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What is the fallacy in this infinite motion machine?

Most of the "troll physics" images I can figure out, but this one has me stumped. What is broken about the following machine's physics?

infinite electricity machine

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    $\begingroup$ You mean apart from the spelling? $\endgroup$ May 31, 2011 at 18:59
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    $\begingroup$ Yes, I did mean apart from the spelling. $\endgroup$
    – Ricket
    Jun 1, 2011 at 3:15
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    $\begingroup$ It actually stalls! The force of water pushing down on the entering ball is greater than the bouyancy of the balls above. The only thing keeping the water from running out is the seal closing. $\endgroup$ Nov 17, 2011 at 14:08

1 Answer 1


The problem is in the seal.

The amount of work to move the seal against the water pressure is the same amount of energy that is gained by the balls when they are pushed up by the water.

Even if we remove the seal and we imagine a magic "one-way pass-through" wall, the ball would still need to displace the same volume of water as itself in order to get into the tank.

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    $\begingroup$ Actually they can't even start to get into the tank. The force needed to overcome the water pressure is greater than the bouyancy of the balls above. It wouldn't be equal unless the balls above were coelesced into a single cylinder from botton to top having the diameter of one ball. $\endgroup$ Nov 17, 2011 at 14:19

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