Earth's Rotation

[diskiller]

Heh. I've had this funny idea lately, so I come on here to post about it and i'm reading about "towing" venus out to 1 AU and "pulling" mars back in to 1 AU. It makes my idea sound less crazy <img src="/images/icons/wink.gif" /><br /><br />Anyway. How feasible would it be to alter the speed of earth's rotation? ie. to change the length of a day?<br /><br />How much energy/effort would be required to alter it (say slow it down) by 1 second a day? 2 seconds? 30? A minute, or hour, or 6 hours? Is it even remotely feasible to undertake such a huge project, or is there no hope whatsoever?<br /><br />Or would the only possible way was to direct huge asteroids to pass by earth picking up momentum and slowing down earth? (simliar to the way we do with satellite to give them a boost when heading out to the outer planets?)<br /><br />I'm just curious i guess. As for mars and venus, you can't just "tow" it, its orbit around the sun needs to be reduced or increased in the way orbits around the earth are changed... so you can't, eg, attach a BigAss Rocket of DOOM on venus and face it at the sun and fire away... you need to actually increase its speed around the sun (thus fire it in the direction its moving to speed it) which will actually cause it's orbit to go out further and SLOW down. (i have that right i think?).<br /><br />Hm. Not sure why i'm answering that here, just rambling. Think i might go now. <img src="/images/icons/wink.gif" />

 

[lewcos]

I've thought about slowing/speeding the rotation with big fans - lots of them. <br /><br />I thought it would be the perfect way to make nuclear weapons ineffective - if you change the rotation while the missles are in the air - they will miss their targets when they land - you only need to change the rotation slightly to make them miss their targets. <br /><br />With GPS though - I'm not positive it would work.

 

[diskiller]

I imagine it would take DECADES to make even a several second change in earth's rotation, so not something you can do i a couple minutes while an ICBM nuke is inflight...<br /><br />Still, a very interesting idea! But would spinning fans work??? I was under the impression you need to lose or gain mass or have some external effect to alter the rotation... can you just do that? Or would that just shift our atmosphere around and make no difference to the rotation?<br /><br />I just want more than 24hrs in a day, dammit! <img src="/images/icons/wink.gif" />

 

[steve01]

Slowing the Earth when ICBM's are inbound would only make WW3 more desirable- as the missiles missed major cities and infrastructures only humans would be destroyed in the insuing fallout. Wouldn't America's enemies love to move into fully functional structures once the radiation levels were at tolerable levels !!!

 

[thalion]

A (very) large mass-driver could do the trick, if it were aimed in a direction that would speed up or slow down the Earth's rotation. But it would still take a while.

 

[rogers_buck]

You could slow the earth by pumping the oil out of the ground and into the atmosphere as polution...<br /><br />But, what you really want to do is tumble the earth pole over pole while leaving the rotation fixed. That way there would be no winter, just spring everywhere. Of course most of the world would be under water.<br />

 

[siarad]

I recall back in the 1970's the earth's rotation being changed by excessive weather conditions, whereby the high winds altered the length of the year by a second I think. I recall we stopped the clocks for 2 seconds to correct this & other accumulated errors. I agree to move Mars to 1AU would mean reducing it's speed & likewise Venus would have to be sped up.

 

[silylene old]

We could just have everyone run to the west, and not stop (trans-oceanic bridges required). The friction would spin the earth faster, like a hamster in a treadwheel. <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[diskiller]

A ha! So the solution would be to absolutely pulverise the moon (sent some antimatter up there? <img src="/images/icons/wink.gif" />) into chunks and let them go out into space.... and then earth, having lost that orbiting mass, would slow its rotation down accordingly?<br /><br />Still, i'm just wondering if there are any realistic ways we could slow down earth. We can't exactly throw large chunks off the earth into space.<br /><br /> <br />

 

[oscarb44]

Why the smeg would you want to slow the Earth's rotation anyway??? Big freaking deal if you have a longer day. The human life span is a finite time. If you have longer days....you just live fewer of them. A better question would be how to slow down the passage of time.

 

[heyscottie]

Actually, the moon does serve to slow the Earth's rotation. Get rid of the moon, and you get rid of the only object capable of slowing us! Removing the moon would possibly cause us to have more polar wander, but our rotation speed would remain constant.<br /><br />Tidal interractions with the moon slow our rotation. Billions of years from now, our day will be about 45 current days (about 1000 hours) long.

 

[mcbethcg]

Move mass from the poles to the equator to slow the planet down, and vice versa to speed it up. The ice skater effect.<br /><br />Of course, I don't think that the planet could structurally accept too much mass piled in any one area- the surface of the earth would sag there, keeping the overal structure fairly spherical. The inverse happens if you try to create too big a hole, too. Its why impact craters from meteors, anywhere in the solar system can be hundreds of miles wide, but never very deep, comparitively.

 

[siarad]

Surely if you believe gravity runs parallel to light then the sun will slow the earths rotation, pulling as it does 8.3 minutes of time, 20 arc seconds, behind the centre of gravity. I'm yet to be convinced the speed of gravity equals light though.

 

[siarad]

The metric system did just that with 20 hours in a day & 10 days in a week but the peasants revolted over the longer working week & shorter time off each day. I think one hangover is the French continuance of 400 degrees in a circle.

 

[CalliArcale]

<blockquote><font class="small">In reply to:</font><hr /><p>Of course, I don't think that the planet could structurally accept too much mass piled in any one area- the surface of the earth would sag there, keeping the overal structure fairly spherical.<p><hr /></p></p></blockquote><br /><br />You're absolutely right -- the Earth would sag. In fact, the enormous bulk of Mauna Kea and the rest of the Hawaiian chain of islands and seamounts is so great that the Earth's crust <i>does</i> sag under it! This further lowers the altitude of Mauna Kea's peak, making it's height even more impressive. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[silylene old]

Since we all know the Earth is hollow <img src="/images/icons/smile.gif" /> ....(remember the long thread on this before the server crash?) I suggest we pull the plug and drain the Pacific Ocean into the hollow shell. Then the rotation rate will slow dramatically, just like trying to spin a raw egg!<br /><br />*hehe* <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[siarad]

Na that would speed it up surely <img src="/images/icons/wink.gif" />

 

[silylene old]

unless the water sloshes !<br /><br />(maybe internal baffles would be desirable) <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[heyscottie]

I don't know what you are all talking about. Superman had no trouble slowing down Earth's rotation. He even REVERSED it (which had the fortunate by-product of reversing time so Lois Lane wouldn't be dead any more). Anyway, the answer is simple: we just have to ask Superman to take care of it.

 

[bobvanx]

From a Google on reserviors and rotation:<br /><br />Benjamin Fong Chao, a geophysicist at the Goddard Flight Center. Changes in the Earth's spin are measured in terms of length of days. A faster spin shortens the length of daylight. "Due to the reservoir effect," said Chao, "the day 40 years ago was longer than today by about 8 millionths of a second." More significant, he said, is the fact that the sporadic spacing of water reservoirs has changed the Earth's axis. Since 1940, water impoundment has pushed the axis of rotation about 60 centimeters away from the North Pole toward western Canada, he said.

 

[mcbethcg]

Can gyroscopes be used to alter the earths rotational speed? Physics folks?

 

[bobvanx]

I'm guessing you've held a spinning bicycle wheel and used it to feel the forces of precession acting on your arms.<br /><br />Suppose there was a large spinning disk at the south pole, as an example. Spin it up, slow the earth or speed it up!<br /><br />Seriously, the angular momentum of the spinning earth is so so great, that only by moving mass from the poles to the equator is there any likelihood of modifying it.

 

[georgios]

Hello everybody and many thanks in advance. <br />i would like to know if earth would rotate around it's axis without having it's burning center, or is just because of it that rotates?