Kardar-Parisi-Zhang scaling in kinetic roughening of fire fronts

We show that the roughening of fire fronts in slow combustion of paper [7] follows the scaling predictions of the Kardar-Parisi-Zhang equation with th ermal noise. By improved experimental accuracy it is now possible to observ e the short-time and short-range correlations of the interfaces. These do n ot adhere to any standard picture, and in particular, do not seem to be rel ated to any of the existing models of front propagation in the presence of quenched disorder. (C) 1999 Elsevier Science B.V. All rights reserved.