## Introduction

So, science is cool - we all know that. It lets us explain why the universe has the properties it does. Everything from why the sky is blue to how to use semiconductors to build the computer on which you're reading this. It also provides us with some fun excuses to supply to our parents:p

## Why is your room so untidy?

It's the classic complaint: the clothes are on the floor, and the desk hosts a pile of papers, books, and other random stuff. So someone asks why your room is so messy? Surely it's your fault? Well, not entirely.

The answer? Entropy.

Entropy can be thought of as the number of ways in which a system could be arranged, how disordered that system is, or how evenly distributed the energy within that system is. So a messy room has higher entropy than a tidy one because its contents are more evenly distributed. An alternative statistical approach would be to consider randomly arranging the contents of the room. A few of the configurations would be considered tidy, however most would be messy.

The observation that a messy room has higher entropy than a tidy room is important. The second law of thermodynamics states that the entropy of a closed system can never decrease. A consequence of this is that a closed system tends towards higher entropy. By the statistical approach, events that alter the state of a system without being directed to change its entropy (such as to achieve a decrease) will tend to increase it.