Perhaps the coolest thing about writing a book is that you have an excuse to interview people you otherwise wouldn’t get to talk with.

Today I interviewed Victor Henning, the co-founder of Mendeley, a very popular desktop app for researchers that indexes your PDFs, provides social reading and researching tools, and aggregates anonymized information about what researchers are actually reading and annotating. There’s a lot packed into Mendeley, all designed to help researchers find out what they need to know, primarily though social means.

Victor and some friends founded Mendeley as grad students when they discovered that although they were in different fields, their research needs and processes were very similar. In the twenty months since its launch in January 2009, it’s grown to 450,000 users, with 33 million documents in its database.

I’m thinking of using Mendeley as an example of how the scientific landscape has changed. Although it’s hard to find uncredentialed amateurs who, thanks to the Web, have made large individual contributions to science — for most of the sciences, you need lots of training and access to expensive equipment — the Net has changed the world in which credentialed experts work. For example, Mendeley is able to provide a much more responsive picture of the trendlines in scientific research than the “impact factor” by which journals measure their significance; the impact factor looks at the number of citations of the articles in a journal over the prior two years, divided by the total number of articles in the journal. Two to three years is a long time to wait to measure impact. Plus, as Victor points out, Mendeley can be much more granular.

As Victor says: “My personal opinion is that some form of credentials will always matter. It’s a heuristic to decide if some other person can be trusted. But credentials will not just be that someone is a tenured profession or is at a top isnstution or is published in Science or Nature. In the Mendeley context it may be that his paper has lots of readers, or lots of rankings or tags.”

The old authorities and credentials are still there and are likely to continue to have weight. But the ocean in which they swim is now filled with a lot more fish.