Modern life makes us tired, right? But research from societies in Africa and South America suggests people in the ancient world slept only 6.5 hours a night.

在全家一起守岁，迎接新一年到来的时候，细心的朋友发现：今年的除夕居然不是年三十而是年二十九！更奇特的是，这个乙巳蛇年出现了两个立春，分别在正月初六和腊月十七，是个双春年，这是怎么回事？

Scientists researching Alpine glaciers store ice in Antarctica. By analysing air bubbles in the ice they may be able to predict the future ...