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Sometimes, it just feels like life would be easier if the days were a little longer. You'd have more time to spend with family or sleep or start another YouTube channel.
有时候，我们会感觉，如果一天不只是24小时，那生活或许更容易些。这样，我们就有更多的时间跟家人相聚、睡觉、看视频了。
But the next time you're wishing for a few more hours, you can be thankful you weren't around 1.4 billion years ago.
但下次大家想多睡一些时间睡觉的时候，不妨心存感激，想想14亿年前的人类。
Thanks to our good friend the Moon, days on Earth were around six hours shorter back then.
因为月球的存在，14亿年前的时候，每天只有18小时。
These results were published on Monday in the Proceedings of the National Academy of Sciences.
这个结果发表于周一发表在了《美国科学院论文集》上。
And while this is something we've known before, what's special is the model the researchers created to confirm it.
我们不是第一次知道这个结论，但这篇论文的特别之处在于研究人员证实该结论所用的模型。
It allows them to look deep into the early history of the solar system — and it could have a lot more to teach us.
这样的模型让研究人员得以深入研究太阳系的早期历史——能让我们了解很多。
Researchers are always trying to understand the processes that shaped the early Earth, and for good reasons.
研究人员一直都在试图了解地球初期的形成过程。
Besides helping us figure out our origin story, it can also help us understand other worlds in the solar system and beyond the solar system.
这不仅能帮助我们理解地球起源的来龙去脉，也能帮助我们了解太阳系里和系外空间的情况。
One way we can study the Earth's climate specifically is through processes called Milankovitch cycles.
通过一种途径，我们可以研究地球的气候，那就是通过米兰科维奇旋回的过程。
They track things like a planet's rotation rate, how it wobbles on its axis, and how tilted and circular its orbit is.
米兰科维奇旋回可以跟踪某颗行星的自转速率、其转轴偏离的方式、其轨道的倾斜角度及曲率。
All of those things affect how much direct sunlight a planet gets.
这些因素都会影响行星获取直射日照量。
And on Earth, these factors add up to produce a cycling of warming and cooling on a ten-thousand to one-million year time scale.
这些因素汇总起来，让地球在长达1万-100万年的时标里保持着冷热交替的循环状态。
To be clear, though, they do not mean climate change isn't also happening and that it isn't also caused by humans. Because it is.
不过这里要说明的是，这并不意味着气候变化没有发生，也不意味着气候变化不是人类造成的。因为气候变化确实存在，也确实是人类造成的。
Researchers can track Milankovitch cycles in the geologic record, in things like isotope ratios, rocks, and ice cores.
研究人员在地质记录中寻找米兰科维奇旋回的痕迹，地质记录包括但不限于同位素比、岩石和冰芯。
Still, these methods aren't very reliable for really old samples — especially those older than around 50 million years — so it's hard to look into the distant past.
不过，这样的方法不太适用于年代久远的样本——尤其是那些大概5000万年以前的样本——所以要了解远古的情况是很有难度的。
There's also a lot we don't know about Earth's orbit and its relationship to other planets from back then, so it's difficult to extrapolate climate cycles from that alone, too.
此外，我们对于很久以前地球的轨道及其跟其他行星间的关系也知之甚少，所以也很难仅凭样本推断出气候旋回情况。
That's where this new model came in. By combining geologic evidence with our knowledge of orbital mechanics, this team was able to bypass a lot of those limitations.
于是，这个新模型便应运而生了。将地质学发现与我们对轨道力学的所知结合在一起后，该研究小组就可以打破许多局限性了。
As a result, they got one of our clearest looks yet into the early solar system.
最后，他们得以得到了太阳系初期最为清楚的观测结果之一。
They used a technique broadly called Bayesian statistics or Bayesian inference, which is wildly important to modern science.
他们用了贝叶斯统计的方法，这个方法对于现代科学来说是非常重要的。
It's used in particle physics and hydrogeology and cell biology — you name it, you can Bayesify it.
这种方法目前应用到了粒子物理学、水文地质学以及细胞生物学中——可以说各个领域都可以使用贝叶斯统计法。
Basically, you start with some initial model, calibrate it to data, then update your model.
用这种方法，先要建立一个初始模型，将其校准到数据上，然后更新模型。
Over time, you get an increasingly precise and probable explanation for whatever phenomena you want to explain.
随着时间的流逝，就能得到一个准确度不断上升的结果，可以解释任何现象。
Kinda like the scientific method, but with statistics!
这个方法有点像科学方法，不同的是，会用到统计数据。
This new model covers things like the shape of Earth's orbit and its gravitational interactions with the planets out to Saturn.
这个新模型应用的领域有：地球轨道的形状、地球与其行星乃至土星的引力作用。
But it also gave a special focus to how the Moon affects Earth's climate and behavior.
该模型还尤其关注了月球影响地球气候和行为的方式。
Among other things, it showed that, thanks to the Moon, our days were a little under 19 hours long 1.4 billion years ago!
除此之外，该模型还显示：由于月球的存在，14亿年前的地球，每天只有不到19个小时的时间。
Admittedly, though, this isn't really surprising.
不过，需要指出的是，这个发现并不足为奇。
Thanks to evidence from ocean models, we've known for a while that interactions between Earth and the Moon have been steadily slowing our rotation rate.
根据我们从海洋模型中得到的证据，很久以前，我们就已经知道，地球与月球之间的作用一直在缓慢改变着自转速率。
But this new model was able to confirm that just using rock formations!
但这个新模型只依靠岩石组成便确认了这一点！
This helps show how well-calibrated it is for those distant time periods.
这也从侧面表明该模型在了解远古情况方面的校准度很高。
And it means we can apply it in ways we can't with other methods.
也就是说，其他方法做不到的事情，我们可以用这个模型来做到。
More data would make it even more accurate, but right now, it can reach back in time really well.
虽然数据越多，准确性就越高，但就现在而言，该模型深入了解远古时期的情况已经非常棒了。
Now, we can start using it to get a better understanding of Earth's early history and habitability, and the dynamics of the early solar system!
现在，我们开始通过该模型来更好地了解地球初期的情况、居住情况、早期太阳系的动力学情况。
Where would planetary science be without computers? Where would any of us be?
没有计算机，行星科学举步维艰，人类发展也无从谈起。
Meanwhile, on the other side of our little neighborhood, there's more news from Pluto!
下面聊聊我们的小邻居冥王星的新闻。
Because even though it's been almost three years since the New Horizons fly-by, we're still learning more about what a lot of people thought would be a boring dwarf planet.
因为虽然新视野号低空飞跃已经有3年的历史，但我们依然在不断了解更多有关冥王星的知识，这个在很多人眼中是一颗无聊矮行星的星体。
One of the major initial discoveries New Horizons made was that Pluto has an atmosphere.
新视野号的其中一个重大发现就是：冥王星是有大气层的。
And this led scientists — and all the rest of us nerds — to wonder whether the atmosphere had any effect on Pluto's topography.
这不免让科学家——以及我们这些吃瓜群众——好奇冥王星的大气层是否会对其地形产生影响。
Wind can erode rock into all kinds of neat shapes, and sculpt big ol' sand dunes like in the Sahara.
风可以通过腐蚀作用将岩石变成各种平整的形状，还可以鬼斧神工地创造出撒哈拉沙漠里的那种沙丘。
And now, thanks to an article published in Science last Friday, we know there are dunes on Pluto, too!
而如今，根据上周五《科学》杂志的一篇文章，我们知道冥王星上也是有沙丘的！
Except, of course, they're very different from the ones we've got here.
只不过，它的沙丘与地球的沙丘很不相同。
First, their composition is different. Earth's dunes are made of little particles of rock — mostly quartzy stuff.
首先是组成不同。地球的沙丘是由小的岩石颗粒组成的——基本上都是石英。
But Pluto's are made of methane. On Earth, methane is a gas — specifically, an odorless part of your fart gas.
但冥王星上的沙丘则是由甲烷组成的。地球上的甲烷是气态的——它是无色的，我们放屁时也会排出甲烷。
And also the natural gas that people frack for, if you want a different comparison. But come on. Fart dunes.
我们还会在生产生活中用到甲烷，这也算是另一个不同之处。但是这里说的气态沙丘哦。
Pluto is so cold that methane is solid there, and there's a whole bunch of it existing in little particles.
冥王星温度极低，所以甲烷都是固态的，并以细小颗粒的形式呈现。
Now, we know that they make up some lovely, ripply dunes on Sputnik Planitia, the west half of Pluto's heart.
现在，我们知道：固态甲烷组成了斯普特尼克平原上波纹状的可爱沙丘，形成了冥王星心脏的西半部。
These dunes also form differently from ours.
冥王星沙丘的组成也与地球上的沙丘不同。
The dwarf planet's atmosphere is a lot thinner than Earth's, so it can't carve out dunes just by whipping across the methane plains.
由于冥王星的大气层比地球的薄，所以单凭风力是无法在甲烷平原上形成沙丘的。
Instead, researchers think the process could be driven by day/night atmospheric cycles.
相反，科学家认为，形成沙丘的过程要依靠日间/夜间的气相型循环。
Just like water vapor in Earth's atmosphere condenses and freezes to form dew and frost, nitrogen gas in Pluto's atmosphere condenses and freezes at night.
正如地球大气层中的水蒸气会液化凝固以形成露水和霜一样，冥王星大气层的氮气在夜间的时候也会发生液化和固化作用。
Then, in the morning, it sublimates and turns back into gas.
等到早上的时候，又会升华为气体。
As it does, it could puff up a bunch of methane sand, which would get caught in Pluto's winds.
在这个过程中，氮气会形成甲烷沙，卷入风中。
And suddenly, you'd have 1001 Plutonian Nights. Or something.
突然之间，就发生了这般神奇的事情。
Another cool thing is that, based on their surface features, the authors of the paper could also tell that these dunes have formed recently.
还有一件事情让人惊奇：根据冥王星的地表特征，本文作者还可以推断出的是，这些沙丘是最近才形成的。
Or at least, within the past 500,000 years, which is very recent for objects like planets.
或者至少也是过去50万年间形成的，这对于行星这样的物体来说，已经是很短的时间了。
That means these processes may be going on right now on Pluto's surface!
这就是说，这样的进程可能正在冥王星表面进行着！
Which is way more dynamic and exciting than most people expected when New Horizons launched.
这比新视野号带给我们的兴奋还要更多。
And in case you were curious…
相信有人一定很感兴趣，那我来细讲一下……
Yes, they figured this out with the help of a model, too. Thanks again, computers.
没错！这个发现也是靠这个模型完成的。依然是在计算机的助力下完成的。
And thank YOU for watching this episode of SciShow Space.
感谢大家收看本期的《太空科学秀》。
If you want to celebrate your love of science with the whole universe, we've added to our finds on SciShowFinds.com.
如果您想与宇宙同庆您对科学的热爱，可以登录SciShowFinds.com来了解我们的新发现哦。
Just today we're adding fossilized Mesosaur Teeth and Ammonite Pairs.
就在今天，我们添加了中龙目牙齿的化石和菊石目化石。
As well as this "wandering womb" pin inspired by our SciShow video on Hysteria.
除此之外，还有受《太空科学秀》启发的“漫游的子宫”。
I'm also excited that we are adding more trilobite fossils, because we sold out of those, and more copies of the book that made me love geology:
让我兴奋的是，我们还添加了更多三叶虫化石的集锦，因为我们卖出了很多，还有很多书的副本让我热爱地质学。
The Story of Earth by Robert Hazen.
此外还有罗伯特·黑森的《地球故事》。
There's a bunch of good stuff on there right now that we love and have selected for you to check out.
这里还有很多我们热爱的好东西是为大家精心挑选的，等你们来看。
And just like last time, these are all available until we run out.
跟上次一样，售完为止哦！
So go to SciShowFinds.com to get your own celebratory artifact of our edgeless universe.
大家可以登录SciShowFinds.com来获取为无边宇宙制作的纪念品。
