Posted by: Glow-worm PJ6 MAY 2009
Friday 15 May 2009 marks the 150th anniversary of the birth of the French physicist Pierre Curie. In print, he has been relegated to the background somewhat, his own scientific contributions having been overtaken by the fame of his wife Marie, who outlived him by 28 years following his death in 1906, when he was run over by a horse-drawn vehicle.
Pierre initially enrolled as a pharmacy student in Paris, but quickly became involved in the study of crystals with his elder brother Jacques. It is now largely forgotten that the brothers discovered the piezoelectric effect (after the Greek piezein, to squeeze or press) when they showed that certain crystals, such as quartz, generated electrical polarisation under mechanical stress.
Reciprocally, when placed in an electric field these crystals become compressed. Recognising the connection between the two phenomena helped Pierre to develop pioneering ideas about the fundamental role of symmetry in the laws of physics.
Piezoelectricity produced from a thin layer of quartz formed the basis of the Curie electrometer, used in the early measurement of radium salts.
Pierre was also a pioneer in the study of magnetism. He discovered a basic relationship between magnetic properties and temperature. The temperature at which certain magnetic materials undergo a marked change in their magnetic properties is called the Curie point, after Pierre.
A few months after marrying Marie Sklodowska, he was awarded a doctorate for his research into magnetism. When Marie’s own thesis research led her to believe she was on the verge of discovering a new element, he joined in her search.
After their discovery of polonium and radium, they divided their labours. He concentrated on the properties of radium, while she did chemical experiments with a view to preparing pure compounds.
It was Pierre, with a student, who first noticed that a speck of radium perpetually emits heat, discovering what is now called nuclear energy, and the skin burns that radioactive substances can inflict.
In 1903, Pierre and Marie, with Henri Becquerel, were awarded the Nobel prize for physics in recognition of their research into radiation. In his Nobel address, with some foresight, Pierre warned of the dangers of radium in the wrong hands, and its possible use as a terrible means of destruction during wartime.