1976 03 00 Science et Vie No 702

Magazine Overview

This issue of "Histoire des Techniques" (History of Techniques) tackles the monumental engineering challenges faced by ancient civilizations and explores the nature of Unidentified Flying Objects (UFOs).

The Enigma of Giant Statues and Megalithic Constructions

The cover story, "QUI A AIDÉ NOS ANCÊTRES A PORTER LES STATUES GÉANTES?" (Who Helped Our Ancestors Carry the Giant Statues?), challenges the notion that supernatural forces or extraterrestrials were necessary for ancient construction. The article, drawing on the work of architect and archaeologist Jean-Pierre Adam, argues that ancient peoples possessed sufficient technical knowledge and simple machines to accomplish these feats.

Baalbek's Colossal Stones

The magazine details the immense stones of the Roman sanctuary in Baalbek, Lebanon, particularly the "trilithon" which consists of three stones weighing approximately 800 tons each. J.P. Adam's proposed method for moving these stones involves a sophisticated system of capstans and pulleys. He suggests using 16 capstans, each with eight bars and operated by 32 men, connected to 4-pulley block and tackle systems. This would require a total of 512 men. The article calculates the forces involved, noting that while rolling the stones on cedar logs required a force of about 660,000 newtons (66 tons-force), placing them on their final foundation, where friction was higher, would demand significantly more force.

The Mystery of the Easter Island Moai

The issue also addresses the enigmatic Moai statues of Easter Island. While the largest statues weigh around 80 tons (significantly less than the Baalbek stones), their transport and erection remain a puzzle due to the limited knowledge of the islanders' technological development. The article dismisses the idea of anti-gravity, as proposed by explorer Francis Mazière, suggesting that the statues were carved in situ and then slid down ramps. J.P. Adam offers an alternative hypothesis: rotating the statue around an eccentric pivot point, a method he compares to how some Africans move canoes.

Ancient Egyptian Engineering: The Pyramids

Focusing on the Great Pyramid of Cheops, the article debunks fantastical theories by citing historian Hérodote, who reported that 100,000 men worked for 20 years on its construction. The pyramid is estimated to be made of 2,300,000 blocks, each weighing 2 to 3 tons, totaling about 6 million tons. The article calculates the effective power required for its construction, suggesting that a 40-horsepower engine could have performed the same work, highlighting that time and manpower, rather than supernatural aid, were the key factors. It is noted that ancient Egyptians likely did not use pulleys, relying instead on inclined planes and sleds.

Roman Mechanical Ingenuity

The magazine showcases Roman mechanical devices, including various types of winches (treuils), cranes (chèvres), and capstans, with detailed calculations of the forces they could generate. These examples illustrate how Romans applied principles of levers and pulleys to lift heavy loads. One example describes how 64 men moved a 1,250-ton granite block for Catherine II's statue in Saint Petersburg using a rolling system, demonstrating remarkable engineering prowess.

UFOs: A Scientific Perspective

Shifting focus, the issue presents a scientific exploration of UFOs, based on research by a CNRS researcher. It describes the typical characteristics of UFOs observed, including their varied shapes (saucers, spheres, cigars), their often luminous and blurry appearance, and their silent or humming operation. The article notes that UFOs create a powerful magnetic field around them and exhibit extraordinary acceleration and speed, yet paradoxically, their supersonic movement does not produce a sonic boom, defying conventional fluid mechanics.

Magnetohydrodynamics and UFO Propulsion

A theory proposed to the Academy of Sciences suggests that UFOs might utilize magnetohydrodynamics for propulsion. This theory posits that the ionized air around the UFO, created by the interaction of charged particles (ions and free electrons), generates a magnetic field that allows for sustentation and movement. The article explains the basic physics of ionized gases, including the role of free electrons and ions, and how applying an electric potential can influence their movement.

Recurring Themes and Editorial Stance

The issue consistently promotes a rational, evidence-based approach to understanding both historical engineering marvels and contemporary unexplained phenomena. It champions human ingenuity and technological advancement, whether in ancient times or the present day, as the primary drivers behind seemingly impossible achievements. The editorial stance clearly favors scientific explanation over mystical or extraterrestrial hypotheses, emphasizing that logical solutions can be found through careful study and application of known principles. The concluding quote by Alain Ledoux encapsulates this sentiment, finding comfort in logical explanations that do not require recourse to the supernatural or extraterrestrial.

Title: Science et Vie
Issue: 685
Date: January 1973
Cover Headline: Les soucoupes volantes: une explication scientifique? (Flying saucers: a scientific explanation?)

This issue of "Science et Vie" delves into a speculative scientific explanation for Unidentified Flying Objects (UFOs), proposing that they could be advanced vehicles utilizing magnetohydrodynamics (MHD) for propulsion. The article, authored by Jean-Pierre Petit, a researcher at CNRS, explores the physics behind such a concept, drawing parallels with known scientific principles and suggesting potential technological implementations.

Understanding Electric Currents and Plasma

The article begins by explaining basic principles of electricity and plasma. It describes how an electric current in a gas, under sufficient voltage, can lead to ionization and the creation of free electrons. This process, when amplified, results in an "electron avalanche" where secondary electrons are produced, significantly increasing the current. This phenomenon is illustrated with diagrams showing electron movement and the concept of radiative recombination, which explains the light emitted by electrical discharges like lightning.

The Hall Effect and Lorentz Forces

A key concept introduced is the Hall effect, which occurs when charged particles (electrons) move through a magnetic field. This effect causes the electrons to spiral, deviating from their expected path. The article explains how this spiraling motion, combined with electric fields, generates Lorentz forces. These forces are crucial for the proposed propulsion system, acting either centrifugally or centripetally depending on the direction of the current and magnetic field.

A Scientific Hypothesis for UFOs

Propulsion System

The core hypothesis is that UFOs are MHD craft. The proposed mechanism involves creating a plasma around the craft using electric discharges. This plasma, interacting with a strong magnetic field (estimated at 50,000 Gauss for a 10-meter craft), would generate Lorentz forces. These forces would then act on the ionized air, expelling it to create thrust. The article suggests this method would allow for silent, shockwave-free flight, even at hypersonic speeds, offering a more energy-efficient alternative to conventional aircraft.

Flight Characteristics

The MHD propulsion system is theorized to allow for sustained flight in the atmosphere, and potentially even underwater, as saltwater is a good conductor. The article speculates that the craft could achieve lift and maneuverability by cyclically varying the current to different electrodes, similar to how a helicopter adjusts the pitch of its rotor blades. This would create asymmetry in the lift, enabling translation and tilting.

Overcoming Shockwaves

One of the significant advantages of MHD propulsion, as presented, is its ability to circumvent the problem of shockwaves generated by high-speed flight. Conventional aircraft at supersonic speeds create shockwaves that result in noise and increased drag (wave drag). The MHD system, by manipulating the air's plasma state, could theoretically avoid this by accelerating the air tangentially, thus preventing the build-up of compressed air at the front of the vehicle.

Powering the Craft

The energy requirements for such a craft are substantial, with a 10-meter saucer needing around 1000 Megawatts. The article suggests that controlled nuclear fusion would be the most plausible power source for generating the necessary magnetic fields and electric discharges. It also mentions the possibility of using superconductivity for generating intense magnetic fields at very low temperatures.

Advanced Concepts and Speculations

MHD Engine Design

The article outlines a potential design for an MHD engine that combines MHD principles with fusion. In this concept, a capacitor discharges into a chamber filled with deuterium, creating a plasma. The Hall effect and Lorentz forces compress this plasma. A laser pulse then initiates fusion, and the subsequent expansion of the plasma generates electricity, with some of it used to recharge the capacitor and the rest for propulsion.

Beyond the Solar System

While the described MHD technology is presented as a potential explanation for UFOs within our solar system, the author acknowledges its limitations for interstellar travel. However, he speculates that these craft might be mere "lifeboats" or auxiliary vehicles for much larger, more advanced interstellar vessels.

Cylindrical UFOs

The article also addresses the phenomenon of large, cylindrical UFOs observed by some witnesses. It proposes that these might be mother ships or carriers for multiple smaller MHD saucers, stacked together to amplify magnetic fields and electrical effects, potentially for group flight or enhanced performance.

Conclusion

Jean-Pierre Petit concludes that while the MHD flying saucer remains theoretical at this stage, the underlying physics are grounded in terrestrial science. The successful demonstration of an MHD craft in a wind tunnel experiment would be a significant step towards scientifically validating the existence and nature of UFOs. The article presents a compelling, albeit speculative, case for a scientific explanation of these enigmatic phenomena.

Recurring Themes and Editorial Stance

The magazine's stance appears to be one of open-minded scientific inquiry, exploring cutting-edge physics concepts to explain phenomena that are not yet fully understood. The recurring themes revolve around advanced propulsion systems, plasma physics, electromagnetism, and the potential for extraterrestrial technology. The editorial approach is to present complex scientific theories in an accessible manner, encouraging readers to consider rational explanations for seemingly inexplicable events like UFO sightings.