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Course: Big History Project > Unit 4
Lesson 1: Earth & the Formation of Our Solar System | 4.0- ACTIVITY: Planet Card Sort
- WATCH: Unit 4 Overview
- ACTIVITY: Unit 4 Vocab Tracking
- WATCH: Threshold 4 — Earth & Solar System
- ACTIVITY: Threshold Card —Threshold 4 Earth & the Solar System
- WATCH: How Did Earth and the Solar System Form?
- READ: How Our Solar System Formed
- READ: The Rocket Scientist - Mary Golda Ross: Graphic Biography
- READ: Gallery — Earth & Solar System
- Quiz: Earth & the Formation of Our Solar System
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WATCH: Unit 4 Overview
In the Unit 4 overview, Rachel Hansen gives us a preview of the topics covered in Our Solar System & Earth. It’s an astronomical reminder that human history goes back long before humans, and that without humans like Alfred Wegener, Marie Tharp, and Harry Hess, we might not value the interdisciplinary skills needed to understand our planet and big topics like plate tectonics! Like what you see? This video is part of a comprehensive social studies curriculum from OER Project, a family of free, online social studies courses. OER Project aims to empower teachers by offering free and fully supported social studies courses for middle- and high-school students. Your account is the key to accessing our standards-aligned courses that are designed with built-in supports like leveled readings, audio recordings of texts, video transcripts, and more. Register today at oerproject.com!
Website: https://www.oerproject.com/Big-History
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Twitter: https://www.twitter.com/oerproject/. Created by Big History Project.
Website: https://www.oerproject.com/Big-History
Facebook: https://www.facebook.com/OERProject
Twitter: https://www.twitter.com/oerproject/. Created by Big History Project.
Video transcript
Far out in the uncharted backwaters of the
unfashionable end of the western spiral arm of the Galaxy lies a small unregarded yellow sun. Orbiting
this at a distance of roughly 92 million miles is an utterly insignificant little blue green
planet whose ape-descended life forms are so amazingly primitive that they still think
digital watches are a pretty neat idea. Douglas Adams, The Hitchhiker's Guide to the Galaxy Yikes. If aliens are ever going to visit us we need better tourism marketing. I mean, come on, take a look at this it lights up how neat is that! [instrumental music] Hi, I'm Rachel Hansen. And this is Unit 4, our
solar system and earth. Our earth is a very, very small part of the universe, but it probably
seems familiar to you. You've been here your whole life, after all. But don't get too comfortable. What if I told you that the ground you stand on is constantly moving? What if I insisted that our homes, our nations our continents, everything rests uneasily on a surging sea of molten magma. You'd probably say, "Duh, Rachel. Plate tectonics. Everyone knows that." Congratulations you paid attention in your earth science class. But you also had several thousand years of collective
learning on your side. The meteorologists Alfred Wegener wasn't so lucky. He claimed that 300 million years ago all the continents were kind of smushed together and they've been drifting apart ever since. He used interdisciplinary evidence to support his theory, which you'll learn about in
this unit. But the world wasn't ready to listen. His colleagues mocked his theory. Most geologists
continued to believe that the continents were fixed in place and that the ocean floor was smooth. But 20 years later, a geologist named Harry Hammond Hess happened to be captaining an American warship
in World War II. His ship had new sonar technology that could locate enemy submarines. But Harry was a geologist at heart and he kept the sonar on continuously, creating a detailed map of the ocean floor. What he found was far from smooth. Valleys, trenches, and volcanoes surged beneath the
waters. By the end of the 1960s we understood that the earth's crust was divided into dozens of huge
plates. Drifting in on the molten mantle of the earth, causing earthquakes and eruptions, excavating
ocean trenches and raising mountain peaks. [instrumental music] Plate tectonics wasn't an accepted scientific
concept until the 1960s. Think about that. By the 1960s humans had nuclear weapons
capable of ending life on this planet, The Beatles were the most popular band in
the world. I mean, humans had been in space, we were about to set foot on the moon. And still, we didn't understand a fundamental part of our home. We didn't know how mountains were made. Stop me if this sounds familiar. Wegener built on the theories and collective learning of past generations. Other scientists had proposed something similar during the 19th century. And it took maps made by early
explorers, sailing across oceans before people began to notice that parts of the Americas
look like they fit together with Afro-Eurasia like puzzle pieces. And earlier thinkers, including
Leonardo DaVinci, often wondered why they found the fossils of sea creatures on the tops of high mountains. Plate tectonics tells us how mountains rise and continents move. It also reveals more about the earliest days of the solar system and the birth of our planet 4.56 billion years
ago. The molten core of our earth and the sea of super hot magma our thin crust of continents
and oceans moves around on are reminders of our planet's earliest days, and how ridiculously
lucky we are that life developed here at all. [instrumental music] In Unit 3, the universe got a whole lot brighter when stars lit up. It also got a lot more complex as some of those
stars died and released new chemical elements. We also crossed over two thresholds in the last unit. As the first stars formed and then as stars began to die, generating the intense heat and pressure
needed to create new elements and more complexity. We examined how scientists have dealt with
the complexity of all these elements by organizing them into this handy table that every
science teacher has hanging in their classroom. And we discovered how those elements are the building
blocks for everything in our lives, including us. [instrumental music] In Unit 4 we'll cross over a new threshold. You'll learn how new chemical elements came
together under the force of gravity to create new stars and planets, like our solar system and earth. That's all thanks to a process called accretion. Gravity pulls together space gases and clumps of
matter into a spinning disk. As this disk spins, its center gets hotter and hotter until gases fuse
together and light up a new star. But, since we now have heavier elements in matter in the disk
this matter crashes together and the force is so strong that these chunks get bigger and bigger
until they form planets that orbit around the star. The universe was over 9 billion years old by the
time enough space stuff had accumulated in our little slice of the milky way to form earth. And it took a while for earth to become a place that could support life. For the first few million years
pummeled the planet as fiery collisions combined with extreme radiation and heat to make
the early earth a lava death trap. Scientists call this lovely time the Hadean Eon, after the
Greek God of the underworld Hades. Luckily for us, and everything else on the
planet, Hades didn't stick around too long. But it did leave behind a lot of molten lava lying beneath the relatively
thin layer of rock your school sits on right now. That's the stuff that spews from the top of
volcanoes and moves the earth's crust around. We spend our entire lives, all of human history,
surfing on lava. Now there's a nice tourism slogan. We'll end this unit by discussing how
scholars like Wegener and others from different disciplines piece together the
origins of our planet and solar system. The plate tectonics developed by Wegener and
Hess is yet another example of the collective learning that helps us understand the history
of our planet and how it impacts our lives. How about "Earth: It's been surfs up for hundreds
of millions of years." Or, "Earth: so hot right now." Y'all, I think this is a real career opportunity
for me. Extraterrestrial Tourist Liaison I've got work to do. Posters to make. Bob, how
many more of these videos do we have to make? Six?!