2006-09-21 06:23:28 · 24 answers · asked by crackles2005 1 in Science & Mathematics ➔ Astronomy & Space
No, as the rotational moment of the planet is far too high.
2006-09-21 06:25:44 · answer #1 · answered by 'Dr Greene' 7 · 1⤊ 2⤋
I'm going to have to go against the majority here, because the majority is entirely wrong. Here's why:
The momentum of the Earth is not being replenished by an outside source. If we take means to slow it down - ANY MEANS AT ALL - and we continue to do it long enough, then OBVIOUSLY we can stop the Earth from spinning if we want to.
That, however, is the rub: doing it long enough. The momentum of the Earth is so massive that even the constant friction from the tides have only slowed its spin by a few hours in the last billion years or so... and if that's any consolation, eventually the tides WILL stop the spin of the Earth. But if you can wait long enough, you don't even have to use jet engines. ANYTHING that uses the friction of the ground accelerates or decelerates the spin of the Earth.
The hard part is doing it only monodirectionally. If your car slows the spin by accelerating (it's pushing off the ground, you know), it also increases the spin by decelerating or turning (as it's using the ground to stop). Your jet engines would apply force to the ground, but some of it would be countered as some of the back blast of the engine pushed against the ground behind it. But at least your engines aren't almost zero-sum game, like the car.
For that matter, why waste your time with expensive engines? Just use explosives. A properly directional blast will probably do much the same thing. You might get even more ooph by firing masses into space with your explosives - not only will the push be against the Earth initially, but you know that most of the counter-momentum won't come back to interfere with your spin-stopping if you can launch it at escape velocity. This is not as far-fetched as it may seem... guns have been built which can fire projectiles hundreds of miles, and they have certainly been tried for the purposes of rocketry almost from the beginning.
Even so you're going to require a lot of patience. But one thing I've learned from human history is that a bunch of determined humans can often accomplish what scoffers would write off as impossible! Good luck!
2006-09-21 07:15:44 · answer #2 · answered by Doctor Why 7 · 1⤊ 1⤋
Fermi knows whereof he speaks!
Basically, the answer is, in theory, yes, but you would need a heck of a lot of engines and a pretty long time. So, in practice, no.
The engines would have to put out enough of a blast so that the weight and speed of the air they were blasting out would total up to the weight and speed of the rocks of the earth spinning in the opposite direction. When the engines blast equaled the spinning force of the whole turning earth, then you would stop. But, OK, that isnt really possible, right?
2006-09-21 08:25:53 · answer #3 · answered by matt 7 · 0⤊ 1⤋
No
Conservation of momentum makes this impossible. The only way around this is to transfer angular momentum to something off the Earth but jet engines just move bits of the earth around.
2006-09-21 09:28:46 · answer #4 · answered by m.paley 3 · 0⤊ 0⤋
No. It would be like trying to lift yourself by pulling up on your belt.
All the forces that the jet engines put on the earth would be exactly balanced by the forces on the air shooting out the back.
2006-09-21 08:56:45 · answer #5 · answered by Demiurge42 7 · 0⤊ 0⤋
Yes. You may have to run them for lot many years.
It is a small thrust. But applying that small thrust till it stops you achieve zero spinning.
You can calculate the time required to stop spinning with a given thrust.
2006-09-21 10:07:00 · answer #6 · answered by Dr M 5 · 0⤊ 0⤋
no the source of the opposing force, ie the jet engines, would be too close to the pivotal point of rotation, ie the centre of the earth.
If you think of the concept of easing the force needed to unbolt a nut but using a longer handle spanner, you should get the point.
2006-09-21 06:32:18 · answer #7 · answered by Anonymous · 0⤊ 0⤋
no the earth spins at a massive rate, we just dont feel it. no number of jets could do it
2006-09-21 06:35:07 · answer #8 · answered by Alan B 2 · 0⤊ 0⤋
Only if everyone on the planet jumped up in the air at the exact same time........and exhaled.........while patting themselves on the head while moving their other hand in a circular motion near their bellies.
2006-09-21 06:34:04 · answer #9 · answered by genenj1 2 · 0⤊ 0⤋
NO. Could an asteroid stop it? Can an earthquake followed by a sunami stop it?
Too silly!
2006-09-21 06:32:17 · answer #10 · answered by Anonymous · 0⤊ 0⤋
certainly not if they were pointing in the same way the earth was spinning!
2006-09-21 06:28:32 · answer #11 · answered by Anonymous · 0⤊ 0⤋