(单词翻译:单击)
We've all seen people act in ways that seem totally irrational —and for most of us, unpredictability is just part of human nature.
我们都见过人们的以完全不理性的方式行事，对大多数人来说，不可预测性只是人性的一部分。
But for scientists, when something is unpredictable, that's usually a sign that they don't fully understand what's going on.
但对于科学家来说，当某些事情不可预测时，这通常是一个迹象，表明他们并不完全了解发生了什么。
Which isn't really shocking when it comes to people.
这并不令人感到震惊。
Our brains are just vastly more complex than we have the tools to understand right now.
我们的大脑比我们现在所掌握能了解它的工具要复杂得多。
But even if we can't understand the brain down to the deepest level,
但是，即使我们不能深入理解大脑，
some psychologists think that a set of ideas borrowed from quantum physics could help us make sense of human behavior.
一些心理学家认为，从量子物理学中借用的一套思想可以帮助我们理解人类的行为。
The notion is called quantum cognition—and it isn't suggesting that our brains actually function at the quantum level,
这一概念被称为量子认知，它并不意味着我们的大脑实际上是在量子层面上运作的，
just that the mathematical tools of quantum mechanics could help make human behavior more predictable.
只是量子力学的数学工具可以帮助人类行为变得更可预测。
Now, the idea that this bizarre branch of physics could be useful for understanding the brain might seem like a stretch—
现在，这个奇怪的物理学分支可能有助于理解大脑的想法似乎有些牵强，
but the reason it's useful is because quantum mechanics is all about statistics.
但它有用的原因是因为量子力学都关于统计。
For instance, it's impossible to know where an electron is at any given time;
例如，在任何给定的时间都不可能知道一个电子在哪里；
you can only know how likely it is that, when you measure it, you will find it in a given place.
你只能知道它的可能性有多大，进行测量时，就能在给定的地方找到它。
And that's not because we're bad at measuring—that's just how the universe works on a fundamental level.
这并不是因为我们不善于测量，这只是宇宙在基本层面上的运作方式。
Statistics are also useful in other branches of science, though, for different reasons.
统计数据在科学的其他分支中也很有用，但是是出于不同的原因，
They can help us understand the big picture even when we don't know all the lower-level details.
它们可以帮助我们了解全局，即使我们不知道所有较低层次的细节。
Like, you can use statistics to predict how a group of people will vote even if you don't know what every individual person will do.
比如，你可以用统计数据来预测一组人将如何投票，即使你不知道每个人都会做什么。
And when it comes to the brain, there are a bunch of low-level details that we don't understand.
当涉及到大脑时，有很多我们不了解的低级细节。
For example, while neuroscientists have figured out where our short-term and long-term memories are stored,
例如，虽然神经学家已经弄清了我们的短期和长期记忆存储在哪里，
it's still not clear how your brain selects certain details to remember and others to forget.
但我们仍然不清楚大脑如何选择某些细节来记忆，而另一些细节又是如何忘记的。
But in some cases, we can use statistics to make decent predictions about how people will behave even if we're not really sure why.
但在某些情况下，我们可以利用统计数据对人们的行为做出合理的预测，即使我们不确定原因。
Traditionally, these cognitive models have relied on classical probability, which can be pretty black or white.
这些认知模型一直依赖于经典性概率，它可以非黑即白。
Like, you either have three aces in your poker hand or you don't.
比如，你要么有三张扑克中的A，要么没有。
You either blew off that important project or you didn't.
你要么放弃那个重要的项目，要么就没有。
Or did you just kind of drag your feet until it was too late?
或者你只是拖着脚走到太迟了？
See, human cognition is full of ambiguities, and classical probability just isn't well-suited to handling them.
看，人类的认知充满了歧义，而经典的概率论并不适合处理它们。
That's where quantum mechanics might be useful.
这就是量子力学可能有用的地方。
The quantum world is anything but black and white, but we've developed really powerful tools to deal with that ambiguity.
量子世界绝不是非黑即白，但我们已经开发出非常强大的工具来处理这种模糊性。
And recently, psychologists have been exploring whether or not those tools could be reused to help understand the brain.
最近，心理学家们一直在探索这些工具是否可以重复使用来帮助理解大脑。
In fact, quantum cognition models are already performing as well or better than classical models at predicting some kinds of human behavior.
事实上，量子认知模型在预测某些人类行为方面已经表现得和经典模型一样好或更好。
For example, it's really tricky to predict how humans will make decisions.
例如，预测人类将如何做决定真的很棘手。
Like, no matter how well you know someone, the things they decide just don't always seem logical.
比如，不管你对某人有多了解，他们决定的事情似乎并不总合乎逻辑。
In the early 1990s, psychologists showed this with a simple experiment.
上世纪90年代初，心理学家通过简单的实验证明了这一点。
In it, they asked 98 subjects to guess the result of a coin flip.
在这项研究中，他们让98名受试者猜测掷硬币的结果。
If they were right, they'd win 200 dollars, and if they were wrong, they would owe 100.
如果他们是对的，就会赢200美元，如果错了，要从他们这拿走100美元。
After the first flip, everyone was asked if they wanted to play again.
做第一次翻转后，都会询问每个人是否想再玩一次。
In general, both winners and losers wanted to flip again,
一般来说，赢家和输家都想再玩，
which is reasonable since you're more likely to win money after multiple rounds than lose it.
这是合理的，因为多轮后赢钱的可能性要大于输钱的可能性。
But that was not true for everyone.
但并非所有人都是这样。
Specifically, subjects who weren't told whether they'd won or lost the first coin flip mostly decided not to play again.
具体来说，没有被告知第一次掷硬币是赢还是输，受试者大多决定不再玩了。
Even though the odds were in their favor.
尽管胜算对他们有利。
From the perspective of classical cognition models, this doesn't make any sense.
从经典认知模型的角度来看，这没有任何意义。
After all, if subjects were told whether they'd won or lost, neither result affected their decision—in general, they all wanted to play again.
毕竟，如果受试者被告知他们是赢还是输，这两个结果都不会影响他们的总体决定，他们都想再玩一次。
This is called the sure thing principle because all the options seem to lead to the same result.
这称为确定性原则，因为所有的选择似乎都会导致相同的结果。
But somehow, not knowing made it not a sure thing.
但不知怎么的，不知道让它不会成为一件确定的事情。
And while classical models of cognition struggle to explain how that could be, one principle from quantum physics does offer a way to understand it.
虽然经典的认知模型很难解释这是怎么回事，但量子物理学的一个原理确实提供了理解它的方法。
See, in the quantum world, just the fact that something is unknown can change the outcome of an event.
看，在量子世界里，仅仅是一些未知的事实就可以改变一个事件的结果。
That's the premise of the famous double-slit experiment.
这就是著名的双缝实验的前提。
In one version of the experiment, physicists fire a beam of electrons at a detector.
在实验的一个版本中，物理学家向探测器发射电子束。
In front of the detector there's a barrier with two slits in it.
在探测器前面有一个带两条缝的屏障。
When the beam is turned on, the electrons strike the detector in a pattern
当光束打开时，电子以一种模式撞击探测器，
that looks a lot like the pattern you get when two sets of ripples interfere with each other.
这种模式与两组波纹相互干扰时的模式非常相似。
The weird thing is, even if you release the electrons one by one, you still get this interference pattern.
奇怪的是，即使你一个接一个地释放电子，仍然会得到这种干扰图样。
In other words, the electron is interfering with itself.
换言之，电子在干扰自身。
That's because it doesn't exist in a single, precise location, so there's some ambiguity about which slit it passes through.
这是因为它不是单一存在于精确的位置，所以它通过哪个狭缝并不确定。
But, if you set up a sensor to measure which gap each electron travels through, this diffraction pattern disappears.
但是，如果你设置一个传感器来测量每个电子通过哪个间隙，这个衍射图案就会消失。
So, the instant the electron's position is known, the ambiguity is gone, and the interference is, too.
所以，一旦知道电子的位置，模糊性就消失了，干扰也消失了。
So, broadly speaking, this shows that in quantum mechanics, simply not knowing can produce a totally unexpected result.
所以，广义地说，这表明在量子力学中，仅仅不知道就能产生一个完全出乎意料的结果。
Similarly, in the coin-flip experiment, just the existence of doubt changed the likelihood that someone would play another round.
同样，在掷硬币实验中，仅仅是怀疑的存在就会改变有人再玩一轮的可能性。
As illogical as these scenarios sound, though, neither one is unpredictable.
尽管这些场景听起来不合逻辑，但两者都不可预测。
In physics, scientists use quantum probability theory, which is a model that accounts for the fact that knowledge of something can affect the result.
在物理学中，科学家使用量子概率论，这是一个模型，解释了知识可以影响结果的事实。
And weirdly enough, you can apply the same theory to human decision-making to predict how people will make decisions,
奇怪的是，你可以将同样的理论应用到人类的决策中去预测人们将如何做决策，
even if we don't understand precisely why.
即使我们不知道为什么。
Psychologists were able to use this quantum model to correctly predict people's decisions in the coin-flip experiment, even when the classical model failed.
心理学家能够使用这个量子模型来正确预测人们在掷硬币实验中的决定，即使经典模型失败了。
