The length of proof is the interest of mathematics, and it is of fundamental significance in philosophy. Mathematics is the language of physics with profound unity. The purpose of physics is to make the world around us meaningful.

The unity of mathematics is attributed to the logical relationship between different mathematical theories. On the other hand, physical theory does not need logical consistency; They are unified because they describe the same physical reality, and physicists usually don't doubt what kind of reality they are trying to describe.

Geometry is an art of correctly reasoning inferior figures.