LifeThe Peeriodic Table of Illusions Illusions can tell us much about how our brains work, but first we need to know how each one works, says Richard L. GregoryOpinion
LifeWhat's the point of a fake 500-day Mars mission? Volunteers are being asked to play astronauts on a simulated Mars mission – but it's not the only way to learn how long-haul spacefarers will cope News