The fireballs observed in our laboratory experiments differ, however, in several aspects from the ball lightning observed in nature [2]. The latter were described by eyewitnesses as possibly larger than our laboratory fireballs (up to 1 m versus 3 cm diameter, respectively), as persisting longer (for seconds versus our 0:04 s measurement), and as moving faster (0:1–10m=s versus 0:3 m=s, respectively) at a roughly constant height.
Natural ball lightnings were seen also as passing through glass windows, unlike our laboratory fireballs that slightly melt and break the glass, and then move forward. Several other features common to the natural ball lightning and to laboratory fireballs include the tendency to attach to metallic bodies (and moving or bouncing along them), the ability to be divided spontaneously [e.g., Fig. 4(b)], and their appearance in various shapes (e.g., ball and column shapes).