This book covers several categories of innovation that have shaped the modern world: glass, artificial refrigeration, sound, and light.

The history of air conditioning and refrigeration is especially interesting, and merits an entire book of its own. Ice is perhaps the only commodity ever shipped from a low energy environment to a high energy environment. After books and photographs, frozen food was one of the earliest forms of time shifting.

There is also a recurring discussion of how innovations come about, through networks of innovation and the expansion of the adjacent possible.

Notes about the other categories are below:

  • Glass was once so valuable that Tutankhamen had a scarab made of it in his tomb.
  • Jazz sounded better than classical music on early (static-prone) radios, contributing to its popularity.
  • The first “flashlights” were a mixture of magnesium and gunpowder fired from revolvers by NYC police patroling slums and tenements.