Biographies | Chemists of the world

Pierre Curie

-Pierre Curie (May 15, 1859- died April 19, 1906) was a French physicist, a pioneer in crystallography, magnetism, piezoelectricity and radioactivity. He shared the 1903 Nobel Prize in physics with his wife, Maria Sklodowska-Curie (Marie Curie), and Henri Becquerel," in recognition of the extraordinary services they have rendered by their joint researches on the radiation phenomena discovered by Professor Henri Becquerel."

Born in Paris, France, Pierre was educated by his father, and in his early teens showed a strong aptitude for mathematics and geometry. By the age of 18 he had completed the equivalent of a higher degree, but did not proceed immediately to a doctorate due to lack of money. Instead he worked as a laboratory instructor.

In 1880, Pierre and his older brother Jacques demonstrated that an electric potential was generated when crystals were compressed, i.e. piezoelectricity. Shortly afterwards, in 1881, they demonstrated the reverse effect: that crystals could be made to deform when subject to an electric field. Almost all digital electronic circuits now rely on this phenomenon in the form of crystal oscillators.

Prior to his famous doctoral studies on magnetism he designed and perfected an extremely sensitive torsion balance for measuring magnetic coefficients. Variations on this equipment were commonly used by future workers in that area. Pierre Curie studied ferromagnetism, paramagnetism, and diamagnetism for his doctoral thesis, and discovered the effect of temperature on paramagnetism which is now known as Curie's law. The material constant in Curie's law is known as the Curie constant. He also discovered that ferromagnetic substances exhibited a critical temperature transition, above which the substances lost their ferromagnetic behaviour. This is now known as the Curie point.

Pierre formulated what is now known as the Curie Dissymmetry Principle: a physical effect cannot have a dissymmetry absent from its efficient cause. For example, a random mixture of sand in zero gravity has no dissymmetry (it is isotropic). Introduce a gravitational field, then there is a dissymmetry because of the direction of the field. Then the sand grains can "self-sort" with the density increasing with depth. But this new arrangement, with the directional arrangement of sand grains, actually reflects the dissymmetry of the gravitational field that causes the separation. Pierre worked with his wife Marie Curie in isolating polonium and radium. They were the first to use the term "radioactivity," and were pioneers in its study. Their work, including Marie's celebrated doctoral work, made use of a sensitive piezoelectric electrometer constructed by Pierre and his brother Jacques.

Pierre and one of his students made the first discovery of nuclear energy, by identifying the continuous emission of heat from radium particles. He also investigated the radiation emissions of radioactive substances, and through the use of magnetic fields was able to show that some of the emissions were positively charged, some were negative and some were neutral. These correspond to alpha, beta and gamma radiation.

The curie is a unit of radioactivity (3.7 x 1010 decays per second or 37 gigabecquerels) originally named in honour of Pierre Curie by the Radiology Congress in 1910, after Pierre's death.

Pierre also legitimated the medium Eusapia Palladino. In a letter to Georges Gouy, July 24, 1905, he writes: "We had at the Psychology Society a few seances with the medium Eusapia Palladino. It was very interesting, and truly those phenomena that we have witnessed seemed to us to not be some magical tricks --a table lifted four feet above the floor, movements of objects, feelings of hands that pinched you or carressed you, apparitions of light. All this in a room arranged by us, with a small number of spectators all well known and without the presence of a possible accomplice. The only possible cheating would be an extraordinary ability of the medium as a magician. But how to explain the different phenomena when we are holding her hands and legs, and the lighting of the room is sufficient to see everything going on?"

In another letter to Gouy (April 14, 1906), Curie wrote: "We had a few new seances with Eusapia... those phenomena exist for real, and I can't doubt it any more. It is unbelievable but it is thus, and it is impossible to negate it after the seances that we had in conditions of perfect monitoring".

Charles Richet, who won the Nobel Prize in physiology in 1913, carried out decades of research into psychical phenomena. He participated with the Curies in the investigations of Eusapia Palladino. Here is one of his accounts of a seance: "It took place at the Psychological Institute at Paris. There were present only Mme. Curie, Mme. X., a Polish friend of hers, and P. Courtier, the secretary of the Institute. Mme. Curie was on Eusapia" left, myself on her right, Mme. X, a little farther off, taking notes, and M. Courtier still farther, at the end of the table. Courtier had arranged a double curtain behind Eusapia; the light was weak but sufficient. One the table Mme. Curie's hand holding Eusapia's could be distinctly seen, likewise mine also holding the right hand. . . We saw the curtain swell out as if pushed by some large object. . . I asked to touch it . . . I felt the resistance and seized a real hand which I took in mine. Even through the curtain I could feel the fingers... I held it firmly and counted twenty-nine seconds, during all which time I had leisure to observe both of Eusapia's hands on the table, to ask Mme. Curie if she was sure of her control . . . After the twenty-nine seconds I said, "I want something more, I want uno anello (a ring). At once the hand made me feel a ring . . . It seems hard to imagine a more convincing experiment . . . In this case there was not only the materialization of a hand, but also of a ring".

Pierre died as a result of a carriage accident in a snow storm while crossing the Rue Dauphine in Paris on April 19, 1906. His head having been crushed under the carriage wheel, he avoided probable death by the radiation exposure that later killed his wife. Both Pierre and Marie were enshrined in the crypt of the Pantheon in Paris in April 1995.

Pierre and Marie Curie's daughter Irene Joliot-Curie and their son-in-law Frederic Joliot-Curie were also physicists involved in the study of radioactivity, and were also awarded the Nobel prize for their work. Their other daughter Eve wrote her mother's biography. His granddaughter Helene Langevin-Joliot is a professor of nuclear physics at the University of Paris and his grandson, Pierre Joliot, who was named after him, is a noted biochemist.