我们银河系的中心是一个极端物理学发生的迷人地方，能研究它是我的荣幸。

Mathematics is not about numbers, equations, computations, or algorithms: it is about understanding.

The state, therefore, has not existed from all eternity. There have been societies that did without it, that had no notion of the state or state power. At a certain stage of economic development, which was necessarily bound up with the split of society into classes, the state became a necessity.