While fire and sharp sticks became power plants and nuclear weapons

當火和尖銳棒狀物變成發電廠和核武時

The biggest upgrade has happened to our brains

腦的大進化已經開始發生

Since the 1960's, the power of our brain machines has kept growing exponentially

自從 1960 年來，電腦的運算能力呈獻指數性的成長

allowing computers to get smaller and more powerful at the same time

使得電腦愈來愈小，同時愈來愈強大

But this process is about to meet its physical limits

但是演化已經快碰到了物理上的極限

Computer parts are approaching the size of an atom

電腦元件尺寸正在趨近於原子的大小

To understand why this is a problem, we have to clear up some basics

為了說明這為什麼是個問題，我們必須要先講解一些基本知識

In a Nutshell -By Kurzgesagt

A computer is made up of very simple components

電腦是由執行簡單功能的簡單元件所組合而成

doing very simple things

電腦是由執行簡單功能的簡單元件所組合而成

Representing data, the means of processing it, and control mechanisms

以呈獻數據，意思就是運算並控制機械

Computer chips contains modules which contains logic gates, which contains transistors

晶片包含模組，模組包含邏輯閘，邏輯閘包含電晶體

A transistor is the simplest form of a data processor in computers

電晶體代表著電腦的處理器裡一個最簡單的型態

basically a switch that can either block, or open the way for information coming through

簡單說是個可以阻擋、通過資訊的開關

This information is made up of bits

而此資訊是由位元構成

Which can be set to either 0 or 1

它可以設為 0 或者 1

Combinations of several bits are used to represent more complex information

多個位元的組合通常代表著更複雜的資訊

Transistors are combined to create logic gates which still do very simple stuff

將電晶體組合後會變成邏輯閘，它還是只有簡單的功能

For example, an AND Gate sends an output of 1 if all of its inputs are 1 and a output of 0 otherwise

例如，一個 AND 閘只有在輸入值皆為 1 時才會輸出 1，否則就會輸出 0

Combinations of logic gates finally form meaningful modules say for adding two numbers

最終組合不同的邏輯閘形成了有意義的模組，比方說加法的功能模組

Once you can add, you can also multiple

一旦你能夠使用加法，你也可以使用乘法

and once you can multiple, you can basically do anything

一旦可以使用乘法，基本上什麼都可以做了

Since all basic operations are literally simpler than first grade math

既然所有基本運算都比一年級的數學簡單

You can imagine a computer as a group of 7 year old answering really basic math questions

你可將電腦想像為一群在回答基礎數學題的 7 歲小孩

A large enough bunch of them could compute anything

足夠數量的小孩可以計算所有的東西

from astrophysics to zelda

不論是天文物理或薩爾達傳說

However, with parts getting tinier and tinier

然而隨著元件愈變愈小

Quantum physics are making things tricky

量子力學讓事情變得很詭異

In a nutshell, a transistor is just a electric switch

簡而言之，一個電晶體只是一個電流開關

Electricity is electrons moving from one place to another

電流表示電子由一端流向另一端

So, a switch is a passage that can block electrons from moving in one direction

所以開關就是可決定是否讓電子流過的單向通道

Today, a typical scale for Transistors is 14 nanometers

現今的電晶體尺寸大約是 14 奈米

Which is about 8 time less than a HIV virus' diameter

是 HIV 病毒（愛滋病是其中之一）直徑的 1/8 倍

and 500 times smaller than a red blood cells

然後是紅血球的 1/500 倍

As transistors are shrinking to the size of only a few atoms

當電晶體小到僅幾顆原子大的尺寸時

Electrons may just transfer them to the other side of a blocked passage

電子會無視阻擋將自己傳送到另一端

viral process called Quantum Tunneling

這現象稱作量子穿隧效應

In the quantum realm, physic works quite differently from the predictable way were used to

在量子世界裡，物理運作方式和我們平常看到的不太一樣

and traditional computers just stop making sense

而傳統的電腦就開始沒邏輯了

We are approaching a real physical barrier for our technological progress

我們的科技正一步步接近物理的極限

To solve this problem

為了解決這問題

scientist are trying to use these unusual quantum properties to their advantage

科學家嘗試利用量子物理不尋常的特性中的優點

by building quantum computers

方法就是製造台量子電腦

In normal computers, bits are the smallest unit of information

在一般電腦中，位元代表著資訊的最小單位

Quantum computers use Qubits which can also be set to one of two values

量子電腦使用的是量子位元

A qubit can be any two level quantum system

一個量子位元可以是任何二階的量子系統

such as a spin and a magnetic field or a single photon

像是自旋和磁場，或是單一的光子

0 and 1 are the system's possible states

0 和 1 是系統中可能存在的狀態

like the photons horizontal or vertical polarization

就像是光子橫向或縱向的偏振

In the quantum world, the qubit doesn't have to be just one of those

在量子世界裡，量子位元不一定是這兩種狀態之一

It can be any proportions of both states at once

他可以在他們間同時表現出所有的偏振狀態

This is called Superposition

這被稱作為量子疊加

But as soon as you test its value say by sending the photon through a filter

但當你想把一個光子送到濾波器做測試時

It has to decide to be either vertically or horizontally polarized

它必須決定自己是縱向或橫向偏振

So as long as it's unobserved

所以當它被觀測之前

The qubit is in a superposition of probabilities for 0 and 1 and you can't predit which it'll be

量子位元就代表著 1 和 0 間所有可能的疊加狀態，你無法預期是哪個狀態

But the instant you measure it

但當你測量它的瞬間

It collapses into on of the definit states

它將會塌陷為一個固定的狀態

superposition is a game changer

量子疊加狀態改變了遊戲的規則

Four classical bits can be in one of two to the power of four different configurations at a time

四個傳統位元中，每個位元各自表示兩種狀態中的一種

that's 16 possible combinations at which you can use just one

這共包含了 16 種不同的組合，但只能使用其的一組

Four qubits in superposition however, can be in all of those 16 combinations at once

四個量子位元則可以同時代表著 16 種狀態

This number grows exponentially with each extra qubit

每增加額外的量子位元，組合數將會是指數性的成長

20 of them can already store a million values in parallel

20 個量子位元就可以平行儲存 100 萬個數值

A really wired and uninsured property qubits can have is Entanglement

量子位元還有一個詭異並不確定性的特性，那就是量子糾纏

A close connection that makes each of the qubits react to a change in the other state instantaneously

他使另一組糾纏狀態的量子位元呈獻與自己相反的狀態

no matter how far they are apart

就算他們之間被分開多遠都一樣

This means when measuring just one entangled qubit, you can directly to use property of it's partner's

這意味著只要測量其中一個糾纏態的量子位元，利用這特性就能不用觀測而得知另一組結果

without having to look

這意味著只要測量其中一個糾纏態的量子位元，利用這特性就能不用觀測而得知另一組結果

Qubit Manipulation is a mind bender as well

操控量子位元就像是腦筋急轉彎

A normal logic gate gets a simple set of inputs and produce one definite output

一個普通的邏輯閘有著單純的輸入並產生一個固定的輸出

A quantum gate manipulates an input of superposition rotates probabilities

量子閘輸入一個疊加，旋轉他改變機率

and produces another superposition as its output

輸出另一個疊加

So a quantum computer sets up some qubits, apply quantum gates to entangle them and manipulate probabilities

所以一台量子電腦操作部份的量子閘產生糾纏

then finally measures the outcome collapsing superposition to an actual seqence of 0s and 1s

並控制機率，最後測量輸出讓疊加狀態崩潰後，得出最後結果的 0 和 1

What this means is you get entire lot of calculations that are possible with your setup all done at the same time

這意味著你可以將這麼多種可能性同時進行運算

Ultimately you can only measure one of the results and it'll only probably be the one you want

最終你只會測量到一個結果，而這結果只是有很高的機率可能就是你要的

So you might have to double check and try again

所以你可能要多計算幾次以檢查結果

But by cleverly exploiting superposition and entanglement

但巧妙地運用疊加和量子糾纏

this can be exponentially more efficient than would ever be possible on a normal computer

效率相比一般電腦將會是指數性的成長

So, while quantum computers will not probably not replace our home computers

所以量子電腦雖然無法取代現在的電腦

in some areas, they are vastly superior

在某些領域他們是非常優越的

One of them is database searching

其中之一就是資料庫搜尋

to find something in a database, a normal computer may have to test every single one of its entries

一般電腦再資料庫中搜尋可能要搜尋每一份資料

Quantum algorithms need only the square root of that time

量子演算法只需要原來運算時間開根號的時間

which for large databases, is a huge difference

這在大型資料庫上會有著極大的差距

The most famous use of quantum computers is ruining IT sercity

量子電腦中最著名的用法就是破解資訊安全機制

right now you are browsing email and banking data is being kept secure by an encryption safety system

現在你瀏覽的銀行郵件還是被加密系統給保護著

in which you give everyone a public key to encode messages only you can decode

藉由你給其它使用者不同組的公鑰，來加密只有你能解密的訊息

The problem is that this public key can actually be used to calculate your secret private key

問題是拿到公鑰的人可以計算出你的密鑰

Luckily, doing the necessary math on any normal computer would literally take years of try and error

幸運的是使用一般的電腦必須花上數年運算，不斷地嘗試錯誤才有辦法解開

But a quantum computer with exponential speed-up could do it in a breath

但對於量子電腦，由於運算速率是指數性的成長，可能只是小菜一碟

Another really exciting new use is simulations

另一個著名的用法就是當作模擬器

Simulations of the quantum world are very intense on resources

模擬量子環境非常地吃資源

and even for bigger structures such as molecules they often lack accuracy

更或者一些巨大的結構體，例如分子結構，他們通常缺乏精準度

So why not simulate quantum physics with actual quantum physics

所以為何不用真實的量子電腦來模擬量子物理環境呢？

Quantum simulations could provide new insights on proteins that might revolutionize medicine

模擬量子環境可能讓我們更了解蛋白質的組成，這可能讓我們醫學大大地進步

Right now we don't know if quantum computers will be just a specallized tool

目前我們並不清楚量子電腦會是個專門用途的工具

or a big revolution for humanity

還是為人類大來大進化

We have no idea where the limits of technology are

我們還不清楚科技的極限在哪裡

and there's only one way to find out

然而只有一種方法可以找出答案

This video is supported by the Australian Academy of Science

這部影片是由澳洲科學院支援

which promotes and supports excellence in science

他們推廣並支持科學的進步

Learn more about this topic and others like it at nova.org.au

到nova.org.au學習更多有關這個和其他類似的主題

It was a blast to work with them, so go check out their site!

跟他們合作很愉快，所以快去看看他們的網站吧！

Our video are also made possible by your support on patreon.com

我們的影片也是有你們在 patreon.com 上的支持才能呈現

If you want to support us and become part of the Kurzgesagt bird army, check out our Patreon page!

如果你想支持我們並成為 Kurzgesagt 團隊的一份子，去看看我們的贊助頁面吧！

Subtitles by James Zhang [revisioned by Pietro Pasquero]