Chapters 19-27 Summary

Dr. Breed explains that scientists, whom he characterizes as "playful," often work on projects suggested by admirals and generals. For example, Dr. Hoenikker was working on a project to eliminate mud suggested by a Marine general. The Marines have been slogging around in mud for 200 years. The general further suggested that Dr. Hoenikker invent a tiny pill or capsule to eliminate it, because they were tired of carrying heavy equipment. Dr. Hoenikker was intrigued by this puzzle and conceived of one microscopic grain to solve the problem.

John expresses doubt that any tiny molecule could solve the mud problem. Dr. Breed disagrees. He explains that materials can crystallize in one of many different ways. He suggests that John visualize the different patterns that cannonballs could be stacked in front of a courthouse. These different patterns, or different crystals of the same...