最近，我探索了火星表面的一片区域，那里有一个看起来像巨大舱盖和孔洞的结构，直径约10公里，周围布满了许多圆形陨石坑。这个结构对我来说既独特又奇异，似乎曾经移动过，分裂成两部分，其中一半似乎消失了。 黑色部分是这个结构本身，蓝色部分是它 ...

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.

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.