Faster Rotation And It's Effect On Civilization..

[Spacescifi]

If Earth's rotation suddenly sped up, what is the max rate of spin it could have and still support life and how would that effect life?

 

My guess is that at the maximum you may get what seems to be a stiff breeze, purely from the Earth spinning faster than the air overhead.

At unlivable rotation speeds it would be like a global hurricane that would wreck all but some sea creatures that do not depend so much on what happens on the surface.

[sevenperforce]

9 minutes ago, Spacescifi said:

If Earth's rotation suddenly sped up, what is the max rate of spin it could have and still support life and how would that effect life?

A more-rapidly rotating planet will tend to become progressively more oblate. The increased distance to the center of the Earth and the increased centrifugal force at the equator combine to have progressively lower and lower effective gravity at the equator. That's about the only change.

9 minutes ago, Spacescifi said:

My guess is that at the maximum you may get what seems to be a stiff breeze, purely from the Earth spinning faster than the air overhead.

At unlivable rotation speeds it would be like a global hurricane that would wreck all but some sea creatures that do not depend so much on what happens on the surface.

My dude, the atmosphere rotates with the Earth.

[Spacescifi]

1 hour ago, sevenperforce said:

A more-rapidly rotating planet will tend to become progressively more oblate. The increased distance to the center of the Earth and the increased centrifugal force at the equator combine to have progressively lower and lower effective gravity at the equator. That's about the only change.

My dude, the atmosphere rotates with the Earth.

 

True... I just assumed because air moves in all sorts of directions but yeah that makes sense.

So in other words it would be a boon for space rocket launch?

Nice!

 

On the other hand the day/night cycle would seem wonky... not unlike it is for the ISS with who orbit every 90 minutws.

Some have said the magnetic field may be effected too from increased spin.

 

I do not know about earthquakes... but maybe.

 

[mikegarrison]

Note that the effect of being in a rotating reference frame does have an impact on wind patterns. The coriolis forces do impact weather.

[Spacescifi]

44 minutes ago, mikegarrison said:

Note that the effect of being in a rotating reference frame does have an impact on wind patterns. The coriolis forces do impact weather.

 

Just in from google since you mentioned weather being effected by a faster rotation speed. In short... we would not have a civilization beyond any structure that can survive hurricanes and underground bunkers.

 

If the Earth spun faster, hurricanes would be stronger because the rotation would push winds further eastward and would make the effects of hurricanes more severe as they would spin faster and have more energy in them.

_{Sep 17, 2022}

 

 

https://www.popsci.com/earth-spin-faster/

 

Edited November 4, 2022 by Spacescifi

[kerbiloid]

5 hours ago, sevenperforce said:

the atmosphere rotates with the Earth.

Oops, I was sure it doesn't, and that's why the wind blows.

[mikegarrison]

The wind blows because the sun warms up the atmosphere, which drives pressure differences between day and night.

[Scotius]

Fun fact: Back in the Mesozoic era, day was only 23 hours long. It didn't seem to have much effect on fauna and flora. As for disastrous hurricanes, distribution of land and sea plays huge effect too. Hurricane can't really spun up if it doesn't have large expanse of warm water to draw energy from.

[magnemoe]

2 hours ago, mikegarrison said:

The wind blows because the sun warms up the atmosphere, which drives pressure differences between day and night.

Who is correct however wind moving north or south are affected by the coriolis effect that is why you get rotating weather systems. 

[RCgothic]

A steady state faster spinning earth wouldn't be too different. Apparent gravity at the equator would be lower, earth would be more oblate, and coriolis effects on wind and weather would be higher, and the natural cycles of lifeforms would be different. Possibly magnetic field would be stronger.

An *accelerating* earth however would likely come with  a lot of very not-fun mantle effects that could range from increased volcanic activity through total destruction of the crust.

[kerbiloid]

4 hours ago, mikegarrison said:

The wind blows because the sun warms up the atmosphere, which drives pressure differences between day and night.

Ah, the solar wind...

[Beamer]

Centripetal force on a mass m is m times angular velocity (w) squared times radius (r). Gravity pull from earth on a mass m is the gravitational constant (G) times m times the mass of the earth (M) divided by the square of the radius. The absolute maximum is the point where centripetal force is bigger than the force of gravity, so m*w^2*r > G*m*M/r^2 or simplified w^2 > GM/r^3. For the earth if you work that out, it is at about 1.25 * 10^-3 radians per second, so 1.99 * 10^-4 full rotations per second, or 1 full rotation per 5027 seconds (84 minutes). At that point the centripetal force on the equator would balance with the force of gravity and stuff starts getting flung off.

Now this is assuming the ideal situation of a perfect sphere, which it isn't of course, as mentioned the earth would bulge at the equator increasing the centripetal force there. But long before that point you would get tremendous earth quakes and volcanic activity and floods and what not (imagine the way the oceans would slosh around and the difference between high and low tide when the water is effectively only pulled down by 1/10th the force it is now).

But in any case, that would be the absolute maximum rotation speed for the earth, any faster than that and there would definitely be no earth.

 

[kerbiloid]

Due to the centrifugal forces, the continental platforms will gather at the equator into a single supercontinental landmass (like Pangaea).

Unlike the terrestrial supercontinents of the past, this equatorial supercontinent will be held together by the centrifugal forces, so unlikely it will be able to split and redistribute uniformly around the planet.

This landmass will be blocking the warm equatorial ocean currents. 
It will be large, so the average distance from the coastline will be great, and the climate of its most part will be continental, with very cold winters and droughts.
Actually it will be mostly a frozen desert, with warmer areas at the coastline.

The ocean and the seas will be shallow, the new landmasses will be attracted to it, the ocean bottom will be young.

The circumpolar air currencies will be existing, as their existence doesn't depend on the landmass, it's an air mechanics.

Due to the climate and to the limited area of habitable zone, the evolution will run slowly, the life conditions wil be bad, so unlikely sapient lifeforms will have enough time to appear before the geological processes get finished.

Bad, bad rotating planet.