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  • 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. Without airplanes, pizza delivery,

  • or the Internet, things moved more slowly across the early earth than they do today.

  • For example, from isolated puddles of water, the oceans formed over the course of 400 to

  • 800 million years. That's how long it would take for your hair to grow around the earth

  • - twice. In that same time, bacterial life did spread across the watery globe. Higher

  • plants and animals, on the other hand, took much longer to develop and disperse. 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. We were much faster than our own hair, which would have

  • grown a meager 27km in the 180,000 years we took to cross Africa and reach all the unfrozen

  • continents.

  • 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. Wheat, for example, was domesticated around

  • 8500BC to make porridge. 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

  • 2500BC.

  • 6000km in 6000 years might seem like a blistering pace, but just wait for the Middle Ages! 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. In the 20th century, mania for both the Beatles and the Hula hoop raced

  • around the world in a year or two. Now even a year is a long time. With millions of people

  • jetsetting across the globe every day, diseases such as SARS can vacation almost anywhere

  • within a few short weeks. 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.

  • In short - the pace of travel on earth has really sped up!

  • But how do we know this stuff? How do we know what happened on earth before the records

  • of written history? Why do we think the earth is 4,500,000,000 years old? And what on earth

  • is going to happen in the next 45 years?

  • Welcome to the story of what we know about the earth and how we know that we know it.

  • This is MinuteEarth.

As far as we know, around 4,500 million years ago this rock that we live on coalesced from


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ミニットアース私たちの惑星の物語 (MinuteEarth: The Story of Our Planet)

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    ivanmis に公開 2021 年 01 月 14 日