Physics Help Forum Perpetual machine

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 Jul 7th 2015, 03:15 PM #1 Junior Member   Join Date: May 2014 Posts: 20 Perpetual machine I was looking at a map of Hudson Bay's gravity anomaly when it occurred to me that it should be fairly simple, though not inexpensive or profitable, to build a free energy generator using this phenomenon. If you built a simple, large wheel where on one side of the wheel would be the greater gravity while on the other lesser gravity, would it not cause one side of the wheel to fall more than the other side, hence creating movement and free energy? I tried to find out what percent difference there is between the greater gravity on the edge of Hudson's Bay and the lesser, but I could not really find that information. But even if the amount of gravity difference was 1 cm/second, or about 1%, then that ought to be enough to create some kind of difference in the weight of one side vs. the weight of the other. And, if this configuration would work, what would that mean to the law of conservation of energy and physics in general?
Jul 7th 2015, 03:28 PM   #2
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 But even if the amount of gravity difference was 1 cm/second, or about 1%,
Did you really mean to say this?

Jul 7th 2015, 04:53 PM   #3
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 Originally Posted by studiot Did you really mean to say this?
I guess I should have said 10cm/second or 0.1%. If the difference is 1cm/second, 10cm/second, more or less, should be irrelevant. Any difference at all ought to cause a rotation of the wheel and free energy; the amount of energy is irrelevant to the principle. I'm not suggesting that we try to build wheels on gravitational anomalies in order to generate electricity. Maybe we could... maybe I'm underestimating the difference. But lacking that information I'm assuming that it would be uneconomical.

The purpose of my post is to question the principle of the law of conservation of energy by suggesting that my idea ought to be a way of disproving it.

Jul 7th 2015, 08:50 PM   #4

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 Originally Posted by wordsworm I guess I should have said 10cm/second or 0.1%. If the difference is 1cm/second, 10cm/second, more or less, should be irrelevant. Any difference at all ought to cause a rotation of the wheel and free energy; the amount of energy is irrelevant to the principle. I'm not suggesting that we try to build wheels on gravitational anomalies in order to generate electricity. Maybe we could... maybe I'm underestimating the difference. But lacking that information I'm assuming that it would be uneconomical. The purpose of my post is to question the principle of the law of conservation of energy by suggesting that my idea ought to be a way of disproving it.
First, 1 cm/s is a speed, not a change whatever it is that your "difference in gravity" means. If you mean difference in gravitational force (see below) then your unit would be "N." Second, this kind of thing has been proposed before in the guise of a wheel tall enough so that the bottom of the wheel has a smaller gravitational force ("difference in gravity"?) on the top than on the bottom. But one reason this cannot be made into a perpetual motion machine is that the wheel is rigid and thus can only spin at whatever speed we start it out with. You would need some kind of mass at one point on the wheel to create a torque, but the wheel would quickly fall into a stationary state where the mass is at the bottom of the wheel. So no dice.

-Dan
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Jul 7th 2015, 10:06 PM   #5
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 Originally Posted by topsquark First, 1 cm/s is a speed, not a change whatever it is that your "difference in gravity" means. If you mean difference in gravitational force (see below) then your unit would be "N." Second, this kind of thing has been proposed before in the guise of a wheel tall enough so that the bottom of the wheel has a smaller gravitational force ("difference in gravity"?) on the top than on the bottom. But one reason this cannot be made into a perpetual motion machine is that the wheel is rigid and thus can only spin at whatever speed we start it out with. You would need some kind of mass at one point on the wheel to create a torque, but the wheel would quickly fall into a stationary state where the mass is at the bottom of the wheel. So no dice. -Dan
http://www.thelivingmoon.com/45jack_...ap/Map_002.png

That's a map of Australia's gravitational anomalies. I did a bit of checking up and found that the difference between some of the peaks and the desert in the mid south west of the map would be between 3-5mm/s velocity. The units they used I converted into mm/s.

The difference of gravitational force would not merely be vertical, but horizontal as well. The wheel itself would have to be 100m-1km in radius. Thus, it would have to be quite massive.

The vertical difference in gravity proposal would never work since gravity in that model is uniform at the top as it is on the bottom, essentially cancelling any perpetual motion or free energy. My model is not the same. My model uses horizontal differences which would make the desert side lighter and the mountain side heavier.

Therefore, my model would work, even if it would be useless as a generator of energy, free or not. In fact, I was hoping someone on here would be interested in helping me build a model despite the fact that it would indeed break a law of physics and be completely economically useless.

The wheel, any weighted wheel whose friction is not greater than whatever bearings are allowing it to turn, will create free energy.

How much lead would it take to create to create a gravitational velocity of 1mm/s is another question I'm asking myself. That might be more practical if one were to actually build the thing (though still uneconomical and expensive).

 Jul 7th 2015, 11:44 PM #6 Senior Member   Join Date: Nov 2013 Location: New Zealand Posts: 552 You could, in principle, get perpetual motion using gravity as a conservative force. That's why planets perpetually orbit the sun. However as soon as you have energy losses you have a system that will eventually run down. I understand that even the tides on the earth cause a loss of energy which will eventually effect the earth in a negative way. As soon as you try and take energy out of the system the perpetual motion will degenerate. I don't know of any way of violating the law of energy conservation. Even the quantum effects of subatomic particles wont allow you to do that. Last edited by kiwiheretic; Jul 7th 2015 at 11:47 PM.
Jul 8th 2015, 02:17 AM   #7
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 Originally Posted by kiwiheretic You could, in principle, get perpetual motion using gravity as a conservative force. That's why planets perpetually orbit the sun. However as soon as you have energy losses you have a system that will eventually run down. I understand that even the tides on the earth cause a loss of energy which will eventually effect the earth in a negative way. As soon as you try and take energy out of the system the perpetual motion will degenerate. I don't know of any way of violating the law of energy conservation. Even the quantum effects of subatomic particles wont allow you to do that.
I agree that the amount of harvestable energy would be minute. But, for as long as the two horizontal values remain different, it should work. Planets, unlike my hypothetical wheel, are not fixed by some kind of arm. The wheel would be. That would be a key difference. I never thought that it would be capable of generating power in a meaningful let alone profitable way. The only purpose of my model is to show that energy can be created, thus breaking the law of conservation of energy. If I can do that, then it would open doors for me (perhaps).

 Jul 8th 2015, 04:31 AM #8 Physics Team     Join Date: Jun 2010 Location: Morristown, NJ USA Posts: 2,354 Sorry, won't work. For any point on the wheel that has a particular force of gravity acting on it causing a torque in one direction (let's call that point A and let's say the torque is clockwise), there is another point A' someplace else on the wheel that has the exact same magnitude of torque acting in the opposite direction (counterclockwise). Hence the sum of torques is zero. In mathematical terms we say that the curl of a gravity field must be zero: $\nabla&space;\times&space;\vec&space;F&space;=&space;0$ I don't have time to give the proof here right now, but will come back later with a diagram and calculations that show why this is so. In the mean time, consider a more idealized system that may be easier to visualize: suppose you have a very large wheel in space above the Earth, but offset in such a way that one side of the wheel is closer to the Earth than the other. This gives the same sort of "imbalanced" gravity force acting on the wheel as in your question. Would such a wheel rotate on ts own due to this "imbalance." Alas, the answer is no. Back later to explain why that is. Last edited by ChipB; Jul 8th 2015 at 04:55 AM.
Jul 8th 2015, 05:48 AM   #9
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 Originally Posted by ChipB Sorry, won't work. For any point on the wheel that has a particular force of gravity acting on it causing a torque in one direction (let's call that point A and let's say the torque is clockwise), there is another point A' someplace else on the wheel that has the exact same magnitude of torque acting in the opposite direction (counterclockwise). Hence the sum of torques is zero. In mathematical terms we say that the curl of a gravity field must be zero: $\nabla&space;\times&space;\vec&space;F&space;=&space;0$ I don't have time to give the proof here right now, but will come back later with a diagram and calculations that show why this is so. In the mean time, consider a more idealized system that may be easier to visualize: suppose you have a very large wheel in space above the Earth, but offset in such a way that one side of the wheel is closer to the Earth than the other. This gives the same sort of "imbalanced" gravity force acting on the wheel as in your question. Would such a wheel rotate on ts own due to this "imbalance." Alas, the answer is no. Back later to explain why that is.
But here you are arguing for differences in vertical pull. This is exactly the same scenario proposed by Topsquark. What you are saying is self evident. However, I am not proposing this kind of scenario. This is very different. Think of it this way: each stress, one greater, one lesser, exist in complete counter balance in a vertical relationship between points in the circle.

I made a quick sketch showing you the difference between my proposal and yours. You can find it on my art blog: http://mymagicart.blogspot.kr/2015/07/free-energy.html

You and I are talking about two different things, and I am not trying to argue that you're wrong. I'm trying to show you the difference between what I'm talking about and what you're talking about. My numbers are not to be taken as exact, but as a rough guide.

 Jul 8th 2015, 05:58 AM #10 Physics Team     Join Date: Jun 2010 Location: Morristown, NJ USA Posts: 2,354 OK, here's a diagram that I hope will explain why the torques always balance to zero. Consider a large wheel and two sources of gravitational force, M and m, where M >> m. On the left of the attached diagram is a figure showing three pairs of points A, B and C, each matched with a second point A', B' and C' respectively. The force acting on A = the force on A', the force on B = the force on B', and the force on C = the force on C'. Note that A and A' are equidistant from the centerline between the wheel and M; hence the torques provided by the forces acting on A and A' cancel. Same with B and B', and C and C'. Thus the total torque acting on all points of the wheel due to M add up to zero. The right side of the diagram shows a similar situation for the smaller attractor m. Again. the torques across all points cancel. Your question dealt with two different sources of gravitational force, similar to the depiction here. You can see that the sum of the two diagrams results in zero net torque on the wheel. In fact you can generalize this by considering an infinite number of masses m and M, all different, which would represent the condition of the wheel being gravitationally attracted to a very odd shape of variable density. Still, the sum of torques is zero. This assumes of couyrse that the wheel is uniform in density around its perimeter, which I believe is the condition you were considering. If the wheel is not uniform then there would be a torque, whihc would cause teh wheel to rotate back and forth, similar to a pendulum. But like a pendulum it could not act as a perpetual motion machine. Attached Thumbnails

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