How exactly does binary code work? - José Américo N L F de Freitas

翻译人员: Robin W 校对人员: Carol Wang

Imagine trying to use words to describe every scene in a film,

想象一下，用词语来描绘 电影中的每一处场景，

every note in your favorite song,

你最爱的歌曲的每一个音符，

or every street in your town.

或者你镇上的每一条街道，

Now imagine trying to do it using only the numbers 1 and 0.

现在想一下试着只用数字 1 和 0 来表达这些。

Every time you use the Internet to watch a movie,

每次你使用因特网观赏电影、

listen to music,

听音乐、

or check directions,

或者查找方位，

that’s exactly what your device is doing,

你的设备就是这样工作的：

using the language of binary code.

使用二进制编码语言。

Computers use binary because it's a reliable way of storing data.

电脑使用二进制，因为它 能可靠地存储数据。

For example, a computer's main memory is made of transistors

举例来说，电脑的主存储器 由晶体管构成，

that switch between either high or low voltage levels,

晶体管在高压与低压之间转换，

such as 5 volts and 0 volts.

例如 5 伏和 0 伏。

Voltages sometimes oscillate, but since there are only two options,

电压有时会振动，但由于 只有高压和低压之分，

a value of 1 volt would still be read as "low."

1 伏仍然被认为是低压。

That reading is done by the computer’s processor,

这些数值由电脑处理器读取，

which uses the transistors’ states to control other computer devices

根据软件指令，通过 晶体管的状态

according to software instructions.

来控制其他电脑设备。

The genius of this system is that a given binary sequence

这套系统的妙处是： 给定的二进制序列

doesn't have a pre-determined meaning on its own.

本身没有既定含义。

Instead, each type of data is encoded in binary

相反的，每种数据 根据一套单独的规则，

according to a separate set of rules.

进行二进制编码。

Let’s take numbers.

让我们以数字为例，

In normal decimal notation,

在通常的十进制计数法中，

each digit is multiplied by 10 raised to the value of its position,

每个数位上的数字 乘以 10 的指数次幂，

starting from zero on the right.

指数从右向左，由 0 开始增长，

So 84 in decimal form is 4x10⁰ + 8x10¹.

因此 84 的十进制形式 是 4x10⁰ + 8x10¹。

Binary number notation works similarly,

二进制计数法的原理也很相似，

but with each position based on 2 raised to some power.

但每个数位上的数值 与 2 的指数次幂相乘，

So 84 would be written as follows:

因此 84 的二进制形式如图所示。

Meanwhile, letters are interpreted based on standard rules like UTF-8,

同时，字母 根据标准规则，如 UTF-8，

which assigns each character to a specific group of 8-digit binary strings.

用一组特定的 8 位 二进制串进行编码。

In this case, 01010100 corresponds to the letter T.

在这种情况下， 01010100 指的是字母 T。

So, how can you know whether a given instance of this sequence

那么，你怎么知道 这个给定的二进制序列

is supposed to mean T or 84?

指的是 T 还是 84 呢？

Well, you can’t from seeing the string alone

事实上，单看这一串数字 的确无法判断，

– just as you can’t tell what the sound "da" means from hearing it in isolation.

就像单纯听到“DA”的声音， 你不能判断它的意思一样。

You need context to tell whether you're hearing Russian, Spanish, or English.

你需要根据语境，判断听到的 是俄语、西班牙语、还是英语。

And you need similar context

你同样需要语境

to tell whether you’re looking at binary numbers or binary text.

来判断你看到的是二进制 数字还是二进制文字。

Binary code is also used for far more complex types of data.

二进制编码也被用在 复杂得多的数据类型中，

Each frame of this video, for instance,

例如，这个视频的每一帧，

is made of hundreds of thousands of pixels.

都是由无数的像素组成的。

In color images,

在彩色图片中，

every pixel is represented by three binary sequences

每个像素由 3 个二进制序列表示，

that correspond to the primary colors.

分别对应红、绿、蓝三原色。

Each sequence encodes a number

每个序列编码成一个数字，

that determines the intensity of that particular color.

决定了特定颜色的强度。

Then, a video driver program transmits this information

之后，一个视频驱动程序将此信息

to the millions of liquid crystals in your screen

传递给你屏幕上数百万的液晶，

to make all the different hues you see now.

形成了你现在看到的不同的色调。

The sound in this video is also stored in binary,

这个视频的声音也通过 二进制的形式储存，

with the help of a technique called pulse code modulation.

通过脉冲编码调制技术实现。

Continuous sound waves are digitized

持续的声波被数字化，

通过对其振幅进行 几毫秒一次的快照，

by taking "snapshots" of their amplitudes every few milliseconds.

These are recorded as numbers in the form of binary strings,

这些声音以二进制串的 数字形式记录下来，

with as many as 44,000 for every second of sound.

每秒的声音包含 多达 44000 个数字。

When they’re read by your computer’s audio software,

当它们被你电脑上 的音频软件读取时，

the numbers determine how quickly the coils in your speakers should vibrate

这些数字决定了 扬声器里线圈的振动速度，

to create sounds of different frequencies.

以转换成不同频率的声音。

All of this requires billions and billions of bits.

所有这些需要数十亿、 数百亿的二进制位。

But that amount can be reduced through clever compression formats.

但是通过巧妙的压缩格式， 这个数值能够显著减少。

For example, if a picture has 30 adjacent pixels of green space,

例如，如果一个图片有 30 个 相邻的绿格像素，

they can be recorded as "30 green" instead of coding each pixel separately -

它们会被记录成“30绿”， 而不是把每一个像素分别编码，

a process known as run-length encoding.

这个过程叫做“行程编码“，

These compressed formats are themselves written in binary code.

这些压缩格式本身 也被编成了二进制码。

So is binary the end-all-be-all of computing?

那么二进制就是 计算的最终目标了吗？

Not necessarily.

不一定。

There’s been research into ternary computers,

三进制计算机已有相关研究，

with circuits in three possible states,

将三种可能的状态形成循环。

and even quantum computers,

甚至有量子计算机，

whose circuits can be in multiple states simultaneously.

可以同时进行多重状态的循环。

But so far, none of these has provided

但是到目前为止， 这些研究中没有一种

as much physical stability for data storage and transmission.

在信息存储和传输方面 具有足够的物理稳定性。

So for now, everything you see,

因此现在，你在屏幕上看到的、

hear,

and read through your screen

听到的、

和读到的一切，

comes to you as the result of a simple "true" or "false" choice,

都是简单的“是” “非”选择

made billions of times over.

运行了数十亿次的结果。