Title: Explosions of ball lightning inside enclosed premises

Abstract:

Sooner or later, the life of ball lightning ends. Having exhausted the supply of energy, it can “dissolve” in the air without a trace or disappear, leaving traces on the painted floor in the room [1, 2]. But in the case of a “violent” death, ball lightning does not have time to use up its energy reserve, and the consequences of its explosion can become significant. The death of ball lightning can occur when it collides with some obstacle. At the same time, a sheaf of sparks flies out of it - elements of its energy core. On May 27, 2013, ball lightning exploded inside a log house in the village of Mogsokhon in Buryatia (Russia). The wall of the house fell out from the explosion, windows and doors were squeezed out, sheets of slate on the roof were torn off (see Fig.). Surprisingly, the owner, Rada Sandanova, who was next to the ball lightning at the time of the explosion, suffered, but remained alive. The energy of this ball lightning, estimated from the equivalent effect of an explosion of TNT, turned out to be about 30-130 MJ [3]. The literature describes similar cases of explosions of ball lightning inside the premises, which caused great destruction. Brand [5] had described the aftermath of a ball lightning explosion on 22 March 1914 in a church in the village of Poggio tre Crosi. The explosion squeezed out the doors, split the pillars of the windows, destroyed the facade of the church. In the summer of 1938, in the Vologda Oblast (Russia), ball lightning the size of a soccer ball exploded inside a smithy. As a result, the wall of the smithy fell to the ground [1]. The witness, being inside the smithy, survived. In August 1924, in the village Gvozdki (Russia), during a thunderstorm, ball lightning penetrated into the hut through the chimney [5]. Having exploded on the stove next to a dough tub, it threw the tub and the boy sitting by the window into the street at a distance of about 20 meters. The boy was not hurt. These features of the action of ball lightning can be explained on the basis of the electrodynamic model [6]. According to this model, ball lightning has an electric charge Q of 10^-3 - 10^-1 C. The charge is inside a spherical shell of radius R, consisting of water molecules, and stretches it with the force F_em = Q²/4πε₀R². Opposite to this force is the shell compression force caused by the polarization of the shell material, F_sh = 2σaQ/ε₀R, where σ = 1 C/m² is the surface charge density of dipoles (water molecules), and a is the shell thickness. When the shell breaks, charge carriers settle on the walls of the room and push them apart from the inside. According to the observation, in 1938, ball lightning with a radius of 16 cm with a shell thickness of a = 2.5 cm exploded in the smithy. Based on the equality F_em = F_sh, we find the charge of ball lightning Q_bl = 8πσaR = 0.1 C. Such a charge, deposited on the wall of a sphere with a radius R_k = 2 m, presses on its surface with a force F_k = Q_bl²/4πε₀R_k² = 2.25·10⁷ N.

For the case of a ball lightning explosion at the furnace [5], ​​it can be assumed that ball lightning with a charge of 3.5·10^-3 C transferred a charge of 3.5·10^-5 C to the dough tub. Starting from this charge, the tub acquired a speed sufficient to fly out of the window of the hut. So, it can be concluded that the effect of a ball lightning explosion differs from that of a domestic gas explosion. In the latter case, destruction is caused by a shock wave. In contrast, the charge of ball lightning “smoothly” pushes

Biography:

Anatoly Ilyich Nikitin is a physicist. In 1965 he graduated from the Faculty of Physics of Lomonosov Moscow University. In 1965 he received a PhD in Physics and Mathematics from the Lebedev Physical Institute, and in 1989 he received a Doctor of Science in Physics and Mathematics from the Karpov Research Institute of Physics and Chemistry. He was engaged in the creation and study of a hydrogen maser and high-power pulsed chemical lasers on reactions of fluorine with hydrogen and deuterium. He studied selective chemical reactions during laser multiphoton dissociation of freon molecules, which are used to separate carbon isotopes, and also studied gas combustion processes stimulated by plasma. In 1998, he proposed a new model of ball lightning and then for 20 years was engaged in modeling its properties. In 2008, he was elected Secretary of the International Committee of Ball Lightning. In 2022, he published the monograph "My Ball Lightning".