Thermodynamics is the study of energy and its transformation. Thermodynamics discusses the relationship between heat, work and the physical properties of working substance. The word thermodynamics derives from two Greek words “therme” which means “heat” and “dynamikos” which means “power”.
Energy exists in many forms, such as heat, light, chemical energy, and electrical energy. Energy is the ability to bring about change or to do work.
According to Van Wylen, “Thermodynamics is the science of energy, equilibrium and entropy” (3 E’S). He treated the subject in such a way that, it deals with energy, matter and the laws governing their interactions.
In simplest terms, the Laws of Thermodynamics dictate the specifics for the movement of heat and work.
The first law of thermodynamics states that energy can’t be created or destroyed, but you can convert it from one form to another. This is also sometimes referred to as the law of conservation of energy.
The second law of thermodynamics states that not all energy can be used and the disorder in the universe always increases. Entropy is a measure of disorder. The flow of energy maintains order and life. Entropy always increases. Entropy wins when organisms cease to take in energy and die.
The third law of thermodynamics tells us that all molecular movement stops at a temperature we call absolute zero, or 0 Kelvin (-273 Degree Centigrade). Since temperature is a measure of molecular movement, there can be no temperature lower than absolute zero.