Mr teacher says its impossible to achieve perpetual motion. I think all things in fact move in perpetual motion, just not in the same magnitude, form , or direction. Another question I have is the entropy equation S = Q/T. By this equation, mass contributes to further entropy because is equal to Q. This goes against basic laws of Kinetics, where we know that lighter objects move faster, and as such also contributes to entropy. A fat man for instance can not move around faster than a thin man, even though the fat man has more stored energy. Another interesting thing we covered on entropy was the law S*universe = S*system + S*surroundings, he used it to explain why its possible for us to have evolved from lower energy organisms. We are the system in the equation, and our organization is offset by the disorganization of the surrounding.