BF2S Forums Brains in a Box- What would happen if the Earth stopped spinning?

CameronPoe wrote:

We would all go flying horizontally at a tremendous speed and probably all die.

Probably, but what would effect would gravity have?

Well let's see, the earth is about 25k miles in circumference and it makes that distance in 24 hours, so that comes out to about 1,000 miles per hour right? 1000(5280)t - 16t² = height above earth in feet at t time.

edit: minus air resistance and actual elevation and blah blah blah, it's rough here. I think that might push us out of orbit however.

NASA should definitely look into it as an alternative to the space shuttle.

You mean an instant full stop? Everything would roll across the floor, the gravity of earth is still the same as it depends on the mass not the rotation.

Gravity would even get higher - well, the "felt" gravity, because the centrifugal force "pushes" us the other way as long as the earth spins.

I actually figured this out once, nerd that I am, because someone made the claim on another forum I frequent that Earth would lose its gravity if it stopped spinning.  At first I called him an idiot because gravity is dependant upon mass.  But then I got to thinking that mass and energy are related by Einstein's famous E=mc^2.  Since Earth's rotation imparts upon it a certain rotational kinetic energy, I decided to calculate it and deduct the corresponding contribution of that energy from the pull we feel now.

I forget the exact figure, but the downward force exerted by a 1-N weight at sea level would have changed by something like a few yoctonewtons.  (That's an SI prefix, like kilo- or nano-, but in this case it's 10^-24.  By way of comparison, it's a micro-nano-nanonewton.)

If pressed, I could be convinced to figure it out again...

topal63 wrote:

Brains in a Box- What would happen if the Earth stopped spinning?

The days would be longer than usual.

Ding ding ding!
Winnar!

Because of inertia, everything not attached would fly east-wards. and die.

I fail to see the word "suddenly" used in the question. Maybe everyone else speaks a different sort of "English" than I do.

We would hit the floor with the face because of the inertia.

Mek-Stizzle wrote:

topal63 wrote:

I fail to see the word "suddenly" used in the question. Maybe everyone else speaks a different sort of "English" than I do.

Yeah. If the Earth slowed down slowly you wouldn't have none of that flying eastwards stuff, and then over a period of time you'd get tidal locking with the sun or something. Read my edit above about tidal locking

Yep. And, the side facing the moon would have its' tide height fixed due to gravitational attraction (of the moon) as well.

Weather patterns would definitely stagnate - compared to now. Growing seasons go bye bye. Though after a long time the side facing the sun would probably evolve to accommodate the stall - and the dark half would of course, more or less, die.

HollisHurlbut wrote:

Mek-Stizzle wrote:

Earth's rotation = 1700Km/h

Escape velocity = 11.2Km/s = 40320Km/h

I just got the figures from wiki.

Well, what Wiki didn't tell you is that "escape velocity" does not mean the same thing as "orbit."  The International Space Station is in orbit, and it travels considerably slower than 40,000 km/hour.  It takes about 90 minutes for the thing to travel once around Earth.  Fast, but not as fast as you're talking.  Then there's geosynchronous satellites that orbit Earth once a day.  Much, much slower that 40 Mm/hour.  (That's a big 'M' for mega, not a small 'm' for milli...)

Escape velocity is something different.  Escape velocity is the speed required to leave an object's gravity well.  If you wanted to shoot something at the Moon, you could get yourself a gun with a muzzle velocity of 40,321 km/hour and you'd get there, as long as you aimed properly.

I agree with you that escape velocity doesn't need to be attained to reach orbit, but the velocity of an orbiting object is irrelevant because it only has to maintain its orbit. Even to get to where they are, they would have to travel faster than what they are currently doing.

topal63 wrote:

Mek-Stizzle wrote:

topal63 wrote:

I fail to see the word "suddenly" used in the question. Maybe everyone else speaks a different sort of "English" than I do.

Yeah. If the Earth slowed down slowly you wouldn't have none of that flying eastwards stuff, and then over a period of time you'd get tidal locking with the sun or something. Read my edit above about tidal locking

Yep. And, the side facing the moon would have its' tide height fixed due to gravitational attraction (of the moon) as well.

Weather patterns would definitely stagnate - compared to now. Growing seasons go bye bye. Though after a long time the side facing the sun would probably evolve to accommodate the stall - and the dark half would of course, more or less, die.

I'd say the light side would ultimately overheat from radiation absorption into the ground and reradiating back into the atmosphere slowly - assuming it didn't stop with the pacific pointing towards the sun.

If it stops instantly then you can expect everything to move very quickly eastwards, everyone dies.

If you end up with one side of the Earth permanently facing the sun, the other side dies due to lack oh photosynthesis, the bit directly facing the sun gets probably too hot for life to exist. The only likely habitable bits are the bits where the sun is in perma evening/morning.

Weather systems will go crazy all over the world as the heating/cooling process that causes most weather will have been massively altered.

You'd find you weight something like 0.5% (I worked this out once but can't remember the exact numbers) more than you did due to the rotation around the Earth that used to be negating a little of your weight no longer does.

According to Superman movies it would make time stop. Don't believe Superman movies.

Last edited by PureFodder (2008-08-06 12:33:18)

HollisHurlbut wrote:

Flaming_Maniac wrote:

I agree with you that escape velocity doesn't need to be attained to reach orbit, but the velocity of an orbiting object is irrelevant because it only has to maintain its orbit. Even to get to where they are, they would have to travel faster than what they are currently doing.

Not at all.  If a rocket had the fuel capacity, it could lift a satellite to an orbit that required a velocity of 50 m/s by only accelerating to 50 m/s and holding that thrust until it reached its injection site.  It wouldn't be terribly efficient, but it is absolutely possible.

That was not my point and you know it.

Of course it doesn't matter what velocity it takes to get to orbit if there is any acceleration at all at or above 9.81 m/s up. You could go at 1 mph and get up there if you could maintain that acceleration. But escape velocity or velocity necessary to attain orbit assumes no acceleration, as if a bullet was fired out of a gun as you exemplified.