电流概念的形成是电学理论发展中最重要的步骤。

The greatest tragedy is not to die, but to be forgotten.

如果你不知道你要去哪里，任何路都会带你到达那里。

"A dreamer is one who can only find his way by moonlight, and his punishment is that he sees the dawn before the rest of the world."

在理论物理学中，近似的艺术往往比精确解更重要。