As part of their “What If?” series, Randall Munroe of xkcd and Henry Reich of MinutePhysics explained via animation what would happen if the Earth suddenly stopped rotating on its axis while the atmosphere remained unchanged. Essentially, the winds would be so catastrophic that nearly all life on Earth would be eradicated. And that’s just the start.
This is a question from Andrew, who asks: What would happen if the Earth and all terrestrial objects suddenly stopped spinning, but the atmosphere retained its velocity? Well, first nearly everyone would die. Then things would get interesting.
Those humans who work or hide underground would probably remain safe but completely disconnected from the outside world, the oceans would dissipate, and the length of a day would be completely redefined, although the moon would still follow its monthly cycles.
If the Earth stopped spinning completely, the normal cycle of day and night would end. The Sun wouldn’t completely stop moving across the sky, but it would slow down a lot. As the Earth’s orbit carried us around in a circle, we would see the Sun rise and set exactly once a year. Well, not exactly once a year.
Luckily, as terrifying as this is, it is all rhetorical. But for a single viewer with a question, we wouldn’t be thinking of this at all.
Remember, this is all Andrew’s fault. Before Andrew, the Earth’s tidal bulge created by the Moon’s gravity slowed down our rotation while dragging the Moon into a higher orbit. After Andrew stopped Earth’s rotation, the Moon’s gravity would tug on Earth and, very very very gradually, speed us up again just a little (while it slowed down), until eventually someone could again ask “what if the earth suddenly stopped rotating?”
