On technological ages

In Sim-Earth, the population's settlements were marked by what technological age they were in: stone age, bronze age, nuclear age etc.

I got to thinking that the past century could be divided up into 'ages', where rapid development was being made and mainstream opinion was largely positive.

1800s:Steam age
1900s-1940s: Mechanical Age
1950s: Nuclear age
1960s-1980s: Chemical Age
1990s-present: Electronic Age