Letters: How Strong is the Armstrong Evidence?
A majority of the mail this week is about our report last week on Lance Armstrong and doping allegations.
Reporting in <em>Science</em>, two teams of scientists say they were unable to replicate the results of a 2010 study claiming to have found 'alien life' on Earth--a bacterium that could build its DNA using arsenic. Science journalist Carl Zimmer talks about how the controversy played out online, and how science corrects itself.