MindThe four types of imagination and how they create our worlds Your imagination isn't just one thing. The latest neuroscience is untangling just how diverse this faculty really is, says cognitive neurologist Adam Zeman Features
MathematicsWhat 7 fiendishly hard puzzles tell us about the nature of mathematics 25 years ago, a $1 million reward was promised to anyone who could solve one of seven incredibly hard maths riddles. With only one of them now solved, what will it take to crack the rest? Features