Quantum cryptography doesn't rely on the difficulty of mathematical problems, but on the fundamental laws of physics.

半夜三更所想的事与清晨八时所想的事情太不一样。

I have always preferred working on concrete problems rather than abstract theories.

Every ending is a new beginning.

Teaching is the most glorious profession under the sun.

最重要的是在工作中要诚实。诚实是伟大表演的关键。

I have learnt how to live... how to be in the world and of the world, and not just to stand aside and watch.