The successful detection of interference fringes with about 40% visibility implies that C70 was in a state superposition involving at least two neighbor slits. More recently, Arndt and colleagues used a similar setup to demonstrate quantum interference for molecules with up to 2000 atoms. Using the fullerene geometries from ref. (available at nanotube.msu.edu/fullerene), we estimated the Diósi-Penrose collapse time of diverse fullerenes under conditions like those of the Talbot-Lau interferometer. We only considered interference between two neighbor slits of the grating, simplifying the estimate to a two-state problem. The original fullerene geometry was assumed to correspond to one of the states. For the second state geometry, we rigidly translated the original geometry along direction x by 991 nm. This information and the Gaussian width for carbon nuclei (given in Table ) are all we need to compute the gravitational self-energy with ( ) and the collapse time with (4).