2016-03-05 - Wire Entropy

One of the most annoying things about dealing with computers is all the wires. They seem to just wrap themselves around each other until you end up with a tangled mess. Well that phenomenon can be explained by entropy. Entropy is a complicated thermodynamic quantity but it can be generalized as a measure of how chaotic a system is.

When you first arrange wires they are very neat and tidy. This is a low entropy or ordered arrangement because the specific arrangement of the parts is very important to the overall state. There are a limited number of arrangements that can be considered “neat” and “tidy”. Wires being tangled up is a high entropy or chaotic arrangement because the arrangement of the parts isn’t very important to the overall state. There are a large number of arrangements that can be considered “tangled”.

The Second Law of Thermodynamics states that the entropy of a system can never decrease without work being done to it. This means that wires won’t straighten themselves out unless someone or something forces them to. The problem is there’s no law saying entropy can’t increase. As you bump your desk, as you pull on the wires, as the world turns they are being jostled about. These small forces tend to be rather random so they can’t really be thought of as directed work. So according to the laws of physics these small forces can’t straighten out the wires and can only tangle them.

And that’s the universe for you.