was the discovery of a planet, the planet Uranus, a name that has entertained countless generations of children, but a planet that overnight doubled the size of our known solar system. Just last month, NASA announced the discovery of 517 new planets in orbit around nearby stars, almost doubling overnight the number of planets we know about within our galaxy. So astronomy is constantly being transformed by this capacity to collect data, and with data almost doubling every year, within the next two decades, me may even reach the point for the first time in history where we've discovered the majority of the galaxies within the universe.
1781年,一位名叫威廉·赫歇尔的 英国作曲家、科学家、 天文学家, 发现浩渺宇宙一微物, 并不像其它星辰,那般移动。 他意识到这 与已知不符。 藉由此,他发现了一颗行星—— 天王星。 它的名字给 数代儿童带来快乐, 而这颗行星的发现,一夜间 将太阳系的已知面积,扩大了两倍。 就在上个月,美国国家航天局宣布: 在附近的恒星轨道上, 发现了五百一十七颗新行星。 这几乎于一夜之间,将我们星系,已知 行星的数量,翻了一倍。 这种数据收集的能力, 正不断改变着天文学。 随着数据逐年递增, 我们甚至开始设想, 在接下来的二十年内 我们可能有史以来第一次, 探索到宇宙的 绝大部分星系。
But as we enter this era of big data, what we're beginning to find is there's a difference between more data being just better and more data being different, capable of changing the questions we want to ask, and this difference is not about how much data we collect, it's whether those data open new windows into our universe, whether they change the way we view the sky. So what is the next window into our universe? What is the next chapter for astronomy? Well, I'm going to show you some of the tools and the technologies that we're going to develop over the next decade, and how these technologies, together with the smart use of data, may once again transform astronomy by opening up a window into our universe, the window of time.
但当我们迈入,这个大数据时代, 忽而惊觉: 更多的数据,可以带来好处, 也可能带来不同。 并能提出新的问题。 关键并不在于,我们收集了多少数据。 而是,这些数据是否为我们认识宇宙, 打开了一扇新的窗户, 又是否能,改变我们认识天空的方式。 那么,下一扇宇宙之窗将会是什么? 天文学的下一篇章将会是什么? 在此,我将向你们展示, 今后十年,我们将开发的一些新工具及新技术。 并向你们展示,这些技术和 数据的灵巧运用 将如何再次改变天文学, 并开启一扇认识宇宙的新窗户—— 时间之窗。
Why time? Well, time is about origins, and it's about evolution. The origins of our solar system, how our solar system came into being, is it unusual or special in any way? About the evolution of our universe. Why our universe is continuing to expand, and what is this mysterious dark energy that drives that expansion?
为什么是时间?嗯,时间关乎起源, 进化。 我们太阳系的起源于何? 它是如何出现的? 它有何特殊性,又有何与众不同之处? 而我们的宇宙呢? 为什么我们的宇宙还在不停地膨胀? 促使宇宙膨胀的那个神秘的暗能量, 究竟是什么?
But first, I want to show you how technology is going to change the way we view the sky. So imagine if you were sitting in the mountains of northern Chile looking out to the west towards the Pacific Ocean a few hours before sunrise. This is the view of the night sky that you would see, and it's a beautiful view, with the Milky Way just peeking out over the horizon. but it's also a static view, and in many ways, this is the way we think of our universe: eternal and unchanging. But the universe is anything but static. It constantly changes on timescales of seconds to billions of years. Galaxies merge, they collide at hundreds of thousands of miles per hour. Stars are born, they die, they explode in these extravagant displays. In fact, if we could go back to our tranquil skies above Chile, and we allow time to move forward to see how the sky might change over the next year, the pulsations that you see are supernovae, the final remnants of a dying star exploding, brightening and then fading from view, each one of these supernovae five billion times the brightness of our sun, so we can see them to great distances but only for a short amount of time. Ten supernova per second explode somewhere in our universe. If we could hear it, it would be popping like a bag of popcorn. Now, if we fade out the supernovae, it's not just brightness that changes. Our sky is in constant motion. This swarm of objects you see streaming across the sky are asteroids as they orbit our sun, and it's these changes and the motion and it's the dynamics of the system that allow us to build our models for our universe, to predict its future and to explain its past.
首先,我想向你们展示一下科技, 将如何改变我们观察天空的方式。 想象一下, 你坐在智利北部的山上, 拂晓时分, 你向西凝望, 细观太平洋。 你将会看到,这样 壮观的夜空: 银河刚刚露出地平线, 静默安然。 而这,就是我们对宇宙的印象: 永恒且不变的。 但实际上,宇宙并不静止。 它在不停地变化。小至按秒, 大至十亿年。 星系融合,他们以 每小时几十万英里的速度相互碰撞, 新的恒星诞生、消亡。 它们以极其华丽的方式爆炸。 实际上,如果我们回首 凝望,智利宁静的天空, 并让时间前进, 观测天空接下来一年的变化。 你们看到的脉动形状, 将是超新星-濒临消亡的恒星们,爆炸时最后遗留的部分- 它们发出光亮,然后渐渐褪去。 每一颗超新星的亮度, 都是太阳的五十亿倍。 所以我们可以在很远的地方看到它们 昙花一现。 在宇宙中,每一秒, 都会有十颗超新星爆炸。 如果我们能够听到的话, 这就像在爆一袋爆米花一样。 现在,如果我们忽略超新星的画面, 变化的可不仅仅是亮度, 连我们的天空也在持续变化。 流淌过天空的这一串物什, 是围绕太阳运转的小行星, 是这些天体的变化和运行, 以及,这一系统的动态变化, 让我们能够建造宇宙的模型, 并用于预测宇宙的未来、同时解释其过去。
But the telescopes we've used over the last decade are not designed to capture the data at this scale. The Hubble Space Telescope: for the last 25 years it's been producing some of the most detailed views of our distant universe, but if you tried to use the Hubble to create an image of the sky, it would take 13 million individual images, about 120 years to do this just once.
但是,过去十年来,我们所用的望远镜, 并非是设计以捕捉这一规模数据的。 哈勃太空望远镜在 过去二十五年里拍摄了 我们的宇宙里 最细致的画面。 但如果你试图用哈勃望远镜来创作一张 天空的图像,这将需要一千三百万张的独立相片, 并花上大约一百二十年的时间来完成。
So this is driving us to new technologies and new telescopes, telescopes that can go faint to look at the distant universe but also telescopes that can go wide to capture the sky as rapidly as possible, telescopes like the Large Synoptic Survey Telescope, or the LSST, possibly the most boring name ever for one of the most fascinating experiments in the history of astronomy, in fact proof, if you should need it, that you should never allow a scientist or an engineer to name anything, not even your children. (Laughter) We're building the LSST. We expect it to start taking data by the end of this decade. I'm going to show you how we think it's going to transform our views of the universe, because one image from the LSST is equivalent to 3,000 images from the Hubble Space Telescope, each image three and a half degrees on the sky, seven times the width of the full moon. Well, how do you capture an image at this scale? Well, you build the largest digital camera in history, using the same technology you find in the cameras in your cell phone or in the digital cameras you can buy in the High Street, but now at a scale that is five and a half feet across, about the size of a Volkswagen Beetle, where one image is three billion pixels. So if you wanted to look at an image in its full resolution, just a single LSST image, it would take about 1,500 high-definition TV screens. And this camera will image the sky, taking a new picture every 20 seconds, constantly scanning the sky so every three nights, we'll get a completely new view of the skies above Chile. Over the mission lifetime of this telescope, it will detect 40 billion stars and galaxies, and that will be for the first time we'll have detected more objects in our universe than people on the Earth. Now, we can talk about this in terms of terabytes and petabytes and billions of objects, but a way to get a sense of the amount of data that will come off this camera is that it's like playing every TED Talk ever recorded simultaneously, 24 hours a day, seven days a week, for 10 years. And to process this data means searching through all of those talks for every new idea and every new concept, looking at each part of the video to see how one frame may have changed from the next. And this is changing the way that we do science, changing the way that we do astronomy, to a place where software and algorithms have to mine through this data, where the software is as critical to the science as the telescopes and the cameras that we've built.
所以,这驱使我们研发新的技术, 和新的望远镜, 这是一种既有深度又有广度的望远镜, 它能以最快的速度, 捕捉到 尽为宽广的画面。 例如,大型综合巡天望远镜, 亦称为LSST, 是天文学历史上, 最伟大的实验之一。 这个名字相当无趣, 事实证明,如果要取名字, 绝不能让一个科学家或工程师, 来给任何事物取名。你的小孩就更不要, 让他来啊(大笑)。 我们正在建造LSST, 我们预计,在这个十年内,就可以用它来捕获数据。 好了,接下来,我将向各位展示, LSST将如何改变我们观测宇宙的方式。 因为,LSST拍的一张照片, 相当于哈勃望远镜, 拍摄的3000张图片。 每张图片相当于天空的3.5度 是满月的7倍宽。 恩,如何才能捕获如此规模的图像呢? 其实,建造这一史上最大望远镜,的技术, 与你的手机摄像头,或者在大街上 可以买到的任何数码相机,所使用的技术一样。 但是,它的直径是5.5英尺, 相当于一辆大众甲壳虫的大小, 一张图像达到30亿像素, 所以,如果你想无损查看 一张LSST图片 大约需要1500块高清电视屏幕。 而这一望远镜,不间断的扫描天空, 以每20秒一张的速度, 环望宇宙。 所以,每过三个夜晚,我们所拍到的智利上方 的天空,都会是一幅全新的景象。 依据这一望远镜的设计寿命, 它将可以探测,400亿颗恒星和星系, 也将第一次, 使我们探测到宇宙星体的 数量超过地球上人类数量。 然后,我们讨论时,就可以用 兆和千兆单位, 以及十亿级个体单位了。 为了理解这一望远镜捕获数据 的数量级, 我们可以这样想象: 这是,你一天24小时,每周7天, 连续10年, 同时播放,所有的TED演讲的总和。 而处理这一数据意味着, 在所有TED演讲中搜索, 新点子和新概念, 查并看每个视频的每一部分 弄清楚每一贞是如何从上一贞 转换来的。 这将彻底改变我们的科研方式, 并改变我们研究天文学的方式。 那时,各种软件和算法, 将不得不用来挖掘这一数据, 而软件也变得对科学至关重要, 同我们建造的望远镜和照相机一样重要。
Now, thousands of discoveries will come from this project, but I'm just going to tell you about two of the ideas about origins and evolution that may be transformed by our access to data at this scale.
那时,该项目将带来, 成千上万的新发现。 但是,我这里要介绍的, 是这一大数据对我们 关于起源和进化的两个认识, 将带来的变化。
In the last five years, NASA has discovered over 1,000 planetary systems around nearby stars, but the systems we're finding aren't much like our own solar system, and one of the questions we face is is it just that we haven't been looking hard enough or is there something special or unusual about how our solar system formed? And if we want to answer that question, we have to know and understand the history of our solar system in detail, and it's the details that are crucial. So now, if we look back at the sky, at our asteroids that were streaming across the sky, these asteroids are like the debris of our solar system. The positions of the asteroids are like a fingerprint of an earlier time when the orbits of Neptune and Jupiter were much closer to the sun, and as these giant planets migrated through our solar system, they were scattering the asteroids in their wake. So studying the asteroids is like performing forensics, performing forensics on our solar system, but to do this, we need distance, and we get the distance from the motion, and we get the motion because of our access to time.
过去五年,美国国家航空和宇宙航行局, 在附近的恒星周围, 发现了超过1000个星球体系。 但我们发现的这些星系 与我们的太阳系不太一样。 而我们提出的一个问题就是, 是我们探测水平有限呢, 还是我们的太阳系就是一个, 特殊和不同寻常的星系呢? 要解开这一疑问, 我们需要知道,并理解 我们的太阳系的详细历史。 而细节将决定我们的成败。 那么,当我们望向 划过天空的小行星, 而这些小行星就像太阳系的碎片, 并且,这些小行星的位置, 就像宇宙早年留下的指纹。 那时,海王星和木星 距离太阳还很近, 而当这些巨型星球在太阳系里迁徙时, 也在他们身后散落下了许多个小行星。 因此,研究这些小行星, 如同在取证一样, -对我们的太阳系进行取证。 要达到这一目的,我们需要距离, -而距离来自于运动, 运动来自于我们对时间的控制。
So what does this tell us? Well, if you look at the little yellow asteroids flitting across the screen, these are the asteroids that are moving fastest, because they're closest to us, closest to Earth. These are the asteroids we may one day send spacecraft to, to mine them for minerals, but they're also the asteroids that may one day impact the Earth, like happened 60 million years ago with the extinction of the dinosaurs, or just at the beginning of the last century, when an asteroid wiped out almost 1,000 square miles of Siberian forest, or even just last year, as one burnt up over Russia, releasing the energy of a small nuclear bomb. So studying the forensics of our solar system doesn't just tell us about the past, it can also predict the future, including our future.
那么,这意味着什么呢? 请注意这些黄色的小行星, 高速从屏幕中划过, 这些是移动地最快的小行星, 因为他们离我们最近,离地球最近。 有一天,我们也许能够向这些小行星, 发送宇宙飞船,从那里采矿。 但也可能,有一天这些小行星, 会撞上地球。 就像6000万年前发生的 恐龙灭绝一样, 或者像上世纪初发生的那样: 一颗小行星落下, 摧毁了西伯利亚1000平方英里的森林。 抑或像去年一样,一颗小行星在俄罗斯上空燃尽, 释放了一个小型原子弹的能量。 所以,对我们的太阳系进行取证, 并不仅仅是研究过去, 而是要预测未来,包括我们人类的未来。
Now when we get distance, we get to see the asteroids in their natural habitat, in orbit around the sun. So every point in this visualization that you can see is a real asteroid. Its orbit has been calculated from its motion across the sky. The colors reflect the composition of these asteroids, dry and stony in the center, water-rich and primitive towards the edge, water-rich asteroids which may have seeded the oceans and the seas that we find on our planet when they bombarded the Earth at an earlier time. Because the LSST will be able to go faint and not just wide, we will be able to see these asteroids far beyond the inner part of our solar system, to asteroids beyond the orbits of Neptune and Mars, to comets and asteroids that may exist almost a light year from our sun. And as we increase the detail of this picture, increasing the detail by factors of 10 to 100, we will be able to answer questions such as, is there evidence for planets outside the orbit of Neptune, to find Earth-impacting asteroids long before they're a danger, and to find out whether, maybe, our sun formed on its own or in a cluster of stars, and maybe it's this sun's stellar siblings that influenced the formation of our solar system, and maybe that's one of the reasons why solar systems like ours seem to be so rare.
那么,当我们获得距离后, 我们将看到这些小行星在原始轨道的样子- 围绕太阳运转时的样子。 所以,你从这一画面中看到的每一个点, 都是这些小行星真实所在的位置。 从它划过天空的运动轨迹,我们计算出它的周转轨道。 颜色可以反映这些小行星的成分。 中间的干燥多岩石, 边缘的富含水分,成分原始, 这些富含水分的小行星, 可能正是它们早期撞击地球时 为地球带来了海洋的种子。 LSST不仅能拍摄广域照片, 还能拍摄无光线物体, 我们能看到, 远离太阳系内圈轨道的小行星, 离海王星和火星轨道很远的小行星, 以及远离我们的太阳几乎一光年 的彗星和小行星。 当我们增加更多的画面细节, 将像素从10增加到1000, 我们就能回答类似这样的问题了: 有证据证明海王星轨道外存在星球吗? 能在危机形成前 就发现冲向地球的小行星吗? 我们的太阳是自成一体的, 并属于恒星之一吗? 或者,是不是太阳的兄弟姐妹星球 在影响这太阳系的形成? 也许这就是为何我们的太阳系显得如此特殊的原因之一。
Now, distance and changes in our universe — distance equates to time, as well as changes on the sky. Every foot of distance you look away, or every foot of distance an object is away, you're looking back about a billionth of a second in time, and this idea or this notion of looking back in time has revolutionized our ideas about the universe, not once but multiple times.
现在,我们来说下宇宙的距离和变化—— 距离相当于时间, 距离相当于天空中的变化。 我们望出去的每一尺距离, 或者一个物体离去的每一尺距离, 你看到的都是十亿分之一秒之前的画面。 而这一概念,或者说时间回溯的概念, 彻底地改变了我们对宇宙的认知。 不是一次,而是好多次。
The first time was in 1929, when an astronomer called Edwin Hubble showed that the universe was expanding, leading to the ideas of the Big Bang. And the observations were simple: just 24 galaxies and a hand-drawn picture. But just the idea that the more distant a galaxy, the faster it was receding, was enough to give rise to modern cosmology.
第一次是在1929年, 天文学家爱德文·哈勃 向人们展示了宇宙是在膨胀的, 诞生了宇宙大爆炸的理论。 而这一观察是很简单的: 仅仅是24个星系 以及一副手绘图。 但就是这一简单的概念: “星系离我们越远,其后退的速度越快”, 就足以开创了现代宇宙学。
A second revolution happened 70 years later, when two groups of astronomers showed that the universe wasn't just expanding, it was accelerating, a surprise like throwing up a ball into the sky and finding out the higher that it gets, the faster it moves away. And they showed this by measuring the brightness of supernovae, and how the brightness of the supernovae got fainter with distance. And these observations were more complex. They required new technologies and new telescopes, because the supernovae were in galaxies that were 2,000 times more distant than the ones used by Hubble. And it took three years to find just 42 supernovae, because a supernova only explodes once every hundred years within a galaxy. Three years to find 42 supernovae by searching through tens of thousands of galaxies. And once they'd collected their data, this is what they found. Now, this may not look impressive, but this is what a revolution in physics looks like: a line predicting the brightness of a supernova 11 billion light years away, and a handful of points that don't quite fit that line.
第二次思想变革,发生在70年后, 两组天文学家证明, 宇宙不仅在膨胀, 还在加速。 这着实让人吃惊,如同我向天空扔出一个球, 但它飞到越高的地方时 飞离的速度却越快。 他们通过测量超新星的亮度, 证实了这一点。 同时被证明的还有,超新星的亮度 在离我们越远时,变得越暗。 这些发现就更加复杂了。 它们需要新的技术和望远镜, 因为超新星所在星系的位置 在哈勃望远镜可观察范围 2000倍以外。 光是发现42颗超新星就花去了3年时间, 因为一个星系里的一颗超新星, 每一百年才爆炸一次。 通过搜索上万个星系, 才能在3年内发现42颗超新星。 一旦它们收集到了数据, 便将结果汇总为发现。 这虽然看上去并不壮观, 但这正是它,发生的表面样式。 一条可以预测超新星亮度的线, 距我们110亿光年, 这条线上还有许多并不甚契合的点。
Small changes give rise to big consequences. Small changes allow us to make discoveries, like the planet found by Herschel. Small changes turn our understanding of the universe on its head. So 42 supernovae, slightly too faint, meaning slightly further away, requiring that a universe must not just be expanding, but this expansion must be accelerating, revealing a component of our universe which we now call dark energy, a component that drives this expansion and makes up 68 percent of the energy budget of our universe today.
微小的变化不断汇集,带来了巨变。 通过量变,我们才有了新发现, -正如赫歇尔发现天王星一样。 微小的变化,改变了我们对, 宇宙的认识。 所以,42颗超新星,慢慢地暗去, 意味着他们正慢慢飞离我们, 也意味着宇宙不仅在膨胀, 而且膨胀的速度还在加快, 这揭示了宇宙的一个组成成分, 我们称之为暗能量, 这是一种驱动宇宙膨胀的物质, 占今天宇宙总全部物质的, 68%。
So what is the next revolution likely to be? Well, what is dark energy and why does it exist? Each of these lines shows a different model for what dark energy might be, showing the properties of dark energy. They all are consistent with the 42 points, but the ideas behind these lines are dramatically different. Some people think about a dark energy that changes with time, or whether the properties of the dark energy are different depending on where you look on the sky. Others make differences and changes to the physics at the sub-atomic level. Or, they look at large scales and change how gravity and general relativity work, or they say our universe is just one of many, part of this mysterious multiverse, but all of these ideas, all of these theories, amazing and admittedly some of them a little crazy, but all of them consistent with our 42 points.
那么,下一次思想变革,将会是什么呢? 什么是暗能量,它为什么存在呢? 请看这些线条,每条都代表了, 对暗能量存在形式的不同理论。 并描绘暗能量的属性。 他们与这42个点都存在一致性, 但他们背后的理论却 截然不同。 一些人认为,暗能量会 随着时间而变化, 或者说,暗能量的成分 取决于你望向天空时的位置。 另一些人认为,暗能量的变化 存在于亚原子表面。 还有一些人认为,暗能量的变化发生在更大的层面, 并改变了重力和广义相对论的作用方式, 或者说,他们认为我们认识的宇宙只是众多宇宙之一, 属于神秘的多重宇宙的一部分, 但是,所有这些概念、理论, 虽然让人吃惊,甚至有些疯狂, 但都与这42个点一致。
So how can we hope to make sense of this over the next decade? Well, imagine if I gave you a pair of dice, and I said you wanted to see whether those dice were loaded or fair. One roll of the dice would tell you very little, but the more times you rolled them, the more data you collected, the more confident you would become, not just whether they're loaded or fair, but by how much, and in what way. It took three years to find just 42 supernovae because the telescopes that we built could only survey a small part of the sky. With the LSST, we get a completely new view of the skies above Chile every three nights. In its first night of operation, it will find 10 times the number of supernovae used in the discovery of dark energy. This will increase by 1,000 within the first four months: 1.5 million supernovae by the end of its survey, each supernova a roll of the dice, each supernova testing which theories of dark energy are consistent, and which ones are not. And so, by combining these supernova data with other measures of cosmology, we'll progressively rule out the different ideas and theories of dark energy until hopefully at the end of this survey around 2030, we would expect to hopefully see a theory for our universe, a fundamental theory for the physics of our universe, to gradually emerge.
那么,我们如何能在未来十年, 弄清楚这一问题呢? 恩,想象一下,如果给你一对骰子, 然后,你想判断这些骰子, 是否平整。 滚一次骰子,你得到的信息很有限。 但滚越多次, 你收集到的信息就越多, 你对自己的判断就越有信心。 不仅是这些骰子是否平整, 而且是平整的程度,哪里不平整等, 你都了如指掌。 我们花费了3年才找到42颗超新星, 是因为我们建造的望远镜, 只搜索天空的一小部分。 而当我们建好LSST后,我们每3个夜晚 就能获得一幅智力上方天空完整的画面。 在LSST运行的第一个晚上, 它发现的超新星数量,就相当于我们发现暗能量, 所需超新星数量的十倍。 在头4个月内, 这一数量将增加到1000倍: 即最终发现150万颗超新星。 每个超新星代表滚一次骰子, 每个超新星能测试一下, 哪种暗能量理论是准确的,哪种是有矛盾的。 因此,整合这些超新星数据, 结合其他宇宙学方法, 我们将排除很大一部分有关暗能量的 假设概念和理论。 如果顺利的话,到2030年, 我们很有希望,能确定一种 关于我们宇宙的理论。 一种关于我们宇宙物理现象的根本理论, 正在眼前徐徐展开。 恩,实际上,我刚才所列举的例子,
Now, in many ways, the questions that I posed are in reality the simplest of questions. We may not know the answers, but we at least know how to ask the questions. But if looking through tens of thousands of galaxies revealed 42 supernovae that turned our understanding of the universe on its head, when we're working with billions of galaxies, how many more times are we going to find 42 points that don't quite match what we expect? Like the planet found by Herschel or dark energy or quantum mechanics or general relativity, all ideas that came because the data didn't quite match what we expected. What's so exciting about the next decade of data in astronomy is, we don't even know how many answers are out there waiting, answers about our origins and our evolution. How many answers are out there that we don't even know the questions that we want to ask?
应该是最简单的问题了。 我们可能不知道答案, 但至少知道问题是什么。 当我们观察上万个星系的时候, 我们将看到42颗超新星, 同时对宇宙有更深层次的理解, 如果我们观察上十亿个星系, 发现的超新星,将是42的多少倍呢? 将与我们的预期有多大出入呢? 正如赫歇尔发现的行星(天王星)那样, 或者正如暗能量, 抑或量子力学,广义相对论那样。 所有这些概念都来源于数据, 与我们预期不相符的数据。 未来十年的天文学数据,让我们为之欣然鼓舞 而雀跃的, 将是什么呢? 我们甚至不知道有多少答案 还在那里等着我们去拾获。 这是,关于我们起源和进化的答案。 还有许多问题 等我们去提出。 许多答案, 等待我们去发现。 谢谢。
Thank you.
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