Thermodynamics/SecondLaw

Let us consider the following questions:
 * How do we unpeel an orange?
 * How do we uncook rice?
 * If we have a book on the edge of a table, it will fall off with just a little touch. But it takes a lot more to move a book on the floor up onto a table. Why?

Closer Examination
Let us look the last question a little more. By the first law the amount of energy to move a book from a table to the floor is exactly the same as the amount of energy to move the same book from the floor to the table (same force, same distance). Hence, the first law is not sufficient to account for the difference.

Heart of Thermodynamics
The above questions point to the reason that we need to have a second law of thermodynamics.

The first law of thermodynamics can be handled by the conservation laws in other fields of physics. It is the second law that we need the field of thermodynamics.

The second law of thermodynamics can be called the Heart of Thermodynamics.

Second Law of Thermodynamics
Now that we can see a rationale for a new law of thermodynamics let us continue to a description of the the Second Law of Thermodynamics.