HealthChilling book exposes true cost of tech bros' immortality dreams Why does it matter that Silicon Valley's tech bros are out to cheat death? Graham Lawton finds out in Aleks Krotoski's The Immortalists, a disturbing new book that charts the territory with brilliantly dispassionate reporting Culture
SpaceBlue Planet Red is wrong about Mars – but it's surprisingly poignant Brian Cory Dobbs's documentary promotes the baseless idea that Mars was once inhabited by an advanced civilisation. But there's some value in how it inadvertently documents a generation of otherwise-sensible scientists, says Simon IngsCulture