The World Ends With a Tasteful Announcement

[Talraven]

I've given a lot of thought to this, but I've no actual scientific basis and it's hard to actually find people who would take me seriously about it. Anyway, I have a scenario with a question, if you'd be so kind as to spare some time for me...

Okay, it starts like this; the world doesn't end with a bang, or a disease. It just stops spinning. I know that there're a lot of reasons why this should be impossible, but say that it does happen. If the world just suddenly stopped spinning on its axis, would anyone actually notice? At least immediately, anyway. I mean, we barely feel it move as it is, and we only know that it does because of wind movement and velocity as well as the rise and set of the sun.

But if it just suddenly, gradually slowed down until it just stops moving at all, would anyone be able to tell for a few hours at least? I imagine the lurch of its arrest would result in tsunamis and probably tremors in certain parts of the earth, but is that at all logical or am I just being too imaginative?

What are your thoughts on this? What do you think would happen in such a situation? How long do you think we would be able to survive if something like this really happened?

 

[Crethox]

Correct me if I'm wrong but hasn't it been actually calculated already that Earth is spinning slower than a lot of years ago? The difference however is very small from what I remember, it's not like Earth would make a full stop or something.

 

[ZeoEmeraude]

I saw a show on Nat Geo about this topic once. I can't recall all of the detail but if the Earth did slow down to a creeping halt it would suck burnt bacon for us all. Without the tidal forces from the spinning, the oceans would eventually dry up...plant life would die, and days would become terribly long. (imagine no nights) Our internal clocks would go haywire, as we are more prone to sleep during nights. And if you were lucky or unlucky enough to be on the side of the planet that had no sunlight, food sources (those needing sunlight) would be non-existant. It would not be a very pleasant way for our species to go out.

 

[Talraven]

Correct me if I'm wrong but hasn't it been actually calculated already that Earth is spinning slower than a lot of years ago? The difference however is very small from what I remember, it's not like Earth would make a full stop or something.

I thought that was actually more of a theoretical thing rather than a definite scientific fact, but I'm not quite sure, either. Do you recall the reason as to why the Earth's rotation has slowed?

I saw a show on Nat Geo about this topic once. I can't recall all of the detail but if the Earth did slow down to a creeping halt it would suck burnt bacon for us all. Without the tidal forces from the spinning, the oceans would eventually dry up...plant life would die, and days would become terribly long. (imagine no nights) Our internal clocks would go haywire, as we are more prone to sleep during nights. And if you were lucky or unlucky enough to be on the side of the planet that had no sunlight, food sources (those needing sunlight) would be non-existant. It would not be a very pleasant way for our species to go out.

Why does Nat Geo never show these kinds of shows when I'm watching?! Anyway, sounds pretty logical. Do you happen to remember the title of the show? I'll try looking it up online and watch it myself.

 

[Crethox]

Sorry to say I can't remember much of it, it was some years ago in an article I read. But what I do remember is that one solar-day is in current time a fraction longer than thousands of years ago. At least in theory, not sure if proven.

And about that show Zeo mentioned, I saw that one too. Wasn't it part of a series about apocalyptic events?

 

[Peregrini]

What would happen if the Earth stopped spinning?
The probability for such an event is practically zero in the next few billion years. If the Earth stopped spinning suddenly, the atmosphere would still be in motion with the Earth's original 1100 mile per hour rotation speed at the equator. All of the land masses would be scoured clean of anything not attached to bedrock. This means rocks, topsoil, trees, buildings, your pet dog, and so on, would be swept away into the atmosphere.
If the process happened gradually over billions of years, the situation would be very different, and it is this possibility which is the most likely as the constant torquing of the Sun and Moon upon the Earth finally reaches it's conclusion. If the rotation period slowed to 1 rotation every 365 days a condition called 'sun synchronous', every spot in the Earth would have permanent daytime or nighttime all year long. This is similar to the situation on the Moon where for 2 weeks the front-side is illuminated by the Sun, and for 2 weeks the back side is illuminated. This situation for the Earth is not the condition of 'stopped' rotation, but it is as close as the laws of physics will let the Earth get.
If it stopped spinning completely...not even once every 365 days, you would get 1/2 year daylight and 1/2 year nightime. During daytime for 6 months, the surface temperature would depend on your latitude, being far hotter that it is now at the equator than at the poles where the light rays are more slanted and heating efficiency is lower. This long-term temperature gradient would alter the atmospheric wind circulation pattern so that the air would move from the equator to the poles rather than in wind systems parallel to the equator like they are now. The yearly change in the Sun's position in the sky would now be just its seasonal motion up and down the sky towards the south due to the orbit of the Earth and its axial tilt. As you moved along constant lines of Earth latitude, you would see the elevation of the Sun increase or decrease in the sky just as we now see the elevation of the Sun change from a single point on the Earth due to the Earth's daily rotation.
For example, if you were at a latitude of +24 degrees North in the Summer and at a longitude where the Sun was exactly overhead, it would slide gradually to the horizon as Fall approached, but since the Sun has moved 90 degrees in its orbit, it would now be due west. Then as we approach Winter, you would now be located on the dark side of the Earth, and would have to travel in longitude to a location 180 degrees around the Earth to see the Sun 1/2 way up the sky because in the Winter, the Sun is 48 degrees south of its summer location in the sky. It's a little confusing, but if you use a globe of the Earth and orient it the right way, you can see how all this works out.
As for other effects, presumably the magnetic field of the Earth is generated by a dynamo effect that involves its rotation. If the Earth stopped rotating, it's magnetic field would no longer be regenerated and it would decay away to some low, residual value due to the very small component which is 'fossilized' in its iron-rich rocks. There would be no more 'northern lights' and the Van Allen radiation belts would probably vanish, as would our protection from cosmic rays and other high-energy particles. This is a significant biohazard.
--------------------------------------------------------------------------------
Copyright 1997 Dr. Sten Odenwald
http://image.gsfc.nasa.gov/poetry/ask/q1168.html

This is interesting too.
http://www.esri.com/news/arcuser/0610/nospin.html

 

[Talraven]

Sorry to say I can't remember much of it, it was some years ago in an article I read. But what I do remember is that one solar-day is in current time a fraction longer than thousands of years ago. At least in theory, not sure if proven.

And about that show Zeo mentioned, I saw that one too. Wasn't it part of a series about apocalyptic events?

Ah, I see, alright, thanks for the info. And if that show is a series about apocalyptic event, does a scenario in which all life on Earth is gone sound familiar? Because I've been watching some glimpses of a series on Nat Geo that has something like that, but it's mostly about the aftereffects of a post-apocalyptic existence in which all human life has been wiped out completely, nothing about how or why as far as I can remember.

What would happen if the Earth stopped spinning?
The probability for such an event is practically zero in the next few billion years. If the Earth stopped spinning suddenly, the atmosphere would still be in motion with the Earth's original 1100 mile per hour rotation speed at the equator. All of the land masses would be scoured clean of anything not attached to bedrock. This means rocks, topsoil, trees, buildings, your pet dog, and so on, would be swept away into the atmosphere.
If the process happened gradually over billions of years, the situation would be very different, and it is this possibility which is the most likely as the constant torquing of the Sun and Moon upon the Earth finally reaches it's conclusion. If the rotation period slowed to 1 rotation every 365 days a condition called 'sun synchronous', every spot in the Earth would have permanent daytime or nighttime all year long. This is similar to the situation on the Moon where for 2 weeks the front-side is illuminated by the Sun, and for 2 weeks the back side is illuminated. This situation for the Earth is not the condition of 'stopped' rotation, but it is as close as the laws of physics will let the Earth get.
If it stopped spinning completely...not even once every 365 days, you would get 1/2 year daylight and 1/2 year nightime. During daytime for 6 months, the surface temperature would depend on your latitude, being far hotter that it is now at the equator than at the poles where the light rays are more slanted and heating efficiency is lower. This long-term temperature gradient would alter the atmospheric wind circulation pattern so that the air would move from the equator to the poles rather than in wind systems parallel to the equator like they are now. The yearly change in the Sun's position in the sky would now be just its seasonal motion up and down the sky towards the south due to the orbit of the Earth and its axial tilt. As you moved along constant lines of Earth latitude, you would see the elevation of the Sun increase or decrease in the sky just as we now see the elevation of the Sun change from a single point on the Earth due to the Earth's daily rotation.
For example, if you were at a latitude of +24 degrees North in the Summer and at a longitude where the Sun was exactly overhead, it would slide gradually to the horizon as Fall approached, but since the Sun has moved 90 degrees in its orbit, it would now be due west. Then as we approach Winter, you would now be located on the dark side of the Earth, and would have to travel in longitude to a location 180 degrees around the Earth to see the Sun 1/2 way up the sky because in the Winter, the Sun is 48 degrees south of its summer location in the sky. It's a little confusing, but if you use a globe of the Earth and orient it the right way, you can see how all this works out.
As for other effects, presumably the magnetic field of the Earth is generated by a dynamo effect that involves its rotation. If the Earth stopped rotating, it's magnetic field would no longer be regenerated and it would decay away to some low, residual value due to the very small component which is 'fossilized' in its iron-rich rocks. There would be no more 'northern lights' and the Van Allen radiation belts would probably vanish, as would our protection from cosmic rays and other high-energy particles. This is a significant biohazard.
--------------------------------------------------------------------------------
Copyright 1997 Dr. Sten Odenwald
http://image.gsfc.nasa.gov/poetry/ask/q1168.html

This is interesting too.
http://www.esri.com/news/arcuser/0610/nospin.html

Thanks for the links and explanation! This was highly informative! A bit complicated, though, I had to reread a few paragraphs before I actually registered everything. Anyway, it all makes it sound terribly dreadful, but increasingly impossible. I suppose we wouldn't last very long if the Earth somehow did stop rotating, too. Just another quick question, though; if the Earth stopped moving, would the gravitational pull of the planet be affected in any way?

 

[Peregrini]

The gravity of the Earth is dependent on its mass. If that doesn't change then the overall gravity won't change. As noted in the second link the spinning causes the elliptical shape of the earth and very slightly different gravity at the poles vs. the equator. That would even out if the Earth stopped spinning.
http://en.wikipedia.org/wiki/Gravity_of_Earth

 

[Talraven]

It says that the rotation of the Earth affects the net acceleration of a falling object, though, as in the stronger the inertia produced by the Earth's rotation, the slower the fall of an object. So if the Earth stopped rotating, falling objects would be slower than normal, wouldn't it?

Correct me if I'm wrong, 'cos most of the stuff are in equations and formulas and I'm absolutely terribly at those.

 

[Peregrini]

You're not wrong but the difference is minimal.

At latitudes nearer the Equator, the inertia produced by Earth's rotation is stronger than at polar latitudes. This counteracts the Earth's gravity to a small degree – up to a maximum of 0.3% at the Equator – reducing the downward acceleration of falling objects.

Basically an object falling at the poles at 100m/s would fall at 99.7m/s at the equator or if at 100m/s at the equator it would fall at 100.3m/s at the poles. If the earth wasn't spinning it would be 100m/s either place. That is if I have it right. There are others here who could give you a more detailed answer. Perhaps someone will.

The second major cause for the difference in gravity at different latitudes is that the Earth's equatorial bulge (itself also caused by inertia) causes objects at the Equator to be farther from the planet's centre than objects at the poles. Because the force due to gravitational attraction between two bodies (the Earth and the object being weighed) varies inversely with the square of the distance between them, an object at the Equator experiences a weaker gravitational pull than an object at the poles.

In combination, the equatorial bulge and the effects of the Earth's inertia mean that sea-level gravitational acceleration increases from about 9.780 m·s−2 at the Equator to about 9.832 m·s−2 at the poles, so an object will weigh about 0.5% more at the poles than at the Equator.[3][4]

The same two factors influence the direction of the effective gravity. Anywhere on Earth away from the Equator or poles, effective gravity points not exactly toward the centre of the Earth, but rather perpendicular to the surface of the geoid, which, due to the flattened shape of the Earth, is somewhat toward the opposite pole. About half of the deflection is due to inertia, and half because the extra mass around the Equator causes a change in the direction of the true gravitational force relative to what it would be on a spherical Earth.
http://en.wikipedia.org/wiki/Gravity_of_Earth