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Computers are cool, and our brain is probably the coolest computer of all.
电脑很酷，我们的大脑可能是所有电脑中最酷的。
When you're shopping around for a new computer,
当你买新电脑的时候，
one of the things you look for is the storage size of the hard drive—how much data your computer can hold.
你考虑的问题之一是硬盘的存储大小——你的计算机能容纳多少数据。
So it's fun to pose the same question about ourselves.
所以对我们自己提出同样的问题是很有趣的。
If our brains were computers, how much data could they store?
如果我们的大脑是电脑的话，我们的大脑能存储多少数据呢？
It's not an easy question to answer—in part because any comparison between a computer and our brain is far from exact.
这不是一个容易回答的问题—部分原因是因为对电脑和人脑进行的任何比较都是不精确的。
They don't really work the same way—but that doesn't stop scientists from trying.
两者运作方式不同—但这并不能阻止科学家们的尝试。
In computer science, the smallest unit of data is a bit, short for "binary digit."
在计算机科学中，最小的数据单位是比特，是“二进制数字”的缩写。
A bit can have one of two binary states: 0 or 1, similar to on and off. 8 bits make a byte.
一个比特可以是两种进制状态之一：0或1，就像开和关一样。8个比特组成一个字节。
By combining bits, you can store more information.
通过组合比特，大家可以存储更多信息。
For example, if you have 2 bits, you can store 4 different states: 00, 01, 10, or 11.
例如，如果你有2个比特，你就可以储存四个不同的进制状态：00、01、10或11.
But not everyone agrees on what the neurological equivalent of a bit would be.
但不是每个人都同意比特神经学等价物的观点。
Since a bit is the smallest unit of storage in a computer, one possible approach is to compare a single bit to a single synapse in the brain.
由于比特是计算机中最小的存储单元，一种可能的方法是将单个比特与大脑中的单个突触进行比较。
That's the area where two neurons meet and exchange information.
这是两个神经元相遇并交换信息的区域。
Synapses are the workhorse of memory—the smallest functional unit, much like a bit.
突触是记忆的主力—像是一个比特，是最小的功能单位。
And like a bit, they were originally thought to have two states: on and off.
和比特一样，它们最初被认为有两种状态：开和关。
There are approximately 250 trillion synapses in our brains, so if one synapse is one bit,
我们大脑中有近250万亿个突触，所以如果一个突触是一个比特，
that would be about 30 terabytes of data in our brain, or 30 trillion bytes. However, it gets trickier.
那么我们的大脑中将有约30万亿字节的数据，或者说30万亿字节。然而，它变得更加棘手。
Signals from neurons at the synapse can vary in size.
来自突触神经元的信号强弱各异。
Instead of just being on or off, a single synapse can carry a signal with varying degrees of strength.
单一的突触可以携带不同强度的信号，而不只是开启或关闭。
These differences in synaptic strength are associated with how strong a memory is.
突触强度的不同和记忆力的强弱有关。
If the synaptic strength is small, you will be less likely to remember something than if the strength is large.
如果突触强度很小，记忆力就没有强度大的时候记得清楚。
For a while, it was believed that a synaptic signal could only be small, medium, or large.
有一段时间，人们认为突触信号只能是小、中或大。
With three possible states, this would make a synapse roughly equivalent to 1 to 2 bits, which boosts the overall estimate a little.
有三种可能的状态，这将使一个突触大致相当于1到2个比特，这将略微提高整体的估计。
But it gets even more complex.
但这样就更复杂了。
A study published in 2015 found that instead of a single synapse being able to have only small,
2015年发表的一项研究发现单一突触不仅有小、
medium, and large signals, there were actually 26 possible states.
中和大信号，其实它们有26种可能的状态。
The researchers measured the synaptic strength of two synapses coming from the same neuron.
研究人员测量了来自同一个神经元的两个突触的突触强度。
They predicted that each would have the same strength. Instead, there was an 8% difference.
他们预测每个人的力量都是一样的，但其实它们之间有8%的差异。
Remember—these two synapses originated from the same neuron.
记住，这两个突触来自于同一个神经元。
When the researchers crunched the numbers, that 8% difference translated into a minimum of 26 different synaptic states.
当研究人员分析这些数字时，8%的差异转化为至少26种不同的突触状态。
This increase in potential states increases the amount of synaptic strength that a single neuron can exhibit,
这种潜在状态的增加提高了单个神经元的突触强度，
making a single synapse capable of storing almost 5 bits.
让单个突触能够储存近5个比特。
Our brains are thought to have around 86 billion neurons, and a single neuron can actually have thousands of synapses.
我们的大脑被认为有大约860亿个神经元，一个神经元实际上可以有数千个突触。
That works out to roughly 250 trillion synapses in the brain.
这相当于大脑中大约250万亿个突触。
If we do some back of the envelope math, at 5 bits per synapse, that gets us in the neighborhood of 150 terabytes.
如果我们以每突触5比特的速度做一些信封背计算法，我们会得到大约150兆兆字节的数据。
It should be noted that these theoretical estimates are just approximations.
应该指出，这些理论估计只是近似值。
We can't really know for sure what our brain can store—this is more of an educated wild guess.
我们无法确切地知道我们的大脑能储存什么——这更像是一个有根据的大胆猜想。
Plus, what our brains do and what computers do are fairly different—
另外，我们的大脑所做的和计算机所做的是相当不同的—
so this is more of a thought experiment than actually saying anything about your brain being a hard drive.
所以这更像是一个思维实验，而不是说你的大脑是一个硬盘驱动器。
Even so, if you figure a DVD can hold about 4.7 gigs, that's in the neighborhood of 30 thousand DVDs.
即便如此，如果你算出一张DVD可以容纳大约4.7 gb的容量，也就是3万张左右。
So give your brain some credit. It's probably pretty spacious.
所以要相信你的大脑，它可能相当宽广。
Thanks for asking, and thanks to our patrons on Patreon for making it possible to spend our time posing
感谢提问，感谢我们的赞助人让我们可以以科学的名义，
and answering such wild hypotheticals in the name of science. Patrons get to choose questions for us to answer,
解决并回答假设性问题。赞助人可以选择问题让我们回答，
so if you've got a burning question of your own, consider supporting us at patreon.com/scishow.
所以如果大家想提问，考虑一下在patreon.com/scishow支持我们吧。
