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(color online). Magnified color images of ball lightning in different time. Saturation pixels are not present in the images. The intensity profile across the image is presented below. The abscissa represents the pixel sequence and the vertical ordinate represents the intensity. FWHM represents the full width at half maximum. The side length of a pixel corresponds to 1.1 m in the images.
Source publication
Ball lightning (BL) has been observed with two slitless spectrographs at a distance of 0.9 km. The BL is generated by a cloud-to-ground lightning strike. It moves horizontally during the luminous duration. The evolution of size, color, and light intensity is reported in detail. The spectral analysis indicates that the radiation from soil elements i...
Contexts in source publication
Context 1
... magnified images of the BL, recorded by the digital video camera, are provided in Fig. 2. As evident in Fig. 2 and Supplemental Material Fig. 1 [18], the color of the BL varies with time. It presents powerful purple white at the beginning, then changes to orange at 80 ms. It approximately keeps the color of white from 160 to 1100 ms and changes to red at the dissipating stage after 1120 ms. Meanwhile, the change of ...
Context 2
... magnified images of the BL, recorded by the digital video camera, are provided in Fig. 2. As evident in Fig. 2 and Supplemental Material Fig. 1 [18], the color of the BL varies with time. It presents powerful purple white at the beginning, then changes to orange at 80 ms. It approximately keeps the color of white from 160 to 1100 ms and changes to red at the dissipating stage after 1120 ms. Meanwhile, the change of first-order spectrum of the ...
Context 3
... stage after 1120 ms. Meanwhile, the change of first-order spectrum of the BL is also consistent with the variation of color (Supplemental Material Fig. 1 [18]). The BL appears to be roughly a spherical shape. The intensity profile across the image shows the peak intensity, the total intensity (area under the curve), and the size, as seen in Fig. 2. The position of the peak intensity corresponding to the center of the BL moves nine pixels in a horizontal direction from 20 ms to 1160 ms, indicating that the average 2D speed of BL is about 8.6 m=s. Considering the BL may simultaneously move in a line-of-sight direction, the actual speed of the BL should be faster than the 2D speed. ...
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A technique was developed for the comparison of observed emission spectra from lightning current arcs generated through self-breakdown in air and the use of two types of initiation wire, aluminum bronze and nichrome, against previously published spectra of natural lightning events. A spectrograph system was used in which the wavelength of light emi...
Two positive cloud‐to‐ground lightning spectra have been captured by a slit‐less spectrograph. In combination with the synchronous electric field change waveshape, the discharge characteristics along the channel have been investigated. The results show that the total intensity of ionic lines in spectra and the electrical conductivity increase with...
Citations
... One of the issues with the ball lightning hypothesis is that it is such a rare, and rarely recorded event, that its existence is not accepted by all researchers. However, relatively recent research has confirmed what is believed to be a ball lightning incident 28 . ...
Sightings of unidentified flying objects (UFOs) or unidentified anomalous phenomena (UAP) have been reported throughout history. Given the potential security and safety risks they pose, as well as scientific curiosity, there is increasing interest in understanding what these sighting reports represent. We approach this problem as an important one of the human experience and that can be examined through a geographical lens: what local factors may increase or decrease the number of sighting reports? Using a Bayesian regression method, we test hypotheses based on variables representing sky view potential (light pollution, tree canopy, and cloud cover) and the potential for objects to be present in the sky (aircraft and military installations). The dependent variable includes over 98,000 publicly reported UAP sightings in the conterminous United States during the 20-year period from 2001 to 2020. The model results find credible correlations between variables that suggest people see more “phenomena” when they have more opportunity to. This analysis is one of few investigations of UAP sighting reports at a national scale providing context to help examine individual reports. Given that these objects are labeled unidentifiable in the personal sense, there are many natural and/or human based explanations worth exploring.
... It can be assumed that some natural ball lightnings [15], like Coulomb balls, consist of charged particles. Thus, in [18], based on the optical spectrum of a luminous ball observed after a lightning strike into the CHEMICAL PHYSICS OF ATMOSPHERIC PHENOMENA ground, it was found that such ball lightnings include excited and charged particles of various soil components. The ball lightnings and Coulomb balls formed in thunderstorm conditions can be represented as a result of the self-organization of charged particles of condensed matter inside the plasma region, which is formed under the influence of a strong electric field or upon contact with a plasma that accompanies various atmospheric electrical phenomena observed at different densities and at different altitudes of the atmosphere. ...
A model for calculating the surface tension coefficient of a spherical cloud of charged microparticles in a plasma is proposed. The coefficients of the surface tension of Coulomb spheres obtained in a lowpressure glow discharge in neon at a temperature of 77K for particles with a diameter of 4 μm and a temperature of 295K for particles with a diameter of 2 μm are calculated. The potential energy of microparticles on the surface of a sphere is determined. In the calculations, a hydrodynamic model of a positive column with charged microparticles is used. The obtained values of the surface tension coefficient are compared with the data obtained by other authors for ball lightnings. A hypothesis is proposed for the formation of Coulomb spheres in the Earth’s atmosphere.
... The curl term may indicate vortex structures in the electric field, akin to those seen in fluids. For instance, ball lightning, a rare and unexplained luminescent spherical object phenomenon [31], may be a potential candidate to study vortex structures in electric fields. ...
Weber’s electrodynamics presents an alternative theory to the widely accepted Maxwell–Lorentz electromagnetism. It is founded on the concept of direct action between particles, and has recently gained some momentum through theoretical and experimental advancements. However, a major criticism remains: the lack of a comprehensive electromagnetic wave equation for free space. Our motivation in this research article is to address this criticism, in some measure, by deriving an electric wave equation from Weber’s electrodynamics based on the axiom of vacuum polarization. Although this assumption has limited experimental evidence and its validity remains a topic of debate among researchers, it has been shown to be useful in the calculation of various quantum mechanical phenomena. Based on this concept, and beginning with Weber’s force, we derive an expression which resembles the familiar electric field wave equation derived from Maxwell’s equations.
... It travelled then at 8.6 m/s on a nearly horizontal level. The spectrum indicated that the membrane contained atoms resulting from vaporization of the ground [42]. They were rapidly dispersed in atmospheric air. ...
... A planar transmission grating with 600 lines per millimeter was installed in front of the objective lenses of the cameras. The spectral response range of the spectrographs was from 400 to 1000 nm, and the spectral resolution was about 1.1 nm [27]. The two spectrometers were placed at the same observation site, 2-3 meters apart. ...
Temperature is one of the crucial parameters reflecting the energy and current transfer characteristics in lightning discharge plasma channels. According to the spectra of six lightning return strokes discharges recorded simultaneously by two high-speed slit-less spectrographs with different time resolutions, the spectral intensity and temperature evolution of the plasma channels over time was quantitatively analyzed. The spectral characteristics show that the ionic line intensity decayed rapidly with time as the current declined, while the atomic line intensity decreased more slowly. Additionally, it is found that the ionic lines existed for a much longer time than previously reported values, up to hundreds of microseconds in the spectra of continuing current process. It further indicates that the ionic line intensities are associated with the discharge currents and that their radiation mechanisms are closely related to the collision excitation under the action of strong currents. The temperature calculated by the ionic lines can reflect the thermodynamic properties of the current-carrying channel. The temperature calculated using atomic lines is significantly lower than that calculated by the ionic lines in the same spectrum. The radiation mechanism for a majority of the atomic lines differs from that of the ionic lines. During the continuing current, the channel temperatures calculated by both ionic and atomic lines showed a similar evolution feature which declined slowly or even remained basically unchanged. This property reflects the persistent heating effect of the current.
... For example, Abrahamson and Dinniss 9 have predicted the temperature at the center of a 15-cm-radius BL-like ball, and Stephan and Massey 10 have roughly estimated the luminous-sphere temperature by silicon discharge spectra. Cen et al. 11 first reported the spectra of the object that occurred just at the bottom of a cloud-to-ground (CG) lightning and had the main features of ball lightning, they and the authors of this paper identified it as natural ball lightning. According to these spectra, namely, the data for the Fe I lines, Shmatov and Stephan 12 have estimated its temperature. ...
... So far, however, there has been hardly any detailed investigation on the temperature of the BL based on experimental observation. In this work, according to the spectra of the BL recorded by Cen et al., 11 we have calculated the temperature of this BL and analyzed its evolution properties for the first time, which will provide reference data for further studies on BL's physical characteristics. ...
... Spectra images of a BL investigated in this work were simultaneously captured by two slit-less spectrographs with a high-speed camera (M310) 11 and a digital video camera as the recording system, respectively. Two cameras were operated at 3000 frames per second (fps) with a spectral response range of 400-1000 nm, and at 50 fps with a spectral response range of 400-690 nm, respectively. ...
Based on the spectra of an apparent natural ball lightning (BL) taken by a slit-less spectrograph with a high-speed camera as a recording system in the Qinghai Plateau of China, the temperature and time-evolution characteristics of this object were investigated. We found that for most of its life, the BL maintains a generally stable luminosity with an obvious periodic oscillation that is only discernible on the spectra captured by the high-speed camera. Soil constituents (Si I, Fe I, and Ca I lines) contribute the majority of bright light, while air compositions (N I and O I lines) dominate the periodic feature of the BL. There are some differences between the temperature values calculated by the spectral lines of different elements in the spectrum. The temperature estimated by the O I lines was the highest, ranging from 7170 to 11 410 K. The mean temperatures gained by O I, Si I, and Fe I lines and continuous spectra were 8750, 4330, 4600, and 2700 K, respectively. This means that the BL has an energy source core, where the spectral lines with higher upper excitation energy should be more intense than that in its periphery. In addition, during the luminously stable stage, the temperature showed an obvious periodic oscillation with time, and its variation tendency was synchronous with the evolution of the light intensity and spectral characteristics.
... This model is suggested to be validated with the existence of Ball Lightning of different sizes which could be reproduced experimentally with high density energy spherical and toroidal magnetically self-confined plasmoïds, activated with 3D stationary solitons (solitary wave is a self-reinforcing wave packet that maintains its shape while it propagates at a constant velocity) [146][147][148][149][150]. We propose next, some new definition of mass and electric charge of particles, and of corresponding gravity and electromagnetic fields. ...
Theories of relativity and quantum physics are basing on some complex abstract mathematical formalism which can be quite confusing and not always satisfactory concerning the interpretation of observed corresponding physical effects. For a revised approach of them, we present a new quantum vacuum energy Aether concept we will discuss qualitatively avoiding some abstract mathematical formalism often far from intuitive physical common sense. This is essentially concerning: the relative velocity of light and the Aether disprove, the particle/wave duality, the single particle interference quantum phenomena, the generalized confusion between absolute quantum determinism and undetermined probabilistic measurements of quantum states and the paradoxical possibility for a same quantum system to have at same time different states. Notwithstanding different suggested flaws about the principle of energy and impulse conservation and concerning the optical doppler effect and the postulate of an absolute light speed limit which is contradicted with some observation of superluminal particle transportation velocity. Paradoxical aspects of both theories of the quantum mechanics and theory of relativity are suggested to be sorted out with the rehabilitation of an absolute space reference and a newly defined Aether concept, basing on the equivalence between density of mass and density of quantum vacuum energy. Different aspects of the Field Theory and wave /mass /electric particles interactions are suggested to be interpreted in terms of Aether hydrodynamical energy displacement, fluctuation and waves. Electric charge and mass of particles and their kinetic energy are described in terms of energy of an associated Aether 3D transversal and/or longitudinal wave-packet moving with its group velocity in form of Aether vortices. This model is expected to sort out contradiction about different quantum phenomena and to open the way for new description and interpretation of corresponding new experimental results.
... In these experiments none of these characteristics or fields are present. It could be also tempting to associate the reported plasma to more exotic structures, like ball lightning [29], but precisely its elusive nature, that only recently and by chance has allowed to document its presence and explore it with some detail [30], at least for a certain subclass of the phenomena, excludes the comparison. ...
Copper gas produced with the exploding wire technique at times much larger than the total current lifetime has been explored, and its excitation temperature estimated from spectrographic data. It has been found that excitation temperature is stable for microseconds after the electrical current finish to flow and dependent only on charging voltage for the conditions of these experiments, with plasma spectra taken at instants more than 10 times longer than total electrical current discharge.
... [1][2][3][4] Observation of the lightning spectrum is the most effective way to reflect the plasma characteristics inside the lightning channel. 5,6 The lightning spectrum has been used to study the physical processes of lightning discharge for over a century. 7 In the 1960s and early 1970s, the techniques of slitless spectroscopy were applied to obtain the lightning spectrum, and numerous works were reported. ...
The high time-resolved spectrum of natural lightning is obtained by a slitless spectrograph. The spectrum of natural lightning is compared to the spectrum of laser-induced air plasma. The results show that the spectra of lightning and the spectra of laser-induced air plasma are similar, but they also have some differences. In the superimposed spectrum of lightning, the intensities of atomic lines are far stronger than those of ionic lines, and the continuous spectrum in the whole wavelength region is very strong. However, in the spectrum of laser-induced air plasma, the intensities of atomic lines are similar to those of ionic lines, and there is almost no continuous spectrum in the near-infrared region. In addition, the Hα line is strong in the lightning spectrum but very weak in the spectrum of laser-induced air plasma. The temperature, electron density, and conductivity are calculated, and their evolution with time is also given. The differences in the three physical parameters between lightning and laser-induced air plasma are analyzed. In addition, the reasons of spectral differences have been explained. These results will provide an important reference for the simulation of the lightning spectrum.
... When ball lightning enters the region of the external electric field, because condition (7) holds true, the electric field strength that ignites the discharge changes and it affects the intensity of the BL glow. This is related with a periodic change in the intensity of the BL glow (spectral lines of nitrogen and oxygen) at a 100 Hz frequency of a high-voltage transmission line near which the ball lightning was observed 4 . ...
The structure of materials with a negative electric susceptibility has been determined. Their electrical properties correspond to vanishing static dielectric permittivity. We give a theoretical explanation of anomalous polarization of powders observed in experiments and the mechanism of emergence in an aerosol cloud of an electric field, which is responsible for spark discharges (lightnings). We also explain the ball lightning properties known from observations. A fundamental scientific problem has been solved and the grounds have been laid for applications of new principles in electronics and electrical engineering.
