My friend believes that he's able to create a perpetual motion machine using carefully arranged magnets and the repelling force between them in order to spin a turbine. To refute this, I argued that perpetual motion is against the laws of thermodynamics and that friction would eventually cause the turbine to come to a rest. HOWEVER, he counters that as long as the magnets keep repelling each other, they will counteract the lost energy. Being a layman, I am unable to really tell him why this wouldn't work at a fundamental level. Intuitively, it really does seem as though the magnets would keep repelling each other. So I'm really hoping that somebody could give me a more satisfying explanation.