The night sky is our earliest library. There, we stored our knowledge, and passed it down around the fire, before we invented the written word.
I remember going to the local university for an astronomy (天文学) night when I was a child. That night, I saw Saturn, one of the planets, and its rings with my own eyes for the first time. The rings shone bright against the blackness of space and suddenly the universe (宇宙) wasn't something that you only read about or imagined in your head. It was right there, and you were a part of it. That moment is priceless.
While starlight is good, light pollution here on Earth can be a real problem. For the past 200 years or so, we have used too much electricity (电) to make the night brighter. However, brighter doesn't usually mean better, especially when a lot of that light shines up into the sky where no one needs it.
Luckily, some cities have taken actions, like setting up new downward-directing lights along the streets. I hope that more cities will join in and continue the practice of controlling unnecessary lighting, so that more of us can watch the night sky in a way humans have for thousands of years.
