A device based on a 155-year-old thought experiment has been realised at the largest scale yet, and it may help us understand how entropy, or disorder, is produced. It could also someday be used to harvest energy from motion.
Maxwell’s demon is a thought experiment first proposed by Scottish mathematician James Clerk Maxwell in 1867. He imagined a tiny demon sorting gas particles by temperature into two chambers, heating up one and cooling down another. In theory, this…