But time travel to the future is easy; we're all doing it right now.

但時空旅行到未來很容易，我們現在都在做著這件事。

So why does time go forward and not back?

那麼時間為什麼是往前，而不是倒退呢？

The idea that time only flows in one direction is called the Arrow of Time.

時間只會往一個方向前進的這個想法稱為「時間之箭」。

But, odd as it sounds, there's nothing in the equations that describe the laws of physics that says it has to be this way.

不過，就算聽起來很怪，描述物理定律的等式中，並沒有說一定得這樣。

The equations can tell you what will happen in the future or what took place in the past based on what's going on in the present,

這些等式可以根據現況告訴你未來將發生什麼事，或是過去發生過什麼事，

but they don't explicitly state that time must go from past to present to future.

但它們並沒有明確表示，時間一定是從過去到現在再到未來。

The math works just as well going either direction.

不管往哪個方向，數學運算上都成立。

The one thing that seems to keep driving this time bus to futuretown is the second law of thermodynamics, which states that entropy must always increase.

讓時間巴士持續開往未來城市的要素，似乎是基於熱力學第二定律，指出熵必須持續增加。

Things must go from order to chaos; heat must disperse from hot bodies to colder ones.

事情必須從秩序到混亂，而熱量必須從熱的物體傳遞到較冷的物體。

This increase in entropy is what keeps the ordered past behind us and the increasingly messy future ahead.

熵的增加，恰好讓我們把有秩序的過去拋諸腦後、漸漸混亂的未來擺在眼前。

But there seems to be a loophole in the second law of thermodynamics, and scientists recently exploited it to turn entropy on its ear.

但熱力學第二定律似乎存在破綻，而科學家近來則利用它轉變熵的新氣象。

Apparently the law doesn't apply to correlated particles, which are like entangled particles, but with less of a connection.

顯然，這定律不適用於相關粒子，也就是連結性較小的糾纏粒子。

When researchers observed a hot hydrogen nucleus that was next to a cooler carbon nucleus inside a trichloromethane molecule, the nuclei behaved as expected: Heat flowed from the hot hydrogen to the cool carbon.

當研究人員觀察三氯甲烷分子內低溫碳原子旁的高溫氫原子時，它們的表現如預期：熱量從熱氫流向冷碳。

But when they tried the same thing with correlated hydrogen and carbon nuclei, the opposite happened.

但他們嘗試用相互關係的氫和碳原子時，發生了相反狀況。

The hydrogen got hotter, while the carbon chilled even more.

氫原子變得更熱，而碳原子變得更冷。

This is akin to putting a hot coffee cup in a cold room and watching it heat up as you feel the room get colder.

這等同於將一個熱咖啡杯放在冷房，在看著杯子發熱的同時，感覺房間變冷。

The scientists went on to make the bold claim that this experiment shows the reversal of the Arrow of Time.

科學家接著大膽宣稱這實驗顯示了時間之箭的逆轉。

But even if that's indeed what's happening, it looks like it only applies under very specific circumstances on an atomic scale.

但儘管那是確實在發生的事，它看起來只適用於在原子標度上極具體的情況。

So, not that I'm a physicist or anything, but did you reverse the Arrow of Time ?

那麼，雖然我並不是物理學家之類的人，但你們真的逆轉了時間之箭嗎？

Does that mean time is suddenly running backwards or is there something else at play with these atoms here?

這意味著時間突然開始倒轉了，還是這些原子中還有其他東西在發揮作用？

Needed is research more.

需要研究更多。

I wouldn't exactly predict a future where broken coffee mugs spontaneously reform or rooms tidy themselves just yet.

我倒是不會預想一個破碎馬克杯會自動重組、或是房間自己變整齊的一個未來，至少現在還不會。

Special thanks to DOMAIN.COM for sponsoring this episode of Seeker.

特別感謝 DOMAIN.COM 贊助 Seeker 這一集的內容。

DOMAIN.COM is awesome; affordable, reliable, and has all the tools you need to build a new website.

Domain.com 很棒！價格合理、可靠，而且擁有你建置新網站需要的所有工具。

They can fulfill all of your website needs.

他們可以滿足你對網站的所有需求。

They offer .com and .net domain names and intuitive website builders.

他們提供 .com 和 .net 的網域名稱，以及直覺式的網站建置幫手。

They have over 300 domain extensions to fit your needs, from .club, .space, to .pizza!

它們擁有超過 300 個拓展網域來滿足你的需求，包括 .club、.space，還有 .pizza！

Take that first step in creating an identity online and visit DOMAIN.COM.

跨出創造網路身分的第一步，並到 DOMAIN.COM 看看。

If you've watched all our past episodes, then please subscribe for our future ones.

如果你已經看過我們過去所有集數，那請訂閱我們未來的影片。

If you haven't seen them all, check out this video on how your perception of time can alter if you speak another language.

如果你還沒全部看過，點集右上角這部影片，了解你的時間觀念如何因為講不同語言而被改變。

In the distant future, when the entropy is at its maximum, there will actually be no Arrow of Time, because nothing will be able to change.

在遙遠的未來，當熵最大化後，實際上將不再有時間之箭，因為沒有任何事物能被改變。

Thanks a lot for watching Seeker.

感謝收看 Seeker。