everyone's probably heard of a dyson sphere. everyone's probably heard of newton's mountain to. well i think that the ultimate way to create electricity is hidden within them. before i start i'll just say that yes this is very impractical and there probably isn't the resources to make it and it could obscure sun light, but it's an idea no more, no less and it doesn't need to be anything else. the idea is that a large ring of wire is built encircling the earth, with some gaps to allow light through and for maintainance. the ring is postioned some where around the region of the geostationary orbit, preferably some where which doesn't interfere with to many satilites. then a very big magnet is placed in side it a roughly the distance which allows it to contiually descend without hitting earth. the magnet will then continually pass through the wire generating huge quantities of electricity without the use of pollutants. the electricity could be relayed back to earth on long wires or cables or maybe even stored in large space bound batteries which can then be transported back to earth using space shuttles or other craft.-- talen, Dec 10 2002 Dyson Sphere http://www.d.kth.se...1-asa/dysonFAQ.htmlNot a ball-shaped vacuum cleaner, then. [my face your, Oct 04 2004] Newton's Mountain http://galileoandei...ectures/newton.htmlScroll to "Projectiles and Planets" [my face your, Oct 04 2004] Newton's Mountain applet http://www.phys.vir...s/newt/newtmtn.htmlWith realistic sound effects. [my face your, Oct 04 2004] Well, I can see that it's something to do with a suspended magnet constantly passing through a suspended coil, but the method of suspension escapes me. However, once that detail gets sorted out, perhaps the resulting energy could be relayed to earth by laser.-- angel, Dec 10 2002 I disagree with the 'marked-for-deletion' tag. There is an idea here that doesn't violate anything about the 'bakery, although it's a little hard to read and lacks presentation. You can't m-f-d something just willy-nilly 'cause you don't like it.
Think monstrous generator with the earth's rotation as the rotor. Days would get longer, though. Now I'm curious as to how much inertia the planet's rotation has; would we be tapping off so little to even be noticable, or would it be a significant slowdown?
Method of suspension: perhaps an orbital ring around the whole earth?-- RayfordSteele, Dec 10 2002 Not entirely sure how talen intends this to work. My reading is that this is a huge magnet hanging from a huge orbital conducting ring.
Passing an induction coil through a magnetic field (or vice versa) will indeed generate electricity. As described, however, the coil of the loop is in line with the Earth's magnetic field lines, not crossing them. If the magnet is supposed to generate the electricity by interacting with the loop, the same problem applies.
If the loop is coiled, then the hanging magnet might well generate an electric current in it, but rather a small one for all that effort, and the magnet will gradually catch up to the loop as it loses energy to the current.
"without the use of pollutants" - neglects all the space rockets required to launch this device, and then return the energy to Earth.
Marassa *is* right about the "pseudo-scientific claptrap," though I would have guessed "4th grade claptrap."-- dalek, Dec 10 2002 With that, I remove my tag. The vote now stands that angel and RS are trying to make sense of this, while dalek agrees with me. I'll await further proof that this is an idea.-- Marassa, Dec 10 2002 I assumed that it's using a magnet in orbit to generate electricity. The problem, of course, is that the generation of electricity slows down the magnet, which means it won't stay in orbit. (Sure, you can boost it, but that requires more energy than you'll get back out of the system.)-- bookworm, Dec 10 2002 //the generation of electricity slows down the magnet, which means it won't stay in orbit.//
Exactly. I think that NASA tried a similar experiment using the Space Shuttle and a trailing wire. It generated electricity as it passed through the earth's magnetic field. Unfortunately, this process uses the space ships stored energy (motion) and slows the ship down. No free lunch...-- namuh, Dec 10 2002 This seems a well intentioned idea. I wouldn't say it deserved the level of harshness it has attracted.
BUT.. It is fundamentally flawed. Even in an ideal world, you'd get a problem in trying to get your magnet to hold orbit. As it moved, you would generate a back E.M.F (electromotive force). This would slow it down and decay its orbit.
You can see this effect when you try to turn a dynamo. Disconnect it from a circuit, and turn the handle. Then connect it to a light bulb, a cell to be recharched, or something similar, and then turn the handle again. Although you are generating electricity, you would find the handle more difficult to turn. This is because the energy being converted to electric potential has to come from somewhere.
So, if talen was proposing that this system would work forever without requiring any input, you could add an mfd "in this house, we obey thermodynamics." But he doesn't explicitly make this claim. So, In my opinion, the idea is a valid one.
Whether or not it was a good (i.e. workable, even if unfeasible) one would rely on whether you'd get more energy out of the thing than you'd need to keep this magnet moving (and magnetised, etc). That excercise I'll leave up to one of the other physics graduates. I think the majority of the science mentioned is sound, otherwise.-- yamahito, Dec 10 2002 damn. two succinct answers while I was typing my lecture. I'll leave it stand, though.-- yamahito, Dec 10 2002 Well I know that it would eventually stop or decay in its orbit, I didn't intend for it to go forever. I thought that you could let it go round and round until it showed some sign of slowing down or decay then have on board booster give it a little kick up the ass to get it going again. All of my ideas have the aim of trying to make the world we live in a better place. I was thinking about this idea and the ring would probably have to be in a polar orbit so that parts of the earth weren't permanently deprived of sunlight.-- talen, Dec 11 2002 If it was allowed to operate for a sufficient time much more than just the energy used during construction could be regained. And instead of using rocks to ferry the batteries to earth they could be dropped from the structure, allowed to decay in orbit then plop safely into the ocean via parachute.
The ring could even be used as a hotel or off earth settlement; it could even power the settlement. We could call it “Outer Earth: home in the skies”…
Now that sounds cheesy even to me!
When dealing with ideas for the future you need a large, insanely big vision just like Dyson had. We could never really ever gain enough resources to build a Dyson sphere round the sun, so why not a big generator around earth? And it would give earth a high-class planetary ring. You have to admit all the best planets have rings.-- talen, Dec 11 2002 Who said it would?-- talen, Dec 11 2002 aw, c'mon. Not every idea posted in the HB is even supposed to work. The point is not to think of ideas or inventions that will work, the point is to think of interesting and original ideas. Hence the half, shirley.
The fact of the matter is whether or not you believe it will work, no-one's yet done the maths to say whether or not it will. Or more precisely, what limits would be required to get it to work, and whether those limits would be possible to acheive around the earth. I've got to say, in my opinion, there is nothing obviously wrong with the science behind the idea.-- yamahito, Dec 11 2002 Hullaballoon.
Is it really much less of a great idea just because it doesn't work?-- yamahito, Dec 11 2002 Well most things don't work, even those which are supposed to. As the great Homer Simpson once said: “When are people going to learn. Democracy doesn’t work!”-- talen, Dec 12 2002 Unless you're planning on breaking any of the laws of Physics, this is a way of turning rocket fuel into electricity. Keep supplying the rocket powered magnet with thrust, it'll keep orbiting, and you can get electricity from it. Basically, a very large dynamo.
I'm not entirely sure why this assembly has to be in geostationary orbit. There's nothing about the idea that would require it to be in the same place in the sky. It suggests to me that talen originally thought that this was going to be a perpetual motion machine, but I'll give it the benefit of the doubt.
Just a big dynamo with lots of words wrapped around it. Fishbone.-- st3f, Dec 12 2002 I think the workable, halfbaked version of this idea would be "Ferris Wheel Generators": - as the earth turns, thousands of ferris wheels all over the world pass through the Earth's magnetic field. Passing a conducting loop through a magnetic field generates electricity, so hook the ferris wheels up to the national power grid for an instant distributed power generation system.-- hippo, Dec 12 2002 You were on the 8:15? Damn, just missed you.-- thumbwax, Dec 12 2002 hippo: that was a joke, right? Right? I mean the ferris wheels need electricity, dynamos will cause the wheel to be harder to turn.... you'd end up using more electricity than if you just unplugged it.
St3f: granted, but I think the fact that it is a dynamo running in a near-vacuum may be interesting. The real fault is the energy you'd need to expend transporting the rocked fuel. What we really need now is a halfbaked solar energy propulsion system..-- yamahito, Dec 12 2002 The sun is the ultimate generator- and politicians can't get their heads out of their arses to take advantage of it yet- how are we going to get them to build a 100,000 mile ring around the planet?-- ASLAN, Dec 12 2002 With great difficulty.-- talen, Dec 13 2002 wouldn't the large coil of wire generate electricity by being close to the earth's magnetic feild?-- kmh, Apr 22 2003 Build a rind of inductors around a magnetic spinning black hole(something halfway between a Kerr and a charged black hole). It geneates electricity, slows the black hole. feed with matter... Practically endless electricity-- angry_scientist, Nov 08 2003 //If it was allowed to operate for a sufficient time much more than just the energy used during construction could be regained.//
The amount of energy removed from the object's orbit would be at least equal to (and in reality slightly greater than) the amount of electrical energy produced. Since the amount of fuel required to add a certain amount of orbital energy is larger than the amount of fuel required to produce that same amount of electrical energy, you gain nothing.
On the other hand, if you turn this idea around it might have merit: one of the major difficulties with things like satellites is that producing thrust requires both energy and expendable "stuff". While nuclear reactors and solar collectors can both provide energy, they don't provide "stuff". Although I doubt it would in practice be effective enough to be useful, it might at least theoretically be useful to equip sattelites with a giant propulsion motor which would be able to maintain the satellite's orbit using electrical energy supplied via either solar or nuclear power.-- supercat, Nov 08 2003 //wouldn't the large coil of wire generate electricity by being close to the earth's magnetic feild?//
The problem is that the only reason stuff in space stays in space is that it has had a lot of kinetic energy added to it at great expense. An "earth-powered" generator would use up as many joules of kinetic energy as it provided joules of electrical power. SInce it's cheaper to produce electrical power than kinetic energy, the tradeoff--even of 100% efficient--would be a bad one.-- supercat, Nov 08 2003 Trying to use satellites to harness their own kinetic energy so as to produce electricity is an unambiguously bad idea. On the other hand, trying to together use electric energy plus the earth's magnetic field so as to produce kinetic energy might be a good one though I'm not sure about the physics.-- supercat, Nov 10 2003 random, halfbakery