Quantum theory pokes holes in our understanding of entropy
Victor de Schwamberg/Science Photo Library
Measuring disorder in the quantum realm is a bit confusing. Mathematical research has revealed that three different definitions of entropy, previously thought to be equivalent, do not necessarily agree for quantum objects.
When two bodies are connected, for example a container of hot gas is connected to a store of cold gas, the two bodies exchange quantities of particles, heat, etc., so the entropy of the colder one may increase. For almost 200 years, physicists have used the same set.
Source: www.newscientist.com
