Today Google added some options to their main search results page. You can now filter by content type, published time, see related searches, or use something called Wonder Wheel (like a thought map of related searches) or a timeline.

I've never seen the timeline before, but I thought it was an interesting way to track the popularity of something through history. For example, a name:

For the name John, we have results going all the way back to 1100 AD. The blue line seems to represent number of mentions during that time period, so this probably isn't an accurate way to say the name "John" was more popular in the 1800s than the 1400s (simply due to availability of information during those time periods). Also, this is based solely on the mention of the word in newspapers and books.

We have more information from the 1900s available and can see that "John" was a more popular name in the 1800s. I wonder how accurately this reflects the actual usage of the name and if so, how this graph is adjusted.