I created a timeline focusing on the Raid on Mers el-Kebir, which I researched for History 299 last semester.
There have been a series of communications advancements in the past couple hundred years, from new roads, to steam power and the telegraph, to automobiles and telephones, to the internet. Downey examines the technological progression from one innovation to another, and how they have affected society. He marks the printing press and transportation networks as the first period, followed by interpersonal communication such as telegraphs and telephones, then broadcast mass communication such as radio and television, and finally communication utilizing computers.
Although it isn’t relevant to his periodization of the information age, I think it is interesting that Downey mentions that technology is not always useful when it is created. Sometimes it is simply novelty or curiosity that drives the development of a technology, rather than necessity or profits.