Why a circular track will not be a perpetual motion device
I have been getting a lot of mail asking what would happen if we made the track circular. Would we get free energy? Would the balls keep accelerating forever?
I have been tempted to reply with the famous quote: "There are two kinds of people in the world -- those who understand the second law of thermodynamics, and those who don't".
However, I am not the kind of person to leave an inquiring mind unsatisfied, and it is more productive (and kind) to explain in a little more depth what is going on.
Suppose you made a circular track, and put two balls after each magnet. When the last ball is released, it encounters a magnet that has two balls at the ground state. There is no energy to be had from this magnet. The ball just bounces back.
Now suppose you had placed three balls after each magnet. When the last ball is released, it hits a ball that is 5/8ths inch from the magnet. It has not gained much momentum, because most of the momentum gained is in the last half inch as the magnet pulls much stronger on things that are closer. But the ball has enough energy from previous accelerations to release the next ball. However, that ball has less energy than the ball that caused it to release. It may have enough energy to release another ball or two, but each ball that is released has less energy than before, and eventually the chain stops.
You can show by inductive logic that no matter how many balls you stack in front of each magnet, eventually the system stops.
To estimate the losses due to heating the balls as they compress when hit, consider a plastic tube standing upright on a table. Place one steel ball at the bottom of the tube. Now drop another ball into the tube, so it hits the ball at the bottom, and bounces back up.
Now measure how high the ball bounced. If it bounces halfway back up, the losses are 50%. Perform the experiment for yourself with the balls from the Gauss Rifle. How high does your ball bounce? Send me mail with your results.
