Many people have questioned the significance of blogs and bloggers. Some think that science blogs have no useful purpose and that they are undermining the peer review process of publication in scientific journals. Science journalists resent the fact that amateur writers can throw up something on a blog and claim that it's contributing to science education.
Over the years I've come to appreciate that science blogs do at least one thing that's new—they provide instant commentary on science news and that helps to serve as authoritative fact-checking. Science blogs monitor science journalism in the same way that political blogs monitor FOX news and the New York Times.
This role has been illustrated in spades over the past few days as we monitor the response to the NASA hype over bacteria that grow in the presence of arsenic. The weaknesses of the Science paper are now well-known thanks to many science bloggers. In the past, this kind of analysis would have had to wait for the publication of an appropriate critique in a scientific journal and that was very unlikely to happen for a number of very good reasons. Thus, in the past shoddy, over-hyped work got a free pass and science journalists who fell for the hype never even realized that they had been duped.
Read David Dobbs on Wired for a thoughtful analysis of the episode and the lesson we need to learn [Is That Arsenic-Loving Bug — Formerly an Alien — a Dog?]. It's interesting that even Nature News got sucked into promoting the hype. This shows that even journalists at the premier science journals are not very skeptical.