字幕列表 影片播放 列印英文字幕 Our planet is an amazing place … but there are parts of it that no one has ever seen! Like where? Like in the middle! No one has ever been to the center of the Earth, not even close! The deepest hole that's ever been dug didn't even make it through the thinnest, outer layer of Earth's four amazing layers. But even if you could go deeper than that, you'd have a really hard time digging! Because those inner layers of the Earth get really hot! So today, we're going to get as close as we can to seeing the center of the Earth, by building a model of our planet! First, let's go through what we know about Earth's four main layers. The first layer is the one you're on right now! It's called the crust. The crust is the outermost layer of our planet, and it includes all of the land you can see … as well as the land that you can't see, like the very bottom of the ocean. The crust is also the thinnest of Earth's layers. But even so, we've never been able to dig all the way through it! The crust is nice and cool on the outside, but once you dig down a kilometer or so, it starts to get really warm really fast. And the deeper you go, the hotter it gets! By the time you reach the bottom of the crust, it's too hot for anything to live in! Now, after the crust comes the second layer: the mantle. It's the thickest of all of Earth's layers. This layer is so hot that the rocks that make up the mantle are actually melted! But we're not done yet! The third layer is the outer core, and beneath that, at the very center of the Earth, is the fourth layer, the inner core, the hottest of all the layers! Now that we know each of the Earth's layers, we can make a model of our planet, from the inside out! All you'll need is a bunch of different colors of art clay. You can use whatever colors you like. But I'm going to use red, orange, yellow, brown, green, and blue. Each layer in our model is going to have its own color, so we can tell them apart. Now, what kind of temperature do you think of when you think of the color red? I think hot! So let's use red for the hottest layer, the inner core. Orange doesn't seem as hot to me, but it does seem warmer than yellow, so we'll use orange for the outer core. Then let's use yellow for the mantle, and brown for the coolest layer, the crust. But what about the green and blue? We can use these colors to make the continents and the oceans, that is, the big masses of land and water, they're parts of the crust, too. Ok, so, let's start with our innermost layer, the inner core. We'll take some red clay and roll it into a ball between our hands. [Music Playing] Once we have our inner core, let's take some orange clay and wrap that around the red ball. [Music Playing] Our Earth is growing! And the outer core is... almost done. There! Next, we'll put on a layer of yellow, which will be our mantle. Do you remember what's special about this layer? The mantle is the thickest of Earth's layers! So let's add a little bit of extra yellow to make sure it's nice and thick. [Music Playing] This looks great! Now we'll cover the mantle with brown, for our crust. The crust is the thinnest layer, so we won't use as much clay for that. [Music Playing] There we go! We got the crust done! But we still have the blue and green left over to make continents and oceans. You can shape the continents to make them look like they do on your globe, or you can make them look however you like. It's your model after all! [Music Playing] This looks great! But now that our model of Earth is done, we can't see the layers inside. So let's ask a grown-up for help, because I have an idea! Ask them to find a butterknife and very carefully cut your globe in half. [Music Playing] Ooooo! Look at that! You can see all of the layers. On the outside is the crust, second is the big yellow mantle, next is the outer core, and finally the very middle is the inner core. [Squeaks squeaking] That's right Squeaks, it does look really cool! But there are lots of other ways you can make your own Earth! You can try making Earth's layers with colored construction paper. Or if you want to take a more delicious route, you and a grown up can make a four-layered cake, with each layer colored to represent a layer of the Earth! Get creative and have fun! Thank you for joining Squeaks and me to create the Earth from the inside out, and we'd like to give a big thank you to Google Making Science for helping us make this episode! Do you have a globe you want to share with us? Or do you have more questions about Earth? We'd love to hear from you! Just grab a grown-up and leave us a comment down below, or send us an e-mail to firstname.lastname@example.org. And we'll see you next time!