There is a strange and mysterious world surrounding us. 有一个奇怪而神秘的世界在我们周围。
For most of the time it's hidden from our senses. 大部分时间，我们无法感觉到它。
I've always loved detective mysteries, and this is really the greatest mystery ever. 我总是喜欢探索奥秘，这的确是有史以来最伟大的奥秘。
It's one of the simplest and yet most profound questions in science. 在科学世界里，这是一个最简单但又最深刻的问题。
The search to understand the nature of reality. 探索现实的本质。
But on this quest, common sense is no guide. 在这一过程中，人类一般的感知没有用。
Quantum mechanics says that I can pass through that wall. 量子力学说 我可以穿越墙。
How often will it happen? Very rarely. 多久会发生？ 非常罕见。
But wait long enough and it will happen. 但等待足够长的时间 它会发生。
Looking for clues has taken scientists to the frontiers of what is possible to know. 寻找线索已使科学家到了可知的边界
From black holes... 从黑洞...
to the deepest structures of space and time. 到空间和时间最深的结构 。
And what they're discovering may change our understanding of reality forever. 他们发现了什么？可能永远会改变我们所理解的现实。
Don't you find this confusing? I find this very confusing. 难道你不觉得这混乱？ 我觉得这是非常混乱。
It's almost impossible to talk about using ordinary human language. 几乎不可能使用普通的人类语言的去讨论它。
This search has attracted some of the finest minds in physics today. 这个研究吸引了一些在物理学中最优秀的人。
But be warned. 但被警告。
Once you've entered their reality, yours may never look the same again. 一旦你进入了他们的现实， 你可能永远不会看的样子了。
Reality, for most us, is familiar, comforting and reliable. 现实世界，是我们最熟悉的，舒适而可靠。
It all sort of makes sense. 一切的安排总是有道理的。
Trees grow vertically, footballs follow well-known laws of motion 树木垂直生长，足球按照运动定律移动
and all our actions take place reassuringly in just three dimensions of space. 我们所有的行动发生在三维空间
But physicists see it a little differently. 但物理学家看到它有一点不同。
Reality is much weirder than it seems. 现实世界比它看上去更离奇
I feel like I'm standing still 我觉得我站着不动
but I'm actually zooming at 67,000 miles an hour around the sun. 但我其实在以每小时67,000英里的速度绕太阳运行。
I feel kind of solid, but I'm mostly empty space. 我觉得自己是固体， 但我几乎又是空的。
And all this stuff going on here with the game, maybe the flow of time is just an illusion. 这里发生的一切是怎么回事，也许时间的流逝仅仅是一种幻想。
The search to understand reality has led physicists far beyond surface appearances 对现实世界的搜索 使物理学家看到远远超出了它的表面
to try and uncover its most fundamental laws and structures. 试图揭示其最基本法律和结构。
But when it comes to defining it, 但是，当涉及到定义现实世界，
reality turns out to be very, very elusive. 非常，非常难以实现。
Is that it? You're going to ask me, what is reality? Oh, boy. 是不是这样？你要问我， 什么是现实？哦，孩子。
What is reality? What...? 什么是现实？什么...？
HE STAMMERS 何斯默斯
You want something even shorter than what I said? What? 你想要比我说的东西更短 ？什么？
Reality is the philosophical concept which we attach to something which is real. 现实世界的哲学概念是： 我们能触摸到的真实的东西。
That doesn't help, right? 这并没有帮助，对吗？
I might say reality is the set of things that we know to be the case. 我可以说现实世界上是一套我们知道的事情，。
Like what? 像什么？
Like the fact that we're sitting here, talking, 就像我们坐在这里，谈话，
like the fact that the world is quantum mechanical, 就像这样的事实，世界是量子力学的，
the fact that the universe has been around for 13.8 billion years, 事实上宇宙有的138亿年，
the fact it's hard to get a date on Saturday night. 事实上很难得到一个约会在周六晚上。
That's reality. 这就是现实。
There's no escaping the fact that understanding reality is a truly daunting challenge. 这是个不争的事实 理解现实是一个真正艰巨的挑战。
But that hasn't stopped physicists from attempting the impossible, 但是，这并没有阻止物理学家从不可能中
trying to find out what it's all made of. 试图找出它的组成。
And for centuries, they've approached this question with a surprisingly simple technique. ，几个世纪以来，他们已经靠令人惊讶的简单技术接近到了这个问题。
They smash reality to smithereens. 他们把现实粉碎成碎片。
Welcome to reality HQ, otherwise known as Fermilab, 欢迎来到现实总部 或称为费米实验室，
a high energy physics laboratory near Chicago. 高能量物理实验室 芝加哥附近。
This is Professor Jacobo Konigsberg, particle hunter, 这是教授雅各布 哥尼斯堡，粒子猎人，
and one of the few people on the planet who can personally claim 地球上少数几个可以解释一点现实的人
to have helped discover a bit of reality.
The machine Konigsberg gets to play with every day is the most powerful particle accelerator in America. 这个机器，哥尼斯堡，美国最强大的粒子加速器，每一天都在运转。
The Tevatron. 在Tevatron。
But like everything to do with reality, it's hidden from sight. 但是，跟现实世界有关的东西一样，它也无法被我们看到。
We're looking at the Tevatron, 我们正在看Tevatron，
the Fermilab proton-antiproton collider. 费米实验室 质子反质子对撞机。
It's ten metres underground. 它的十米地下。
These are the fields outside Batavia, Illinois. 巴达维亚外，伊利诺伊州。
Gorgeous day to look at it. 很适合观看它的天气。
And as we speak, 当我们说话，
underground you're having about ten million proton-antiproton collisions occurring every second. 每一秒在地下约千万质子反质子碰撞发生。
It's been working for 20 years 它已经工作了20年
and every day we basically push the boundaries of what's known. 每天，我们基本上都在推近已知的边界。
It's the chocolate factory. We love it. 它的巧克力工厂。 我们喜欢它。
What goes on beneath these fields in the Tevatron 在Tevatron的实验
are some of the most violent collisions in the universe. 是一些宇宙中最暴力的碰撞。
Deep underground in a four-mile vacuum pipe, 深层地下 在四英里的真空管，
encased by superconducting magnets, 由超导磁体包裹，
they smash together two subatomic particles 他们一起粉碎 二亚原子粒子
at close to the speed of light. 以接近光速的速度。
Their aim is to find, among the debris of these collisions, the elementary particles of reality. 他们的目的是要发现，其中这些碎片的碰撞产生的现实世界的基本粒子。
Tiny and indestructible. 很小，坚不可摧。
But there's just one hitch with this dramatic method. 但这里有一个顺利 这种戏剧性的方法。
When you collide a single proton with a single antiproton and you create this point of energy, 当你用一个反质子碰撞一个个质子 创造了一个能量点，
out of a single collision you can actually generate hundreds of particles, 单次碰撞实际上可以生成数百个粒子，
hundreds of different particles that one, as a physicist, needs to try to identify. 数百个不同的粒子， 需要一个物理学家尝试辨认。
Working out which of these are elementary, 研究其中最基本的粒子，
is a problem that's defined particle physics for over 60 years 是一个问题的定义 超过60年的粒子物理
and has required an extraordinary coming together of theory and experiment. 并已要求 不平凡的走到一起 理论和实验。
The problem started with atoms, 这个问题开始与原子，
once thought to be the only elementary particles. 曾经被认为是 唯一的基本粒子。
When experimenters first broke into them, they discovered even smaller bits inside. 当第一个实验者 打破原子，他们发现里面有 更小的粒子。
Electrons and neutrons and protons. 电子和中子和质子。
But when they tried to smash protons up... 但是，当他们尝试粉碎质子...
they encountered a different kind of problem. 他们遇到另一个问题。
Small particles need high energies to wrench them apart, 更小的粒子需要高能量扳手，
which meant building bigger and bigger machines. 这意味着建设 越来越大的对撞机。
But what came out of these fabulous feats of engineering was a big surprise. 但这些出来 工程神话般的壮举 是一大惊喜。
To the experimenters' delight, the first proton collisions 让实验者高兴的是， 第一次质子的碰撞
produced not just a handful of new particles but hundreds. 产生的不只是少数新的粒子而是数百个。
And when it came to identifying them, 当查明这些粒子的时候，
they realised they needed help. 他们意识到他们需要帮助。
To work out what was going on, the experimenters turned to theoreticians, 为了弄明白发生了什么事， 实验物理学家求助于理论物理学家，
the maths geniuses who solve physics problems with the pure power of thought. 那些纯粹靠思想力量解决物理问题的数学天才。
This is Professor Frank Wilczek, a Nobel prize-winning theoretical physicist. 这是教授弗兰克威尔茨克， 诺贝尔奖得主 理论物理学家。
How are you? Just fine! I got a collection of whoopie pies... 你好吗？还好！我有whoopie馅饼...
He lives in Cambridge, Massachusetts. 他住在剑桥， 马萨诸塞州。
But he comes out to the beautiful countryside of New Hampshire to do his thinking. 但他去美丽新罕布什尔州的乡村去做他的思想。
Wilczek is one of the key architects of our current best description of reality, 维尔泽克是最好的描述现实世界结构的人之一，
the standard model of elementary particles. 基本粒子的标准模型。
This model is a detailed description of the basic building blocks of matter 该模型是物质的基本组成部分的详细说明
and the forces that bind them. 还有结合他们的力量。
We got you a good selection of fundamental bits of reality. Yeah, you certainly have! 我们给你买了很好的选择 对现实的根本位。 是啊，你一定有！
When the experiments were actually done, there was a big shock 当实验的时候，大家都很震惊
because what happened was people found that when they collided two protons really hard together, 他们发现当很难的去碰撞两个质子的时候，
out came totally new and unexpected particles, 产生出了全新和意想不到的颗粒，
like K mesons, omega baryons pi mesons, electrons, 如K介子，重子欧米加 丕介子，电子，
neutrinos, other mesons. 中微子，介子等。
They ran out of names because the Greek alphabet is only so big. 他们用光了这些名字，因为希腊字母只有这么多。
There were such a bewildering variety of these baryons and mesons 有这么多的重子和各种介子
that together, they became known as the particle zoo. 说起来，他们被称为 粒子动物园。
A whole new layer of reality had being discovered, 一个全新的现实世界层面被发现了，
but the question no-one could answer was, 没有人能回答是，
which ones were elementary? 哪些是最基本的粒子？
They were discovered experimentally 他们实验所发现的东西
with no underlying theoretical understanding of what was happening. 没有相关理论了解发生了什么事。
So the theorists, who wanted to get down to a simple description of nature, 因此，这些想要对大自然的简单的描述的理论家，
thought they were ready to almost close the book on the laws of nature, were totally stymied 还以为他们几乎可以合上这本自然法则的书，现在完全受阻
and had to go back to the drawing board. ，不得不回到绘图板。
Faced with having to explain these unexpected particles, 去面对如何解释这些意外的颗粒，
the theorists tried to come up with a simple and beautiful solution. 理论家试图想出 一个简单而优美的解决方案。
They wondered if the zoo would make sense 他们想，如果动物园 才有意义
if it were actually combinations of fewer more basic units. 如果它实际上组合 更少的更基本的单位。
They called this new set of particles the quarks. 他们称这种新的粒子 夸克。
Altogether, six quarks were described by the theory. 总之，六夸克 通过理论进行了描述。
Up and down quarks, strange and charm, and bottom and top. 上，下夸克，奇 和魅力，以及底部和顶部。
At first, no-one believed they were real. 起初，没有人相信 它们是真的。
Then hints of them began to show up 然后，提示他们 开始出现
and before long, these imaginary particles were actually discovered, 不久之后， 这些假想粒子 实际上发现，
one by one, until the theory hit a roadblock. 一个接一个，直至理论 受到阻拦。
The top quark was still missing. 顶夸克是人仍下落不明。
Either they hadn't found it yet or it didn't exist, 他们要么现在还没有找到 或者不存在，
an unthinkable proposition. 一个不可思议的命题。
So together, the theorists and the experimenters decided to take a gamble. 所以合计，理论家 和实验者 决定采取一种赌博。
They invested billions of dollars in a new class of accelerator, 他们投资数十亿美元 在一类新的加速器，
massively more powerful than anything that had gone before. 大量更强大 比任何以前去了。
By 1990, Jacobo Konigsberg had joined the hunt for the top quark. 到1990年，雅各布哥尼斯堡了 加入追捕的顶夸克。
He had at his disposal the biggest toy in particle physics, 他在他的掌握的最大 粒子物理学的玩具，
the shiny new Tevatron, and a beautiful theory to guide him. 闪闪发亮的Tevatron实验，并用一个美丽的理论来指导他。
All eyes were on Fermilab. 所有的目光都在费米实验室。
Jacobo's team were looking for something so small, it had no discernible size. 雅各布的团队在寻找 如此小的东西， 它没有明显的尺寸。
They didn't know its mass. 他们不知道它的质量。
And if it existed at all, it was extremely rare. 如果它存在于一切， 这是极其罕见的。
It was predicted to be the heaviest of the quarks. 据预测它将是最重的夸克。
But even if it did turn up, it would only last a trillionth of a trillionth of a second. 但即使它露面， 它也只能维持的万亿 作为一兆分之一秒。
Finding the top quark was really, really very difficult. 寻找顶夸克 真的，真的很困难。
We had to create thousands of billions of those collisions 我们必须创造数千 对这些碰撞数十亿
in order to finally detect a few dozen of them that produced top quarks. 以最终检测 他们中的几十个 顶夸克的产生。
As if creating the collisions wasn't hard enough, 至于如果碰撞不够强大，
analysing the fleeting fragments of reality they produced 稍纵即逝的片段分析 他们生产的现实
depended on the perfect performance of the most intricate scientific instruments ever built, 依靠完美的表现 最复杂的科学 文书有史以来建造，
the collision detectors. 碰撞探测器。
This is one of the pieces of the detector. 这是件一 该探测器。
It's a big chamber 这是一间大房子
that has very, very tiny wires running across it, 有非常，非常微小的电线 运行境而过，
it's full of gas, 它充满了气，
and as particles come out of the collision point, 当粒子 从 碰撞中产生的时候，
they leave tiny traces of ions that are picked up by these wires, 他们留下微小的痕迹 由这些电线捕获，
and then you can reconstruct the actual trajectory of each of the particles 然后你可以对每个粒子 重建 实际轨迹
as they emerge from the collision point. 当他们从碰撞点出现 。
This helped us tremendously. 这有助于我们良多。
So this is a piece of history 因此，这是一段历史
and we have it here shown as one of the most magnificent pieces of apparatus 而我们在这里展示 为一体的最壮丽 件仪器
that have helped us to decode reality. 那些帮助我们 解码现实世界。
Jacobo's team searched for the top quark for four years. 雅各布的团队搜寻了四年的顶夸克。
His handwritten diaries record their frustrated ambitions. 他手写的日记 记录他们的野心受挫。
Over six million collisions, but still no top quark. 六百多万的碰撞， 但是仍然没有顶夸克。
Then one day, everyone came together for a meeting. 后来有一天，大家都 聚集在一起开会。
This is the room where, after years and years of taking data, 这是房间里，后 岁，以数据来，
we finally realised we had discovered a new particle, 我们终于意识到 我们发现了一个新的粒子，
we had discovered the top quark. 我们已经发现了顶夸克。
January 21st, 1995. 1995年1月21日。
The first reaction from the whole room was silence, and then we broke into an applause. 第一反应是整个房间的沉默， 然后我们闯进了掌声。
Everybody was in disbelief 每个人都在怀疑
because it all had come together after so many years of hard work, 因为这一切都来到 经过这么多年的努力，
so many years of searches through many accelerators, 这么多年的搜索 通过许多加速器，
we finally had it here, and we were convinced beyond any doubt 我们终于在这里，我们都很 毫无疑问相信
that this was going to become part of reality. 这是去 成为现实的一部分。
The top quark was here to exist, to stay and here to be part of the history of scientific discoveries 顶夸克在这里存在， 留下来，这里成为团队的一分子 历史上的科学发现
So the feeling was ecstasy - pure ecstasy. 所以感觉是狂喜 - 纯粹的狂喜。
We all feel, I think, that this is our baby. 我们都觉得，我认为， 这是我们的孩子。
It's the particle that we unveiled and now we're studying and taking care of. 这是粒子， 我们推出，现在我们 学习和照顾。
With the discovery of the top quark Physicists are close to understanding 随着顶夸克的发现 物理学家接近 理解
one of the greatest mysteries of reality - what it's all made of. 其中一个最大的奥秘 现实 - 它的所有组成的。
They've finally tamed the particle zoo into an elegant set of unbreakable bits called 他们终于驯服了粒子 动物园成为一个优雅集 所谓的牢不可破的位
the Standard Model of Elementary Particles. 标准模型的基础 粒子。
Six quarks, their six electron cousins - the leptons, 六夸克，他们的六电 远亲 - 对轻子，
and four particles that carry force. 四粒子携带的力量。
Together, these 16 pieces make up the world we see around us. 总之，这16件组成 我们看到在我们周围的世界。
It's an amazing achievement 这是一个了不起的成就
to have drilled down through the visible world 向下钻过可见世界
to the bottom layer of reality itself. 到底层 现实的本身。
But there's a puzzle at the heart of this picture. 但还有一个谜 在这个图片的心。
You like the fact that you're seeing it, you like the fact that you can explain how these characters 你喜欢你所看到的事实， 它，你喜欢这样的事实，你可以 如何解释这些字符
interact with each other, and who they are and what their basic properties are. 互相交流， 他们是谁和什么 它们的基本性质。
But then you don't know why there are so many, you want to think, what drives those numbers? 但是你不知道为什么 有这么多，你要 想，是什么驱使这些数字？
What's so magical about six quarks? What's so magical about six leptons? Why six? 为何如此六夸克神奇吗？ 什么是六轻子这么神奇吗？ 六，为什么？
Every time in history where we've had a really complicated description of reality, 历史的每一个时刻，我们已经 有一个非常复杂的描述 现实，
someone has come along and unified this into something beautifully elegant. 有人已经到来 统一此 一些精美典雅。
And right now I think our best understanding of physics, again, 而现在，我认为我们最好的 了解物理学，再次，
is just a bit too complicated to be the real deal. 只是有点太复杂 是真正的交易。
While particle physicists dream of simplicity, 当粒子物理学家 简单的梦想，
there's a whole other branch of physics that questions 还有的完全是另外一个分支 物理学的问题
whether reality as we know it can even be said to exist at all. 是否现实，因为我们知道这 甚至可以说是存在的。
Welcome to the weird world of quantum reality... 欢迎来到怪异的世界 量子现实...
..where nothing is quite as it seems. ..那里任何事物都是相当 因为它似乎。
Here, in Vienna, experimental physicist Anton Zeilinger 在这里，在维也纳，实验 物理学家安东Zeilinger
is about to unlock the mysteries of the quantum world. 即将解开的奥秘 量子世界。
He's going to perform a remarkable experiment that puts the very existence of reality into question. 他要执行一个显着 实验，提出了非常 存在质疑的现实。
Known to physicists as the double-slit experiment, 作为著名物理学家 双缝实验，
it's remarkable because it reveals two astonishing paradoxes about the nature of reality 这是了不起，因为它揭示 两个惊人的悖论 关于现实的本质
That no-one can fully explain. ，没有人能完全解释。
I'm now showing you the two-slit experiment 我现在向您展示 在双缝实验
which contains one of the basic mysteries of quantum mechanics. 它包含了基本的一 量子力学的奥秘。
It is very simple. 这是非常简单。
We have a laser, we have a two-slit assembly 我们有一个激光， 我们有一个双缝大会
where the light can only go through two slit openings and we have an observation screen. 在光只能走 通过两个狭缝开口 我们有一个观察屏幕。
The experiment has one crucial feature - Zeilinger can control his laser beam so that it fires 这个实验的一个关键 功能 - Zeilinger可以控制 他的激光束，使其火灾
single particles of light, called photons, through the slits. 单个粒子的光，称为 光子通过狭缝。
Just single particles. 只是单一的颗粒。
Lets do the experiment with a camera that's able to detect individual photons. 让我们做实验 用相机的能力 探测单个光子。
We have to cover it now because of the background light. 我们现在覆盖 由于背景灯。
Sven, can you help me? 斯文，你能帮我吗？
As the laser fires single photons, some will pass through the slits, some will bounce off. 由于激光单光子火灾， 有些人会穿过狭缝， 有些人会反弹。
Gradually, a pattern will emerge. 渐渐地，一个模式将会出现。
Now you see the photons arrive one by one at the camera. 现在你看到的光子到达 一个接在相机之一。
Here's one, here's one, here's one. 这里有一个，这里的一个，这里的一个。
So they really behave as mini bullets. 所以，他们真的表现 作为迷你子弹。
What would you expect them to do at the double-slit setup? 请问您期望他们做 在双缝设定？
You would expect some of them going through this slit, 你会以为一些 他们将通过这个缝隙，
some going through this slit, so we would expect two stripes, 一些通过这个缝隙去， 所以我们需要两个条纹，
But what you get is something completely different. 但你得到的是什么 完全不同的。
Even though only single photons of light are being fired through the slits, 即使只有单光子 光被解雇 通过狭缝，
they don't create two lines. They mysteriously create three. 他们不创造两行。 他们神秘地创建三个。
According to physics, this pattern of multiple stripes is what you get 根据物理学，这种模式 多条纹就是你
when you shine a beam of light at the two slits. 当你闪耀的光束 在这两个狭缝。
Because when it's a beam, light behaves like a wave, 因为当它的梁， 光的行为像波，
creating a classic pattern of light and dark stripes 创造一个经典模式 光与暗条纹
But it's totally incomprehensible how SINGLE particles of light can create this wave pattern. 但它的完全不可理解 如何轻型单粒子 可以创建此波模式。
There's a contradiction here. 有一个矛盾。
On the one hand, we have individual particles which can go through one slit only at a time. 一方面，我们有个别 粒子，可以通过 一狭缝只有一次。
On the other hand, we have the stripes which indicate they are waves which go through both slits. 另一方面，我们有 这表明他们条纹 震波穿过两个狭缝。
How can something go through one slit and both slits at the same time? 如何才能通过一个狭缝的东西去 并在同一时间都缝？
The idea that a single particle of light can somehow split in two 那种认为一个粒子 能以某种方式的光分成两
and go through both slits at once 去一次通过两个狭缝
goes against all the laws of nature that we know. 违背所有法律 自然，我们知道。
From a basic intuitive point of view, this is not possible to understand 从直观的基本观点来看， 这是不可能的理解
if you stick to a picture of reality as we are used to in everyday life. 如果你坚持一个现实的图片 因为我们在日常生活中使用。
Over the last two decades, Zeilinger and his colleagues have tested quantum theory to its limits. 在过去的二十年里， Zeilinger和他的同事们 测试量子论到了极限。
They've even proved that it's not just photons that behave strangely, but atoms and molecules, too. 他们甚至已经证明了它不是 光子，其行为只是奇怪的是， 但原子和分子，太。
You might ask, why can't we observe quantum reality? 你可能会问，为什么我们不能 观察量子现实？
But this is where things gets even more weird. 但是，这就是事情 变得更加怪异。
If you put detectors by the slits, the mysterious behaviour stops. 如果您所提出的狭缝探测器， 神秘的行为停止。
The photons behave just like bullets. 光子的行为 就像子弹。
Take the detectors away... 以探测器而去...
the multiple stripes mysteriously reappear. 多条纹 神秘再现。
What's going on? 这是怎么回事？
Rather astonishingly, it seems that we can change the way reality behaves... 更令人惊异的， 我们似乎可以改变 现实的行为方式...
just by looking at it. 刚才去看它。
But this also means that reality has a secret life of its own. 但是，这也意味着，现实 有它自己的秘密生活。
We know what the particle is doing at the source when it is created. 我们知道是做什么的粒子 在创建时源。
We know what it is doing at the detector, when it's registered, 我们知道它是在做 检测器，当它的注册，
but we do not know what it is doing in between. 但我们不知道什么 这就是要在两者之间。
We cannot describe that with our everyday language. 我们不能描述的 与我们的日常用语。
If you're finding this hard to get your head round, don't worry - you're in good company. 如果你发现这很难得 你的头围，不要担心 - 你在好的公司。
The paradoxes of quantum theory drove even Albert Einstein to despair. 量子理论的悖论 开车甚至爱因斯坦 绝望。
There's a famous story from the history of physics. 有一个著名的故事 从物理学的历史。
One day, Albert Einstein 有一天，阿尔伯特爱因斯坦
asked his friend, Niels Bohr, a Danish physicist, 问他的朋友，尼尔斯玻尔， 丹麦物理学家，
"Do you really believe the moon is not there, when nobody looks?" “你真的相信月亮 不存在，当没有人看？“
Bohr's answer was, "Can you prove to me the opposite? 玻尔的回答是： “你能证明我的对面？
"Can you prove to me that the moon is there when nobody looks?" This is not possible. “你能证明给我看，今天的月亮 没人看它时是否有？“ 这是不可能的。
For more than 70 years, physicists have debated what quantum theory means for reality. 在超过70年， 物理学家们一直在争论什么 量子理论的现实。
Zeilinger's detective work may yet lead us to an answer. Zeilinger的侦探工作 还可能导致我们一个答案。
Quantum physics is an exciting theory because it is extremely precise, 量子物理学的理论是一个令人兴奋的 因为它是非常精确，
it is mathematically beautiful and it describes everything. 它是数学美丽 它描述了一切。
It just doesn't make sense. 它只是没有意义。
So reality turns out to be stranger than we ever imagined. 因此，现实证明是 陌生人比我们的想象。
Everything has the power to be in two places at once. 一切有权力 要在两个地方。
But we'll never see it. 但我们永远不会看到它。
It's all very peculiar. 这一切都非常奇特。
You'd be wrong to think you can ignore it, because quantum reality 你也许会错误地认为可以 忽视它，因为量子现实
might be about to change our lives in a big way. 可能即将改变 大张旗鼓地在我们的生活。
Here at MIT is a physicist who sees, in reality's strange behaviour, 麻省理工学院的物理学家是谁在这里看到， 在现实的奇怪的行为，
enormous power and opportunity. 巨大的权力和机会。
Seth Lloyd is aiming to revolutionise our lives, 劳合社的目标是赛斯 改变我们的生活，
with a new class of computers, like nothing the world has ever seen. 与一类新的电脑， 像什么世界 从未见过。
This is a quantum computer. It actually happens to be 这是一个量子计算机。 它实际上正好是
the best and most powerful quantum computer of its kind in the world. 最好的和最强大的量子 计算机在世界上同类。
It runs on superconducting circuits that are cooled to within 它运行的超导 被冷却到内部电路
a few thousands of a degree of absolute zero. 一个数千 度的绝对零度。
And it contains in its guts a little tiny bit 它包含在其胆量 一点点小
where a current going round like this represents a zero, 在当前的兜兜 这样代表一个零，
and a current going like that represents a one 和我听到的电流 代表一
and a current going both directions at once is zero and one. 和电流去两个方向 一次是在零和一。
And that's what's going on in here at the moment. 而这是怎么回事 在此间举行的时刻。
Whereas a normal computer bit can only represent a zero or a one, a quantum computer bit can be zero 而一个正常的计算机位可 只能代表一个零或一， 量子计算机可以是零位
AND one at the same time. 和一在同一时间。
Link these multi-tasking bits together 链接这些多任务位 一起
and they can do vast numbers of calculations simultaneously, opening up new worlds of possibility. 他们可以做广大 同时计算开放 注册新的世界的可能性。
Quantum mechanics is weird and quantum computers use quantum weirdness 量子力学是怪异 与量子计算机 利用量子古怪
to process information in ways that ordinary classical computers could never even comprehend of doing. 处理信息的方式 普通电脑可以经典 甚至从来没有理解这样做。
As a result, even a tiny quantum computer with a few hundred quantum bits in it could be more powerful 因此，即使是一个微小的量子 计算机与量子几百 也可能是更强大的位
than a classical computer the size of the whole universe. 比传统计算机 整个宇宙的大小。
What's unique and impressive about Seth's engineering of the quantum world 什么是独特的和令人印象深刻 关于赛斯的工程 量子世界
is that, for the first time ever, 是，为有史以来第一次，
he's opening up a line of communication between our reality and quantum reality. 他的开放线 之间的沟通 我们的现实和量子现实。
Quantum bits are very small, really teeny, cannot see it with the naked eye, 量子位是非常小， 真的很小，看不到 它与肉眼
cannot see it through a microscope. 可以通过显微镜看不到它。
But you need this whole roomful of equipment to tickle this quantum bit and get information 但是你需要这整个屋子 此设备以痒痒 量子位和获取信息
from our human scale down to this extremely microscopic scale where quantum bits actually live. 从我们人类缩小到 这种极其微观尺度 其实生活在量子比特。
If you talk to them just right, and massage them 如果你去问他们恰到好处， 他们和按摩
till they're happy enough, then you can get them to do what you want. 直到他们感到快乐的话，那么你 可以让他们去做你想做的。
Sounds easy 听起来很容易
but Seth has to overcome the most mysterious rule of reality - 但必须克服赛斯最 神秘的规则的现实 -
the fact that his quantum bits stop being able to do two things at once 事实上，他的量子位 不再是能够做到 两件事情立刻
as soon as he tries to observe them. 当他试图去观察他们。
The quantumness of reality is apparently very sensitive. 对现实quantumness 显然是非常敏感。
This is actually one of the main problems with building large-scale quantum computers 这实际上是主要原因之一 问题与建筑 大型量子计算机
because it doesn't take just me or you to look at something and make the computer fail, 因为它不只是我，或采取 你看东西的时候，使 电脑故障，
it can just be some passing electron wandering around, 它可以只是一些路过 电子四处流浪，
bounces off this little superconducting loop and says WHOA! 这个小反弹 超导环，并说哇！
The electrons in there are going around like that, that's enough to mess up your quantum computation. 在那里，将电子 围绕这样，这就够了 搞砸你的量子计算。
Seth clearly faces some of the most difficult technical challenges science has ever known. 显然面临着一些赛斯 最困难的技术 科学史上著名的挑战。
That's going up again. 这将再次出现。
But if he overcomes them, quantum computing has a huge potential to change our world. 但如果他克服了他们， 量子计算有巨大的 可能改变我们的世界。
It's very real. 这是非常真实的。
My favourite use for quantum computers 我最喜欢使用 量子计算机
is to use them to understand the weird features of the universe. 就是用他们明白 宇宙的怪异特征。
Classical computers - lets face it - they kind of think the way we do, 经典计算机 - 让我们面对它 - 他们那种认为我们的工作方法，
they're not so good for understanding quantum mechanics. 他们没有这样好， 理解量子力学。
If we're ever really to understand how this quantum universe works at bottom, we need quantum computers 如果我们曾经真正理解 如何量子宇宙工程 底部，我们需要的量子计算机
to serve as our intuition, for understanding the fundamental workings of the universe. 作为我们的直觉， 理解的根本 运作的宇宙。
Seth's computer depends on things being in two places at once for its power... Seth的计算机取决于 事情都是在两个地方 在一次为它的力量...
..but there's a growing number of physicists who don't believe that ..但有越来越多的 物理学家不相信谁
this is what reality is really like at all. 这就是现实 是真的很喜欢的。
They think the answer to this puzzle lies beyond our universe. 他们认为，这个问题的答案 益智在于超出了我们的宇宙。
Just checking to see whether reality is still there. 只是检查，看看是否 现实依然存在。
Max Tegmark is a cosmologist. He's studied the greatest mysteries 最大Tegmark是宇宙学家。 他研究了最大的谜团
of the universe, from the big bang to black holes. 对宇宙， 从大爆炸到黑洞。
When it comes to explaining how reality works, 当谈到解释 如何现实的作品，
he draws his inspiration from one of the most bewildering ideas in cosmology... 他的灵感来自他提请 一个最令人困惑 在宇宙学的想法...
parallel worlds. 平行世界。
This theory says that beyond the edges of our universe 这种理论认为，超越 我们的宇宙的边缘
there are an infinite number of other universes. 有无限数量 其他宇宙。
It sounds like the stuff of science fiction... 这听起来像的东西 科幻小说...
that there's another you living more than a trillion trillion light years away. 存在的另一个你 居住超过一万亿美元 万光年。
But it's not the only version of this theory. 但它不是唯一的 版本的这一理论。
Max thinks that parallel worlds don't just exist beyond our universe. 马克斯认为，平行世界 不只是存在 超出了我们的宇宙。
They're here, millimetres away. And they're being created all the time. 他们来了，毫米了。和 它们被创建的所有的时间。
I'm here right now 现在我在这里
but there are many, many different 但也有很多很多不同的
Maxes in parallel universes doing completely different things. 平行宇宙Maxes 这样做完全是两回事。
Some branched off from this universe very recently 有些分支开来此 最近宇宙
and might look exactly the same except they've put on a different shirt. 并可能看起来一模一样 除非他们已经把 不同的衬衫。
Other Maxes may have never moved to the US in the first place or never been born. 可能有其他Maxes 的转移到美国在 第一名或从来没有出生。
This vision of reality says that any time we go to work, 这种现实眼光说 在任何时候，我们去上班，
there'll be another universe where we stay at home. 还会有另一个宇宙 我们呆在家里。
There are universes where we all have different careers. 我们有宇宙 都有不同的事业。
There are also universes where we don't even exist. 还有宇宙 我们甚至不存在。
It's a disturbing idea, developed in the 1950s, 这是一个令人不安的想法， 发达国家在50年代，
but for Max, it's the best and only solution to the paradox at the heart of quantum reality. 但马克斯，这是最好的 只有解决了悖论 在量子现实的心。
The big problem with quantum mechanics is that the little 与量子大问题
particles that we're all made of can be in multiple places at once,
yet I'm made of little particles and you never see me in two places at once, so what's going on here?
Max thinks that the maths of quantum theory is telling us something remarkable.
So whenever the equations say that this tennis ball is in
many different places at once, what that really means is that
our reality is branched out into multiple universes and in each one, the ball's in a definite place.
According to this theory, when the photon of light faces two slits...
it doesn't split in two.
It splits the world in two.
Every photon in the double slit experiment creates a new parallel world...
..which means what we think of as reality is just one
of an infinite number of realities, each one slightly different from the next.
However strange this theory sounds,
Max believes you have to accept reality as you find it.
Like if I get a parking ticket, there's always a parallel universe where I didn't.
On the other hand, there's yet another universe where my car was stolen,
so you win some, you lose some. But seriously...
my job as a scientist isn't to tell the universe how to conform to my preconceptions of how it should be,
but to look at the universe and find out how it really works.
It seems that whatever our senses are telling us about reality,
we only get to experience a fraction of what's really going on.
Take it as it comes, you know - we've been humiliated before by the vast universe,
since Copernicus, since the discovery of the distant galaxies,
the Big Bang, and, er, this is a dis... this is another
sort of humiliation where... er, we're finding that our thought... our ordinary, er, sensing
of the world is so very, very partial, we only see tiny averages of this very rich structure.
Quantum reality is about the strangest discovery that physics has ever made.
But it's also fantastically powerful.
Not only has it helped to create our modern computer age but it's helped us understand all kinds of phenomena
from the shining of stars, to the colour of gold.
It's changed our relationship to reality forever, philosophically and practically.
But that relationship might be about to change again.
In the last few decades, an astonishing new idea has been taking shape.
An extraordinary vision of what reality might be
that combines every field of physics from quantum to the Big Bang.
If it's true, it will trigger a bigger change in thinking about reality than anything we've seen.
And it all began one day in San Francisco.
Professor Lenny Susskind is one of America's most eminent theoretical physicists.
Back in 1981, he was developing a theory about how matter was made out of strings,
when a local entrepreneur asked him to host a small, private science conference.
Susskind invited a British cosmologist to give a talk.
It was Stephen Hawking, and the lecture he gave about black holes
was to change the course of Lenny's life.
That's where Stephen dropped the bombshell that left us so confused for 20 years.
At the time, Stephen Hawking was the pre-eminent scholar working on black holes.
He'd achieved amazing insights into the inner workings of these mysterious objects.
Black holes are the most terrifying places in the universe.
Created when a giant star dies, at their dark hearts is a point of infinite gravity,
so powerful, nothing can escape it - not even light.
Lenny was expecting to learn something interesting about black holes.
What he didn't expect was for Hawking's new theory to challenge everything he knew about reality.
I had absolutely no idea at the time
that this was going to change my life for the next 20 years.
Stephen began to talk about black holes and told us a story which seemed so crazy and so strange.
It seemed absolutely wildly impossible - that black holes
would violate all the principles of physics that we knew.
Hawking's revelation was that black holes, instead of lasting forever, as everyone thought,
eventually disappear,
leaving no trace of anything,
including something physicists consider a fundamental part of reality - information.
If information was lost in ordinary circumstances in this room, that would be bad,
because then all kinds
of weird stuff would start happening, like,
the hour of time could start going backwards,
you know, clocks might not work, we all might disappear like that.
The fact that information is conserved in ordinary physics, is at the very basics of physical law.
Today information is as important a part of reality as matter and energy.
Everything physical contains information.
It's the description of what something is - its colour, its mass, its location.
And crucially, like energy, information can never be destroyed.
I just knew, or felt, deep in my gut, that Stephen had to be wrong.
That lecture set me on a mission, you bet, and that mission was to reconcile the two
competing and conflicting points of view about black holes -
that they eat information and evaporate but information is not allowed to be lost.
As Lenny drove home that night, he knew his first task was to learn as much about his subject
as possible - mysterious and terrifying black holes.
Every black hole has a boundary known as the event horizon.
It's the point of no return.
If you pass it, you'll never escape the black hole's gravitational pull.
If you get too close to a black hole,
you're done. If you get sucked into it,
nothing can come out, not even your screams, not even your...
radio transmission for help, nothing.
If anything passes the event horizon,
it takes its information with it.
Lenny had to find some way for black holes to evaporate
without destroying the information inside them.
But the physics of black holes is so complicated that he wrestled with the problem for the next 12 years.
Then in 1993, one fine day in Stanford, Lenny wandered into the physics department
and saw something that gave him an amazing insight into what the true nature of reality might be.
The insight...
to what became known as the Holographic Principle simply happened one day
when I was walking in the physics department and came upon a hologram.
Well, when I saw the hologram it occurred to me that there's
a very big difference between a hologram and an ordinary picture.
When you see a hologram you can look around it and you can see what's behind the lady's head there.
Not just the surface, but you can see what's behind her,
there's a sense in which it's really capturing three-dimensionality.
It was capturing the full three-dimensional
structure of the room and everything behind her, so when I passed it by,
almost jokingly I said to myself, maybe the horizon of a black hole is something like a hologram.
The stuff that falls into the black hole is three-dimensional.
The stuff of the horizon is two-dimensional.
But maybe in some way, the stuff of the horizon is like a hologram,
capturing the full three- dimensionality of the things that fell into the black hole.
Holograms are created from information encoded on a flat surface.
Lenny realised that if black holes were like holograms,
then there's only one place where their information could be stored - the event horizon,
which would mean it would never fall in and it would never be destroyed.
Not only did Lenny's insight help save information from black holes,
but it lead to a new mathematical tool, called the holographic principle,
that says all three-dimensional objects can be encoded in only two dimensions.
The holographic principle has morphed from a wild speculative almost crackpot idea.
Complete consensus has formed around it.
It is almost completely accepted across theoretical physics.
It has gone from being a wild idea to being an everyday tool of theoretical physics.
But Lenny didn't stop there.
He and other physicists made a truly shocking leap of the imagination.
They asked - what if the whole of reality is a hologram?
Projected from our own event horizon -
the far edges of the universe.
Maybe the real information in the world is not where it seems to be.
Maybe it's way out far away at the boundaries of the universe
and that it's completely wrong to think that things fall into black holes,
rather the black hole and things that fell into them are really holograms,
or really images of things taking place very, very far away.
If Lenny is right and the ultimate nature of reality is holographic,
it would mean our three dimensions are an illusion,
that we're being projected from information that's stored at the outer reaches of our universe.
It's an incredible vision...
but if you think you understand it, you probably don't.
OK, I think I'm getting it, so that...
Don't think you're getting it, cos you're not getting it
and the reason you're not getting it is because nobody get it.
There are some times when we...
It's like quantum mechanics - nobody understands quantum mechanics.
We know how to use it and we know how to make predictions of it, but nobody has their heads around it.
It seems utterly bizarre that the ultimate nature of reality might be holographic.
That at the edge of our universe, there might be a shimmering sheet
of information that describes the entire universe within,
including you and me and everyone we know.
But incredibly, this theory is about to be put to the test.
We maybe on the brink of finding out that the world is a hologram.
Back at Fermilab,
a unique million dollar experiment is just beginning.
Expert technicians are building an extraordinary machine they call the holometer.
Designed to be so sensitive, it can measure the smallest units of space and time.
It's the brain-child of Professor Craig Hogan,
the Director of the Centre for Particle Astrophysics at Fermilab,
who became intrigued by an unexplained sound, recorded by scientists in Germany.
WHITE NOISE
This recording is noise picked up by a gravitational wave detector.
But it's not gravitational waves.
Hogan thinks that buried within it might be the sound of holographic reality.
So he's designed an experiment to test his theory.
Hogan's holometer will bounce beams of light between mirrors,
timing how long the beams take to return.
It will be able to detect infinitesimally small delays, or as he calls it -
fuzziness in space and time.
So this is one of the beam tubes of our holometer.
It's a six inch steel pipe and we're going to bolt them together
in one big tube, 40 metres long
and do that five different times
and the laser light's going to go down the centre of the tube.
So before we do that, we have to clean them out
cos the optics are super precise, need to be kept super clean.
Right now, they're cleaning out the end station,
this is this sardine-can like object,
it's where the business guts of the holometer are going to be.
It's where the mirrors and so on that are doing the precise measurement are going to be.
Ultimately, this machine might tells us that space time is sitting still.
If the light goes out the two arms and comes back at exactly the same time and there's no extra jitter
then that's a classical space time,
but it could be that we'll find a little bit of air or fuzziness
in there and that would be the clue that we live inside a hologram.
Craig thinks that if reality really is holographic
then the closer you look at it, the more insubstantial it will be,
like a photograph
enlarged over and over again.
This fuzziness will disturb his laser beam and that's the evidence he's looking for.
Well, it's very exciting to actually be building a machine with this kind of
precision to be able to do this, you know, we're measuring
the arrival time of wave fronts of light to a very small fraction the size of an atomic nucleus.
And timing those pulses to microsecond accuracy.
Nobody's ever done that before, nobody's ever tested to see
whether space time actually stands still at that level.
If Craig Hogan proves that reality is holographic,
it will be one of the most important discoveries in physics.
It may cause as big a change in thinking as the revelations of quantum theory.
But if there's one thing that stands out about all the theories used,
to probe and explore reality today,
it's this - their best and most perfect expression is not in words, it's in maths.
The connection between mathematics and reality is a miracle, but it works.
It's actually unreasonable how well mathematics works,
why should the world behave according to mathematical laws?
It is not only that it becomes easier to describe with mathematics
as you go deeper and deeper into reality,
mathematics becomes the only way to describe reality.
If our most detailed knowledge of reality, from fundamental particles to ripples in space time,
is really best described in maths,
could it be that the ultimate definition of reality is staring us in the face?
Cosmologist Max Tegmark seems to be fond of radical explanations of reality
and it's no different when it comes to maths.
Instead of just accepting mathematical order in the world,
he's been trying to figure out why it exists and where it comes from.
He thinks he has a solution.
To me, maths is the window on the universe.
It's the master key to understanding what's out there.
I wouldn't say I'm completely monogamous with equations,
but there are just a very few I love the most.
I love them because they describe exactly what's going on
outside the window in our universe.
These equations describe how light behaves.
This equation describes how gravity behaves.
This equations describes how atoms behave.
These equations describe what happens when you go really fast near the speed of light
And it's just amazing to me that a little bit of scribbles like this
can capture the essence of what's going on in this very complicated looking universe out there.
Galileo way back in the renaissance already remarked that nature seems
to be a book written in the language of mathematics.
This all came after Galileo,
so why are we discovering even more and more
mathematical regularities out there, what is it telling us?
I think the universe isn't just described by math...
I think it is math.
I think our entire universe is a giant mathematical structure that we are a part of.
And that, that's the reason why the more we study physics
the more mathematical regularities we keep discovering.
Max's theory pushes at the edges of physics and into the realm of philosophy,
conjuring up the oldest question of all -
what is real?
I think the universe is a mathematical object, it's just out there,
existing,
in a sort of platonic sense, it's not that it's existing inside
of space, and time, but space and time exists inside of it.
And that really changes our perspective of it and that
really means that reality is very different from how it seems.
If Max is right, maths isn't a language we've invented,
but a deep structure we're gradually uncovering like archaeologists.
An abstract, unchanging entity that has no beginning and no end.
As we peel back the layers, we're discovering the code.
Strange as it seems, it's a comforting theory
because if reality is a mathematical object,
understanding it might be within our reach.
If I'm wrong, it means fundamental physics is going to eventually hit a roadblock
beyond which we can't understand reality any better.
If I'm right, then there is no roadblock
and everything is, in principle, understandable to us.
And I think that will be wonderful because we'll only be limited by our own imagination.
These two grand visions of reality - the mathematical structure and the cosmic hologram,
represent theoretical thinking at its most imaginative and beautiful.
They may lead us towards a bright future or they may end up being discarded
because as all physicists know, nothing becomes real without being put to the test.
Few know this more acutely than the scientists at Fermilab.
Right now they're engaged in the greatest race of modern physics -
trying to find a bit of reality that's been missing for 40 years.
It's the most important particle of all - the Higgs Boson.
Nobody really understands the origin of mass and the Higgs particle
was introduced to explain why different particles
have different masses.
So, it is important because it answers one of the most fundamental unknowns
in reality, in particle physics, mass makes reality and we don't know where it comes from.
It's round-the-clock work, and people running computer codes,
sifting through the data, finding new ways of looking for
the Higgs because you can get incredibly creative.
In fact, this is one of the things that happens here, that you start doing the easy analysis,
the easy way to look for things and as it gets harder, you get more and more creative...
The Higgs is now Fermilab's number one priority,
but they aren't the only ones looking for it.
They have competition...
..from the biggest particle accelerator of them all -
the Large Hadron Collider in Geneva.
It's more than three times as powerful.
So it may yet be the one that discovers the Higgs first.
Meanwhile, the Tevatron continues its ten million collisions a day.
I feel really proud of this machine.
It's been a beauty of an instrument for many years
and hopefully it will help us find unveil one more secret of reality in the very near future.
Billions of dollars have been poured into this quest
and thousands of physicists around the world are looking for the Higgs Boson,
but it's still theoretical.
What if we don't find it?
OK, so if we don't find anything that has the properties
that are expected of this Higgs Boson
or some combination of things that can do the job,
we'll really, really, really have to rethink a lot of what we thought we knew...
That won't happen, we'll find something!
It may be that we are standing on the verge of a new version of reality.
We have these clues, quantum mechanics, relativity,
the holographic principle, a few others,
and it's just waiting around for somebody to really
put it together into, what does it really say about reality?
Physicists have redefined reality by close measurement and observation of the material world.
They've drilled down to the bottom layer,
discovered that we can change reality just by looking at it...
..and begun to sense that information encoded at the edge of our universe,
could be more important than matter.
But in the end, reality is perhaps best defined
as an intelligent conversation with the universe,
that will continue as long as we're around to ask questions.
It's human nature to keep asking questions,
it's fun and it's challenging and it's what makes us human.
If there is an ultimate version of reality, I think it's a long way before we get there...
so I don't want to be part of that.
I would guess that there are limits to what we can understand,
but old people always think there are limits to what we can understand,
it's the young people who push past those limits.
MUSIC: "Is That All There Is" by Peggy Lee
Subtitles by Red Bee Media Ltd
E-mail subtitling@bbc.co.uk