As a child, Ronald Mallett wanted to travel back in time to try to prevent his father’s death, and hence went on to study physics. Despite now believing that the present cannot be affected by meddling with the past, he has announced his intention to build a ‘time machine’ based around circulating laser beams, using equations based on Einstein’s work on realtivity. The project is in need of financial backers, but he reckons he can have the desktop device made and ready to confirm (or falsify) his theory within a decade. Stop giggling at the back.