Search engines narrow your information search in ways that eliminate discovery. Here's an example. I'm a grad student in a university library. I'm struggling with a particular problem in algebraic topology, so I decide to take a break and get up to walk around a bit. I go down a floor and am just walking through the racks of books and periodicals when the title of a journal catches my eye. I take it off the shelf and sit down to read a few pages and discover that research is being conducted into ancient canal building in the US desert Southwest. Now, I'm sure that if I googled "algebraic topology" eventually a link about Native American canal building in the desert Southwest would show up, right?