I'm using this speaker to vibrate a petri dish containing silicon oil

我在用這個音響來讓含有矽油的培養皿振動

Now if I take this toothpick and make a little droplet on the surface

現在，如果我用這支牙籤，在表面上做出一個小液滴

the droplet will stay there, hovering above the surface

液滴會在那裡逗留，徘徊在表面上

The droplet is actually bouncing

液滴其實是在彈跳

and it will keep bouncing for a very long time

並能持續彈跳很長一段時間

Now the reason for this is a little layer of air between the droplet and the surface

現在，會有這層在空氣與液滴和油面之間的薄膜

And the droplets bouncing so rapidly that that layer never shrinks to about 100 nanometers

和液滴彈跳如此迅速到該層永遠不會縮至約100奈米

Which is what it would take for the droplet to recombine with the oil

是因為液滴會與油重組

Now, every time the droplet lands on the surface, it creates a wave

現在，每一次液滴落在油面時，會造出一個波

But this is a special type of wave

而且這是一種特殊類型的波

Driven by the vibration of the oil bath

透過油的振動來驅動

It is a standing wave

這是一個駐波

Meaning that it is not traveling out

這意味著它不會跑進油裡

It's just oscillating up and down

它只是上下擺動

So the droplet makes the wave

所以液滴造成了那個波

And then it interacts with that wave on its next bounce

然後它的下一次彈跳會與那個波相互影響

If the drop lands on one side of the wave, it is pushed forwards

如果液滴只落在波的一側，他會被推著走

And as long as the bounce of the droplet remains synchronized with the wave

只要液滴的彈跳依然與波形同步就會一直持續

It will keep landing on the front side of the wave getting pushed farther forwards

它會繼續落在波的前側且被推得更遠

Droplets like these are known as "Walkers"

像這些液滴被稱為“步行者”

The bouncing oil drops has been known about since the 1970s

自1970年代以來，彈跳的油滴就是已知的了

But only recently has it been discovered that you can use these little droplets

但直到最近才發現，你可以用這些小液滴

to replicate many of the strange phenomena of quantum mechanics

來複製許多量子力學的怪現象

Now obviously this is not a quantum system, the droplets are about a millimeter in diameter

現在很明顯，這不是一個量子系統，液滴直徑約一毫米

But you can think of the droplets like, uh, quantum particles, say electrons

但是你可以這樣想，嗯，量子粒子液滴，例如電子

One experiment that captures the key features of quantum mechanics is the Double-Slit Experiment

捕獲量子力學主要特點的實驗是雙狹縫實驗

If you send a beam of electrons at two narrow slits

如果向兩個狹窄的縫發送電子束

Well, the electrons, rather than behaving like particles and ending up in two clumps behind the slits

那麼，電子不會只落在窄縫後的兩個區域

They produce an interference pattern

它們會產生的干涉圖樣

Even when you send each electron through one at a time

即使你一次只讓一個電子通過

With Walking droplets, the pilot wave goes through both slits

因為液滴在走動，兩個縫隙導航波都會經過

Interfering with itself, while the droplet only goes through one slit

與自身形成干擾，但液滴只會經過一個狹縫

The droplet does move in a straight line though

液滴並以直線移動

It's deflected by its interaction with the wave

是因為它與波相互影響而偏轉

The resulting distribution of where the droplets end up

液滴最後產生出來的分布

Looks very similar to quantum double-slit interference patterns

看起來與量子雙縫干涉圖樣非常相似

Or take tunneling

或穿隧效應

In quantum mechanics, it's possible for a particle to get through a barrier

在量子力學中，粒子有可能穿過障礙物

that it wouldn't classically have enough energy to get over

它一般不會有足夠的能量來穿越

This has been demonstrated with Walkers by

這已經由這些步行者證明

creating a shallow barrier under the surface of the oil

油的表面下創建一個淺屏障

Usually the barrier reflects the pilot wave and its bouncing droplet

通常屏障會反彈導航波和液滴

But in rare cases, the droplet does cross the boundary

但是，在極少數情況下，液滴的確會穿過

And the probability of the droplet crossing the barrier

而液滴穿越屏障的概率

Decreases exponentially with increasing width of the barrier, just as in quantum tunneling

隨著屏障的寬度，就像在量子穿隧的指數下降

Perhaps the most surprising thing about these Walkers is they exhibit quantization, just like electrons bound to atoms

或許，這些步行者最令人驚奇的是， 他們表現出的量化，就像原子中彈跳的電子

Here the Walker is confined to a circular corral

在這裡，步行者被限制在一個圓形的圍欄

The droplet seems to move around randomly as it interacts with its pilot wave

液滴似乎四處隨機移動，因為它與它的導航波相互影響

The complex interaction between the droplet and the wave leads to chaotic motion of the droplet

液滴和波之間的複雜相互作用導致液滴的混亂運動

But over time, a pattern builds up

但隨著時間的推移，慢慢建立了一個模式

This is the probability density of finding the droplet at any point within

這是在圈內所有可能看到液滴的概率密度

the corral and it looks very similar to

它看起來和電子的概率密度

the probability density of electrons

非常相似

confined in a quantum corral

當限制在量子圈中。

all of these similarities are no coincidence

所有這些相似之處都不是巧合

the walking droplets actually create a

走動的液滴事實上創造了

remarkable physical realization of a

一個顯著的物理實現

theory proposed by de Broglie nearly a

由德布羅意提出的理論

hundred years ago in the early days of

在近一百年前，初期的

quantum mechanics he postulated that all

量子力學，他推測所有

particles have a wave that accompanies

粒子都伴隨著一個波

them and guides their motion and that

並引導其運動而

wave is actually created by tiny

那個波實際上是由微小

oscillations of the particle

的粒子振動創造出來

Now this pilot wave theory was marginalized when

這個導航波理論在當時被邊緣化

the standard Copenhagen interpretation

當標準哥本哈根詮釋

became widely adopted

為廣泛採用的時候

the Copenhagen interpretation excludes anything that

哥本哈根詮釋排除任何

cannot be directly observed and it says

不能直接觀察到的東西，它說

everything that can be known about a

我們可以知道有關粒子

particle is contained in its so-called

在它被所謂的

"Wave Function" but adopting this view

“波函數”包含，但採用這種看法

forces you to give up on some common

迫使你違反一些常識

sense notions like the idea that

如一些概念，像是

particles have a definite position and

粒子有一個確切的位置或動量，即使在沒有被測量的情況下

momentum even when they're not being measured

它也意味著

and it also meant that the

宇宙

universe was

不再具有確定性

no longer deterministic

隨機性建立了標準的量子力學

randomness is built into standard quantum mechanics

拿雙狹縫實驗做舉例

for example take the double-slit experiment

根據量子力學

according to quantum mechanics the wave

電子的波函數是一個

function of the electron is a

由電子同時通過

superposition of the electron going

一個縫隙與另一個縫隙的疊合

through one slit and the other slip simultaneously

使用此波函數可以計算出

using this wave function you can calculate the probability of

電子可能會在哪裡出現的概率

where the electron is likely to be and

然後當你在屏幕上偵測電子

then when you detected at the screen the

它會在隨機一個點彈出

electron pops up at one point at random

而結果分布會一樣，我們可以說

that was in that distribution we say

波函數塌縮在

that its wave function collapses

測量的瞬間

instantaneously at the moment of

而不能說那個電子

measurement you can't say that the

在你測量之前就在那裡了

electron was there before you measured

甚至不能說

it and you can't even say that the

電子必須通過一個狹縫

electron must have gone through one slit

或其他的狹縫

or the other

與由彈跳液滴

compare that with the picture provided

所顯示出的圖片比較，這個情況下

by the bouncing droplets in this case

導航波通過兩個縫隙

the pilot wave goes through both slits

但液滴只通過一個

but the droplet only goes through one

液滴被它自己的波相互影響而

the droplet is pushed around by its

推著走，所以

interaction with the wave so that the

這個分佈結果統計是

resulting statistical distribution is

一模一樣的，液滴不會同時出現

the same the droplet never exists in two

在兩個地方，也沒有隨機性。

places at once and there's no randomness

如果有任何的不確定性，只是

if there is any uncertainty it's just

因為我們不知道發生了什麼事

due to our ignorance of what's going on

它不是不存在，所以導航波

it's not that it doesn't exist so pilot

的活動可以提供很多

wave dynamics can produce many of the

相同的結果，就如同量子力學

same results as quantum mechanics does

這意味著這是量子粒子

this mean that this is really what

真的在做的事?

quantum particles are doing

不是，但我認為它至少意味著

no but I think it'll at least suggest

這是可能的，這些都是可能的動態

that this is possible these are possible

可能導出從

dynamics that could lead to the

量子力學理論中

statistics which are captured in the

所獲得的統計

quantum mechanical theory and what's

這吸引人的是它給了你一個

appealing about this is it gives you a

清晰的概念，對於發生了什麼事

clear idea of what's going on you don't

你不得不丟棄

have to abandon the idea that the

宇宙具有確定性的想法，和

universe is deterministic and you get

粒子有確切的位置或有確切的動量的想法

particles with definite position and momenta.

我認為我們有

I think it's great that we have

兩個為同樣的實驗互相競爭的理論是很好的。

two competing theories for the same

而這兩個理論都讓你得

experiments and they both asked you to

接受古怪的事物，只是為不同的古怪。

accept odd things just different odd

而你可以選擇看哪個

things and it comes down to what you're

比較適合你的，真的，不管你

comfortable with really whether you

比較喜歡的哥本哈根詮釋是標準的量子力學

prefer the Copenhagen interpretation is standard quantum mechanics

或者是導航波理論

or a pilot wave theory

讓我從留言知道你怎麼想

let me know what you think in the

你喜歡導航波

comments do you like the pilot waves I

我是說..這絕對是一個非常有吸引力的

mean it's definitely a very appealing

圖像是否符合現實

picture whether or not correspond to

，尚待觀察

reality that remains to be seen

嘿，這集的Veritasium是被各位在Patreon上所贊助

Hey this episode of Veritasium was supported in part by viewers like you on Patreon

和谷歌的Making & Science提倡，它是在

and by Google's Making & Science Initiative which seeks to

激發人們去學習更多有關

inspire people to learn more about

科學與追求自己的科學目標

science and pursue their science goals

現在，我知道有人在本週末追求

now I know someone else who is pursuing

他們的科學目標，

their science goals this weekend that is

那就是德斯坦在他的"SmarterEveryDay"頻道

Destin over it Smarter Every Day he

他和我基本上是在觀察相同的

and I were looking at basically the same

現象，不同的是他在觀察水滴

phenomenon but he was looking at water

和為什麼它們不會合併在一起

droplets and why they don't coalesce so

如果你想看看它是如何運作的

if you want to see how that works and

和它在宇宙中的作用，去看看

how it works in space go check it out on

他的頻道"SmarterEveryDay"吧!

his channel over at Smarter Every Day

和往常一樣感謝收看

and as always thanks for watching

看著幀數只有一的彈跳

looking at only one frame per bounce you

你可以看到液滴運動是如何

can see how the droplets motion is

透過它的波有效的引導飄移

guided by the wave it's effectively

而波仍然存在，即使

surfing on and the wave remains even if

液滴已經消失了，

the droplet disappears has happened

有時會發生，如果遇到一點點

sometimes if it encounters a little bit

污垢

of dirt

真正酷的東西是

what's really cool about this is the

這個波會存儲有關

wave actually stores information about

液滴到過哪裡的資訊

where the droplet has been.

這是因為每次液滴彈跳

This is because every time the droplet bounces

它就創造一個的圓波

it creates a new circular wave centered

且以它現在的位置為中心，而那個波

on its present location and that wave

附加在現有的波場表面上

adds to the existing wavefield on the

所以當液滴移動時

surface so as the droplet moves the

它創造的波不斷的附加上去，

waves it makes keep adding up, storing

存儲著它到過那裡信息

the information of where it's been

其實你真的可以看到

in fact you can actually get the droplet

它落在波的後面

to land on the backside of the wave so

現在，它被向後推

now it's pushed backwards and it

它會追溯其步驟，一個個的消除

retraces it steps erasing each way that

先前製造的路徑

made previously one-at-a-time