...At school he accomplished a certain amount of unpublished personal works on a supersonic disk nozzle, and on very thin hypersonic flat jets, which were full of many paradoxical features.
...In 1961 he was invited to join Princeton University and for the journey there he boarded the steamer named Mauretania, the one which was built just before the Titanic, in England. Fortunately it was a good journey an no iceberg was encountered.
...In Princeton he joined the James Forrestal Center, directed by Professor Bodganoff, but his stay was very short.
...When he arrived at the laboratory, he found it was deserted as everyone had gone out for lunch. Petit's curiosity got the better of him and he decided to have a look around. He neglected the signs saying "restricted area, authorized persons only", and he discovered a very strange machine which was disk shaped. He decided to inspect it, so he got on-board.
...When Dr. Bogdanoff got back from his lunch, Petit decided to talk to him about what he'd seen. Bodganoff got angry :
' Your crazy" he says "do you know that is a top secret machine !".
Petit replies :
"No kidding, it will never work. It is just a ground effect machine, you will never de able to take off with that '".
...The conversation turned sour and Petit had to quit the university and leave Princeton immediatly. Without a penny, he earnt his living in New York selling drawings in Greenweich Village in order to earn the money for his return ticket.
...The steamer he took for his journey, back to France, was the "Liberté" of the well-known "French-Line" and this was to be the last trip as she had been sold to a Japanase Comany who wanted to transform her into a floating hotel.
...No icebergs were seen during the return voyage, just an autumn storm with an extremely violent west wind. The waves were 30 meters high and the sea was covered in foam. Nearly everyone suffered terribly with sea-sickness. The distance between to tops of the successive waves finished comparable to the length of the ship, approaching 300 meters. Like the wind, the waves arrived from behind and on one side. The ship which has been navigated at just about the same speed, suddently started to oscillate. Petit remembers :
- On all the ups and downs, the ship inclined at 43°. On board two were dead. An old lady fell in her cabin and knocked herself on her basin and a stewart who didn't have the presence of mind to let go of his tray, smashed the top of his head at the far end of the corridor.
Petit was able to observe this phenomenon from a superior deck of the ship.
...The captain decided to turn to the west in order to face the very dangerous waves. Petit was fascinated by the storm. One night he wanted to explore the lower deck, normally forbidden to passengers, to observe at close quarters the raging sea. The mountains of block water and whote foam blocked the horizon. Suddently Petit realises that one of the waves floods the ship bridge, which becomes swamped with water and he himself risks being swepted out by one of the waves to be left alone in the middle of the Atlantic Ocean, in the middle of the night, in the ship's wake. He just manages to save himself.
...When Petit returned to France, he took up his military service, became a lieutenant in the Army, and ran a military gliding club in Fribourg, Germany. In his spare time he made 200 free-fall parachute jumps.
...Somewhat disappointed by his experiences in Princeton, he became an artist for several years. He made a profession in painting and engraving copper and lithographic stones in Paris. Then he joined a company located in the south of France which had a test-site for powder propelled rockets.
...But he he got rapidly bored with it and joined a State Research Institute. He worked on a MHD power plant, a short duration system based on a so-called "shock-tube" (short-duration shock driven wind tunnel). The latter produced hot and dense argon flow during 200 microseconds at pressure : one bar, temperature : ten thousandd degrees, velocity : 2500 m/s.
...Combining this flow to a transverse two tesla magnetic field, one gets a strong induced electric field VB, and an electric current, flowing through wall electrodes and external loads. At such high temperatures the electric conductivity of argon is high enough to have huge amounts of electric power density : two megawatts for a MHD channel as large as a beer can.
...We are now in 1965. People were interested in high efficiencies of MHD power plants (theoretically : up to 60 %). The labs were rich in all countries and they spent money.
...MHD men dream to be able to couple their generators to high temperature reactors (htr). Inert gases like argon or helium would cool the heart of the reactor and pick out thermal energy from it. Adding 2% of cesium would increase the electrical conductivity.
...Htr people refuse to think about reactors working at temperatures higher than 1500°. MHD needs 2000 ou 2500.....
...Then people think about a two temperature system (in the US : Kerrebock, and in Russia Shendlin and his coworkers). The idea is simple. A fluorescent tube is a two temperature device. The gas, neon, is cool. Proof's that you can touch it with your hand. But the electric field gives large energies to free electrons. These electrons strike the fluorescent layer, inside the glass wall, which therefore reacts, emiting white light.
...Americans and Russians think that in certain adequate conditions, a two temperature MHD generator can work, say at a gas temperature of 1500° and electron temperature of 2500-3000° Kelvin. You get good electrical conductivity (which depends on electron temperature), good efficiency, in fact, good everything.
...But in 1964 a young Russian went to an International MHD meeting in Newcastle, U.K. The young E.Velikhov, who belonged to the Russian team. As a theoretician, he prohesizes :
- Your two temperature plasmas will be fairly unstable. You will have plane electron density waves, transforming your working gas into a ... capaciror, a succession of high and low electrical conductivity layers. The electric current will not flow, therefore no electric power, nothing. "I have calculated all that" he said.
...Nobody believed him, but it turns out to be the true. In Warsaw in 1967, Ricateau, the French builder of the plant "Typhée" in Fontenay-aux-Roses, concludes :"we face the wall the the Velikhovs electrothermal instability".
...In 1965 Petit joined the Institute of Fluid Mechanics at Marseille, which was directed by Professor J.Valensi, (now deceased). Copying the American Bert Zauderer, the French used shock tubes to produce at source hot gas flow, quickly driven towards small MHD channels. They proved to be relatively low cost experiments. The two teslas magnetic field was delivered by a capacitor bank. The MHD channel was built in plexiglass and the electrodes were made of red copper.
...In France the French Commissariat à l'Energie Atomique (CEA, the Frenche department dor atomic energy) held almost the MHD activity in "closed cycles". But their huge generator "Typhée", in its large room, turned out to be unstable as all his brothers over the world. The electric power output was close to nothing.
Then the guys at the CEA say :
"Why don't we try to simulate that with these small shock tubes, in the lab of Marseille ?".
...The idea came from a young student of Kerrebrock : Solbès. In Marseille the contract was rapidly signed up, although there nobody knows what a two temperature generator is. Recently engaged, Petit learns plasma physics. In 1967 Sutton and Sherman had just published their excellent book (Mac Graw Hill) entitled "Engineering magnetohydrodynamics". Petit understood the problem, buildt, and published his own theory of Velikhov's instability and had an original idea. He discovered, through his theoretical studies, that when the plasma becomes "fully ionized", if fast enough, the instability does not occur. The ionization stabilizes the plasma. This phenomenon was rediscovered fifteen years later by a Japanese, who called it "to climb the mount Fuji" (due to the peculiar shape of the instability growth rate curve, looking like the famous Japanese vulcano).
...In 1966, the experiment calculated by Petit was fully successfull. For the first time in the world a MHD generator works with two temperatures and large power output, in stable conditions. Gas temperature : 6000°, electron température : 10,000°. Output power : two megawatts (during 200 microseconds...).
Petit's collegues were skeptical. But Petit said :
- Let's put 2% of carbon dioxyde in the gas. It will absorb the energy of the electron gas, transforming it into vibration energy and radiative output. The process will be very fast, due to large cross section of the CO2, and I have been able to compute that.
...Once again, Petit's predictions were sound. He confirmed that he is a good prophet and he was able to present his work at the International MHD Meeting of Warsaw in 1967. Later the temperature of the gas was successfully lowered to 4000° Kelvin. The stability of the plasma was confirmed by photos taken of it on the first available american electronic camera.
...The director of the lab was enthusiastic. Everybody thought that this was the solution and all dream to lower the gas temperature to 1500°. Of course, the shock tube is just a simulator. But people think the idea is great and should solve the problems of the "big brothers", the full size MHD converters.
...The lab's boss decides to run the experiment on his own, as usual. He put his own team on the plant built by Petit by his own hands, and rejects him in a small room, under the roof. There, Petit calculates again and laughs : the boat is a pierced boat. The theory shows that this method will not allow them to make the gas temperature lower than 4000°. All that excitement for nuts....
...During the next few monthes Petit works like hell to build his "lifeboat" : a Phd thesis based on kinetic theory of ionized gases. He knows he will have to give up seven years of hard work, here, and leave the lab.
...Downstairs, things don't work so well. The boss' collaborators have made many errors and almost destroyed the MHD convertor. Valensi orders Petit to come back and rebuild the almost destroyed machine. But too late. Petit's Phd thesis has come to an end and he leaves the lab, whick sinks. Tired by all that noise, Petit decides to transform electrons into stars, in the equations, and to join the Observatory of Marseille. (Practically, for the specialist : transforming the Boltzmann equation into the Vlasov equation, whose second member is zero).
He works there since for than 25 years.
...We writes 30 books. Some were translated into English (The Adventures of Archibald Higgins). These books were printed in the US, England, Germany, Italy, Portugal, Russia, Poland and... Iran.
...In the little stories of the Iranian Ayatollah, you find the heroine Sophie scantilly dressed, and they exercise their right to make her dress decently as customary, with a tchador. An Iranian artist takes charge of this operation for her. Iran is not the only who exercises these changes of clothing of the heroine. The second country was America. When these books came out in the U.S.A., they were taken by the department of mathematics at the University of Berkeley. Petit came to this University to give a conference and he brought with him the books already printed in England. He offered the books to the library which put at the disposition of the students two types of books, all in English language. Some carried the words "cleaned version" and the others" carried the words "original version".
...It was twenty years ago. These issues are, without a doubt, difficult to find now. The series includes :
- Here's looking at Euclid
- Computer magic.
- Everything is relative.
- Black hole.
- Big Bang
- The silent barrier
- Run, robot, run.
18 titles were printed in France.
...In 1977 Petit discovers the first micro-computers Apple-II. He writes the first computer's assisted 3d designer program (Conception Assistée par Ordinateur ou CAO), which works efficiently on small systems (48K, the 64K). He sells 1,500 copies of this software.
next 8 years he runs a computing Center. At the same time he learns modern
geometry with Bernard Morin, a famous blind mathematician, and draws the eversion
of the 2-sphere. He also invents a new eversion of the torus, and publish
this work at the French Academy of Science. He shows that the meridian lines
of the mysterious Boy's surface can be ellipses. This will later enable Apery
to build the first implicit equation of the surface, sixth degree.
...In 1975 Petit belongs to the Observatory of Marseille. But the old MHD ideas still run around inside his head. In 1965, during the MHD experiments, the slowing down of the plasma, in the MHD channel, was so strong that a front shock wave occured and moved at the input of the channel. This was due to Lorentz force JB. Producing electric energy slows down the gas : its' kinetic energy is transformed into electricity.
...The higher electricity production the higher the gas slowing down effect. As predicted by Petit, a shock wave should appear, and it did.
...Later, at the end of the sixties, clever and low cost acceleration experiments were carried out in the Fluids Mechanics Institute of Marseille, by two researchers : B.Fontaine and B.Forestier. They showed that using the MHD converter as an accelerator, the velocity of the argon plasma ( 2,750 m/s when entering the channel) could grow up to 8,000 m/s, in a ten centimeters long MHD accelerator.
...But at the beginning of the seventies, the MHD research stopped in all countries.
...In his observatory Petit was still thinking about the marvellous MHD world. One day, he said :
- If having an effect, with the Lorentz force is intense enough that I can produce a shock wave, why can't I cancel a shock wave, located in the front part of a body moving in a gas at supersonic velocity, just by sucking this gas by suitably designed Lorentz force field. In a word, is shockless flight possible, at supersonic velocities ?
...The idea seemed completely foolish to conventional fluid mechanics specialists. They said :
- You must have a shock wave system.
...Petit was not convinced. When he attended his aeronautical school in Paris, he used a water free surface flow analogic simulator. Today they have completely disappeared from universities and labs. But, in the sixties, one used it to simulate the shock wave system around, for an example, a flat wing :
...If some readers are interested, some information can be eventually given in that web site, about MHD topics and shock wave cancellation.
...In short, in 1976, Petit calculates the parameters of an MHD experiment, used a one tesla magnetic field, water, plus chlorid acid, free surface flow, electrodes and cancels the water wave located in front of a one centimeter model.
...Later he directed a Phd thesis on the field, the one of Bertrand Lebrun.
...For the fluid mechanics specialist, shock waves occur because "Mach lines focuss" :
...Where Mach lines accumulate, shock waves tend to grow. But Lorentz force changes the local Mach angle and the local Mach lines system. With his student, Bertrand Lebrun, Petit shows in 1982 that through a convenient Lorentz force field, the self crossing of the Mach lines could be avoided, so that the shocks do not form.
...Furthermore, all that could be experimentally tested, with a transverse magnetic field and a wall electrodes set. Petit and Lebrun present the work at the 7 th International Meeting of Tsukuba, Japan, 1987 (but, due to lack of money, they couldn't get there).
...Lebrun computed the field with a set of Mac Intosh computers, old ones belonging to colleagues of Petit. Each night, each machine worked on a piece of the field, and each morning Lebrun picked up the results as he passed by with his motorcycle and synthetized it on his own Mac Intosh. An original multiprocessor system.
...Anyway the calculations were quite convincing. Petit had planned to test it with a shock driven channel, as usual. These old systems were almost obsolete, but a lab, located in Rouen, France, still owned an old one. Petit conviced to french CNRS (Centre National de la Recherche Scientifique) to support his reseach and an MHD program was planned, with some financial support. The idea was simple. The old shock tube provided a short duration (200 microseconds) hot (10,000°K) and dense (pressure : 1 bar) argon flow. In a first step, a strioscopic system, based on the light of a small laser, showed the shock wave system, around a flat wing, with sharp edge.
...Then, during another test, MHD would be operated, with an adequate magnetic field (a 2 teslas filed, provided by a capacitors' bank) and suitable electric discharge in the plasma, through wall electrodes (also due to capacitors' discharge). Then one may have expected that the Lorentz force would cancel the wave, especially the front waves.
- I'm sure this would have worked successfully on the first test. All was carefully computed....
...But the French Army stopped all that. The military were very much interested by the concept, for their own use, but their underlying idea was... a supersonic cruise missile and perhaps something else, who knows.
...At the end of the eighties Petit discovered that the reason of State was a solid reality.
...Nobody can fight against the Army. He finally gave up and shifted towards theoretical cosmology, in 1987.
...In 1987 Petit came to the department of Fluid Mechanics of Berkeley, whose director, today retired, was his old good friend Tonio Oppenheim, who invited him to give a lecture about MHD and shock wave cancellation.
...In the same room, another collegue named Kunkle was sat. He was the director of particules accelerator in Berkeley University. During Petit's lecture, he laughs all the time. Finally, Oppenheim, puzzled by this colleagues unusual behaviour, asks him :
- Dear professor Kunkle, we have been for friends since many years. You trouble the conference of my friend Petit, why ?
- Sorry, it's just too much for me. Petit is explaining, to all these young students, in clear words, a lot of research which are currently held in the Lawrence Livermore Laboratory. But there, they are considered as highly classified. In fact so classified that I am not authorized to tell you one word about it. But they are... very similar. That's all that I can say.
In 1987, for Petit, it was the end of the MHD story. He published three papers of theoretocal cosmology in Modern Physics Letters A, in 88-89.
...Since 1977 Petit had been very interested in Sakharov's ideas (twin universe model). He published two papers in the french Comptes rendus de l'Académie des Science, this year. Ten years after the MHD parenthesis was indefinitely closed, he was back on the subject.
...He published a new paper in Nuovo Cimento in 1994, entitled "The missing mass problem" (reproduced in Geometrical Physics A, 1). Another one in Astrophysics and Space Science, 1995 (reproduced in Geometrical Physics A,2). Then the troubles started. Many papers, sent to several journals, were returned without submission to a referee, with short sentences, like :
- Sorry, we don't publish speculative works.
...In February 1997, at last, an answer, from Astronomy and Astrophysics. The referee answered "I think the paper is provocating and interesting" and asked a dozens of different questions.
...The game began and continued for ten months. The questions were relevant, but enlarged the papers a lot. The initial paper had 22 pages. As when new questions arrived, the paper grew more and more, finally up to 90 pages.
...The referee asked for a complete cosmological model, and asked .. sixty questions. Petit wrote seven successive versions. The epistolary exchanges with this anonymous expert were always cordial. Petit thanks the referee for his relevant questions and the referee thanks him for his patience.
As the paper is now too large, Petit suggested to cut it into two parts. Then suddenly, in December 1997, the Director of the Journal, James Lequeux, wrote to Petit :
- That's enough now. This will never end. I'm stopping it. That's my decision and it's final.
...No warning, no incitement to end the job, nothing. Just this abrupt and unexpected decision.
...Petit asked for a chance to get some pages published in Astronomy and Astrophysics, and suggested submitting a shortened version to the referee, composed by that which the man had approved along the long correspondence. Lequeux refused.
...Petit asked Dr. Lequeux to transmit a last letter to his referee, in which he asked :
- Do you confirm the rejection decision of the Directeor of Astronomy and Astrophysics ? If yes, could you send me your final scientific arguments.
...No answer has been received since January 1998, the twelfth. In a last letter(26/03/98), Dr Lequeux wrote to Petit (see the Log Book) :
- I recall that the Director of the Journal is the only one who decides if a paper is or is not suitable for publication and that the referee's report is only consultative.
End of story.
The web site created by Petit has several aims :
- To submit past and new works to scientists, in order to receive their eventual opinion and remarks, if they have some to formulate. They will be reproduced. If they are relevant the papers will eventually be modified. If they are not the author will try to explain why.
- To diffuse some knowledge about groups theory, geometry and other different topics.
- To inform people.