(单词翻译:单击)
This episode is sponsored by Blinkist.
本期内容由Blinkist赞助。
Blinkist takes all of the need-to-know information from thousands of nonfiction books and condenses it down into just 15 minutes.
Blinkist从成千上万的非小说类书籍中提取所有需要知道的信息，并将其压缩到15分钟内。
Go to Blinkist.com/SciShowSpace to learn more.
访问Blinkist.com/SciShowSpace了解更多信息。
By now, you’ve probably seen some news articles announcing the discovery of a parallel universe where time runs backwards.
目前为止，你可能看到过一些新闻，宣布人类发现了一个时间倒流的平行宇宙。
I’m sorry to say we have discovered no such thing.
很遗憾，这个消息并不是真的。
But let’s look at what the research behind that announcement was really all about, and how the story got so twisted.
但是让我们来看看这个声明背后的研究到底是什么，以及它是如何被曲解的。
The whole thing started a few years ago, when a radio telescope known as ANITA made two really weird detections.
整个事情开始于几年前，当时一架叫做安妮塔的电波望远镜发现了两件非常奇怪的事情。
ANITA sits in a balloon over Antarctica, and its job is to detect high-energy particles called cosmic rays that rain down from space.
“安妮塔”位于南极洲上空的一个气球里，它的任务是探测来自太空的被称为宇宙射线的高能粒子。
It does that by picking up radio pulses that get emitted when cosmic rays interact with Antarctic ice or the atmosphere.
它是通过接收宇宙射线与南极冰层或大气相互作用时发射的无线电脉冲来实现这一点的。
But between 2016 and 2018, ANITA detected something strange.
但在2016年至2018年间，安妮塔发现了一些奇怪的事情。
It picked up two signals that looked like they’d been triggered by neutrinos, which are a type of cosmic ray, but weirdly, they were coming up from the ground, instead of down from space.
它接收到两种看起来像是由中微子触发的信号，中微子是一种宇宙射线，但奇怪的是，它们是从地面向上而不是从太空向下发射出来的。
Now, because neutrinos are so small and have no charge, they can travel straight through a lot of matter without interacting with it.
因为中微子非常小而且不带电荷，它们可以直接穿过很多物质而不与它们相互作用。
So the idea that they’d originally come from space and traveled all the way through the Earth wasn’t inconceivable, but there was one problem.
因此，认为它们最初来自太空并穿越地球的想法并非不可思议，但有一个问题。
By working back from the detections, the scientists working on the project found that the neutrinos that produced those signals must have had a ton of energy.
通过对探测结果的分析，参与该项目的科学家们发现，产生这些信号的中微子一定有大量的能量。
And according to the Standard Model, which is basically all the math behind our current understanding of particle physics, neutrinos with higher energies are more likely to interact with matter.
根据“标准模型”，也就是我们目前对粒子物理学理解的基本数学原理，高能量的中微子更有可能与物质相互作用。
So the Earth should have absorbed these neutrinos before they reached the surface.
所以地球应该在这些中微子到达地面之前就已经把它们吸收了。
If the detections were real, that could overturn the Standard Model and everything we thought we knew about the subatomic world.
如果探测结果是真实的，那将推翻标准模型以及我们对亚原子世界的所有认知。
Because even though neutrino interactions are just one part of the Standard Model, it’s kind of like a Jenga tower: Pull out one piece of math, or one piece of evidence, and the whole thing comes crashing down.
因为即使中微子的相互作用只是标准模型的一部分，它有点像叠叠塔：去掉一部分数学，或去掉一个证据，整个东西就会崩塌。
But the Standard Model has held up to a lot of tests, so the authors weren’t so quick to suggest it was wrong.
但是标准模型已经经受了很多次测试，所以作者并没有迅速指出它是错误的。
As another possibility, they suggested that maybe a bunch of neutrinos had come from a really strong, focused source, like a massive supernova.
作为另一种可能，他们提出，也许是一束中微子来自一个非常强大的、聚焦的来源，比如一个巨大的超新星。
Because even though no single neutrino with that much energy is likely to pass through Earth, if you had enough of them,
因为即使单个中微子没有那么大的能量穿过地球，但如果中微子数量足够多，
then the odds are a little better that at least a few might make it all the way through.
那么至少有几个能通过地球的可能性就会大一些。
Still kind of a long shot, but if the idea was right, we wouldn’t have to completely redo all of particle physics.
这个猜测依然比较大胆，但如果它是正确的，我们就不需要重新研究所有的粒子物理学。
But before the team even had a chance to investigate that possibility, another paper, published in 2018,
但该团队还没来得及调查这种可能性，2018年发表的另一篇论文提出，
suggested that something else could explain those weird detections, and it was also a long shot: a thing called the CPT-symmetric universe.
有其他东西可以解释这些奇怪的探测结果，而且可能性也不大：一种叫做CPT对称宇宙的东西。
CPT stands for “charge, parity, and time,” and CPT symmetry means that the laws of physics should hold if all the particles in the universe flipped their charges and spacetime were a mirror-image of itself.
CPT代表“电荷、宇称和时间”，CPT对称意味着，如果宇宙中所有的粒子都翻转了它们的电荷，而时空是自身的镜像，那么物理定律应该成立。
But it’s purely hypothetical.
但这纯粹是假设。
All it says is that, if all you consider is the math, it’s hypothetically possible to have a universe that’s full of antimatter where time moves backward.
它只是说，如果你只考虑数学，假设宇宙中充满反物质，时间会向后移动，这是可能的。
And the scientists suggesting that these cosmic rays might have come from a CPT-symmetric universe weren’t saying that it was a sure thing or even a likely thing.
科学家们认为这些宇宙射线或许来自于CPT对称的宇宙，但他们并没有说这是确定无疑的，甚至是可能的。
They were just saying that the math checks out, and that if a CPT-symmetric universe exists, it would have particles that behave the opposite of particles we’re familiar with.
他们只是说数学检验出来了，如果存在一个CPT对称的宇宙，它会有一些与我们熟悉的粒子相反的粒子。
And they suggest that one of those particles could potentially, potentially, explain these upward-moving cosmic rays.
他们认为这些粒子中的某一个或许可以解释这些向上移动的宇宙射线。
So, at this point, scientists had a weird observation and three possible explanations that all seemed unlikely:
因此，在这一点上，科学家有一个奇怪的观察和三种可能的解释，但它们似乎都不太可能:
Either our understanding of particle physics is fundamentally flawed, or this super-energetic supernova event sent some cosmic rays all the way through the Earth,
要么是我们对粒子物理学的理解存在根本性的缺陷，要么是这个超高能量的超新星事件让一些宇宙射线穿过了地球，
or there’s a parallel universe that’s a mirror image of ours.
要么是存在一个与我们平行的宇宙，它是我们的镜像。
Earlier this year, scientists ruled out the supernova explanation, because data from a second cosmic ray detector in Antarctica failed to find evidence backing up that scenario.
今年早些时候，科学家们排除了超新星的解释，因为来自南极的第二个宇宙射线探测器的数据未能找到支持这一假设的证据。
They suggested that maybe the observations had just been an error, or maybe they were a sign of some weird physics.
他们认为，也许这些观测只是一个错误，或者它们是某种奇怪物理现象的征兆。
But the explanation could also be something no one has thought of yet.
但是，也许是人们还没有想到它的原理。
Unfortunately, when reporters covered that paper, some of them highlighted the CPT explanation, and then other outlets went running with that angle.
不幸的是，当记者们报道那篇论文时，有些人强调了CPT这种解释，于是其他的媒体也开始纷纷效仿。
In reality, there’s still no answer to the mystery, but there’s also no evidence for a parallel, mirror universe.
事实上，这个谜仍然没有答案，但也没有证据表明存在平行的镜像宇宙。
Thanks for watching this episode of SciShow Space News!
感谢收看本期太空科学秀!
Even though so far there’s no evidence of a parallel universe where time runs backwards, if you want to learn more about the strange nature of time, you could check out the book “The Order of Time” on Blinkist.
尽管目前还没有证据表明存在时间倒流的平行宇宙，但如果你想了解更多关于时间的奇怪性质，你可以看看Blinkist网站上的《时间的顺序》一书。
Blinkist highlights the most important insights and need-to-know information from nonfiction books and condenses them down to 15 minutes.
Blinkist强调了非小说类书籍中最重要的见解和需要了解的信息，并将其压缩到15分钟。
So if you don’t have time to sit down with an entire book, you can still find time to develop yourself.
所以，即便你没时间坐下来读完整本书，也可以提升自己。
Whether you’re interested in self-help, business, science, history, or something else, you can find what you like on Blinkist, which has over 3000 titles in its library.
无论你对自助、商业、科学、历史还是他东西感兴趣，都可以在Blinkist上找到你喜欢的东西，它的图书馆里有3000多种书籍。
And in 15 minutes, you can give any one of them a read or a listen.
在15分钟内，你可以读或听其中的任何一本。
There are currently 12 million users on Blinkist, and you can sign up too at Blinkist.com/SciShowSpace.
目前Blinkist上有1200万用户，你也可以去Blinkist.com/SciShowSpace注册。
You’ll get free unlimited access for a week if you’re one of the first 100 people to sign up, and you’ll get 25% off if you decide to get a full membership.
如果你是前100名注册人之一，你将获得一个星期的免费无限制访问，如果你想成为正式会员，可以获得25%的折扣。
