This hot material from the fulgurite cavity would instead disperse up into the air, after decay of the strike pressure. This action of a fulgurite cavity has been simulated 19 by an evacuated chamber with an opening to the atmosphere temporarily sealed with a breakable diaphragm. The vortex above a fulgurite cavity is expected to form its own spherical quiescent space, thereby allowing formation of delicate filaments. The materials chosen above 19 did not contain metal elements, eliminating any long-lived oxidation and luminosity. Soot nanoparticles from the plastic pyrolysis would oxidize in several milliseconds.
Ball lightning is commonly spherical, and shows elastic behaviour.
This is consistent with observed elastic properties of nanoparticle chains 9 . Our quantitative model for a net-filled ball lightning assumes negligible temperature difference between the network and the enclosed gas, and negligible local relative motion between network and gas. By mixing, these will rapidly cool the jet to a particular final temperature. The soil particles are expected to have melted like those observed in our SEM study, and to become attached to the network. They add to the specific heat capacity of the ball.