< p >几年前,我有机会爬喜马拉雅山。当然不是珠穆朗玛峰,但纳营地海拔约4公里。< / p > < p >期间的晚上我出去做一些空想,我发现晚上非常明亮,如此明亮,我能够辨认出字母一本书。(当然我没读。)我认为,由于几乎没有光线从地面照射空气几公里,月亮和星星的光线比较明亮(恰恰相反,为什么我们不能清楚地看到星星从一个城市)。< / p > < p >但最近它打我,好吧,晚上应该是黑暗。住在城市的人都告诉我。缺乏光源从地面将月亮< em > < / em >亮,因为将会有更大的对比但不会让月光到达地面任何光明,会吗?这困惑我。那天晚上在喜马拉雅山脉明媚怎么样?是预期的事情如果我如此之高,或有一些因素让这个夜晚如此明亮? Or are nights outside cities normally bright regardless of the altitude (assuming clear sky and near-full moon)? One thing I suppose could be the reason is that the thinner air due to the altitude meant there was less scattering of the light. I'm not sure if the air was thin enough to make such a difference though.