of stars . High temperatures and densities allow hydrogen and helium nuclei to get close

氫核和氦核高溫和高密度使得氫核和氦核能夠接近於恆星。

enough to fuse together into bigger nuclei and release a TON of energy, powering even

足夠融合成更大的原子核，並釋放出大量的能量，甚至可以驅動更多的原子核。

more fusion while releasing enough extra to power the star, or if you set this situation

更多的核聚變，同時釋放出足夠的額外能量為恆星提供動力，或者如果你將這種情況設置為

up on earth, you might have a hydrogen bomb.

在地球上，你可能有一個氫彈。

But it's actually possible for fusion to occur at temperatures much, much lower than

但實際上，核聚變有可能發生在溫度遠遠低於

the core of the sun - like, room temperature, for example.

太陽的核心--比如說，室溫。

Now, I'm not talking about the infamous “cold fusion” of the 1980s that hasn't

現在，我說的不是20世紀80年代臭名昭著的 "冷核聚變"，它還沒有... ...

been shown to work or involve any, well, fusion - no, I'm talking about the room-temperature

已被證明是有效的，或涉及任何，嗯，核聚變 - 不，我說的是在室溫下的核聚變。

fusion of the 1950s that actually does work: fusion with the help of muons!

20世紀50年代的核聚變，實際上確實有效：在μ子的幫助下進行核聚變!

Nuclear fusion, of course, happens when atomic nuclei, like hydrogen nuclei , come close

當然，當原子核，如氫核，接近時，就會發生核聚變。

enough together that their strong nuclear attraction can overcome their electric

足夠多的人在一起，他們強大的核吸引力可以克服他們的電荷。

repulsion, and they fuse together into a single, bigger nucleus - like helium .

斥力，它們融合成一個更大的單核--就像氦。

This typically happens in a plasma, that is, a super hot soup of electrons and atomic nuclei,

這通常發生在等離子體中，也就是電子和原子核的超熱湯中。

where if it's hot enough every once in a while two nuclei bump hard enough into each

如果它足夠熱，每隔一段時間，兩個原子核就會狠狠地撞在一起。

other to fuse . But fusion can in principle happen in regular, non-plasma molecules, too

融合，但原則上核聚變也可以發生在普通的、非等離子體的分子中。但原則上，核聚變也可以發生在普通的非等離子體分子中。

- like the hydrogen molecule, in which two hydrogen nuclei are kept relatively near to

- 就像氫分子一樣，其中兩個氫核保持相對靠近

each other by sharing electrons . The nuclei don't stay separated a rigid distance apart,

彼此共享電子。核子之間的距離並不是固定的。

though - they vibrate and wiggle and every so often, they can, in principle, get close

不過，它們會震動和擺動，每隔一段時間，它們原則上可以接近

enough to fuse together.

夠融合在一起。

But with hydrogen - or nitrogen, or oxygen, or pretty much all other molecules - this

但是，對於氫氣，氮氣，氧氣，或者幾乎所有其他分子來說，這種

happens exceedingly rarely (which is why our atmosphere, which has a fair amount of molecules,

發生得極為罕見（這就是為什麼我們的大氣層，有相當多的分子。

isn't a giant fusion bomb).

是不是一個巨大的核聚變炸彈）。)

However, things are different if you replace the electrons with particles called muons,

然而，如果你把電子換成稱為μ子的粒子，情況就不同了。

which are basically exactly the same as electrons except 200 times heavier . Muons, being

基本上與電子完全一樣，只是重了200倍。 繆子，是

essentially heavy electrons, form atoms and molecules in almost the exact same way as

基本上是重電子，形成原子和分子的方式幾乎完全一樣。

electrons, but since they're heavier, their orbits are much closer to the nucleus than

電子，但因為它們更重，所以它們的軌道比核更接近

an electron with the same energy and angular momentum would be . And this means that atoms

同樣能量和角動量的電子將是 。這意味著原子

and molecules held together with muons instead of electrons are about 200 times smaller,

而用μ子而不是電子固定在一起的分子則小200倍左右。

and their nuclei are correspondingly about 200 times closer together.

而它們的原子核也相應地相距200倍左右。

And being closer together makes nuclei many many many times more likely to fuse together,

而距離較近，核子融合在一起的可能性就會增加很多很多倍。

so much so that hydrogen molecules made with muons can fuse together at temperatures much

以至於用μ子製造的氫分子可以在溫度高得多的情況下融合在一起。

lower than the core of the sun - even room temperature!!

比太陽核心還低--即使在室溫下!

Which was predicted in 1947 and experimentally achieved in 1956 . Physicists have even managed

這是1947年預言的，1956年實驗實現的 。物理學家甚至已經設法

to achieve muon-aided nuclear fusion at temperatures close to absolute zero.

以在接近絕對零度的溫度下實現μ子輔助核聚變。

So at this point, you're probably asking yourself: if room-temperature nuclear fusion

所以此時，你可能會問自己：如果室溫核聚變。

exists, why aren't we using it to power modern civilization?

存在，為什麼我們不利用它來推動現代文明？

Well, while muon-facilitated fusion is indeed fully legit nuclear fusion at non-crazy temperatures,

好吧，雖然μ子促進核聚變確實是在非瘋狂溫度下完全合法的核聚變。

there are some major problems which prevent it from being used as a power source.

有一些主要的問題使它不能作為電源使用。

First, muons don't live very long . Unlike electrons which have an in principle infinite lifespan,

首先，μ子的壽命不長 。不像電子原則上有無限的壽命。

after about 2 microseconds muons spontaneously decay

2微秒後μ子自發衰變

into an electron and some neutrinos, so if you're going to do anything with muons,

成電子和一些中微子，所以如果你要做任何事情與μ子，

you have to do it real quick!

你要做的是儘快！

This turns out not to matter much for the purposes of facilitating fusion, but because

事實證明，這對促進融合的目的並不太重要，但由於

of their short lifespan, there aren't a ton of muons around - so if you want a reliable

壽命很短，周圍沒有大量的μ子--所以如果你想獲得一個可靠的

supply of muons, you pretty much have to make them with a high energy particle accelerator

你幾乎必須用高能粒子加速器來製造它們

, which takes a lot of energy per muon - at best about 5 giga electron volts , or about 50

每一個μ子需要大量的能量 - 最好的約5吉電子伏特，或約50

times the E=mc^2 mass-energy of a muon itself.

乘以μ子本身的E=mc^2質能。

Now, luckily you don't need a muon for every single pair of hydrogen nuclei you want to

現在，幸運的是，你不需要一個μ子的每一個單一的氫核對，你想的。

fuse, because after a pair of nuclei fuses into helium the muon can go off and help more

因為一對原子核融合成氦後，μ子可以去幫助更多的

nuclei fuse …and then help more… and more… and more….

細胞核融合......然後幫助更多......更多......更多......更多......。

EXCEPT, every so often , the muon doesn't - it'll get stuck as part of the newly fused

但是，每隔一段時間，μ子就會被卡在新融合的部分

helium atom , and can't facilitate any additional fusing.

氦原子，並不能促進任何額外的融合。

This means that each muon only helps an average of 150- fusions of nuclei before it gets stuck

這意味著，每個μ子只能幫助平均150核融合之前，它被卡住了

. And since each fusion of nuclei releases about 18 mega electron volts of energy , this

.由於每一次核聚變都會釋放出大約18兆電子伏特的能量，所以這

means that, after 150 fusions, each muon facilitates an average of 2700 mega electron volts, or

意味著，在150次核聚變後，每個μ子平均促進2700兆電子伏特，或。

2.7 giga electron volts, of energy generation.

2.7吉電子伏特，產生的能量。

Which means that, unfortunately, the numbers don't add up - Remember it currently takes around

這意味著，不幸的是，這些數字並沒有加起來--請記住，目前需要大約5年的時間。

5 GeV of energy to produce a muon, but each muon only generates about two and a half GeV

5 GeV的能量來產生一個μ子，但每個μ子只產生大約2.5 GeV的能量

of energy before getting stuck to a nucleus.

的能量，才會卡在核上。

That is, muon-facilitated fusion is a net consumer of energy (rather than being a source

也就是說，μ子促進的核聚變是能量的淨消耗者（而不是能量的來源）。

of energy).

的能量）。)

This is the best case possible with current technology, and the numbers are still off

這是以目前的技術最好的情況，數字還是有偏差的。

by a factor of 2 before even reaching any sort of break-even where muon-facilitated

在達到任何形式的盈虧平衡之前，增加了2倍，而在這種盈虧平衡中，介於μ子促進的。

fusion could generate as much energy as it consumes.

核聚變產生的能量與消耗的能量一樣多。

And we'd need to be much better than just breaking even, energy-wise, to make a viable

而且我們需要做得更好，不僅僅是收支平衡，能源方面，使一個可行的。

commercial power plant.

商業發電廠。

Pretty much the only hope for muon-facilitated-fusion is to figure out how to make muons for less

幾乎是唯一的希望對於μ子促進核聚變 是想出如何製造μ子更少。

energy, or figure out how to have less of them stick to the helium nuclei, or how to

能量，或者想辦法讓它們少粘在氦核上，或者想辦法讓它們少粘在氦核上。

unstick them once they're stuck - which are all hard problems limited by the unchangeable

粘住了就解開--這都是受制於不可改變的硬問題。

physical properties of muons and nuclei, and so we've made quite slow progress in over

的物理性質，所以我們在超微子和核子的物理性質方面取得了相當緩慢的進展。

70 years of research.

70年的研究。

The summary is that muon-induced fusion exists, it's fascinating science, but it's not

綜上所述，μ子誘導核聚變是存在的，它是引人入勝的科學，但它不是

going to be powering the world any time soon.

很快就會成為世界的動力。

To dive deeper into the energy sources that DO power the world, I highly recommend checking

要深入瞭解那些為世界提供動力的能源，我強烈建議你查看

out the “Fuel the World” course on Brilliant.org, this video's sponsor.

在Brilliant.org的 "Fuel the World "課程中，本視頻的贊助商。

Fuel the world is part of their series on the “Physics of the everyday”, and guides

燃料世界是他們的 "日常物理學 "系列的一部分，並指導他們的工作。

you through the basics of solar power, fossil fuels, nuclear reactions, dyson spheres, and

通過太陽能、化石燃料、核反應、戴森球的基礎知識，以及

how much energy mammals need to survive.

哺乳動物需要多少能量才能生存。

There's even a section about the fusion reactions that happen in the sun!

甚至還有一節是關於發生在太陽上的核聚變反應!

And the “physics of the everyday” course as a whole gives a great overview of the physics

而 "日常物理 "這門課程從整體上對物理學進行了很好的概括。

of household items, sports, weather and climate, and more.

的生活用品、運動、天氣和氣候等。

And the first 200 people to go to Brilliant.org/minutephysics can get 20% off of a premium Brilliant subscription

而前200名進入Brilliant.org/minutephysics的人，可以獲得20%的Brilliant高級訂閱優惠。

with access to all of brilliant's courses and puzzles.

可以使用所有輝煌的課程和謎題。

Again, that's Brilliant.org/minutephysics which gets you 20% off premium access so you

同樣，那是Brilliant.org/minutephysics，可以讓你享受20%的高級訪問權，所以你可以...

can seriously hone your math and science skills, and it lets Brilliant know you came from here.

可以認真地磨練你的數學和科學技能，它讓Brilliant知道你來自這裡。