The meaning of the term “fake news” has been completely transformed – so what does it mean now, and is the phrase even useful at all? How Louis Bachelier scooped economists by half a century. A forgotten French mathematician’s unusual approach to the stock market. He anticipated both Einstein's theories and the application of maths to the stock market and his ideas were rediscovered decades after his death. Why high levels of noise affects all of us. David Baker explores how different sounds can impact on people without them even knowing and how to make our lives more tranquil. (Photo: Pocket watch. Credit: Kanyapak Lim/Shutterstock)