Pierre Curie (15 May 1859 – 19 April 1906) was a French physicist, a pioneer in crystallography, magnetism, piezoelectricity and radioactivity. In 1903 he received the Nobel Prize in Physics with his wife, Marie Salomea Skłodowska-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".

Early life

Born in Paris, France, Pierre was the son of Dr. Eugène Curie (28 August 1827 – 25 February 1910) and Sophie-Claire Depouilly Curie (15 January 1832 – 27 September 1897). He was educated by his father, and in his early teens showed a strong aptitude for mathematics and geometry. When he was 16, he earned his math degree. 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 (1856–1941) demonstrated that an electric potential was generated when crystals were compressed, i.e. piezoelectricity. To aid their work, they invented the Piezoelectic Quartz Electrometer. 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 in the form of crystal oscillators.

Pierre Curie met Maria Skłodowska (later Marie Curie) when a friend introduced him to her. What attracted Pierre to Marie was that she wasn't like other girls—she was devoted to science. He proposed to her but Maria (Marie) refused, even though she loved him, too.[citation needed] She finally agreed to marry him on 26 July 1895.

Research

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 behavior. 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, and 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 × 1010 decays per second or 37 gigabecquerels) originally named in honor of Curie by the Radiology Congress in 1910, after his death. Subsequently, there has been some controversy over whether the naming was in honor of Pierre, Marie, or both.

In the late years of the nineteenth century, Pierre Curie was investigating the mysteries of ordinary magnetism and simultaneously became aware of the spiritualistic experiments of other European scientists, such as Charles Richet and Camille Flammarion. Pierre Curie initially thought that systematic investigations into the paranormal would help him with some unanswered questions about magnetism (Hurwic 1995, p. 65). He wrote to his fiancée Marie, "I must admit that those spiritual phenomena intensely interest me. I think in them are questions that deal with physics" (Hurwic 1995, p. 66) Pierre Curie's notebooks from this period show he read many books on spiritualism. (Hurwic 1995, p. 68)

About some séances with Eusapia Palladino, Pierre Curie wrote to physicist Georges Gouy in a letter dated 24 July 1905 (Hurwic 1995, p. 248):

"We had at the Psychology Society a few séances with the medium Eusapia Paladino. 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 caressed 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. Cheating would only be possible if the medium had extraordinary abilities 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?"

Pierre did not go to séances as a mere spectator, and his goal certainly was not to communicate with some spirits. He saw the séances as scientific experiments, tried to monitor different parameters, took detailed notes of every observation. (Hurwic 1995, p. 247)

Personal life

Marie Curie (1911) The crypt at the Panthéon in Paris

Pierre and Marie Curie's daughter Irène Joliot-Curie and their son-in-law Frédéric Joliot-Curie were also physicists involved in the study of radioactivity. They were awarded a Nobel prize for their work as well.

The Curies' other daughter, Ève, wrote a noted biography of her mother.

Their granddaughter Hélène Langevin-Joliot is a professor of nuclear physics at the University of Paris, and their grandson Pierre Joliot, who was named after Pierre Curie, is a noted biochemist.

Pierre Curie died in a street accident in Paris on 19 April 1906. Crossing the busy Rue Dauphine in the rain at the Quai de Conti, he slipped and fell under a heavy horse drawn cart. He died instantly when one of the wheels ran over his head, fracturing his skull.

In April 1995 Pierre and Marie were enshrined in the crypt of the Panthéon in Paris.

Awards

• Nobel Prize in Physics (1903)
• Davy Medal (1903)
• Matteucci Medal (1904)
• Elliott Cresson Medal (1909) awarded posthumously during Marie Curie's award ceremony

See also

• Eusapia Palladino