过去是知识的源泉，未来是希望的源泉。热爱过去意味着对未来的信心。
我们教授一门学科不是为了培养关于该学科的小型活图书馆，而是让学生自己学会数学思考。
In the quest to understand quantum gravity, we are like children playing on the shore of a vast ocean, occasionally finding a smooth pebble or a pretty shell, while the great ocean of truth lies undiscovered before us.
The theory of probabilities is at bottom nothing but common sense reduced to calculus.