Listening to physics is like a fog, watching physics is like a fog, ignoring it.

Tour the West Lake and carry a tin pot. The tin pot will drip into the West Lake, but you will cherish the tin pot.

2. Modern

Listening to physics is like looking at flowers in the fog, looking at physics in the fog and ignoring physics.

Which to learn, to talk about mathematics, to go into the tree hole and observe mathematics from the tree hole?