Ball lightning is considered as self-closed alternating displacement current,
which produces air luminescence (electroluminescence).

«These facts bring out clearly that ball lightning can generate electric currents. ... Ball lightning explosion makes the impression of electric discharge upon many people, especially upon competent observers. ... Physiological action of ball lightning as usual lies in electric trauma.»
I.P. Stahanov. Physical Nature of Ball Lightning. Moscow: "Scientific World" ("Nauchny Mir"). 1996 p.106. (In Russian)
 
Thus, all facts prove that ball lightning as well as streak lightning is electric current, that is ball lightning is self-closed alternating displacement current. According to electrodynamics, current is always closed, with the conductivity currents flow in the conductors, and displacement currents in the dielectrics.
 
«For some seconds it was quiet then from the receiver there was heard some growing rustle gradually turning into boom. The receiver had to be turned off, but hissing and acute crackle was already heard from the direction of the river. Looked out the tent Dmitriev saw a ball lightning which was slowly moving above the river in the direction of the tent.»
I.P. Stahanov. Physical Nature of Ball Lightning. Moscow: "Scientific World" ("Nauchny Mir"). 1996 p.88. (In Russian)
 
The radiointerference occurrence is a direct proof, that ball lightning is an electrical current, since the chemical reactions can not cause radiointerference. There is no smoke, even at the explosion of a ball lightning (as well as of a streak), there are only sparks without smoke, that is a purely electrical phenomenon. A ball lightning is sometimes called an electromagnetic bomb. You can find a variety of assumptions about the nature of a ball lightning, up to a UFO. It has been speculated that the ball lightnings are powered with radio radiation, caused by lightning discharges of atmospheric electricity, but it is contrary to the observations. For example, the ball lightnings are observed in the premises, at that the metal roof, shielding the radio waves, has no effect on the ball lightning. Also, the ball lightning can not be just a ball of plasma, since such formation can not exist for a long time. And more, if a ball lightning is hot air, it would rise up like a flame, but this is not observed. The properties of both streak lightning and ball lightning are well-known, therefore basing on electrodynamics it is possible to imagine electromagnetic processes proceeding inside them.
 
In Nature self-closed alternating displacement currents (self-closed longitudinal electromagnetic waves) can be observed as luminescent spherical formations at thunderstorm. Great alternating (high-frequency) displacement current gradually heats up ambient air, generating luminescence of the ambient air. This can lead to such electric breakdown as an explosion (flap). These self-closed displacement currents can put electrical appliances out of operating; in addition, contacting with these appliances a human can be rushed with electric current. At thunderstorm prebreakdown displacement current flows before streak lightning. It is polarization current which is invisible before the moment of breakdown. This displacement current value is comparable with the value of current inside lightning. If the lightning changes its direction, for example, branches out, then "gaped" displacement currents close themselves, as currents are always self-closed, and can produce air luminescence (prebreakdown processes).
 
«Current strength value in the basic discharge of lightning reaches tens and hundreds thousand of Amperes.»
A.A. Detlaf, B.M. Yavorskiy. Course of physics. Moscow: "the Higher School" ("Vysshaya Shkola").2000 p.263. (In Russian)
«... energy content enclosed in the ball lightning of an average size, probably, comes to 20-50 kJ.»
I.P. Stahanov. Physical Nature of Ball Lightning. Moscow: "Scientific World" ("Nauchny Mir"). 1996 p.90. (In Russian)
 
For example, if the radius of self-closed cyclic displacement current is 10 cm, and the current strength is 50 kA, then the magnetic energy of current is about 30 kJ.
 
«... some canals were crossed in the point of branching. After the discharge was stopped a luminescent sphere remained in this place, ...»
I.P. Stahanov. Physical Nature of Ball Lightning. Moscow: "Scientific World" ("Nauchny Mir"). 1996 p.38. (In Russian)
«... a sphere, which glows as excited nitrogen atoms do.»
I.P. Stahanov. Physical Nature of Ball Lightning. Moscow: "Scientific World" ("Nauchny Mir"). 1996 p.47. (In Russian)
 
A ball lightning is air electroluminescence created by the excitation of the nitrogen atoms, which can be observed experimentally under the laboratory conditions. That is, the alternating electric displacement, acting on the electrons in the gas excites the atoms, which create the electroluminescence, which is observed as a cold air lighting. The example of ionized air lighting is the Northern Lights, and the ionized air forms a waveguide.
 
«Seemingly, rain drops which fell onto the lightning, evaporated, because a steam was going up from it. It was heard hissing which resembled sounds of electric welding. Then the sound became higher; the lightning was exploded with loud flap and disappeared. At that it fell to cascade of small sparks.»
I.P. Stahanov. Physical Nature of Ball Lightning. Moscow: "Scientific World" ("Nauchny Mir"). 1996 p.85. (In Russian)
 
After the ball lightning stopped, air was gradually heated due to polarization current, and the electric breakdown occurred. Self-closed alternating displacement current changed into conduction current. This phenomenon can be observed at contact with conducting objects. Ball lightning representing displacement current can come through the solid dielectrics of small thickness, for example, through thin glass. If lightning is not exploded, that is the electric breakdown does not occur, then displacement current gradually becomes decaying. At the same time the excitation and ionization of air atoms decrease, effect of waveguide for self-closed longitudinal electromagnetic wave disappears, and displacement current is dispersed in the space.
 
«The sphere changed its colour from scarlet to garnet, then a dark stain appeared in its centre and, at least, it disappeared.»
I.P. Stahanov. Physical Nature of Ball Lightning. Moscow: "Scientific World" ("Nauchny Mir"). 1996 p.43. (In Russian)
«If non-linear dielectric or plasma are irradiated with powerful electromagnet waves then self-sustaining dielectric waveguides can be generated inside these mediums, ...»
Physical encyclopedia / edited by A.M. Prohorov. Moscow: "Soviet Enciclopedia". 1988 p.306 (In Russian)
 
Due to the strong alternating electromagnetic field the air ionization occurs, its dielectric capacitance changes and a self-supporting dielectric waveguide emerges, in which an alternating alternating displacement current flows in the form of the closed longitudinal electromagnetic wave, there is an integer number of wavelengths on the orbit. Due to the in-phase motion of waves in an orbit all the emerging secondary waves are coherent and, according to Huygens' principle, interfering with each other, cancel each other out, that is there is no wave radiation into space. The transverse electromagnetic wave form with different polarization may be also move in the waveguide. The fact that the air ionization can create the waveguide effect can be seen from the example of the radio waves propagation around the earth as a result of the ionization of the atmosphere. Some witnesses reported the smell, that accompanies the occurence of ball lightning, it resembles the smell of ozone, burning sulfur or nitrogen oxides. Such odor characteristics are similar for the type of products, that emerge from the ionization of air molecules by a streak lightning discharge.
 
«At the ball lighting occurred in the Archangel Cathedral the smell of ozone emerged, which indicates its active interaction with the environment and the slow energy dissipation. No one, however, felt any heat from the lightning, but its light is literally blinded everyone.»
http://www.vokrugsveta.ru/vs/article/5797/ (In Russian)
 
Pre-breakdown displacement current is a current value, when there is ionization emerges, observed in the form of air cold-light, but it is still insufficient to electrical breakdown and that the displacement current transfers to the conduction current. When a ball lightning stops, ionization of the air in the surrounding space increases, making it conductive, which leads to the electrical breakdown - explosion with sparks. The displacement currents have magnetic energy, that is closed variable displacement current has a variable magnetic field, so the attraction may occur. For example, from the stories of climbers, who saw the ball lightings in the mountains, they are attracted to the iron crutches, but not attracted to titanium.
 
«Maxwell attributed to displacement current just the ability to produce magnetic field in ambient space.»
T.I. Trofimova. Course of physics. Moscow: "the Higher School" ("Vysshaya Shkola").1998 p. 250. (In Russian)
«Then the ball lightning was gravitated to a central heating radiator and disappeared with acute hissing having fused 3-4-milimeter section of the radiator.»
I.P. Stahanov. Physical Nature of Ball Lightning. Moscow: "Scientific World" ("Nauchny Mir"). 1996 p.38. (In Russian)
«Suddenly the sphere was abruptly gravitated to an oak which was in several meters from observers. A metal hook fixed on a long wooden handle was leaned against the oak. Having raised the sphere struck the hook. A blinding flash appeared, and something like the canal of average lightning was generated between the hook and ground. The extensive cascade of sparks fell, and the sphere disappeared. ... the hook was much fused, some streaks of as-fused metal appeared on it, the edge was fused at all and turned into a shapeless cone.»
I.P. Stahanov. Physical Nature of Ball Lightning. Moscow: "Scientific World" ("Nauchny Mir"). 1996 p.96. (In Russian)
«These fusions take place only in the case of direct contact with ball lightning, and are the evidence that at this contact the great amount of energy can be generated. They do not prove that lightning matter has high temperature value. The proof of this is the fact that in many cases when metallic parts of an object were much fused, non-metallic parts were remained untouched.»
I.P. Stahanov. Physical Nature of Ball Lightning. Moscow: "Scientific World" ("Nauchny Mir"). 1996 p.87. (In Russian)
 
Thus only if displacement currents are changed into conduction currents that can occur in a conducting object then the object is fused, since displacement current, in contrast to conduction current, is not accompanied with heat generation but only produces magnetic field.
 
Do not forget that in the formation of any lightning not only the conduction current is involved, but also the displacement current (invisible until the moment of breakdown), which can appear in the form of ball lightning. All properties of a call lighting are explained by the properties of prebreakdown closed the variable displacement current. The streak lightning is a conduction current, the ball lightning if a displacement current. In the streak lightning the current flows in straight lines, but in the ball around the circle. A ball lightning is a good example of that, in addition to conduction currents, there is also the displacement currents in nature, which in free state, according to the laws of electrodynamics, are always closed. That is, a ball lightning is also explained within electrodynamics, and there is no reason, for example, to refer it to a UFO or come up with a fabulous plasmoids. The singularity is a great strength of the displacement current, which causes the air luminescence (electroluminescence). Thus, it is possible to protect from the effects of ball lightning, for example, with metal screens. In contact with the conductor the displacement current changes to the conduction current and the ball lightning disappears. The Ball lightning has energy and is fairly stable field form of matter. Since all the energy (mass) of the ball lightning is field, it has virtually no weight.
 
«It emits light as a heated body, but at the same time it practically does not radiate heat. Its movement almost is not connected with gravity, which usually determines the movement of bodies which surround us.»
I.P. Stahanov. Physical Nature of Ball Lightning. Moscow: "Scientific World" ("Nauchny Mir"). 1996 p.23. (In Russian)
 
The longitudinal electromagnetic waves (in the form of variable displacement currents) have been applied so far only for the transfer of energy in waveguides. In the long term the development of closed longitudinal electromagnetic waves can lead to, for example, creation a "vacuum accumulator (battery) power" - to store energy in the form of the excited state of the vacuum (the field). As such, even a very large stored energy, according to the relation W = mc², will have almost no weight. The ball lightning is actually observed as the storage of such energy. The vacuum is a "perfect conductor" for the displacement current, wherein when the whole length of the wave fit orbit (in-phase motion of the waves - the Bohr orbits), there is no radiation. For example, if such "clumps" of electromagnetic energy are accumulated and pulsed, that at a distance the fusion (electric welding) of the conductive bodies may be produced. The electrical displacement current does not emit heat until it goes into the conduction current.
 
«Net current, which is equal to the sum of displacement current and conduction current, is always self-closed.»
B.M. Yavorskiy, A.A. Detlaf. Handbook of physics. Moscow: "Science". 1996 p.290. (In Russian)
 
The displacement currents, as well as the superconducting currents, create the magnetic field only and are not accompanied by the emit of heat.
 
Let's sum up. A ball lightning is resulting from the ionization of air self-sustaining circular waveguide carrying, along which the closed alternating electrical displacement current in the form of electromagnetic waves flows. On the other hand, the same alternating displacement current on the verge of breakdown and maintains ionization, which occurs in the form of cold air luminescence (electroluminescence). That is, when the value of the displacement current strength is on the verge of breakdown, the ionization of the air emerges, which in its turn represents the waveguide, through which the alternating displacement current flows. Such representation of a ball lightning on the basis of electrodynamics can explain such its properties, as: cold glow, occurrence of ozone smell, no smoke and air heat, lack of weight, passing through the glass, magnetic properties, metals melting, large energy supply, output of the electrical systems, radiointerference, electrical breakdown observed in the form of an explosion with electric sparks without smoke, electric shock to people at the contact with it, and so on - in other words, all of the observed properties. There are many facts which clearly indicate that ball lightning is the electrical current, so from the point of view of electrodynamics there is nothing sensational in the ball lightning, just the usual displacement current flowing in a circle. Since the bias current is not accompanied by heat emit (such as superconducting current), it may flow rather long, consuming energy only for its cold air luminescence. For example, photons are electromagnetic waves, in which the displacement current flows, and it can go on for billions of years.