Yet it is undoubtedly one of the disciplines of physics that includes the better "with your hands." This is more a perspective on the world that a theory in itself. And it is a very rich.

Thermodynamics, the world seen through the prism of energy. Energy is the key concept in this regard - though this concept comes, in fact, mechanics, and is also common to electromagnetism, among others: Can we really create? Does it really disappears when we say we wasted? What forms might it take?

To answer such questions that invented thermodynamics. The law states that it is in fact originate in the microscopic laws (conservation of energy), even if it did not really see any on (see the statistical origin of entropy). And finally, thermodynamics answers questions that are not so remote that it matters of cosmology ... which it explains that they can not not confuse the past and future, and that there is a sense of unfolding events: the second principle is the only physics to differentiate between past and future!

Thermodynamics, in my opinion, is really to discover.....