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What Would Happen if the Earth Started Spinning in the Other Direction?



We can’t feel it, but we’re happily spinning through space on this globe we call the Earth at about 1000 mph at the equator. From above, Earth is turning counterclockwise in a prograde motion, which means the planet moves west to east relative to the stars. This is how we’ve moved since the Earth first formed...but what if, like Venus, the Earth spun in the opposite direction? Would anything change?

1. As sure as the sun rises in the west.
The first thing you would notice would be the opposite patterns of the movements of the Sun, Moon, and the stars. Instead of rising in the east and setting in the west, they would all rise in the west and set in the east. Seasons wouldn’t be affected much since presumably the speed of rotation would remain the same.



2. Wind patterns would change.
The Earth has some pretty set wind patterns that result from the Earth’s spin. These winds would change direction, blowing eastward rather than west. So, rather than having “westerlies” (weather patterns), these storm systems would be opposite. Also, instead of moving from east to west, hurricanes would travel from west to east across the ocean.



3. Winter temperatures in the North Atlantic could drop, and deserts might shrink.
Because of these weather patterns, certain climates would change. In Europe, winds blowing across Russia would bring colder winter temperatures, and the rest of the North Atlantic could drop in temp by about 10 degrees. Rain patterns would also change as a result of the new weather systems, bringing more rainfall to deserts and a greater abundance of plant life.
 
Sep 2, 2020
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I was looking for some info about this and unfortunately, there are no theories that might be interesting or at least plausible, so I decided to provide your post with my own. I suppose if the Earth started spinning in the other direction, we would observe the sunrise and sunset from different sides, but I do not think that the forest would grow on the places of the desert as well as the ocean would not be formed instead of a forest.
 
Jun 1, 2020
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Also, the Moon would begin slowly migrating inward until it impacted the Earth.

And, the brighter early-morning meteor showers would be less bright.
 
Nov 20, 2020
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Right now the celestial objects take East-South-West Path. If the direction of spin changes, will it be West-North-East Path?

If the it doesn't change, when is a W-N-E path possible?
 
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Reversing Earth’s spin would be like reversing the clock, thus the objects would simply appear to go backward along the same path (ecliptic).
 
Nov 2, 2020
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In the second point you said that the wind patterns would change, and I agree. All of your speech in your second point is understandable, but I have read, I don't remember where, when the Earth begin to spin in the other side, the wind will change in some horrible very high rate wind ( the speed would be about 1000 Km/s) that is able to destroy the whole human kind. I don't know why this wind is taken in account, maybe because of the inclination of the thinker (the person that said this, maybe it is refearred to the phase in which the Earth changes rotation...).

Also, the Moon would begin slowly migrating inward until it impacted the Earth.
Why? Why would the moon have to hit our ground?
 
Jun 1, 2020
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I don't remember where, when the Earth begin to spin in the other side, the wind will change in some horrible very high rate wind ( the speed would be about 1000 Km/s) that is able to destroy the whole human kind. I don't know why this wind is taken in account, maybe because of the inclination of the thinker (the person that said this, maybe it is refearred to the phase in which the Earth changes rotation...).
I would expect this view is assuming a more sudden stop. If in a car and the brakes are slammed, what happens? Whatever is lose is “thrown forward”. Actually this phrase is a bit in error since it is more that the car is thrown in a reversing direction and all the lose stuff simply keeps going - right into the windshield. This is simple momentum.

The atmosphere is a huge mass and if you suddenly stopped the Earth it would also simply keep going. It would take some time for the friction to slow it down. The speed would depend on the latitude, of course. Only near the equator would such a sudden stop produce a wind speed near 1000mph.

But all this depends on what caused the Earth to stop. In GR, it was predicted that a rotating mass would also have rotating space time around it as well (i.e. frame dragging). This was verified by space probes (Planck probe, IIRC). But what if the slowing of Earth was due to something slowing the spacetime frame around Earth. Perhaps all things would experience nothin unusual except a longer day time. I really don’t know, admittedly.

Ignoring frame dragging, if the Earth slowed slowly, over many hours, not seconds, then such a slow deceleration rate might not be all that noticeable as far as people falling down, oceans sloshing or winds going wild.

Why? Why would the moon have to hit our ground?
Yeah, this is that something that humans started suspecting off and on, especially with Copernicus and others, but not made universal until Newton, namely action at a distance (gravity).

When a moon orbits a planet that is rotating faster than the moon’s orbit, the gravity of the two will pull the moon in the direction the planet is rotating. This is true with our Moon.

So, if a moon is orbiting a non-rotating planet, the planet will drag the moon backwards, slowing its orbital speed, which causes it to slide closer and closer to the planet. That, of course, will eventually cause a huge impact.
 
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The speed would depend on the latitude, of course.
I didn't take in account this, maybe who lives in a poles, doesn't even realize it!

The atmosphere is a huge mass and if you suddenly stopped the Earth it would also simply keep going.
Just for this reason I said it. When you are in a boat, I'm speaking of a boat only because it was one of the Galilei's most famous experiments, and you are running in a costant speed, it is alright. When you stop your run suddenty, you will go ahead. The example of the car is correct and it was the same of the boat, I only wanted to make another comparison. If you are on Earth, and suddently the atmosphere is pushed, your feet are on the ground but the body in the atmosphere, and you will follow the atmosphere. For this reason there could be this patterns of wind, only because of the second principle of the dynamic.

When a moon orbits a planet that is rotating faster than the moon’s orbit, the gravity of the two will pull the moon in the direction the planet is rotating. This is true with our Moon.
I didn't know it, thanks!
 
Nov 20, 2020
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Just so that we are clear - with the anti-clockwise spin of the earth all celestial objects appear to rise on East, travel South and set on West.

If earth starts to spin clockwise, will these objects rise in West, travel North and set in East?

If clockwise spin doesn't make this happen, what else can make it?
 
Jun 1, 2020
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Just so that we are clear - with the anti-clockwise spin of the earth all celestial objects appear to rise on East, travel South and set on West.

If earth starts to spin clockwise, will these objects rise in West, travel North and set in East?
Yes, but it's really either East to West or, if a great magic wand spins us in reverse, West to East. Whether an object moves north or south from when it comes over the horizon depends on the Earth's axial tilt (seasonal circumstance) and one's latitude.

If clockwise spin doesn't make this happen, what else can make it?
Nothing unless you mean from one spot that includes mirrors and such. Either the Earth spins or the universe spins. There is no other imaginable solution I can think would work.
 
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How is the Roche Limit affected when bodies are of more comparable size?
Great question because the answer is surprising, at least for me.

The Roche limit varies as the cube root of the mass ratio. But the mass is a function of the volume, which varies as the cube of the radius. And, of course, the cube root of a cube makes no difference at all. :)

However, the density of a massive object will certainly be greater than say a comet. If we, say, double the density of the secondary we will reduce the Roche limit by about 1/3.

Here is the equation at Wiki
 
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Mar 5, 2020
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The Coriolis Effect would reverse for the different hemispheres. Hurricanes and typhoons would go in opposite directions. Currents and prevailing winds would be disrupted, reversed or eliminated.

Sara Rayne would become a household curse for jinxing us.
 
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Feb 18, 2020
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Great question because the answer is surprising, at least for me.

The Roche limit varies as the cube root of the mass ratio. But the mass is a function of the volume, which varies as the cube of the radius. And, of course, the cube root of a cube makes no difference at all. :)

However, the density of a massive object will certainly be greater than say a comet. If we, say, double the density of the secondary we will reduce the Roche limit by about 1/3.

Here is the equation at Wiki
BUT . . . . . . see also Earth's Moon Destined to Disintegrate | Space

Don't worry - 5 billion years to go Cat :)
 
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Feb 18, 2020
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Great question because the answer is surprising, at least for me.

The Roche limit varies as the cube root of the mass ratio. But the mass is a function of the volume, which varies as the cube of the radius. And, of course, the cube root of a cube makes no difference at all. :)

However, the density of a massive object will certainly be greater than say a comet. If we, say, double the density of the secondary we will reduce the Roche limit by about 1/3.

Here is the equation at Wiki
Your Wiki equation gives:

"This does not depend on the size of the objects, but on the ratio of densities."

(Of course there are several caveats)
 
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Jun 1, 2020
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Your Wiki equation gives:

"This does not depend on the size of the objects, but on the ratio of densities."

(Of course there are several caveats)
Thanks.

FWIW, I have an Excel file with perhaps 40 or so tabs. I find so many topics interesting enough to pick the ones I think I can wrestle down in the math. So the easy ones are in the tabs. :) The Roche limit is one of those.

The variable cell I highlight in green so I can jump into it even a year from now and get answers (yellow highlight) quickly.

By working through the math in the tabs, I learn more about what the math is saying. The Roche limit, for instance, is the distance from the centers, but we often are more interested in what the distance is from the surface (altitude), so I provide two answers to allow for this.
 

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