The hidden network that makes the internet possible - Sajan Saini

譯者: Lilian Chiu 審譯者: SF Huang

In 2012,

2012 年，

a team of Japanese and Danish researchers set a world record,

一支由日本和丹麥研究者 組成的團隊創造了世界記錄，

transmitting 1 petabit of data—

傳送了 1 千兆位元的資料——

that’s 10,000 hours of high-def video—

等同於一萬小時的高解析度影片——

over a fifty-kilometer cable, in a second.

用一條五十公里的纜線， 只花了一秒鐘。

This wasn’t just any cable.

那可不是一般的纜線。

It was a souped-up version of fiber optics—

那是加速版本的光纖——

the hidden network that links our planet

就是將世界各地連結起來，

and makes the internet possible.

讓網際網路成為可能的隱藏網路。

For decades,

數十年來，

long-distance communications between cities and countries

城市與國家間這種長距離的通訊，

were carried by electrical signals,

都是透過銅線所傳輸的電子訊號。

in wires made of copper.

This was slow and inefficient,

這種方式既慢又沒效率，

with metal wires limiting data rates and power lost as wasted heat.

金屬線會限制資料速率， 也會發熱而造成能量的損失。

But in the late 20th century,

到了二十世紀末，

engineers mastered a far superior method of transmission.

工程師掌握了一種更優異的傳輸方法。

Instead of metal,

不用金屬材料，

glass can be carefully melted and drawn into flexible fiber strands,

而是小心地熔化玻璃 並拉長為具彈性的纖維線絲，

hundreds of kilometers long and no thicker than human hair.

其長度可達數百公里之長 且比人類頭髮還要細。

And instead of electricity,

這類纜線傳輸的不是電，

these strands carry pulses of light, representing digital data.

而是代表數位資料的光波脈衝。

But how does light travel within glass, rather than just pass through it?

但，光是怎麼在玻璃中行進的？ 為什麼不會穿過玻璃？

The trick lies in a phenomenon known as total internal reflection.

秘訣在於一種叫做 「全內反射」 的現象。

Since Isaac Newton’s time,

從艾薩‧克牛頓的時代起，

lensmakers and scientists have known that light bends

鏡片製造者及科學家就已經知道

當光傳過空氣和水或玻璃 這類材料時，會產生轉向。

when it passes between air and materials like water or glass.

When a ray of light inside glass hits its surface at a steep angle,

當玻璃內的一道光線 以很大的角度碰撞到它的表面，

it refracts, or bends as it exits into air.

在它進入空氣時會發生折射或轉向。

But if the ray travels at a shallow angle,

但，如果光線行進的角度較淺，

it’ll bend so far that it stays trapped,

它轉彎的方向會讓它 一直被困在玻璃中，

bouncing along inside the glass.

延著玻璃內部不斷反彈。

Under the right condition,

只要條件對了，

something normally transparent to light can instead hide it from the world.

通常光線可穿透的東西，

反而可以將光線隱藏起來 讓外界看不見。

Compared to electricity or radio,

和電或無線電相比，

fiber optic signals barely degrade over great distances—

光纖訊號即使傳送了很長的距離， 也幾乎不會減弱——

a little power does scatter away,

的確會有一點點能量會散失掉，

and fibers can’t bend too sharply,

且纖維的彎曲角度不能太大，

otherwise the light leaks out.

否則光就會外洩出去。

Today, a single optical fiber carries many wavelengths of light,

現今，一條光纖就能傳送 許多不同波長的光，

each a different channel of data.

分別代表不同的資料通道。

And a fiber optic cable contains hundreds of these fiber strands.

一條光纜內含數百條這類的纖維線絲。

Over a million kilometers of cable crisscross our ocean floors

超過一百萬公里的纜線 在我們的海底交錯，

to link the continents—

將各大陸連結起來——

that’s enough to wind around the Equator nearly thirty times.

這總長度足以繞赤道近三十圈。

With fiber optics,

有了光纖，資料的傳輸 幾乎不受距離限制，

distance hardly limits data,

which has allowed the internet to evolve into a planetary computer.

讓網際網路得以演化 成為一台行星級的電腦。

Increasingly,

我們行動裝置的工作和娛樂，

our mobile work and play rely on legions of overworked computer servers,

越來越仰賴過度操勞的 電腦伺服器大軍，

warehoused in gigantic data centers flung across the world.

這些伺服器被存放在世界各地 巨型資料中心的倉庫中。

This is called cloud computing,

這叫做「雲端運算」，

and it leads to two big problems:

它會導致兩個問題：

heat waste and bandwidth demand.

熱能浪費以及頻寬需求。

The vast majority of internet traffic shuttles around inside data centers,

網際網路的流量，絕大部分 是在資料中心內穿梭，

where thousands of servers are connected by traditional electrical cables.

在資料中心內，數千台伺服器 用傳統電纜線連結在一起。

Half of their running power is wasted as heat.

半數的運作能量 以熱能的形式浪費掉了。

Meanwhile, wireless bandwidth demand steadily marches on,

同時，對於無線頻寬的 需求穩定地上升，

and the gigahertz signals used in our mobile devices

而我們在行動裝置中使用的 千兆赫（gigahertz）訊號

are reaching their data delivery limits.

即將達到傳遞數據的極限。

It seems fiber optics has been too good for its own good,

似乎，光纖太好了， 這對它自己並沒有好處，

fueling overly-ambitious cloud and mobile computing expectations.

激發出野心過大的雲端 和行動計算期望。

But a related technology, integrated photonics, has come to the rescue.

但，有一項整合了光子學的 相關技術來救援了。

Light can be guided not only in optical fibers,

不僅光纖能引導光，

but also in ultrathin silicon wires.

超細的矽線也能。

Silicon wires don’t guide light as well as fiber.

矽線引導光的能力沒有纖維好。

But they do enable engineers to shrink

但矽線讓工程師可以

把一百公里內光纖網路中的所有裝置

all the devices in a hundred kilometer fiber optic network

down to tiny photonic chips that plug into servers

縮減成能插入伺服器的 小型光子晶片，

and convert their electrical signals to optical and back.

並將電訊號轉成光訊號， 再反轉回來。

These electricity-to-light chips allow for wasteful electrical cables in data centers

這些電轉光的晶片， 讓資料中心裡不經濟的電纜線

to be swapped out for power-efficient fiber.

被換成高能源效率的光纖。

Photonic chips can help break open wireless bandwidth limitations, too.

光子晶片能協助打破無限頻寬的限制。

Researchers are working to replace mobile gigahertz signals

研究者致力於把 行動裝置的千兆赫訊號

with terahertz frequencies,

換成兆赫（terahertz ）頻率， （ 註：別名「太赫茲」）

to carry data thousands of times faster.

讓資料傳輸的速度加快數千倍。

But these are short-range signals:

但，這些是段距離的訊號：

they get absorbed by moisture in the air,

它們會被空氣中的濕氣給吸收，

or blocked by tall buildings.

或被高樓給阻擋。

With tiny wireless-to-fiber photonic transmitter chips

若能將小型的無線轉光纖 光子傳輸晶片

distributed throughout cities,

放置在城市各處，

terahertz signals can be relayed over long-range distances.

兆赫訊號就能被分程傳遞 到大範圍的距離。

They can do so via a stable middleman,

透過穩定的中間人，即光纖， 就可以做到這一點，

optical fiber, and make hyperfast wireless connectivity a reality.

實現超快速無線連線。

For all of human history,

在人類歷史上，

light has gifted us with sight and heat,

光帶給我們的禮物是視覺和熱能，

serving as a steady companion while we explored and settled the physical world.

當我們在實體世界中探索、 安頓下來時，光是個穩定的夥伴。

Now, we’ve saddled light with information and redirected it

現在，我們在光上加載了資訊 並將它重新導向，

to run along a fiber optic superhighway—

讓它延著光纖 超級高速公路奔馳——

with many different integrated photonic exits—

整合了許多個不同的光子出口——

to build an even more expansive, virtual world.

來建造一個更廣闊的虛擬世界。