The second law of thermodynamics says that the amount of disorder in a thermodynamic system always increases. It places limits on how much say that useful work can be extracted from heat. The second law of thermodynamics led us to better steam engines, estimates of the efficiency of renewable energy, the ‘heat death of the universe’ scenario, proof that matter is made of atoms, and paradoxical connections with the arrow of time.

Z Proportions
Becca Hirsbrunner photographed this fabulously constructed Z proportions letter. Interestingly, every element but the diagonal bar can be rationalized.