So, I guess the night sky ISN'T actually dark to begin with. Right… so if our telescopes tell us that the night sky isn't dark, then why does it look dark?

因此我觉得，夜空从一开始就不是黑的，而既然望远镜告诉我们，夜空不是黑的，那它为什么看上去是黑的呢？

youdao

Just after dark every night, two hyena men begin their ritual at sites just outside the city walls.

BBC: Africa��s wildlife in the raw