  We re-examine previous observations of folding kinetics of compressed lipid
monolayers in light of the accepted mechanical buckling mechanism recently
proposed [L. Pocivavsek et al., Soft Matter, 2008, 4, 2019]. Using simple
models, we set conservative limits on a) the energy released in the mechanical
buckling process and b) the kinetic energy entailed by the observed folding
motion. These limits imply a kinetic energy at least thirty times greater than
the energy supplied by the buckling instability. We discuss possible extensions
of the accepted picture that might resolve this discrepancy.
