If the planet simply came to a grinding halt billions would be dead in seconds.
The first thing that would happen is millions of people would smash into walls and buildings at the almost twice the speed of sound and be turned into mush.
The earth at the equator rotates at about 1000mph (1,600 km/h) eastwards – though it slows towards the poles.
If the earth suddenly stopped spinning everything not tied down – including people - would keep on moving eastwards at up to 1000mph relative to the ground. If the planet’s revolution actually reversed it would be even worse meaning people would hit static objects at almost 2,000mph.
Anyone who survived that horror would then face 1000 mph super-hurricane force winds – far stronger than anything ever experienced - which would likely reduce every human structure from New York skyscrapers to Egypt’s pyramids to ruins.
And again billions would be killed.
The earth’s rotation and friction with the ground mitigates much of the force of the planet’s winds – but if the globe stopped spinning an onslaught would ensue.
Life on Earth would be in really bad shape.
The word’s Coriolis effect – which governs weather patterns and oceanic currents – and causes winds at the equator to blow toward the west (opposite the direction of the earth’s spin at the equator) would be reversed too.
BBC meteorogist Peter Gibbs has worked through this thought experiment.
He concluded the reversal of the Coriolis effect together with the famous tradewinds would see jungles become deserts and vice versa.
He said: "Patterns of human discovery, subsequent empire-building and the resulting political geography would all be different.
"It's reasonable to assume that a reversal would alter the pattern of habitable land."
Oddly, although the Earth has never stopped spinning it has spun a great deal faster.
Luhman said: “Our planet has almost certainly always spun in its current direction but the speed of the spin has changed dramatically over time.
"When the Earth was born, it was probably spinning about once every six hours, so the length of a day would have been only about six hours back then."