Earth's Crystalline Center

While in in the past we thought of the earth's core as fairly homogeneous, it's now clear that the solid center of the earth is an aggregation of crystals.

Scientists now think they know why seismic waves traveling between the Earth's poles move faster than those traveling east-west. It has to do with the way that the iron alloys at the planet's core have crystallized. While in in the past we thought of the earth's core as fairly homogeneous, it's now clear that the way the core is set up is a little more complicated. "The center of the earth is literally a crystal," said David Stephenson, a geologist at CalTech. Over time, the crystal grew, and now it is an aggregate of them.

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Sponsored
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Politics & Current Affairs
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Strange Maps
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Photo by CHARLY TRIBALLEAU / AFP/ Getty Images
Mind & Brain

MIT News

The big day has come: You are taking your road test to get your driver's license. As you start your mom's car with a stern-faced evaluator in the passenger seat, you know you'll need to be alert but not so excited that you make mistakes. Even if you are simultaneously sleep-deprived and full of nervous energy, you need your brain to moderate your level of arousal so that you do your best.

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