This thought experiment will help you understand quantum mechanics - Matteo Fadel

譯者: Zoe Walmsley 審譯者: Helen Chang

After a long day working on the local particle accelerator,

在結束一天在粒子加速廠的辛苦工作後

you and your friends head to the arcade to unwind.

你與幾個朋友前往遊戲場去輕鬆一下

The lights go out for a second, and when they come back,

燈光熄滅一秒鐘，重新亮起後

there before you gleams a foosball table nobody remembers seeing before.

眼前多出了一個前所未見的 桌上型足球遊戲

Always game, you insert your coins.

向來勇於嘗試新事物的你投進了硬幣

And with a fanfare, Quantum Foosball begins.

樂聲響起，量子足球賽正式開始

Here are the rules: as with normal foosball,

遊戲規則與平常桌上型足球機並無二致

the object is to score points

得分的規則是

by spinning levers with tiny players to sink the ball in your opponent’s goal.

轉動刻有足球員的橫把 將量子足球送進對手球門即可

Only instead of a standard ball, you’ll be playing with a giant electron.

唯一不同處是所用的球 是一個巨大的電子

It behaves like a normal electron in all respects, it’s just much larger.

它與一般電子一樣 只是體積大了許多

Though the rules are simple, gameplay is anything but.

儘管遊戲規則簡單 玩法卻完全不是那麼一回事

Instead of the familiar laws of Newtonian physics,

原本熟悉的牛頓物理定律被取代

the movement of the ball is governed by quantum mechanics.

改由量子力學決定球的行進方向

To minimize the influence from photons and air molecules,

同時為了減少光子及空氣分子的影響

you’ll be playing in a vacuum. In the dark.

遊戲會於真空及黑暗的環境中進行

But that’s ok, because you can watch for the flashes of light

那也不是問題

因為看得見每次 球碰撞桿上人形的閃光

given off by collisions between figures and the ball.

The goals themselves will flash when the electron

電子觸及門上的感應器時 球門本身也會發光

hits their particle detectors.

Now you just have to figure out how to get the electron to go where you want.

你只需要控制電子的行進方向即可

As soon as it enters play, the electron will never rest.

因為電子一進入遊戲狀態就停不下來

This is a direct consequence of the Heisenberg Uncertainty Principle,

這是「海森堡測不準原理」的直接後果

which says that the better you know where a quantum particle is,

就是越確定量子的所在位置

the less you know about its velocity, and vice versa.

就越不確定其速度

反之亦然

Since you know it’s on the field, its velocity is largely uncertain.

既然知道電子是在場上 就多半無法掌握其速度

The electron will behave more like a wave than a particle,

電子的行為不像粒子而更像是波

with its position described by probability distributions that you’ll have to imagine.

想像它出現的位置以機率分佈

These distributions are spread throughout the entire field,

這分佈遍布整個球場

making it possible to observe a goal at any time and in either side.

因此雙方可以隨時隨地觀察目標

The way to win is to control and concentrate the distribution

獲勝的方式是掌控及專注

over the opposite goal,

在對手那半邊的機率分佈

giving yourself the highest likelihood of scoring points.

就能讓你的得分機率提到最高

Your skill as a player will be determined by your ability to predict

玩家的技巧有很大一部分

取決於預測電子最可能出現的位置

where the electron is most likely to be,

then manipulate the probability distribution by spinning the rods

然後透過轉動把手及施力大小

with just the right amount of strength.

影響控制機率的分配

Quantum particles only receive energy in precise amounts, called quanta.

量子微粒只對一定的能量 (quanta) 才會有所反應

So spin too hard or too soft,

因此如果轉動的力道太強或太弱

and the electron will stay on its previous course.

電子就依循原先的軌道前進

The game board has been carefully constructed to contain the electron,

遊戲板經過精心設計，不讓電子逸出

but even so, sometimes it’ll quantum tunnel through the walls

儘管如此，有時候電子會在 無明顯原因的情況下穿透量子隧道

without any apparent reason.

At that point it could be anywhere in the universe,

一旦如此，就可能跑到宇宙的任一角落

so to save you the trouble of tracking it down,

為了避免浪費時間找球

the game will spit out a new ball.

機器會立刻核發新球

The fact that quantum particles behave like waves

量子像波的特性

becomes particularly evident in the presence of obstacles.

在有障礙物的情況下尤其明顯

As the particle travels through the rows of miniature figures,

隨著粒子穿過微型的球員陣列

complicated interference patterns will develop in the probability distribution,

（波的）干擾使概率分佈更形複雜

要正確地預測電子的位置就更難了

making it even more difficult to accurately predict its position.

And here’s where your advanced physics degree can finally come in handy:

此時你的高階物理學位 終於可以派上用場了

you can use the laws of quantum mechanics to your advantage.

用上你所知的量子力學

The only moments when the electron will behave as a particle,

電子只在碰到障礙物時

rather than a wave, are when it hits something.

表現得像粒子而不像波

With frequent enough kicks,

如果撞擊得夠頻繁

the particle would have no time to evolve like a wave and, therefore,

粒子來不及呈現波的特性 就無法向外擴展

not spread out in space.

So if you can pass it very quickly between two of your miniatures,

因此只要讓它快速通過迷你障礙物

you can keep it localized.

就能侷限它所處的區域

Masters of the game call this the Quantum Zeno Maneuver.

大師稱之為「量子芝諾效應」

Now, if you really want to dominate your opponents,

如果你真想取得上風

there’s one more thing you can try, but it’s pretty tricky.

有個方法可行，但非常棘手

One of the distinctive features of the quantum world

量子的世界有個特色

is the possibility of state superpositions,

是「量子疊加」的可能性

where particles’ positions or velocities

指的是粒子的所在或速度

can be simultaneously in two or more different states.

能同時處於兩種以上的不同狀態

If you can put the electron into a superposition

如果你能讓電子處於疊加現象

of being simultaneously kicked and not kicked,

即同時處於「撞到」 和「沒撞到」的狀態

it’ll be almost impossible for your opponents to figure out

那麼你的對手就幾乎無法判斷

where and how to strike.

何時及如何發動攻勢

It’s said that Erwin Schrödinger,

據說埃爾溫•薛丁格

那個有史以來 最偉大的量子足球冠軍

the greatest Quantum Foosball champion of all time,

is the only player to have mastered this technique.

是唯一深諳此道的玩家

But maybe you can be the second:

不過或許你有機會排名第二

Just figure out a way to simultaneously turn and not turn your rods.

只要你能夠同時 轉動及不轉動把手就成了