On Aetiology, Tara C. Smith continues her series on the science of The Walking Dead, explaining how diseases spread and how they might cause zombiism. One thing that would be observed in any real contagion would be an incubation period— the time between when a virus (for example) enters your body and you start showing symptoms of infection. For a virus like the flu, this could be about two days during which you don’t feel sick but could still be infecting people around you—even if you don’t bite them. Tara also expresses nerd rage at the show's "doctors" pursuing antibiotics to treat the flu…