"Entropy is a measure of whether a system is in a special, very particular state, in which case the system has low entropy, or whether it is in one of many states that look more or less the same, in ...

The following is an extract from our Lost in Space-Time newsletter. Each month, we hand over the keyboard to a physicist or two to tell you about fascinating ideas from their corner of the universe.

Can quantum systems become more disordered, as thermodynamics would predict? Yes, they can - if a proper definition of "entropy" is used. It is one of the most important laws of nature that we know: ...