The Laws of Thermodynamics

The laws of thermodynamics explain energy flows. While seemingly common sense, these laws are supported by complex mathematics allowing strong system descriptions and predictions.

The first law states that energy is neither created nor destroyed, but changes forms. This law highlights the tendency of energy to flow between different forms.

The second law introduces entropy, described as disorder. The total entropy of a system and its surroundings always increases, meaning the universe's disorder is constantly growing.

Examples, like a messy bedroom, illustrate increasing entropy. Entropy can also be understood through computer code, where ordered states require more information to describe than disordered ones.

Heat flows from hot to cold because energy is more disordered when dispersed. This exemplifies the effect of entropy on everyday processes.

The third law states that a perfect crystal at absolute zero has zero entropy, representing the most ordered state possible.

Gibbs free energy (G) determines if a process is spontaneous. It's calculated using enthalpy, entropy, and temperature (G = H - TS). A negative delta G indicates spontaneity.

A process can be spontaneous if it is enthalpically or entropically favorable, or both. Temperature influences spontaneity, especially for entropically driven processes.

While the universe's entropy always increases, order can arise spontaneously on a small scale if enthalpically favorable, as seen in soap micelle formation.

Soap molecules, with polar and nonpolar ends, form micelles to trap dirt in water. This demonstrates how ordered structures can form spontaneously due to energy storage and favorable interactions.