One of the seemingly easiest concepts to understand is heat, a word so widely used that anyone knows what it means. Or is it not?
Because what is heat? Ponder it for a moment. When, tired of sweating, you say "I'm hot", what are you referring to? It is curious that we use the verb "to have" together with heat or cold, with which it is expressed that something is owned or, as in this case, that something enters the body.
Perhaps it is some type of substance or matter that penetrates our body and commits atrocities such as making us sweat. At the end of the 18th century, scientists believed the same thing, that heat was a weightless substance, and therefore undetectable, that passed from one body to another: caloric.
We have this idea so implanted in our brain that it is quite difficult for us to accept what heat really is. We will surely be surprised to discover that heat does not exist , in the sense that it is not a substance, it is not a thing. In reality, heat is nothing more than a process, a way of transmitting energy from one body to another that has a clear effect: to increase the temperature of the body in question.
