As far as we know, around 4,500 million years ago, this rock that we live on coalesced from the dust and debris left over from the formation of our sun.
据我们了解，我们脚下的这片土地（地球）是在 45 亿年前由太阳成型时残留的灰尘和残骸所构成的。
Without airplanes, pizza delivery, or the Internet, things moved more slowly across the early earth than they do today.
没有飞机，披萨外卖，互联网，相比现在，早期时地球上万物都移动得缓慢。
For example, from isolated puddles of water, the oceans formed over the course of 400 to 800 million years.
例如，从孤立的水坑开始，海洋用了 4 到 8 亿年的时间形成。
That's how long it would take for your hair to grow around the earth, twice.
那就是你头发长到可以绕地球两圈时所要花的时间。
In that same time, bacterial life did spread across the watery globe.
与此同时，细菌生命在全球水体中传播开来。
Higher plants and animals, on the other hand, took much longer to develop and disperse.
另一方面，高型植物和动物花费了更长时间进化和扩散。
But we're going to skip those 3 billion years (during which your hair would have grown to the moon) and talk about us, Homo sapiens.
我们将要跳过这三十亿年 (一段你的头发长到月球所花费的时间) 来讨论我们自己，现代人。
We were much faster than our own hair, which would have grown a meager 27 km in the 180,000 years we took to cross Africa and reach all the unfrozen continents.
相较于头发，我们本身进化得更快，毕竟头发长到 27 千米长要花 18 万年，而这段时间，人类已经穿越非洲，并抵达了所有不结冰的大洲。
In many of these places, we were able to develop useful practices like agriculture, but because we were scattered across the globe, the best ideas and tastiest regional foods could only gain ground through trade or human migration.
在很多地方，我们都发展了有用的实践，例如农业，但因人们分居各方，无论是好的想法还是美味特产，只能通过贸易和移民普及。
Wheat, for example, was domesticated around 8500 BC to make porridge.
例如小麦，约在公元前 8500 年被人们培育，用来做粥。
Actually, some speculate it might have been for beer, but either way, wheat made it from the Fertile Crescent to both the Atlantic and the Pacific by roughly 2500 BC. 6000 km in 6000 years might seem like a blistering pace, but just wait for the Middle Ages!
实际上有人猜测可能是为了做啤酒，但无论如何，约在公元前 2500 年，小麦已经从新月沃土传播到了大西洋和太平洋地区。6000 年行进了 6000 千米，看起来速度很快，但来看看中世纪！
The bubonic plague and the printing press each spread across Europe in less than a hundred years, bringing death and literacy to the populace before their hair could have even grown 15 meters.
黑死病的爆发和印刷机的发展都在不到 100 年的时间里传遍了整个欧洲，给人类带来了死亡和文明，而这段时间，头发只能长 15 米。
In the 20th century, mania for both the Beatles and the Hula hoop raced around the world in a year or two.
在 20 世纪，披头士和呼啦圈的狂热在一两年间便传遍了整个世界。
Now even a year is a long time.
而现在，一年都算是很长的一段时间。
With millions of people jet setting across the globe every day, diseases such as SARS can vacation almost anywhere within a few short weeks.
每天有上百万人乘坐飞机环游世界，像 SARS 这样的疾病几乎可以在短短数周内传播到任何地方。
And the 0s and 1s that make up this video take, on average, less than a tenth of a second to get to you – that's about half a nanometer, or two atoms, of hair growth.
而 0 和 1（的代码，指二进制）组成了这个视频，传播到每个人的时间平均不到十分之一秒，这段时间里，头发只生长了半纳米或两个原子的长度。
In short, the pace of travel on earth has really sped up!
长话短说，这个世界的确在加速！
But how do we know this stuff?
但是我们怎么知道的呢？
How do we know what happened on earth before the records of written history?
我们怎么知道历史未被记录之前世界上发生的事呢？
Why do we think the earth is 4,500,000,000 years old?
我们是怎么知道地球有 45 亿岁年龄的呢？
And what on earth is going to happen in the next 45 years?
而在接下来的 45 年里，到底会发生什么呢？
Welcome to the story of what we know about the earth and how we know that we know it.
欢迎来到我们所了解的地球的故事，我们也会分享获悉这些知识的过程。
This is MinuteEarth.
这里是《分钟地球》。
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