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The earth spins once per day which means that if you live at the equator,
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the surface of the earth with you on it is moving around a thousand miles per hour to the east relative to the center of the Earth.
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Even at 45 degrees latitude, the Earth's surface is moving 700 miles per hour to the east.
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So it kind of seems like it should be faster for airplanes to fly west.
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I mean their destination is literally spinning towards them.
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At the same time, however, they're spinning away from their destination.
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When we say the earth is going a thousand miles per hour to the east,
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that means that the ground, and airplanes on the ground, and even the air above the ground are also moving a thousand miles per hour to the east.
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For an airplane to get anywhere, it has to start moving relative to the ground and through the air, at something like a hundred or so miles per hour.
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So when it flies east, it's actually moving a thousand plus a hundred mile an hour to the east.
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And when it flies west, it's actually moving a thousand minus a hundred miles an hour to the east.
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Yes! To go west, you go east just slower than the Earth is going east.
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Unless you're within 10 or so miles of the poles in which case a brisk westward walk will take you legitimately west.
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That said a plane do often take different amounts of time to fly the same route in different directions.
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Because of wind in the upper atmosphere like the jet stream that they either have at their tail or have to fly into.
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The prevailing direction of these winds is largely caused by the Coriolis effect,
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which is caused by the fact that different parts of the Earth are moving east at different speeds,
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which happens because the Earth is round and spinning.
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So airplane travel times are influenced by the rotation of the Earth, just not in a straightforward way.
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I highly recommend the book K2 by Ed Viesturs and David Roberts,
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about climbing the second highest mountain on Earth and all the human drama the successes and failures that have unfolded on its slopes.
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