“What is the most efficient possible heat engine?”
The Heat engine is one of the most productive inventions of humanity, allowing our civilization to take in exterior heat and channel it into useful energy. However, since there are so many different processes to choose from, which one is the most efficient? Well, let’s think about it. A heat engine cycle can be boiled down (pun definitely intended) to one core principle, an oscillation between a hot temperature and a cold temperature. One very efficient way to accomplish this is to have an isothermal process to expand the gas for a given amount and then use an adiabatic one to cool it down while further expansion takes place. Then, one can reverse this process by using an isothermal compression combined with an adiabatic one to raise the temperature and pressure back up to the original value, therefore completing the process known as a carnot cycle.