Google has released a remarkable toy for history buffs and armchair sociologists: The so-called Google Ngram, which allows you to see how often a given word has been used in books, ever since 1800.
The tool can create a fascinating snapshot of historical macrotrends based on buzzwords. Above, for example, we see the development of energy in the United States, with "steam" peaking in the early 1900s, and "nuclear" in the 1980s. (Contrast that to electricity, which stays pretty consistent throughout time, evidence that it hasn't -- and isn't -- going anywhere.) Below, we have a portrait of media: Magazines and newspapers peaked in the 1940s. The Internet, meanwhile, starts creeping up before the millennium and looks poised to overtake its print brethren in the near future. It's something everyone talks about, but rarely do we see it in such stark visual form.
Here's our ever-increasing obsession with the apocalypse (or at least writing books that tap into people's fear of the apocalypse):
And a huge dip in the frequency of "Christian," as western society itself grows more secular:
Ngram works by showing the percentage a single word or phrase pops up in books compared with other words or phrases over time. You decide on the terms and things like the dates and language you want to include, and how raw you want the data. Play around with it here.