The dinosaurs became extinct because they didn't have a space program. And if we become extinct because we don't have a space program, it'll serve us right!

当一个人用本真的面目说话时，他最不像自己。给他一个面具，他就会告诉你真相。

真正的挑战不在于解方程，而在于理解解的含义。

A woman must have money and a room of her own if she is to write fiction.

To every action there is always opposed an equal reaction； or， the mutual actions of two bodies upon each other are always equal， and directed to contrary parts.