Mathematics is not about numbers, equations, computations, or algorithms: it is about understanding.
数学不是关于数字、方程、计算或算法的:它是关于理解的。
The truth is, we are all waiting for something to happen, even when we don't know what it is.
We must build a world in which there shall be no economic domination, no exploitation, no unemployment, and no war.
永远不要停止提问——进步就从那里开始。
The art of living is to know when to hold fast and when to let go.