Nevertheless, balancing the precise measurement conditions for such an experiment would still be a challenge. It could be achieved, for instance, by diffracting small, charged crystals of a dense material like osmium. If each crystal has a mass M = 5.6×10 -18 kg, its radius is about 0.04 m and could be diffracted at a grating with a d = 0.4 m period (Figure ). It would have a Diósi-Penrose collapse time of just about 1334 s using ( ) with  = 25.2 a0 -2 (fitting in Table with Rat = 2.44 Å given in ref. ). If it is prepared at velocities as low as v = 10 -3 m/s, the Talbot length (L = Mvd 2 /h, where h is the Planck's constant) would be about L  1.3 m. With these parameters, the wave/particle would travel for about one-third of a day before reaching the first L point, which is (on purpose) near the collapse time. To give an idea of how far we are from such a setup, some of the matter-wave diffraction studies with the biggest masses were made with molecules with about 10 -22 kg (2000 atoms) and Talbot length under 2 m. In turn, quantum interference with wave packets separated by 0.5 m on a scale of 1 s was reported for ultra-clod atoms. Other proposed setups to verify the Dósi-Penrose model experimentally are discussed in refs. 6, 15, 30, 33, 55-59