Explicit analytical expressions for the linear growth (and decay) rate
s of long-wave modes in Benard-Marangoni convection are derived and di
scussed. These analytical predictions are shown to be in good agreemen
t with experimental observations and are used to estimate the minimum
experimental time necessary in order to observe the long-wave instabil
ity under microgravity conditions. (C) 1997 American Institute of Phys
ics.