Tracing the Second Law

摘要

While man learned to control and use fire many thousands of years ago, only in the last 300 years has the nature of heat been given serious consideration. In this short time, it has been explained as phlogiston, a mysterious fluid created by fire, and as caloric, a material fluid flowing from hot to cold. The modern view, that heat is a convertible form of energy, is fewer than 200 years old.