PID控制器的本质在于它能够根据系统的过去和现在状态预测其未来行为。

天下的老百姓如果都向上统一于天子，而不向上统一于天的意志，那么灾祸就还没有完全离去。 

The key to performance is elegance, not battalions of special cases.

The study of mathematics is the indispensable basis for all intellectual and spiritual progress.

The past is never dead. It's not even past.

创造力不是天赋，而是一种运作方式。