Quote:Original post by AndreTheGiant
Heres a question
I know the idea is to stop the melting of the ice caps, but since at the time being they are melting anyway, why dont we capture the water and use it to drink? Im pretty sure its pure water. In the meantime theres this global scare that we are running out of fresh water. And some places have already run out.

Because most people don't live on arctic ice sheets and transporting the water to where its needed would take oil and oil shortages are the reason were short on everything else.

Quote:Original post by PouyaCat
Back on the flywheel subject...:

You *CAN* generate energy (electricity) from gravity. You stupid people! Geez!

Gravitational pull between large bodies. Sure, if you keep your flywheel in one position on earth and only think about earth, then yeah, you don't move, so you can't turn the potential of gravity into power.

But now imagina another, moving gravitational source pulling on your object. As long as your object remains stationary against source A, and source B orbits source A, you are pulled all around the place; or, more interestingly, slightly up and down.

Up and down movement = labour being done = possible to be extracted to generate electricity.

I know this is right. I already built it once :D

All you need is this:

1) A main gravitational body. Ie: the earth.
2) A second body orbiting it. Ie: the moon.
3) A large mass to be affected by it. Liquids work. Ie: the oceans.
4) Knowing what moves. Ie: the tides.
5) Harnessing energy. Ie: tidal generators.

Power due to gravity. *snickers*

No one said energy from gravity was impossible, we just said infinite magical free energy was impossible (be it from gravity or any other source). Anyway, water mills are another for of power from gravity, as are dams. They just don't use the moon to pull the water up, but rather geological processes.

Quote:Original post by Samith

Quote:Original post by PouyaCat
Back on the flywheel subject...:

You *CAN* generate energy (electricity) from gravity. You stupid people! Geez!

Gravitational pull between large bodies. Sure, if you keep your flywheel in one position on earth and only think about earth, then yeah, you don't move, so you can't turn the potential of gravity into power.

But now imagina another, moving gravitational source pulling on your object. As long as your object remains stationary against source A, and source B orbits source A, you are pulled all around the place; or, more interestingly, slightly up and down.

Up and down movement = labour being done = possible to be extracted to generate electricity.

I know this is right. I already built it once :D

All you need is this:

1) A main gravitational body. Ie: the earth.
2) A second body orbiting it. Ie: the moon.
3) A large mass to be affected by it. Liquids work. Ie: the oceans.
4) Knowing what moves. Ie: the tides.
5) Harnessing energy. Ie: tidal generators.

Power due to gravity. *snickers*

No one said energy from gravity was impossible, we just said infinite magical free energy was impossible (be it from gravity or any other source). Anyway, water mills are another for of power from gravity, as are dams. They just don't use the moon to pull the water up, but rather geological processes.

technically you aren't getting energy from gravity but using it to extract energy from the momentum of the earth and moon, its not unlimited either since this will eventually knock the moon from earth's orbit

Quote:Original post by stimarco
Why? You could mount the whole thing inside a container that's had the air sucked out of it. No air, no drag, no friction, no nada. Power could be generated by mounting coils on the flywheel and having them pass through magnets -- the dynamo principle.

You do realise that a coil that is producing current from a magnetic field actually generates a magnetic field itself. This would slow the flywheel (even inside a vacuum chamber and even assuming that there is no friction itself from whatever bearings you choose to keep that flywheel moving)

You see, one can NEVER extract more energy from a system than has been put into the system.


Here, try a simple experiment which should satisfy the coil extracting energy from a moving magnetic field.

Take an electric motor (A hobby motor if you will) Give the axle a spin and time how long it comes to a stop (A good spin might last a half a second or so) Now short the two leads together and give the axle another spin (same speed as before) and time how long it takes. This time, as soon as you let go of the axle, it will come to stop in less than a tenth of second.

Everything is the same inside the motor between the two spins, brush friction, weight of the axle, weight of the coil and iron core all except on thing, the counter magnetic field which is caused by the current you generated by spinning the axle. Note that the first spin produced no current because the effective resistance between the two leads was infinite.

Very nice... I like it :)