Thermodynamics in a nutshell

karthik · updated · flag

Thermodynamics is all about heat flow and the work it does and how it affects the physical properties of a matter like pressure and volume in a surrounding. In other words, Thermodynamics is a framework that explains pretty much the entire universe. And it can be succinctly defined by just four laws.

To understand those laws, familiarise yourself with these terms and proceed to the next lesson.

  • System - A thermodynamic system is the part of the universe that is being observed or studied.
  • Surroundings - The rest of the universe except the system is called as the surrounding.
  • Internal energy - The energy from all the molecular kinetic and potential energy of the system or the surrounding.
  • Entropy - A measure of how smooth energy is distributed. In other words, it’s the measure of the number of ways the molecules in a system can be rearranged at a given temperature.

For example, consider a glass of water in a room for a thermodynamic analysis. The glass and the water it contains is the thermodynamic system and the room and the entire universe that’s out of the system boundary is the surrounding (sometimes called as a reservoir). And for both the system and surrounding, you can make sense what internal energy and entropy is.

In the practical world, understanding this heat transfer between systems and surroundings is what helps us build stuff like engines and refrigerators. Now that you understand what the common terminologies and concepts, you can proceed to the next lesson to explore the laws of thermodynamics.