"Books are the maps of human experience."
发现恒星围绕银河系中心的超大质量黑洞运行是天体物理学的一个转折点。
开玩笑是件严肃的事情。
I’m a great believer in solving hard problems by using a checklist. You need to get all the likely and unlikely answers before you; otherwise it’s easy to miss something important.