Tell me why my perpetual motion idea won't work?

Question

Imagine a small device that resembles a ferris wheel. There are magnets spaced equally around the rim. There is another strong magnet at the bottom such that when the wheel turns each magnet around the rim passes close to it and is pulled by it causing the wheel to speed up.

Normally the wheel would slow down again as the rim magnet passes the stationary one and is attracted in the opposite direction. I get that. But imagine each rim magnet is enclosed in a small superconducting box which blocks magnetic fields. One side of the box has hinges so that it can open as it approaches the stationary magnet and thus the magnet within will be drawn toward the stationary magnet and speed the wheel up. As it passes the stationary magnet the box closes preventing the attraction that would normally slow the wheel again.

A bit of the wheel's spin energy is used to open and close the box but if the wheel is large enough and the boxes small and light enough there should extra energy left over.

Answer 1

You must be assuming that the magnetic fields do not help or hinder the opening or closing of the box. That is an unwarranted assumption I think.

Anyway, all perpetual motion ideas violate conservation of energy. No example of a true violation of conservation of energy has ever been found. That is what makes it such a powerful concept. If you have a new idea, but it does not obey conservation of energy, then you have missed something. You may not know exactly what you missed, but it is a red flag telling you to think harder.

Answer 2

The energy spent to POWER the superconductive boxes (ie, to keep them cold enough to remain in a state of superconductivity) would FAR outweigh any energy created by the spinning of the wheel.

You have also not accounted for the fact that your boxes may be as small as possible, but must still be large enough to contain a very powerful magnet, and of sufficient quality to block magnetic fields.

Finally, you have discounted friction as a force in slowing the wheel (acting against your magnets). It's an interesting idea, and maybe a step in the right direction (since superconductivity technology is still advancing), but as it stands now it just wouldn't work.

Oh, and as an aside, no one has ever invented a perpetual motion machine with conservation of energy, regardless of any energy gain.

Answer 3

For heaven's sake try it and let me know the results! BTW: someone did create a perpetual motion machine, but 100% of the energy is used to keep the wheel in motion, so if your idea has energy left over, even a fraction of a per cent, you've done something nobody else has. Be certain to get patent protection!!!

Answer 4

Well,
Your idea is a little sketchy, but I have also wondered why perpetual motion is impossible. It seems like it is very possible, but if it were, then they would already be using it right now.