Alice in a micro-factory: modeling materials and mechanisms of natural nano-machines

Imagine an under water factory which is about $10 \mu$m long in each direction. The factory is filled with machines, each typically a few tens of nanometers long, which perform specfic tasks and operate in a well coordinated manner. A cell, the structural and functional unit of life, is not very different from this micro-factory. In this article, I begin with Alice's guided tour of this micro-factory in her dream during which the guide shows her wide varieties of the nano-machines in this factory. The style of presentation of the first half of this article is inspired by Lewis Carrol's {\it Alice in Wonderland}. In the second half, I introduce the methods of studying the materials and mechanisms of the molecular machines through dialogues; the three participants in this discussion are Alice, her elder brother Alex and her father Albert. The style of presentation of the second half of this article, in terms of a dialogue, is adapted from Galileo's {\it Dialogue Concerning the Two Chief World Systems}. Albert, a professor of biophysics, emphasizes the crucial differences between the mechanisms of the natural nano-machines and those of their macroscopic counterparts. He also points out some practical applications of this interdisciplinary research in biomedical science and nano-technology.