1981 11 00 Science et Vie No 770

Magazine Overview

Title: SCIENCE & VIE
Issue: 770
Cover Price: 10 F
Cover Headline: LA FOUDRE EN BOULE (Ball Lightning)

This issue of SCIENCE & VIE features a prominent article on "LA FOUDRE EN BOULE" (Ball Lightning), exploring this enigmatic atmospheric phenomenon. Other articles cover the isolation of cancer genes, a national food guide, and a test of 14 skis.

La Foudre en Boule: Une Brillante Énigme (Ball Lightning: A Brilliant Enigma)

The article begins by recounting the tragic death of Dr. Richman in 1753, killed by ball lightning while measuring atmospheric electricity, marking the first scientific observation of this phenomenon. It describes a typical sighting of a luminous orange sphere on a road in the Morvan region, observed by two artisans. The phenomenon is distinguished from flying saucers and meteorites, being considered a curious manifestation of atmospheric electricity.

The article differentiates between simple lightning, which has been extensively studied, and the more enigmatic ball lightning. It presents examples of unusual lightning effects, such as a strike on trees that killed sixty of them, and a strike on a fir tree that traveled to a chêne, splitting it and leaving behind hundreds of thin fibers. The typical description of ball lightning involves a luminous sphere appearing during a lightning strike, hovering near the ground, and sometimes exploding upon contact with an object. Its dimensions are compared to a grapefruit, and its duration is typically a few seconds.

Eyewitness accounts are numerous and ancient, suggesting it's not an exceptionally rare phenomenon, but its random nature makes it difficult to study and photograph. The article notes that some researchers, including prominent ones, are skeptical due to the lack of concrete evidence.

Challenges in Study and Observation:

The primary difficulty in studying ball lightning is its rarity and unpredictable nature. While laboratory reproduction is impossible due to the immense energies involved, some research stations exist, like the one in France at St-Privat-d'Allier, though US stations have more frequent storms.

Diversity of Observations:

Testimonies vary significantly regarding the size (1 cm to 1 m), duration (fraction of a second to an hour), and color (white to orange) of the luminous balls. American researcher Rayle of NASA proposed considering any object described as ball lightning by a witness, allowing for the identification of different classes of phenomena.

Categories of Ball Lightning Phenomena:

1. Balls observed in contact with objects or the ground: These include the case observed in Morvan, which had an unusually large diameter and long duration (nearly an hour). Other cases involve luminous spheres appearing on the ground at the point of impact, with diameters typically between 10 and 30 cm. This category also includes luminous balls observed on high-tension wires, mountain cable car cables, and crane cables.
2. Balls preceding lightning: These observations involve a luminous ball preceding a lightning strike, often seen falling on a church steeple and rolling down tiles before the lightning hits. Specialists separate these from strict ball lightning cases.
3. Strict Ball Lightning: This category, illustrated by the testimony of an EDF engineer, involves a luminous ball floating freely indoors, not touching any object, for several seconds. The example describes a melon-sized ball moving through a house, causing small holes in paper, indicating high voltage.

Explanations and Theories:

• Optical Illusions: This explanation has been largely abandoned because witnesses consistently describe the ball moving with them, and multiple witnesses report the same trajectory, unlike a persistent retinal image.
• Electrical Phenomena: The phenomenon is undeniably linked to atmospheric electricity.
• Powell and Finkelstein's Theory: This suggests a difference in the ionization potential of the air near the ground, possibly due to a low concentration of volatile organic vapors from decomposing organic matter. This could create a localized area of combustion.
• P. Hubert's Experiments: Experiments at St-Privat-d'Allier produced luminous balls near simulated chimney conduits filled with soot, which emitted organic vapors that modified air ionization potential. These balls had durations similar to lightning flashes.
• Chemical Combustion: This theory is discounted because it doesn't explain the electrical phenomena observed.
• Nuclear Reactions: Ruled out due to the lack of radiation effects on witnesses.
• Confined Plasma: This hypothesis is rejected because the phenomenon's duration (2-3 seconds) is too long for plasma confinement by magnetic forces from the currents within the ball.
• Electromagnetic Wave Concentration: This theory suggests energy is accumulated as molecular excitation in a metastable state, explaining the long duration. Barry termed this "molecular electroluminescence."

Certainty and Remaining Mysteries:

It is certain that the phenomenon is electrical. Two examples support this: the observation of a luminous ball in a country house that disappeared after nearby high-tension pylons were grounded, and the phenomenon of "beaded lightning" (éclairs en chapelet), which consists of a series of luminous balls along the lightning channel.

While the formation of luminous balls along a lightning path is scientifically accepted, and the persistence of such a ball at the impact point is also considered a fact, the exact mechanism of its formation and persistence remains an enigma for physics.

Other Articles

• On a isolé des gènes du cancer: Research has successfully isolated genes related to cancer.
• Un guide alimentaire national: The issue includes a national food guide.
• 14 skis au banc d'essai: Fourteen skis have been tested on a bench.

Recurring Themes and Editorial Stance

The magazine consistently explores scientific advancements and unexplained phenomena. The editorial stance appears to be one of objective reporting and scientific inquiry, presenting various theories and eyewitness accounts while acknowledging the limitations of current scientific understanding, particularly concerning complex natural events like ball lightning. The focus on "LA FOUDRE EN BOULE" suggests a continued interest in mysteries that bridge the gap between the known and the unknown, often touching on topics that border on the paranormal but are approached with a scientific lens.