Jean-Pierre Petit (born 5 April 1937, Choisy-le-Roi) is a French scientist, senior researcher at National Center for Scientific Research (CNRS) as an astrophysicist in Marseille Observatory, now retired. His main working fields are fluid mechanics, kinetic theory of gases, plasma physics applied in magnetohydrodynamics power generation and propulsion as well as topology and astrophysics applied in cosmology.

He is a pioneer in magnetohydrodynamics and has worked out the principle and techniques of parietal MHD converter. In cosmology, he works on the Janus cosmological model, a bimetric theory of gravity published through peer review, presented in international conferences, and popularized through science comics, as well as course videos.

Jean-Pierre Petit is the founder of the “LAMBDA” laboratory (Laboratory for Applications of MHD in Bitemperature Discharges to Aerodynamics) and he co-founded the “Ufo-Science” non-profit organization dedicated to the study of the unidentified atmospheric phenomena or potential unidentified flying objects. He argues that a thorough scientific study of UFO phenomena (including cameras equipped with diffraction gratings) could potentially advance our scientific knowledge.

Jean-Pierre Petit also demonstrates a sustained interest in a wide variety of subjects not directly related to his work in cosmology, astrophysics and physics. In particular, on the UFO question, on the events of September 11, 2001, the UMMO case, the construction of pyramids, Aurora-type military technologies and French domestic policy issues.

**Professional work**

Jean-Pierre Petit obtains his Engineer’s degree in 1961 at the French aeronautical engineering school ENSAE (Supaero). In the 1960s he works for several months in a French rocket engine test facility as a test engineer in the development of the first nuclear intercontinental missiles SLBM. Because he feels uncomfortable within the military R&D, he prefers to integrate civilian research. In 1965 he is hired by the Marseille Institute of Fluid Mechanics (IMFM), a French laboratory affiliated with CNRS and the French atomic agency CEA, as a research engineer where he makes his first studies in magnetohydrodynamics (MHD). In 1972 he fully incorporates the CNRS after his EngD thesis defense. In 1974 he officially stops experimental research in MHD and starts working at the Marseille Observatory where he reconverts himself in fundamental research as an astrophysicist. However, he personally carries on his experimental research on MHD propulsion until 1987. Convalescent after many months of hospitalization following an industrial injury, he becomes between 1977 and 1983 codirector of the Calculation Center at the French University of Provence where he develops with students some CAD software marketed in 1978. He retires from CNRS in April 2003 but keeps working. In 2007, he founds a non-profit organization called UFO-Science to concretize some research ideas he could not experiment on while working due to lack of allocated funds at the time.

**Professional work overview in MHD**

His career in the field of MHD is well-known: first method of electrothermal instability control and first usable MHD generator with non-equilibrium ionized gas (1967); kinetic theory of non-equilibrium plasmas (1972); MHD aerodynes with ionization control (1975); Shock wave cancellation by MHD force field around a cylindrical profile imbedded in a liquid flow (1983); 2nd method of electrothermal instability control by magnetic pressure gradient in an MHD accelerator (1981); Thesis director about shock wave annihilation around a flat wing in a hot supersonic gas flow: Resolution of Navier–Stokes equations within an MHD force field by the method of characteristics (1987).

**Plasma physics and magnetohydrodynamics (MHD)**

Petit is a pioneer in magnetohydrodynamics involving fluid mechanics, plasma physics and electromagnetism, in both MHD types:

The well-known MHD with high magnetic Reynolds number, as the astrophysical plasma inside a star for example.

The less-known MHD with low magnetic Reynolds number and critical Hall parameter, involving weakly ionized gases in a non-equilibrium state (i.e. where the electron temperature is higher than the gas temperature) known as “cold plasmas”, which are mathematically handled with dyadic tensors in a 7-dimensional phase space. But these non-thermal plasmas are also magnetized plasmas, and the combination of these attributes gives rise to the problematic electrothermal instability which compelled most engaged countries to cancel their engineering MHD programs in the early 1970s.

**MHD Power generation**

He starts working in this field with shock tubes, acting as pulsed power MHD generators delivering several megawatts through direct conversion of supersonic hot gases into electricity, a device invented by Bert Zauderer and Jack Kerrebrock. In 1967, he presents the first experimental results of electrical power generation in a pulsed non-equilibrium high-Hall parameter MHD generator, producing two megawatts of electric power within a magnetic field of 2 teslas in a volume the size of a beer bottle, constituting the first step to cool down the gas in order to protect materials from heat, by controlling the electrothermal instability within MHD converters.

In 1972 he defends in front of Evry Schatzman his Doctor of Science thesis:

The first part presents the basis for the first kinetic theory of non-equilibrium plasmas, starting from the Chapman–Enskog method for the transport phenomena and extending it to a biparametric expansion in series. This work is published through peer review.

The second part is an application of the kinetic theory of gases to galactic dynamics. Through this he resumed the work of Subrahmanyan Chandrasekhar, by compacting the calculations into a matrix form.

**MHD flow control and supersonic flight without shock wave**

Petit calculates that MHD forces in the case of an active flow control with high energy can create a partial vacuum area on front or on top of the device, powerful enough to evacuate incoming upstream molecules at supersonic speed before they accumulate at the stagnation point, therefore preventing the formation of shock waves and cancelling sound and heat barriers. MHD acceleration can indeed be very powerful, even more than chemical propulsion, because the acceleration efficiency grows like the magnetic field strength and is not limited by propellant’s inertia as in chemical propulsion. For example, a pulsed small MHD accelerator can accelerate an ionized gas over 5,000 meters per second with only 10-centimeter electrodes and a moderate 2-tesla magnetic field, as shown at IMFM in 1970.

Petit obtains from 1975 to 1983 several positive experimental results with his MHD flow control devices:

In hydraulics: MHD parietal accelerator experiments and bow wave cancellation by Lorentz forces around a cylinder embedded in an acidulated water flow. This work is an hydraulic analogy of shock wave cancellation in gas, allowing to consider the possibility of supersonic cruise in dense air without any sonic boom.

In magnetized Low pressure discharges with high Hall parameter: creation of spiral currents, plasma confinement to wall and electrothermal instability cancellation by magnetic pressure gradient.

He publishes these results in specialized journals and conferences.

In 1983 he summarizes his research about MHD propulsion and aerodynamic flow control in a scientific comic book titled The Silence Barrier where he popularizes these innovative concepts.

In 1987, the student engineer Bertrand Lebrun from the French Engineering institute ENSAM defends his Doctor of Engineering thesis under the direction of Jean-Pierre Petit.[25] The subject is the mathematical calculation of shock wave cancellation around a flat wing in a supersonic gas flow, where they develop a method to solve the Navier–Stokes equations within an MHD force field by the method of characteristics. This work is presented at international MHD meetings, and published in peer-reviewed journals.

**New research**

In 2007 Petit creates UFO-Science, a non-profit organization devoted to scientific study of the UFO phenomenon. Electromagnetic plasma propulsion and supersonic flight without shock wave through flow control by MHD force field are studied in a new laboratory running with private funds, called LAMBDA λ (Laboratory for Applications of MHD in Bitemperature Discharges to Aerodynamics). He created this concept of “Citizen Research” because he claims the Establishment represented by official scientific public administration, such as the CNRS and the CNES, failed to concretize his ideas because of military strategic implications.

This laboratory publishes scientific result since 2008 with several publications in the scientific peer-reviewed journal Acta Physica Polonica and associated presentations in international MHD conferences: Vilnius in 2008, Bremen in 2009, Jeju, Korea in 2010, Prague in 2012, Warsaw and Princeton in 2013.

Astrophysics and cosmology[edit]

**Galactic dynamics and Newtonian cosmology**

In 1942, Subrahmanyan Chandrasekhar first attempted to describe stellar dynamics as self-gravitating non-collisional systems. In 1972, Petit extends this approach using more compact techniques inspired by the work done by Sydney Chapman and Thomas Cowling in the kinetic theory of gases. In this theory of galactic spiral structure, the Friedmann equations emerge from an elliptic solution of the Vlasov equation coupled with Poisson’s equation.

He then publishes a rewriting of the Newtonian cosmology, resuming a work from 1934 by Arthur Milne and William McCrea, but from the point of view of his kinetic theory of non-equilibrium plasmas, which allows one to find the rotating universe model of Otto Heckmann and Engelbert Schücking.

**Variable constants cosmology**

In 1988, Petit introduces the idea of variable speed of light in cosmology, along with the joint variations of all physical constants combined to space and time scale factors changes, so that all equations and measurements of these constants remain unchanged through the evolution of the universe. The Einstein field equations remain invariant through convenient joint variations of c and G in Einstein’s constant. The invariances requirement of Schrödinger and Maxwell’s equations fulfill the set of gauge joint variations laws of the constants. The fine-structure constant becomes an absolute constant. Late-model restricts the variation of constants to the relativistic radiation-dominated era of the early universe, where spacetime is identified to space-entropy with a conformally flat metric.

**Janus cosmological model**

From 1977, Petit starts to build an atypical bimetric theory of gravity called the Janus cosmological model in reference to the two-faced god who “looks simultaneously to the future and to the past”.[66] Petit produces science comics and videos to popularize the various aspects of this cosmological model.

Previously known as the twin universe theory, it would explain various observational facts that the standard model cannot answer, the gravitational interaction of positive and negative masses being an alternative candidate for the explanation of dark matter, dark energy, cosmic inflation and the accelerating expansion of the universe. Despite being peer reviewed, this non-standard cosmological model has not triggered much interest in the scientific community throughout the years, except with mathematicians and geometers who seem more interested than cosmologists in its topological subtleties.

However, in particle physics, the theory shares similarities with the mirror matter of hidden sectors addressing CP violation. In general relativity, later independent work about bimetric gravity with positive and negative masses lead to the same conclusions regarding the laws of gravitation.

The Janus model has the same foundation as a model previously published by Andrei Sakharov ten years before. In 1967, Sakharov addressed the baryon asymmetry of the universe considering for the first time events in CPT symmetry occurring before the Big Bang:

We can visualize that neutral spinless maximons (or photons) are produced at t < 0 from contracting matter having an excess of antiquarks, that they pass “one through the other” at the instant t = 0 when the density is infinite, and decay with an excess of quarks when t > 0, realizing total CPT symmetry of the universe. All the phenomena at t < 0 are assumed in this hypothesis to be CPT reflections of the phenomena at t > 0.

— Andrei Sakharov, in Collected Scientific Works (1982).

Sakharov was the first scientist to introduce twin universes he called “sheets”. He achieved a complete CPT symmetry since the second sheet is populated by invisible “shadow matter” which is antimatter (C-symmetry) because of an opposite CP-violation there, and the two sheets are mirror of each other both in space (P-symmetry) and time (T-symmetry) through the same initial gravitational singularity. He continued developing this idea for twenty years.

**Claims and public matter of controversies**

Petit is known to the general public through his popular science publications (books and comics) and by his appearances in French media, mostly about the UFO phenomenon. He is indeed favorable to the extraterrestrial hypothesis explaining some UFO cases, and the conspiracy theory about a cover-up from the armed forces to take a decisive technological, thus strategic advantage over other nations. He loudly denounces the tight relationship between the army and scientists since the Manhattan Project, which has created according to him a powerful military R&D leading to futuristic weapons of mass destruction and unmoral crowd and riot control technologies, to the exclusive use of the military-industrial complex. He also gives credit to 9/11 conspiracy theories through his web site. He thinks that global warming and geopolitics evolution caused by the unconsciousness of world political leaders will create fatal irrevocable disorders in the near future. According to him, becoming aware that we are not alone in the universe and that we are visited by people having a better technology than ours is the last chance for mankind. Such unconventional opinions has raised various enmities against him.

**Ummo case and ufology**

In the 1990s he publishes several books about ufology and the Ummo case, from which he would have studied documents since 1974. He claims to have found there useful inspiration for some of his work about MHD propulsion and cosmology. Thereafter those unidentified correspondents even sent mail to him for a while, where he would have again, according to him, found other starting points for additional research developments. His hierarchy does not welcome these books and after the publication of the third one, Petit is not able to publish any paper in peer-review journals during the rest of his career at CNRS.

**American secret weapons**

After an international conference on advanced propulsion, Petit writes a book, where he proclaims a leading edge science would have secretly emerged inside the US black projects sanctuaries, involving intensive study of aerial plasma propulsion with electromagnetic flow control. He suggests such an acceleration of these technological programs would have been undertaken after military forces of the United States would have the proof of existence of intelligent extraterrestrial life forms visiting Earth in the 1940s, in particular with the so-called Roswell UFO crash which he thinks was real.

Using his knowledge about plasma physics and magnetohydrodynamics, Petit describes a model of hypersonic airplane working with an MHD bypass system, claiming it would correspond to the mythic Aurora secret spyplane US Air Force would have brought into service in the 1990s. He gave several lectures on this subject, especially at the French aeronautical engineering school ENSAE where his object lesson was not criticized. Conversely, detractors of this idea never provided any technical argument in support of their denials.

Petit also envisages that the U.S. Army would have accidentally discovered how to generate antimatter through superdense states of matter by the use of magnetically focused underground thermonuclear explosions of several megatons. Some antimatter bombs would have been created, but too powerful to be tested on Earth they would have been camouflaged into what was known as the comet Shoemaker–Levy 9, then detonated on Jupiter. Most of his colleagues judge this story as overly fanciful.

**Aneutronic fusion energy vs pure fusion bombs**

After the breakthrough made by Sandia National Laboratories at the end of 2005 where researchers generated more than 3 billion degrees within the MHD compressor Z machine, he tries to draw the attention of scientists, politicians, ecologists and the public to what he presents as a possible future clean nuclear civilian energy, thanks to aneutronic nuclear fusion reactions with none or very few radioactive waste byproducts. But again this technology is potentially proliferating and Petit claims it could also lead to new pure fusion weapons, where the central fission A-bomb used classically for ignition of the H-bomb would be useless, replaced by a fast electric pulsed power detonator (a compact z-pinch fed with some explosively pumped flux compression generator).