“It would be a beautiful thing, a thing I dare not hope, if we could spend our life near each other,
hypnotized by our dreams: your patriotic dream, our humanitarian dream, and our scientific dream.
We can aspire to accomplish something … every discovery, however small, is a permanent gain.”
~Pierre Curie, in a letter to Maria Skłodowska
When it comes to power teams in the laboratory, there is perhaps no other couple more widely known than Pierre and Marie Curie, who came together through a shared love of science and research. The Curies spent their marriage working side by side, sharing groundbreaking scientific discoveries. They are best known for their pioneering work as a team in the study of radioactivity, which led to their discovery in 1898 of the elements radium and polonium—and their subsequent shared Nobel Prize in Physics in 1903.
The Curie legacy—and the results from this true marriage of minds—is far-reaching.
- The Curie family holds the most Nobel Prizes awarded to a single family.[i]
- Their children and grandchildren[ii] also became important scientists.
- Curie scoring[iii] and the element curium[iv] are named for them.
- The unit of measure for measuring radioactivity[v], Curie’s law (later Curie-Weiss law)[vi], Curie temperature/Curie point (TC), Curie constant (C)[vii], and Curie’s principle[viii] are named for Pierre Curie.
- The Curie balance (Curie scale), a quartz balance, was constructed by Pierre Curie and is still used today.[ix]
Women physicists were a rarity in the 19th century, but even rarer were husband-and-wife collaborative teams. Pierre and Marie Curie not only made history in this respect, but also because their scientific teamwork led to the discovery of radioactivity and two new elements in the periodic table, for which they shared the Nobel Prize in Physics.
To understand and appreciate the importance of the seismic—or shall we say, atomic—event which occurred in the world of science when these two brilliant minds collided, we first need to learn a bit about who they were as individuals and what drove them towards each other and their mutual love of physics, chemistry, and discovery.
Pierre Curie (b.1859 – d.1906)
French physicist and physical chemist, Pierre Curie, is often overlooked in favor of Marie Skłodowska Curie, his brilliant student, and later, his wife and laboratory partner. Widely considered one of the “founding fathers” of modern physics, he pioneered scientific work in the fields of crystallography[x], magnetism, and piezoelectricity. More than two decades before being awarded the Nobel Prize in Physics, he had already distinguished himself (along with his older brother Jacques) in the study of the properties of crystals. The unorthodox nature of his education, however, meant Pierre was never quite accepted by the French scientific establishment.
A child prodigy who showed an extraordinary aptitude for mathematics and geometry—in particular, spatial geometry (which later helped in his work on crystallography), Pierre was educated at home by his father, Eugene Curie, a physician who believed his son’s intellect and personality could be best nurtured through private tutoring.
At age 14, Pierre entered the Sorbonne and began his university studies. It was there where he conducted his first work calculating of the wavelength of heat waves. While preparing for his undergraduate degree, Pierre worked as a laboratory assistant. At age 16, he earned his Bachelor of Science in Physics.
In 1878 at age 18, he had completed the equivalent of an American Master of Science in Physics. He didn’t proceed immediately to a doctorate due to a lack of money, working instead as a laboratory instructor and demonstrator in charge of the physics students’ lab work until he could return to his research.
One of Pierre’s major preoccupations was the problem of the distribution of crystalline matter according to the laws of symmetry. Jacques was working in the mineralogy laboratory at the Sorbonne at which time the two began a productive five-year scientific collaboration.
- In 1880, they demonstrated an electric voltage was generated when crystals were compressed (piezoelectricity). To aid this work, Pierre invented several delicate pieces of apparatus, including the piezoelectric quartz electrometer.[xi]
- In 1881, they demonstrated the reverse effect: – 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.)
During this time, Pierre continued his work as a demonstrator in the Sorbonne’s physics laboratory until 1882 when he was appointed supervisor of all practical work in the Physics and Industrial Chemistry Schools.
In 1883, Jacques took a position at the University of Montpellier in the south of France, thus ending the brother’s collaboration. The same year, Pierre also left the Sorbonne. He took charge of all practical work and eventually became Professor of General Physics and Electrical Theory at The City of Paris Industrial Physics and Chemistry Higher Educational Institution (ESPCI).
Marie Curie (b.1867 – d.1934)
Polish by birth, Marie Curie (née Maria Salomea Skłodowska) faced seemingly insurmountable obstacles on the road to making history as a woman in the sciences. She was born in Warsaw, the city which had once been the capital of Poland. Through wars and treaties, by 1815, the countries surrounding Poland (Prussia, Russia, and Austria) had partitioned the country, and Poland was a province of the Russian Empire and under Tsarist rule. Marie’s parents raised their children to be patriots of a nation which no longer existed. They were determined to preserve Polish culture at all costs, and they suffered for their patriotism. Her parents—both teachers (her father of mathematics and physics)—taught their five children only modern education offered a way to rise from their circumstances.
As a child, Marie was remarkable for her brilliant mind, prodigious memory, and great thirst for knowledge. Although higher education was not available for girls in Poland, her parents encouraged her interest in science. When Marie was 10, her mother died, and Marie started boarding school before being moved to a gymnasium, a selective school for academically strong students. She completed her secondary education at age 15, winning the gold medal as top student.
Because Polish women were denied access to higher education, Marie, her elder sister Bronisława (Bronya), and several friends attended a “floating university”: an illegal night school whose classes met in changing locations to evade the Tsarist authorities. There, Poles learned about Polish culture and studied practical science, both of which had been suppressed by the Tsarists.
Marie and Broyna dreamed of studying at the Sorbonne in Paris, but this was beyond their family’s means. At age 18, the two sisters, made a pact. Marie would work as a governess to help finance Bronya’s medical school tuition. When Bronya had completed her medical degree, she would contribute to Marie’s studies. For the next several years, Marie worked to earn money for herself and Bronya. In the evenings, if she had time, she studied chemistry, physics, and mathematics textbooks.
Finally, in 1891, at age 24 after several impoverished years as a teacher and governess, Marie joined Bronya in Paris and enrolled at the Sorbonne to study chemistry, mathematics, and physics. Her plan was to get her teacher’s diploma and return to her beloved Poland after earning degrees in physics and mathematics. Although her math and science background was woefully inadequate, Marie worked hard to catch up with her peers. In 1893, she finished first in her master’s degree program in physics. In 1894, she finished second in her master’s degree program in mathematics.
Before completing her Master of Science in Mathematics, Marie was commissioned by the Society for the Encouragement of National Industry to do a study relating magnetic properties of different steels to their chemical composition. She needed to find a lab where she could do the work.
Pierre and Marie meet
Marie’s search for lab space led to a fateful introduction. In the spring of 1894, she mentioned her need for a lab to an acquaintance, Józef Wierusz-Kowalski, a Polish physicist and professor. It occurred to him, his friend and colleague, Pierre Curie, might be able to assist her. Unaware of how inadequate Pierre’s own lab facilities were, the professor suggested perhaps Pierre could find room there for Marie to work.
The meeting between Pierre and Marie would change not only their individual lives, but also the course of science.
[i] The Curie family has received five total Nobel Prizes. Pierre, won one (Physics in 1903), and Marie won two (Physics in 1903 and Chemistry in 1911). Their elder daughter, Irène Joliot-Curie and her husband, Frédéric Joliot-Curie, shared the Chemistry Prize in 1935. (Their younger daughter, Ève Denise Curie Labouisse, was married to American diplomat, Henry Richardson Labouisse, Jr., who was the director of the United Nations International Children’s Emergency Fund (UNICEF) when it won the Nobel Peace Prize in 1965.) Marie was the first woman to win a Nobel Prize and the first person to have won two (she is still the only person to have won two in two different sciences).
[ii] Their granddaughter Hélène Langevin-Joliot is a professor of nuclear physics at the University of Paris. Their grandson, Pierre Joliot, named after Pierre Sr., is a noted biochemist and biophysicist who has contributed to the study of photosynthesis. Hélène and Pierre are Irène Joliot-Curie and Frédéric Joliot-Curie’s children, and they are alive today.
[iii] The Curie score, or CS, is a scoring method used in cancer diagnosis.
[iv] Curium, atomic number 96, was discovered in 1944.
[v] Named in honor of Pierre Curie by the Radiology Congress in 1910, the Curie is a unit of ionizing radiation (radioactivity).
[vi] The Curie law / Curie-Weiss law is a law of magnetism.
[vii] The Curie constant is a material-dependent property which relates a material’s magnetic susceptibility to its temperature.
[viii] Curie’s Principle or Curie’s Symmetry Principle, is a maxim about cause and effect formulated by Pierre Curie in 1894.
[ix] To measure magnetic coefficients, Pierre constructed an extremely sensitive torsion balance, measured 0.01 mg.
[x] Crystallography is the branch of science which deals with discerning the arrangement and bonding of atoms in crystalline solids and with the geometric structure of crystal lattices.
[xi] These inventions would prove crucial when Pierre and Marie begin their work together. One device in particular, the piezoelectric quartz electrometer, helped Marie in her early research nearly two decades later.