Excerpted from Volcanoes Are Hot: Oliver’s Great Big Universe #2 by Jorge Cham. September 2024. Revealed with permission by Amulet Books, an imprint of ABRAMS.
Earth is lots like a boba tea drink.
You understand these boba tea drinks they promote in some retailers the place they shake it, however after they give it to you all of the various things in it have floated to a distinct spot within the cup? The ice floats to the highest, then the bits of fruit float beneath that, and the boba balls all fall to the underside?
Nicely, the identical factor occurred to Earth. Again when it was an enormous ball of lava billions of years in the past, all of the various things in it floated to a distinct stage. The lighter rocks floated to the highest, the heavier rocks floated just under that, and all of the metallic stuff sank to the underside.
Earth is spherical, kind of, so when the heavy stuff sank, it went to the middle of Earth, and when the lighter stuff floated, it went to the outer a part of Earth.
That makes the within of Earth appear like what occurs while you reduce an avocado or a hard-boiled egg in half, and you may see all of the layers.
I instructed my aunt somebody ought to make an avocado and egg boba tea drink, and she or he stated that positively wouldn’t assist my lavatory scenario.
My aunt says in the event you tried to dig a gap to the opposite aspect of Earth, that is what would occur: First, you’d dig by way of unfastened stuff, like dust or sand. It is perhaps just a little, or it is perhaps as a lot as a complete soccer discipline of it (about 0.1 kilometers).
You then’d hit the primary layer of rock.
The dust and the layer of rock are referred to as the crust. That’s as a result of it’s . . . crusty. It’s largely made from rock that’s additional brittle, or crumbly. It’s 5 to 70 kilometers thick, which appears like lots, but it surely’s fairly skinny in comparison with the entire Earth. It’s about as thick as an eggshell is to its egg.
Then the second layer you must dig by way of known as the mantle. This one is made from heavier rocks, and it’s fairly thick. You’d must dig by way of 2,800 kilometers to get by way of it.
The mantle is the place lava comes from. That’s the place it will get shaped as magma, earlier than it shoots up by way of the cracks within the crust. If you happen to’re ever digging by way of the mantle, you higher hope you don’t by accident dig into some magma.
Then after the mantle is Earth’s core. This can be a massive ball in the midst of the planet that’s largely made from a metallic referred to as iron. The primary 2,200 kilometers of it’s referred to as the outer core, and it’s oozy and melted, which implies you’ll be able to’t dig by way of it. And within the middle is a stable metallic ball referred to as the interior core, which is 2,450 kilometers extensive.
So in the event you tried to dig to the opposite aspect of the world, it could take you a very long time, you may hit some magma, and also you’d must swim by way of liquid metallic and reduce by way of cast-iron.
Not solely that, my aunt stated it’s SUPER HOT inside Earth. It’s nonetheless sort of sizzling from when Earth was an enormous ball of lava, AND there’s lots of radioactive stuff inside Earth, which heats up the rock and metallic.
The floor of Earth is sweet and funky as a result of we’re near house, which is admittedly chilly. However contained in the mantle, the temperature is 3,500°C, and the core is 6,000°C. That’s fairly sizzling if you consider the truth that the floor of the solar can also be about 6,000°C.
There’s additionally lots of stress inside Earth. That’s from all of the rock and metallic making an attempt to squish collectively due to gravity’s pull. If you happen to had been to dig down that deep, you’d get squished right into a pulp fairly fast.
Talking of stress, I nonetheless needed to go to the lavatory.
Jorge Cham is the bestselling, Emmy Award–nominated creator of . . . many issues: from the hit PBS present Elinor Wonders Why to the hit nonfiction e-book for adults referred to as We Have No Concept, together with the hit podcast Daniel & Jorge Clarify the Universe and the favored webcomic PHD Comics. He’s, undoubtedly, an skilled on explaining issues in regards to the world in fascinating and enjoyable methods. He obtained his PhD in robotics from Stanford College and was an teacher and analysis affiliate at Caltech from 2003 to 2005. He’s initially from Panama.
