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Limitless Green Energy?

by GRDixon
Tags: earth's rotation, energy, green, gyro
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GRDixon
#1
Jan23-10, 05:41 PM
P: 250
The Earth rotates in inertial space. The amount of rotational kinetic energy is enormous ... millions of mankind's annual consumption. Is there any kind of apparatus, perhaps one based on gyros, that could tap into this energy?
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Buckleymanor
#2
Jan25-10, 05:39 PM
P: 488
Don't know where you will get the gearbox from.
http://www.halfbakery.com/idea/Foucault_27s_20Flywheel
GRDixon
#3
Jan25-10, 05:55 PM
P: 250
Quote Quote by Buckleymanor View Post
Don't know where you will get the gearbox from.
http://www.halfbakery.com/idea/Foucault_27s_20Flywheel
Fascinating. Thanks for the link(s).

willem2
#4
Jan25-10, 07:41 PM
P: 1,395
Limitless Green Energy?

I don't this can work at all. To use the kinetic energy of the earth we must slow it down, and that can only be done by transferring the angular momentum of the earth to something else (the moon for tidal energy).
pallidin
#5
Jan27-10, 03:04 PM
P: 2,292
Gyros? Well, the energy required to sustain their action exceeds the energy able to be extracted from this or any other arrangement.
Pythagorean
#6
Jan27-10, 06:23 PM
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From an engineering perspective, I think it would be rather difficult to get the other portion of the contraption to stand still (i.e. you have to have something that's not rotating with the Earth to take advantage of the Earth's rotation). Good luck with that!

Addendum:

I hadn't considered Foucault. Neat idea.
fluidistic
#7
Jan27-10, 06:47 PM
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Anyway, if you change the period of rotation of the Earth, many species wouldn't adapt and die.
Pythagorean
#8
Jan27-10, 06:54 PM
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Quote Quote by fluidistic View Post
Anyway, if you change the period of rotation of the Earth, many species wouldn't adapt and die.
Well, I wouldn't deny that's true for a significant change in the period. But at what point do we consider it significant?
cesiumfrog
#9
Jan27-10, 08:15 PM
P: 2,050
Quote Quote by Pythagorean View Post
I hadn't considered Foucault. Neat idea.
What about conservation of angular momentum?

Try tidal power.
Pythagorean
#10
Jan27-10, 08:24 PM
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Quote Quote by cesiumfrog View Post
What about conservation of angular momentum?

Try tidal power.
Another good one! This one is already being used too! There's several different engineering approaches to it.
Buckleymanor
#11
Jan28-10, 02:36 AM
P: 488
Quote Quote by fluidistic View Post
Anyway, if you change the period of rotation of the Earth, many species wouldn't adapt and die.
Don't imagine that there would be any significant change in the period of rotation if you consider the mass of the Earth.
It might actualy be speeding up at present due to the amount of hydro electric scheems in the northern hemisphere.
I imagine any slowing would be counteracted by rainfall, by angular momentum when it falls or dams.
russ_watters
#12
Jan28-10, 12:16 PM
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...anyone going to attempt to quantify the issue...?
willem2
#13
Jan28-10, 05:18 PM
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Quote Quote by russ_watters View Post
...anyone going to attempt to quantify the issue...?
If you do not use the moon in some way, the energy you can gain is exactly zero, since there's no way to reduce the angular momentum of the earth.
Zula110100100
#14
Jan28-10, 08:54 PM
P: 253
there's no way to reduce the angular momentum of the earth.
How's that? doesn't driving a car give angular acceleration the the earth?
willem2
#15
Jan29-10, 12:12 AM
P: 1,395
Quote Quote by Zula110100100 View Post
How's that? doesn't driving a car give angular acceleration the the earth?
And it takes it away again as soon as you stand still again. The angular momentum of the earth with the car remains the same.
jambaugh
#16
Jan29-10, 01:00 AM
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Quote Quote by willem2 View Post
If you do not use the moon in some way, the energy you can gain is exactly zero, since there's no way to reduce the angular momentum of the earth.
As the Earth rotates, the tidal bulge follows a bit behind the Earth-Sun line (neglecting the moon) and so there is a tidal torque on the Earth reducing its rotational angular momentum and converting some of that to orbital angular momentum. You can alter the angular momentum of the Earth but not of the Earth-Sun or Earth-Sun-Moon system except by exterior effects (e.g. Jupiter).

As mentioned tapping tidal energy is tapping the rotational kinetic energy of the Earth. Tapping tidal energy would imperceptibly but quantifiably increase the lag of the tidal bulge, increasing the rate of tidal slowing of the Earth's rotation.


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