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1,670 km/h at equator

What If Earth
Stopped Spinning?

Right now you're hurtling east at 1,670 km/h. Press the button to stop everything — and watch the consequences unfold, second by second.

1,670 km/h — the rotational speed at Earth's equator right now

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A World Transformed

You've witnessed 1 million years of consequences. Earth would become a tidally locked world — one side a scorched desert, the other a frozen void.

1,670
km/h wind speed at impact
12
phases of destruction
geological time

What Is This Interactive Experience?

This interactive physics timeline explores what would happen if Earth's rotation suddenly stopped. Using real astrophysical data and physics equations, each phase reveals the catastrophic — and ultimately fascinating — chain of events that would unfold from the very first second to a million years later.

Earth rotates at about 1,670 km/h (1,037 mph) at the equator — everything on the surface is moving at that speed right now. The atmosphere, the oceans, and every building on the planet are all in motion together. Remove that rotation instantly, and the results are almost beyond imagination.

How It Works

The timeline is divided into 12 phases, each with animated visualizations and physics explanations. You can autoplay the sequence or skip ahead using the progress bar. The color scheme shifts from cool blues (normal Earth) to fiery reds and oranges as catastrophe escalates — and finally to a cold, dark palette for the tidally locked future.

All physics are grounded in real science: the wind speed calculation uses conservation of momentum, tsunami heights are based on fluid dynamics models, and the magnetic field decay follows known magnetohydrodynamics principles.

Frequently Asked Questions

What would happen if Earth stopped spinning?

If Earth suddenly stopped spinning, the atmosphere and oceans would continue moving at around 1,670 km/h — creating supersonic winds that would flatten everything. Tsunamis would surge eastward as water kept moving, temperature extremes between day and night sides would intensify, the magnetic field would weaken over millennia, and eventually Earth would become tidally locked to the Sun — one side in eternal day, the other in eternal night.

Why does Earth rotate?

Earth rotates because of conservation of angular momentum from the solar nebula that formed our solar system 4.6 billion years ago. As the gas cloud collapsed under gravity, it spun faster — like a figure skater pulling in their arms — and this rotation was inherited by all the planets. Earth completes one full rotation roughly every 23 hours and 56 minutes (a sidereal day).

Is Earth slowing down?

Yes — Earth's rotation is very gradually slowing due to tidal friction caused by the Moon's gravity. The Moon pulls on Earth's oceanic tidal bulges, and the energy required draws from Earth's rotation. We lose about 1.4 milliseconds per century. Days were about 22 hours long 500 million years ago. In the far future — billions of years from now — Earth and Moon could become tidally locked to each other.

Related Experiences

Solar System Explorer · Gravity Playground · Size of Space

Last updated: March 2026 · whatifs.fun — Free interactive simulations & what-if explorations