Gravity Seems Holographic. What Does That Mean for Reality?
I n my first months as a physics journalist nearly a decade ago, I kept running into an inscrutable string of characters: AdS/CFT.
大约十年前，在我作为一名物理记者的头几个月里，我不断遇到一串难以理解的字符：AdS/CFT。
Thoroughly intimidated, I decided to just ignore it.
我被彻底吓到了，决定无视它。
But I couldn’t keep my head in the sand for long.
但我不能把头埋在沙子里太久。
I soon learned that those characters are shorthand for a surprising connection between the seemingly inharmonious worlds of gravity and quantum mechanics.
我很快了解到，这些字符是看似不和谐的引力世界和量子力学之间令人惊讶的联系的简写。
And even more bizarrely, this “anti-de Sitter/conformal field theory” correspondence suggests that gravity eliminates the distinction between volume and area.
更奇怪的是，这种“反德西特/共形场论”对应表明重力消除了体积和面积之间的区别。
This broader idea is known as the holographic principle, and it now strikes me as the most profound proposal in theoretical physics in the last 30 years.
这个更广泛的想法被称为全息原理，现在我觉得它是过去 30 年来理论物理学中最深刻的提议。
I n philosophy, “qualia” refers to the subjective qualities of our experience: what it’s like for Alice to see blue or for Bob to feel delighted.
在哲学中，“感受性”指的是我们体验的主观品质：爱丽丝看到蓝色或鲍勃感到高兴是什么感觉。
Qualia are “the ways things seem to us,” as the late philosopher Daniel Dennett put it.
正如已故哲学家丹尼尔·丹尼特所说，感受性是“事物在我们看来的方式”。
In these essays, our columnists follow their curiosity, and explore important but not necessarily answerable scientific questions.
在这些文章中，我们的专栏作家追随他们的好奇心，探索重要但不一定可以回答的科学问题。
Theoretical physicists tend to vote with their feet, and AdS/CFT sparked a stampede.
理论物理学家倾向于用脚投票，AdS/CFT 引发了踩踏事件。
The three foundational papers on the topic in the late 1990s have garnered tens of thousands of citations, making them by far the most highly cited theoretical physics works of the digital era.
20 世纪 90 年代末有关该主题的三篇基础论文已获得数万次引用，使其成为迄今为止数字时代被引用次数最多的理论物理著作。
In my interviews with physicists who study holography, they often seem genuinely stunned, and reach for words like “magical” and “miraculous” to describe it.
在我采访研究全息术的物理学家时，他们常常看起来真的很震惊，并用“神奇的”和“奇迹般的”这样的词来形容它。
And it doesn’t hurt that holography led to a widely accepted answer to the most famous puzzle in physics : Contrary to what Stephen Hawking argued, black holes are not inescapable prisons.
全息术为物理学中最著名的难题提供了一个被广泛接受的答案，这并没有什么坏处：与斯蒂芬·霍金的观点相反，黑洞并不是无法逃脱的监狱。
But even after covering numerous developments in holography and having countless conversations with the physicists involved, I still felt confused.
但即使在了解了全息术的众多发展并与相关物理学家进行了无数次对话之后，我仍然感到困惑。
I had heard that holography suggested that gravity and quantum mechanics are one and the same, and that space might be an illusion.
我听说全息术表明引力和量子力学是同一回事，而空间可能是一种幻觉。
I had also heard holography described both as a mathematical fact and as a speculative flight of fancy.
我还听说全息术既被描述为数学事实，又被描述为一种推测性的幻想。
So I tried to triangulate these wild ideas and figure out what, exactly, the holographic principle implies about our universe.
所以我试图对这些疯狂的想法进行三角测量，并弄清楚全息原理对我们的宇宙到底意味着什么。
Put a box around any region of space (space-time, really, but I’m going to drop time throughout this essay for ease of visualization, as physicists often do).
在空间的任何区域周围放置一个盒子（实际上是时空，但为了便于可视化，我将在整篇文章中省略时间，就像物理学家经常做的那样）。
The holographic principle asserts that no matter what’s going on inside — from gas molecules pinging around to black holes colliding — you can decipher the entire contents of the box just by repeatedly measuring points on the surface.
全息原理声称，无论里面发生什么——从气体分子的撞击到黑洞的碰撞——你只需通过重复测量表面上的点就可以破译盒子的全部内容。
Pause for a moment to reflect on how outrageous this assertion is.
停下来思考一下这个断言是多么令人愤慨。
You can’t see into the box at all.
你根本看不到盒子里面。
Nevertheless, holography says that you can learn exactly what’s happening everywhere in the box without any access to the interior.
尽管如此，全息技术表明，您无需进入内部即可准确了解盒子内各处发生的情况。
Observing the surface alone is enough.
仅观察表面就足够了。
In this sense, the amount of stuff that fills a box is the same as the amount of paint that covers it.
从这个意义上说，装满盒子的东西的数量与覆盖盒子的油漆的数量相同。
That’s a violation of logic and geometry.
这是违反逻辑和几何的。
It asks us to erase the categorical difference between square meters and cubic meters.
它要求我们消除平方米和立方米之间的绝对差异。
It recalls how holographic images appear to have depth despite being flat, except the bird in the hologram is the same as an actual bird.
它让人回想起尽管全息图像是平坦的，但看起来却具有深度，只不过全息图中的鸟与实际的鸟相同。
Bartek Czech , a theorist at Tsinghua University in China, highlights the power of the principle by comparing it to a CT scan of the brain, which uses X-rays to look inside the organ and reconstruct it from hundreds to thousands of cross-sectional images.
中国清华大学的理论家巴特克·捷克（Bartek Czech）通过将其与大脑 CT 扫描进行比较，强调了这一原理的威力，CT 扫描使用 X 射线观察器官内部，并根据数百至数千个横截面图像对其进行重建。
Holography implies that you can do that — reconstruct every fold, vessel, and neuron in three dimensions — without actually looking inside.
全息术意味着你可以做到这一点——在三个维度上重建每一个褶皱、血管和神经元——而无需实际查看内部。
Simply photographing the surface of the brain somehow suffices.
简单地拍摄大脑表面就足够了。
Why would anyone entertain such a far-fetched notion?
为什么会有人抱有如此牵强的想法？
It’s rooted in thought experiments and math, and it appears to trace back to one force: “a miracle of gravity,” Czech said.
它植根于思想实验和数学，并且似乎可以追溯到一种力量：“重力奇迹，”捷克说。
Scientists have known for more than a century that gravity is different from the other forces.
一个多世纪以来，科学家们就知道重力与其他力不同。
Imagine a box filled with electric charges, representing one of the other fundamental forces, electromagnetism.
想象一个充满电荷的盒子，代表另一种基本力，电磁力。
The stuff in the box consists of the charges and the electric field they create, which also passes through the outer surface.
盒子里的东西由电荷和它们产生的电场组成，电场也穿过外表面。
You will have a problem if you try to infer what arrangement of charges generates the field by looking at the surface alone.
如果您试图仅通过观察表面来推断电荷的排列方式会产生电场，则会遇到问题。
Because positive charges neutralize negative charges, different arrangements can look the same.
由于正电荷会中和负电荷，因此不同的排列可能看起来相同。
If you observe no field, it could mean there’s no charge inside — or it could mean that the effects of the positive charges are perfectly blocking the effects of the negative charges.
如果您没有观察到电场，则可能意味着内部没有电荷，或者可能意味着正电荷的影响完全阻止了负电荷的影响。
From the surface, you can’t tell the difference.
从表面上看，你无法分辨出区别。
With gravity, mass plays the role of charge.
在重力的作用下，质量扮演着电荷的角色。
It bends space-time around it, and it is always positive.
它会弯曲周围的时空，而且总是积极的。
There is no negative mass, so you can always infer the one real arrangement of stuff inside from the warping of space-time at the surface of your box.
没有负质量，所以你总是可以从盒子表面时空的扭曲推断出里面东西的一种真实排列。
“Intuitively, this is why holography is plausible,” said Laurent Freidel , a physicist studying quantum gravity at the Perimeter Institute for Theoretical Physics in Waterloo, Canada.
加拿大滑铁卢周边理论物理研究所研究量子引力的物理学家劳伦特·弗雷德尔（Laurent Freidel）说：“从直觉上看，这就是全息术看似合理的原因。”
But holography really starts to bite only after you take the intricate details of quantum mechanics into account.
但只有在考虑到量子力学的复杂细节之后，全息术才真正开始发挥作用。
The first clues came in the 1970s, when Jacob Bekenstein and Stephen Hawking calculated the entropy of black holes — typically a measure of how much stuff fits inside an object.
第一个线索出现在 20 世纪 70 年代，当时雅各布·贝肯斯坦 (Jacob Bekenstein) 和史蒂芬·霍金 (Stephen Hawking) 计算了黑洞的熵——通常用来衡量一个物体内部容纳了多少物质。
They used quantum theory to predict how a black hole would grow as it swallowed particles.
他们利用量子理论来预测黑洞在吞噬粒子时将如何生长。
Perplexingly, as they imagined adding particles to the black hole, they found that the entropy grew in lock step with the surface area — not the volume, as you would expect.
令人困惑的是，当他们想象向黑洞添加粒子时，他们发现熵与表面积同步增长，而不是像你想象的那样与体积同步增长。
Leonard Susskind , a physicist at Stanford University, built on their result in the 1990s and proposed that the black hole was literally a hologram, that everything happening inside can be observed from the outside.
斯坦福大学物理学家伦纳德·苏斯金德 (Leonard Susskind) 在 20 世纪 90 年代的研究成果基础上提出，黑洞实际上是一个全息图，内部发生的一切都可以从外部观察到。
In some sense, the interior was superfluous.
从某种意义上说，内饰是多余的。
“I thought it was a little bit crazy,” Susskind said, “but I thought it was the least crazy of all the possibilities.” (Gerard ’t Hooft, a Nobel laureate, and Charles Thorn, a physicist at the University of Florida in Gainesville, came to similar conclusions around the same time.)
“我认为这有点疯狂，”苏斯金德说，“但我认为这是所有可能性中最不疯狂的一个。” （诺贝尔奖获得者杰拉德·特·霍夫特和佛罗里达大学盖恩斯维尔分校的物理学家查尔斯·索恩大约在同一时间得出了类似的结论。）
I’ve always found this black hole entropy argument compelling, because any patch of space can become a black hole if you put enough mass into it.
我一直发现黑洞熵的论点很引人注目，因为如果你在其中放入足够的质量，任何一块空间都可以变成黑洞。
Despite their reputation for weirdness, black holes are representative examples of space.
尽管黑洞以怪异而闻名，但它却是太空的代表性例子。
They just have a way of bringing space’s stranger properties to the fore.
他们只是有办法让太空中奇异的特性脱颖而出。
So if a black hole is holographic, and any region of space can become a black hole, then, the argument goes, even the room you’re sitting in should be holographic.
因此，如果黑洞是全息的，并且空间的任何区域都可以成为黑洞，那么，即使你坐在的房间也应该是全息的。
“It’s completely general,” Susskind said.
“这完全是普遍现象，”苏斯金德说。
In the 1990s, physicist Leonard Susskind conceived of black holes as literal holograms.
20 世纪 90 年代，物理学家 Leonard Susskind 将黑洞设想为真正的全息图。
He determined that you could know the inside merely by measuring the surface.
他认为仅通过测量表面就可以了解内部。
Linda A Cicero/Stanford News Service
琳达·西塞罗/斯坦福新闻社
This argument has a rock-solid universality, but I’ve also heard physicists describe holography as a speculative idea with an uncertain connection to reality.
这个论点具有坚如磐石的普遍性，但我也听到物理学家将全息术描述为一种与现实之间不确定联系的推测性想法。
So I called up Latham Boyle , a physicist at the Higgs Center for Theoretical Physics at the University of Edinburgh, hoping for an alternative view.
于是我给爱丁堡大学希格斯理论物理中心的物理学家莱瑟姆·博伊尔打电话，希望能得到另一种观点。
He did not disappoint.
他没有让人失望。
Boyle doesn’t dispute Bekenstein and Hawking’s black hole findings, but he does question the holographic interpretation.
博伊尔并没有质疑贝肯斯坦和霍金的黑洞发现，但他确实质疑全息解释。
He suspects that the act of putting a surface around a region of space — as happens when a black hole forms — creates two distinct types of entropy.
他怀疑在空间区域周围放置表面的行为（就像黑洞形成时发生的那样）会产生两种不同类型的熵。
One entropy tells you how many particles can fit inside — and that really does depend on the volume.
一个熵告诉你里面可以容纳多少个粒子——这确实取决于体积。
The existence of the surface gives you a second, “entanglement” entropy .
表面的存在给了你第二个“纠缠”熵。
Particles inside share a quantum connection, known as entanglement, with those outside; the bigger the surface, the more entanglement crosses it.
内部的粒子与外部的粒子共享量子连接，称为纠缠。表面越大，穿过它的纠缠就越多。
The entanglement entropy depends on the area, not the volume.
纠缠熵取决于面积，而不是体积。
They’re not, Boyle posits, the same thing.
博伊尔认为，它们不是同一件事。
“That seems like a less mystical, more down-to-earth interpretation of what’s going on,” he said.
“这似乎是对正在发生的事情的一种不那么神秘、更实际的解释，”他说。
But it helps holography that there is a second, more conceptually airtight finding behind it: AdS/CFT.
但它背后还有第二个概念更严密的发现：AdS/CFT，这对全息摄影很有帮助。
I thought it was a little bit crazy, but I thought it was the least crazy of all the possibilities.
我觉得这有点疯狂，但我认为这是所有可能性中最不疯狂的。
Leonard Susskind, Stanford University
伦纳德·苏斯金德，斯坦福大学
AdS/CFT asks us to imagine a universe that is not like our own, one that curves in such a way that its infinite expanse of space can be pictured as fitting inside a finite snow globe.
AdS/CFT 要求我们想象一个与我们的宇宙不同的宇宙，它的弯曲方式使得其无限广阔的空间可以被描绘成适合在有限的雪球内。
That might sound like a big ask, but it’s one that mathematicians — and mathematically minded artists such as M.C.
这听起来可能是一个很大的问题，但这是数学家以及 M.C. 等具有数学头脑的艺术家提出的问题。
Escher — are perfectly comfortable with.
埃舍尔——非常满意。
This geometry is known as anti-de Sitter (AdS) space.
这种几何形状称为反德西特 (AdS) 空间。
Other than its peculiar curvature, the interior of the anti-de Sitter snow globe is a lot like our universe, filled with electrons and atoms.
除了其独特的曲率之外，反德西特雪球的内部很像我们的宇宙，充满了电子和原子。
More importantly, it also ripples in response to that matter, providing the effect of gravity.
更重要的是，它还会响应该物质而产生涟漪，提供重力效应。
The snow globe’s surface, meanwhile, is a universe of its own.
与此同时，雪球的表面就是一个自己的宇宙。
It’s also populated with quantum particles, but it’s rigid, so it can’t react to the particles: no gravity.
它也充满了量子粒子，但它是刚性的，所以它不能对粒子做出反应：没有重力。
This surface world is ruled exclusively by a type of quantum theory known as a conformal field theory (CFT), where the rules of physics don’t change as you zoom in or out.
这个表面世界完全由一种称为共形场论（CFT）的量子理论统治，其中物理规则不会随着放大或缩小而改变。
The blockbuster trilogy of papers in the late 1990s showed that, mathematically, these two theoretical worlds (the AdS interior and the CFT surface) are the same .
20 世纪 90 年代末的轰动一时的论文三部曲表明，在数学上，这两个理论世界（AdS 内部和 CFT 表面）是相同的。
This is the AdS/CFT correspondence.
这是 AdS/CFT 对应关系。
As with the black hole entropy argument, the volume and surface are equivalent.
与黑洞熵论证一样，体积和表面是等效的。
But unlike the black hole argument, AdS/CFT is essentially a mathematical fact about gravity and quantum mechanics with no alternative interpretation.
但与黑洞论证不同的是，AdS/CFT 本质上是一个关于引力和量子力学的数学事实，没有其他解释。
Even skeptics find this genuinely surprising.
即使是怀疑论者也觉得这确实令人惊讶。
“I don’t know of any mundane way to explain it,” Boyle said.
“我不知道有什么世俗的方法可以解释它，”博伊尔说。
The undeniable message of AdS/CFT is that, at least in this special snow globe, the rules of gravity and the rules of quantum mechanics are secretly describing the same game — despite the storied antagonism between the two theories.
AdS/CFT 不可否认的信息是，至少在这个特殊的雪球中，重力规则和量子力学规则正在秘密地描述同一个游戏——尽管这两种理论之间存在着传奇的对立。
“Far from being opposed, they’re actually intertwined,” said Brian Swingle , a physicist at Brandeis University.
布兰迪斯大学物理学家布莱恩·斯温格尔表示：“它们非但没有对立，反而交织在一起。”
“One emerges from the other.”
“一个从另一个中显现出来。”
The correspondence came as a shock.
这封信令人震惊。
I think of it as akin to discovering a way of converting any checkers move into a valid chess move: Why on Earth would that work?
我认为这类似于发现一种将任何跳棋动作转换为有效的国际象棋动作的方法：这到底为什么会起作用？
When I ran that picture by Sebastian Mizera , a physicist at Columbia University who studies the mathematical structure of quantum theories, he told me it wasn’t dramatic enough.
当我浏览哥伦比亚大学研究量子理论数学结构的物理学家塞巴斯蒂安·米泽拉（Sebastian Mizera）的那张图片时，他告诉我这还不够引人注目。
“That’s a good analogy,” he said, except “it’s more like checkers and basketball.”
“这是一个很好的类比，”他说，只不过“它更像跳棋和篮球。”
But does the holographic nature of the snow globe tell us anything about our reality?
但是雪球的全息性质是否能告诉我们有关现实的任何信息呢？
On this point, physicists disagree.
在这一点上，物理学家意见不一。
Skeptics emphasize that our universe is the opposite of a snow globe.
怀疑论者强调，我们的宇宙与雪球相反。
The accelerating expansion of the cosmos implies that we live in a space that curves outward, in the opposite direction — a de Sitter space.
宇宙的加速膨胀意味着我们生活在一个朝相反方向向外弯曲的空间——德西特空间。
Because our space does not curve back in on itself, it has no boundary surface where you can project the hologram.
因为我们的空间本身不会弯曲，所以它没有可以投影全息图的边界表面。
So there’s little reason to think that AdS/CFT has anything to do with the real world.
因此，没有理由认为 AdS/CFT 与现实世界有任何关系。
The most dedicated holographers, however, take a ground-level perspective.
然而，最专注的全息摄影师会采取地面视角。
An ant living deep inside the snow globe can’t easily detect any curvature, and therefore can’t tell the difference between anti-de Sitter and de Sitter space.
生活在雪球深处的蚂蚁无法轻易察觉到任何曲率，因此无法区分反德西特空间和德西特空间。
So perhaps what’s true of one space, they argue, should more or less hold for the other.
因此，他们认为，也许一个空间的真实情况或多或少也适用于另一个空间。
(And in case you were wondering, we’re the ants.)
（如果你想知道的话，我们就是蚂蚁。）
While both arguments have merit, I lean toward the holographers.
虽然这两种论点都有道理，但我倾向于全息摄影师。
Black holes provide intriguing but circumstantial evidence that all types of space are holographic.
黑洞提供了有趣但间接的证据，证明所有类型的空间都是全息的。
And the AdS/CFT correspondence essentially guarantees that anti-de Sitter space — which happens to be the space physicists understand best — is holographic.
AdS/CFT 对应关系本质上保证了反德西特空间——这恰好是物理学家最了解的空间——是全息的。
What are the odds that our universe works in a totally different way?
我们的宇宙以完全不同的方式运行的可能性有多大？
It absolutely could, but I wouldn’t bet on it.
绝对可以，但我不会打赌。
I take seriously the possibility that gravity makes every kind of space, including ours, holographic.
我认真对待重力使各种空间（包括我们的空间）变得全息的可能性。
And so what would it mean for us to live in a hologram?
那么生活在全息图中对我们来说意味着什么呢？
I found that most physicists are hesitant to speculate about the connection between the holographic nature of space and “ontology” — the capital-T truth about what’s real.
我发现大多数物理学家对于推测空间的全息性质与“本体论”（关于真实事物的大写真理）之间的联系犹豫不决。
“I don’t try to answer that question,” Susskind said.
“我不想回答这个问题，”苏斯金德说。
“That’s beyond my pay grade.”
“这超出了我的工资等级。”
This strikes me as a prudent response, one that stays true to the ultimate goal of physics, which is not, as I am often tempted to think, to explain what is real.
在我看来，这是一种谨慎的回应，它忠于物理学的最终目标，而不是像我经常想的那样，解释什么是真实的。
Rather, physicists seek to identify a few simple concepts, expressed in mathematical relationships, that make reliable predictions in many different situations.
相反，物理学家试图找出一些用数学关系表达的简单概念，以便在许多不同的情况下做出可靠的预测。
Gravity is a powerful concept because it holds for falling apples, sloshing tides, and orbiting planets.
重力是一个强大的概念，因为它适用于下落的苹果、晃动的潮汐和绕轨道运行的行星。
Holography is another step in that tradition, an equivalence between area and volume that holds at least for certain spaces.
全息术是这一传统的又一步，面积和体积之间的等价至少适用于某些空间。
We are fooled into thinking that there is more stuff in the universe than there actually is.
我们被愚弄了，认为宇宙中的物质比实际存在的物质多。
“Physicists build models,” Czech said.
“物理学家建立模型，”捷克说。
And it’s exciting that holographic models are even possible to build.
令人兴奋的是，全息模型甚至可以构建。
But I craved something more intuitive, less prudent.
但我渴望一些更直观、不那么谨慎的东西。
I wanted to know what holography would mean for us if we lived in anti-de Sitter space (which we don’t), or if physicists developed a holographic theory of de Sitter space (which they haven’t).
我想知道如果我们生活在反德西特空间（我们没有），或者如果物理学家发展了德西特空间的全息理论（他们没有），全息术对我们意味着什么。
When I framed the question in that way, Vijay Balasubramanian , a physicist who studies holography at the University of Pennsylvania, gamely laid out a short menu of possibilities.
当我以这种方式提出这个问题时，宾夕法尼亚大学研究全息术的物理学家 Vijay Balasubramanian 勇敢地列出了一份简短的可能性清单。
If our universe ultimately has just one nature (as opposed to multiple equivalent natures, which Balasubramanian said is possible), then there are three options: The quantum surface is the real thing, the gravitational volume is the real thing, or something else is the real thing.
如果我们的宇宙最终只有一种性质（而不是巴拉苏布拉曼尼安所说的多种等效性质），那么就有三种选择：量子表面是真实的东西，引力体积是真实的东西，或者其他东西是真实的东西。
The first interpretation — the surface is real — is the most popular among physicists who spend their time studying AdS/CFT.
第一种解释——表面是真实的——在花时间研究 AdS/CFT 的物理学家中最受欢迎。
They suspect that the space we experience is as illusory as water.
他们怀疑我们所经历的空间就像水一样虚幻。
If you look closely enough at the smooth, clear liquid, it resolves into ricocheting molecules — the “real thing.” Similarly, if you were to look at our universe closely enough, you’d find that it’s emptier than it seems.
如果你足够仔细地观察光滑、清澈的液体，它会分解成弹跳的分子——“真实的东西”。同样，如果你足够仔细地观察我们的宇宙，你会发现它比看起来更空虚。
In this scenario, we would resemble characters in a video game.
在这种情况下，我们就像电子游戏中的角色。
The apparently bulky buildings and trees of the 3D game world around us would actually be pixels flickering on a flat screen.
我们周围 3D 游戏世界中看似庞大的建筑物和树木实际上是平面屏幕上闪烁的像素。
“We are fooled into thinking that there is more stuff in the universe than there actually is,” said Charles Cao , a theorist at Virginia Tech.
弗吉尼亚理工大学的理论家查尔斯·曹 (Charles Cao) 表示：“我们误以为宇宙中的物质比实际存在的物质还要多。”
You can “compress all of the three-dimensional world into two dimensions.”
你可以“将所有三维世界压缩成二维”。
This perspective abounds in the research program called “it from qubit,” which posits that the space around us (“it”) is made up of quantum units of information (qubits).
这种观点在名为“it from qubit”的研究项目中随处可见，该项目假设我们周围的空间（“it”）是由量子信息单位（qubit）组成的。
These qubits would make up the true fabric of our reality in the same way that screen pixels make up the physical reality of the video game characters.
这些量子位将构成我们现实的真实结构，就像屏幕像素构成视频游戏角色的物理现实一样。
The profound implication of this interpretation is that it flips the normal relationship between distance and influence, said Ning Bao , who studies holography at Northeastern University.
东北大学研究全息术的鲍宁表示，这种解释的深刻含义在于它颠覆了距离与影响力之间的正常关系。
We typically imagine that two things don’t influence each other because space separates them: Flares from alien stars are far away, and that’s why they don’t knock out power on Earth.
我们通常认为两件事不会相互影响，因为空间将它们分开：来自外星恒星的耀斑距离很远，这就是为什么它们不会破坏地球上的电力。
But it from qubit suggests we have it backward.
但来自量子比特的数据表明我们已经落后了。
Perhaps space seems to separate two things precisely because they don’t influence each other.
也许空间似乎将两件事分开，正是因为它们不相互影响。
Consider a video game sun passing behind a video game tree.
考虑一下电子游戏太阳从电子游戏树后面经过。
The sun pixels touch the tree pixels directly, yet the tree does not burst into flames.
太阳像素直接接触树木像素，但树木并没有燃烧。
This is because the sun pixels are independent of the tree pixels.
这是因为太阳像素独立于树像素。
Their independence is what makes the sun “far” from the tree.
它们的独立性使得太阳远离树。
The correspondence goes both ways, however.
然而，通信是双向的。
The holographic principle puts the two pictures of the world on equal footing.
全息原理将世界的两幅图画置于同等地位。
So why can’t the gravitational volume be the real thing?
那么为什么引力体积不能是真实的呢？
Holographers shy away from this interpretation because they don’t have a full quantum handle on space — even anti-de Sitter space.
全息学家回避这种解释，因为他们对空间没有完整的量子处理——甚至是反德西特空间。
But that’s just our ignorance, Balasubramanian said.
但这只是我们的无知，巴拉苏布拉曼尼安说。
Some direct quantum theory of space and matter, such as string theory, must exist, and that could be the fundamental description.
某些空间和物质的直接量子理论，例如弦理论，一定存在，这可能是基本的描述。
If that were the case, the 3D video game world would be the real one, and it would merely seem as if it were made of 2D pixels.
如果是这样的话，3D 视频游戏世界将是真实的，而且它看起来只是由 2D 像素组成的。
Holography would be a mathematical coincidence.
全息术将是一个数学巧合。
In this scenario, “the reality is you’ve got all [three] of these dimensions.
在这种情况下，“现实是你已经拥有了所有[三个]维度。
It just so happens that they have some [holographic] description,” Balasubramanian said.
碰巧他们有一些[全息]描述，”巴拉苏布拉马尼安说。
And then there’s door number three, the nuclear option: Neither the interior volume nor the surface area is real.
然后是第三扇门，核心选项：内部体积和表面积都不是真实的。
Both gravity and quantum mechanics are rough drafts of a sharper, truer, completely unknown theory.
引力和量子力学都是更清晰、更真实、完全未知的理论的草稿。
At the risk of stretching the video game analogy, you could argue that neither the video game world nor the screen pixels are “real,” and that both are just reflections of the complicated ways that electrons physically flow through the game console and television.
冒着扩大视频游戏类比的风险，你可以说视频游戏世界和屏幕像素都不是“真实的”，两者都只是电子在游戏机和电视中物理流动的复杂方式的反映。
In this case, holography tells you how the pixels of the screen relate to the objects of the game world, but it has nothing to do with the nature of the electrons.
在这种情况下，全息术告诉您屏幕的像素如何与游戏世界的对象相关，但它与电子的性质无关。
“The actual theory is something else,” Balasubramanian said.
“实际的理论是另外一回事，”巴拉苏布拉曼尼安说。
At this point, I subscribe to a more extreme variation of the it from qubit interpretation — mostly just following the rumble of the stampede.
在这一点上，我同意量子比特解释的更极端的变化——主要是在踩踏的隆隆声之后。
I’d bet that the qubits are the real things, but that they don’t live on anything as familiar as a flat screen.
我敢打赌，量子位是真实的东西，但它们并不存在于像平面屏幕这样熟悉的东西上。
Physicists have tried to stretch the AdS/CFT correspondence to fit de Sitter space — which has no obvious screen — for decades, with limited success.
几十年来，物理学家一直试图扩展 AdS/CFT 对应关系以适应德西特空间（德西特空间没有明显的屏幕），但成效有限。
In recent years, they’ve started to get more creative.
近年来，他们开始变得更有创造力。
Susskind and other teams have made progress on holographic de Sitter models that differ radically from AdS/CFT.
Susskind 和其他团队在全息 de Sitter 模型上取得了进展，该模型与 AdS/CFT 截然不同。
Instead of squashing a volume into an area, these universes seem to cram all the dimensions into a lone quantum point.
这些宇宙似乎不是将一个体积压缩成一个区域，而是将所有维度塞进一个单独的量子点。
I imagine a bunch of quantum pixels all coexisting in one spot, rather than spreading across a screen.
我想象一堆量子像素共存于一个点，而不是分布在屏幕上。
That might be hard to visualize, but we’re already accepting the idea of dropping one dimension of space.
这可能很难想象，但我们已经接受了放弃一维空间的想法。
Why should tossing the others be so different?
为什么要把别人折腾得那么不一样呢？
Balasubramanian suspects that even this kind of radical model doesn’t go far enough.
巴拉苏布拉曼尼亚怀疑，即使是这种激进的模型也还不够。
Einstein’s theory fused space with time, and so if the three dimensions of space emerge from a spaceless point, then time should emerge from something timeless.
爱因斯坦的理论将空间与时间融合在一起，因此，如果空间的三个维度从无空间的点出现，那么时间应该从永恒的东西出现。
Somehow, we and everything we experience exist within an unblinking dot of no size.
不知何故，我们和我们所经历的一切都存在于一个不眨眼的、没有大小的点中。
Physicists are nowhere close to constructing a functional theory of this form, much less finding hard evidence that our universe works this way.
物理学家距离构建这种形式的功能理论还差得很远，更不用说找到我们的宇宙以这种方式运行的确凿证据了。
But to paraphrase Niels Bohr, during an earlier era when physicists were seeking the next big thing, this sort of theory strikes me as just radical enough — and just simple enough — to be right.
但套用尼尔斯·玻尔的话来说，在物理学家寻求下一个重大事物的早期时代，这种理论让我觉得足够激进——而且足够简单——是正确的。
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