Geeks from Google and Harvard University built an online tool called Culturomics which checks the frequency of keywords in any books of the past 500 years.
Why should one do that?
Digitization of books (like Google is doing with their actual archive of +15 million scanned copies, which equals 12% of the total book stock of mankind) allows for the first time to reconstruct the written culture of the people by mathematical means.
A major thing to see from such data is our culture of forgetting stuff which is now to be proven by the decline in written references to the past. And this trend is gaining momentum: One could see the number of back references to events around 1900 decline to 50% within 32 years, while around 1970 it took only ten years.
Yes, we do forget faster than ever. At least one thing we learned from the new media.
quod erat demonstrandum.