Question

c. For most inventions, the US Patent Office only requires a written description of your invention that would allow others to understand how to make your invention. It does not require a working prototype. However, for an invention that claims to be a “perpetual motion machine" - something that, when started up, will continue moving forever without consuming additional energy - they will not accept a mere description and demand a fully working prototype. Despite thousands of claims over many decades, no one has made a working prototype that qualifies for a patent. With reference to your understanding of the laws of thermodynamics, why does the US PO demand a working prototype for a perpetual motion machine? And why has no one managed to claim such a patent?

Answer 1

Perpetual motion implies violation of the second law of thermodynamics. Hence any working machine if so it claims to do so needs to be substantiated by a working machine, which is again impossible since the second law of thermodynamics forbids it from doing so. In short second law of thermodynamics says any isolated system will move towards disorder, and a perpetual machine will not allow one to do so!