SpaceThe Big Questions: Will we ever have a theory of everything? 2000 years of rational enquiry may be approaching their crowning glory. Just one more push could be enough, says Michio KakuFeatures
LifeHow Santa's reindeers work through the night Reindeer body clocks rely not on the cycle of day and night, but on their eating habits, so a well-fed Rudolph can stay awake for his Christmas duties News