发明的进步使人类拥有了世纪前最大胆的想象也无法梦见的力量。
The march of invention has clothed mankind with powers of which a century ago the boldest imagination could not have dreamt.
The act of writing is an act of optimism. You would not take the trouble to do it if you felt it didn't matter.
如果你想得到一切，就放下一切。
Mathematics is not about numbers, equations, computations, or algorithms: it is about understanding.