What impact would reversing the Earth's rotation have?

EatYouWell@lemmy.world to No Stupid Questions@lemmy.world – 97 points –

We just watched the Futurama episodes where alien cats stopped the Earth's rotation, and they fixed it by making it rotate in the opposite direction.

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Regardless of how fast or slow you reversed the direction. Pretty much every weather pattern and ocean current on the surface of the planet would be thrown into a massive calamity. The Corolis effect and momentum imparted to surface fluids around our rotating ball is a huge, huge deal with weather flow, like the "jet stream". It directs how storm systems (the flow of water that all life depends on) form and track and which typical track they take as the rotation of the earth is constantly deflecting them. There would be huge, unending storm systems as existing patterns now crashed head on into new ones, with storm fronts spanning entire continents. Even after the storms subsided and it settled into a new normal after 20, 30, maybe 50 years... agricultural breadbaskets would be either destroyed, completely inhospitable to their original crops, or stranded in drought. And human civilization would likely fall with them.

Lois Lane would be resurrected and unburied by rocks if there had been an earthquake caused by a nuclear strike shortly before this happened.

Didn't they make a documentary about this?

We all die, a lot us rapidly when the water keeps moving across the rock that just stopped and super tsunamis a good portion of the planet. The rest of us die slowly as the weather patterns are ruined for likely decades or centuries and we starve due to crop failures and the fact that the worldwide logistics we depend on is forever gone.

Edit: actually I thought some more, if it’s sudden then we’re all crushed by flying into the air into stuff at 1000 miles an hour when the rotation stops. If it’s gradual then we all starve since the weather is ruined

You forgot about air. If the planet suddenly rotates in the other direction, it would level everything, and the probably turn the planet into a molten marble from the friction.

I don't know. Couldn't it be gradual enough that we barely noticed the acceleration changes but still only take a couple of hours?

Randall Munroe made an xkcd about this. It's not on his website unfortunately, but someone else uploaded it. I would recommend using a adblocker though.

But OP asked a different question. Not what happens when earth stops spinning but what happens when earth spins in the other direction.

The answer is largely the same if you make the same assumptions though, just roughly twice as bad because not only does the earth stop and everything not attached goes yeet, but everything attached starts moving just as fast as you in the opposite direction

Time goes backwards and I get to eat that cake I had last week?

You had it last week it has to back in first

Imagine reversing every bathroom break you've had in your life. "Hang on I gotta run to the restroom and conjure up a poop from the sewer"

Imagine people casually walking into the restroom and then coming back out and running away in a sweaty panic with diarrhea

It changes the way stars appear to move for us. Astrology teachings would have to do a full 360 degree turn to retain their accuracy.

I can’t say this with any authority, but I think the biggest effect would be in weather patterns and the subsequent downstream effects of having different weather.

Nah, the biggest effect would be in every single thing at or above ground level being instantly shot eastward at somewhere between 0 and 1,000 miles per hour. After that the weather is pretty much irrelevant because anything that would experience it would be dead as shit.

Only if the rotation would stop immediately. A slow deceleration would not let that happen

But who cares about the obviously much more boring option?

I mean, people have survived all kinds of crazy shit, I'm confident that many would actually somehow survive.

At least anyone in space at that time

Ehm, good one... what would happen to all satellites and ISS? Would all that junk still spin in the same orbit or would it be flung out into space?

I think they would be going on with their business because gravity would be still the same. IANAP

I mean, sure, there will be some people on the lower end of that 0-1,000 MPH curve that are not in very close vicinity to any objects to splort against. Inupiat, Aleut, Sami, Yamalo-Nenets... anyone inside the arctic circle should be relatively fine, speed-wise.

The earth's magnetic field would probably 'follow' and change it's direction. But only a while later and very slowly. During the change, that would leave us without a magnetic field for some time. Then we have lots of cosmic rays hitting us, damaging some of the life on eath.

Only a change in rotational speed would be bad. If earth were to rotate in the opposite direction since the beginning it would behave just like today.

That was my thought. The only major change I could see happening (besides the cataclysmic events from the change) is the direction of sunrise/sunset.

Exactly

Proof: define Antarctica as North. Now earth is rotating in the other direction.

Need more info. Does the earth immediately stop spinning and start spinning in the opposite direction? Or does it gradually stop over an arbitrary amount of time and reverse directions? Haven't seen the episode....

In the episode it had stopped for a while first, then they slowly spun it up.

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I don’t really know but based on the answers here this is the disaster movie I need next

If it happened suddenly, there would be massive tidal waves on western coasts.

The sun would rise in the west and set in the east. Timezones would be backward. People in different areas would have oddly desynchronized sunlight exposure relative to the time on their clocks. For example, if this happened at sunset for you, the sun would rise first from the east and set in the west, then rise again from the west and set in the east. You'd be halfway through a double day at the moment of switching. Other people would have a double night.

Nothing. Only have to swap N-S poles and East becomes West. 💈 🧭

All the wind on the planet now blows to the opposite direction

Would somebody smarter than me take these seeds of an idea and expand on how the physical forces would affect the composition of the Earth? My intuition tells me the shear forces would obliterate the planet, but I'm not sure.

Because of the nature of a sphere, the material rotating at the poles is effectively not moving at all. Whereas the material moving at the equator is moving at the maximum rotational speed of the Earth.

Likewise the core of the Earth is effectively still and the speed of each strata moves correspondingly faster as you get closer to the surface.

Let's entertain a thought experiment here.

  1. The earth suddenly reverses rotation. Basically the entire surface of the earth is subjected to a massive reversal of force. The tidal waves would wash over most of the land we have everything would be wrenched asunder the crust of the earth would tear spilling magma into barren oceans.

  2. The earth slows down stops then starts spinning again. Gravity would become weaker and weaker one side of the earth would be perpetual night and the other side perpetual day the atmosphere would dissipate into space along with anything loose on the surface which includes all the water we have all life would perish. Slowly, as the earth starts to spin again gravity might pull some of its materials back down but hardly enough to make a difference. The earth would be a barren wasteland.

  3. The earth suddenly stops spinning. Everything on the surface of the earth including all its water and the atmosphere would be violently flung into outer space. All life would perish as our human corpses hurled at extreme speeds through our solar system.

😃

The earth slows down stops then starts spinning again. Gravity would become weaker and weaker one side of the earth would be perpetual night and the other side perpetual day the atmosphere would dissipate into space along with anything loose on the surface which includes all the water we have all life would perish. Slowly, as the earth starts to spin again gravity might pull some of its materials back down but hardly enough to make a difference. The earth would be a barren wasteland.

Why would gravity become weaker and things float off into space? Gravity has nothing to do with the earth spinning. It's a property of mass. The mass of the earth wouldn't change because it stops spinning.

Tides would stop. One side would heat up, the other side would cool down. The diurnal cycle of animals and plants would cause havoc, but the planet itself wouldn't have a huge issue. Everything on it, yes, but that's because the ecosystem is built around the flow around the planet, not because of the physical motion.

The planet has been slowly slowing down for millennia and will eventually stop.

So you're absolutely right. Full disclosure I have been sick the last week and on prescribed narcotic medication and in my opioid muddled mind a massive body needed to rotate to produce gravity.

It sounded cool in my head.