flu
rabies
positive feedback
A hurrican requires positive feedback. The feedback: the winds
mix up the warm water and the air faster. This produces more
winds. As a result the storm builds itself.
Tornadoes must do same. Column of ascending/descending air with
coriolis spin.
Flu, rabies: the infected infect others. Positive feedback.
Vicious spiral some disciplines approximate.
but its positive feedback. In nature, its awesome. Evolution
is positive feedback.
