All right, so maybe the one accomplishment doesn’t measure up to the other, but the map is still pretty neat.  As Gray explains it on the Inside Google Book Search blog (with a hat tip to Philipp Lenssen for discovering the post), “I wanted to show the Earth viewed from books, where individual mentions of locations in books combine to yield another interpretation of the globe.”

If this concept still hard to imagine, Gray supplied pictures of his maps and gave a more detailed explanation.  “The intensity of each pixel,” he wrote, “is proportional to the number of times the location at a given set of coordinates is mentioned across all of the books in Google Books Search.”

As you might imagine, this indicates a probable bias in the source material towards English-language books, and a bias in the maps towards places where English is spoken; Asia, Africa, and South America are all pretty much invisible (Australia, too, for some reason).

Yet Gray readily these quirks/problems, and notes that, thanks to them, “there’s a lot of additional analysis that’s fun to do.  Filtering the map by publication date, you can see global patterns like the growth and westward expansion of the United States in the 19th century.”

All right, all right – again, I admit that this is more of an interesting gadget than a revolutionary invention.  But Gray’s only been with Google for one month, so it seems that he’s off to a pretty great start.