The biography of Marie Curie continues with marriage to Pierre
Curie, Marie's discoveries about radioactivity, and celebrity.
In 1893, Marie completed her Masters degree in Physics on schedule, graduating
first in her class as usual. Student life in Paris must have appealed to
her because she continued her studies, enrolling next in a Masters program
in mathematics. She finished this in one year, graduating second in her
class. These were wonderful achievements for a student who was forced to
study on her own for six years attending a secret "university"
on and off. But her educational triumphs were dimmed somewhat by an even
more important event that occured a few months before graduation. One spring
day, at a friend's apartment, Marie was introduced to a dreamy somewhat
detached, 35 year-old physicist who had made a name for himself, in scientific
circles, as the discoverer of piezo-electricity. This would be a turning
point in both their lives. Pierre Curie was his name, and in a few months,
he would propose that they spend the rest of the scientific lives together.
Pursued by Pierre Curie
The Curie French 500 Franc
Both of these young physicists had been disappointed in love, and they were
both dedicating their bachelor lives to physics in all its complexity and
beauty. Yet, they were different in some obvious ways. Marie was a "go-getter",
a woman with tremendous drive and ambition. She was a product of the school
system, racking up many firsts by the time she met Pierre. Pierre, on the
other hand, was a school system drop-out. His parents had him home-schooled
with some capable tutors in the more advanced courses. Like Albert Einstein
and Neils Bohr, Pierre may have had a learning disability. Nevertheless,
he passed his entrance exam for the Sorbonne and obtained his masters degree,
the licence es sciences, at the age of 18. Working with his
brother, he began investigating crystals. This research led to the discovery
of piezo-electricity three years later. He published a number of important
papers, but his unorthodox schooling and his failure to write up his thesis
and finish his doctorate virtually barred him from positions at all the
top schools in France. Pierre was the "ultimate outsider" as one
biographer has described him.
"It would be fine thing ... to pass our lives near to each
hypnotized by our dreams; your patriotic dream,
our humanitarian dream, and our scientific dream."
Pierre to Marie, in a letter, 1894
When Pierre met Marie, he was working as an instructor at the EPCI, a technical
college in Paris. His career had been stagnating for several years, but
all that was about to change. Once he decided to win over Marie and persuade
her to marry him, he took steps to make himself a viable husband and provider.
He wrote up his PhD thesis, for example, and he was awarded his doctorate,
albeit somewhat late in his career. He hated any type of self-promotion,
believing that if one were talented, they would rise to the top. The more
practical Marie may have pushed him to get his doctorate. He also signed
several royalty contracts on instruments he designed. The royalty fees would
add to his modest salary from the EPCI.
Marie still had serious reservations about marrying Pierre. For one thing,
she didn't want to give up her independence as a single woman. Married to
Pierre, she would have to do the usual cooking and cleaning, leaving less
time for physics. Pierre countered with the suggestion that they "live
together" in adjacent apartments. Another major obstacle was the fact
that Pierre was not Polish. If she married him, she would have to give up
her patriotic dream of returning home to liberate Poland. Pierre then offered
to emigrate to Poland and live with her there. As the months passed, Marie
realized that she and Pierre were compatible, and that they shared a postivist
political and scientific vision. Slowly, she fell in love with this eccentric
idealist. They were married in a simple ceremony on July 26, 1895.
Collaboration on Radioactivity
The next 14 years spent collaborating with Pierre on radioactive elements
would be the most thrilling time of Marie Curie's life. Marie assumed the
role of chemist, extracting and purifying radioactive elements while Pierre
focused on the physics of radioactive substances. Marie picked her own topic
for research: to find more radioactive elements like the Uranium discovered
by Becquerel one year earlier. Pierre arranged for her to work in a room
provided by the EPCI on rue Lhomond. It was a drafty, dirty "potato
shed" compared to the laboratories over at the Sorbonne. Radioactive
substances were probably not the best choice for a PhD thesis either, but
it was a very new phenomenon and that sort of thing would have appealed
to Pierre. His influence on her research is evident in other ways. For example,
Marie surveyed a large number of mineral ores similar to the way Pierre
surveyed crystals earlier in his career. Marie also relied on piezo-electrical
instruments invented by Pierre to measure the radiative particles emanating
from her purifed samples.
"Errors are notoriously hard to kill, but an error
which ascribes to a man what was actually the work
of a woman has more lives than a cat."
- Hertha Ayrton
While it may be true that Pierre acted like her thesis advisor, Marie Curie
published several papers under her own name, during this time, in which
she set out her own theories and conclusions about the new radioactive elements
she believed existed in uranium ore. Critics have charged that Pierre came
up with all the ideas, and that in the years after he died, she did not
publish anything important. The fact is that physics is a young persons
game, so to speak, and most physicists come up with their best ideas while
they are graduate students or post-docs. If they keep meticulous lab notebooks
and records, they might actually get credit for their theories. Luckily
for Marie, she kept very detailed notes in her lab books which now reside
in the Bibliotheque Nationale in Paris. It is clear from these notebooks
that Marie contributed some of the most important ideas during the Curies'
years of collaboration. The most important one was her conclusion that radioactivity
is an "atomic" phenomenon, not something caused by the molecular
structure of the mineral compounds. Around 1900, not all scientists were
convinced that atoms existed; the physical evidence like Einstein's explanation
of brownian motion was still very skimpy. It was daring to propose that
there are processes going on inside atoms causing radioactivity.
"Marie Curie . . . the one person whom fame has not corrupted."
- Albert Einstein
Yet, Marie Curie was exactly right. The importance of her "atomic"
radioactivity cannot be over-estimated. In many ways, it launched the atomic
age and what we think of today as modern physics. For the next 100 years,
physicists would focus their investigations on processes and particles inside
the atom. Unraveling the mysteries of the atom would ultimately lead to
the theory of Quantum Mechanics, one of the greatest scientific achievements
of the twentieth century. In 1903, both Marie and Pierre Curie and Henri
Becquerel were awarded the Nobel Prize in Physics for their work on radioactivity.
The Dangerous Beauty of Radium
The actual process of extracting the radioactive element radium from uranium
ore was a physically grueling task. It took Marie several years to produce
one tenth of a liter of pure radium from tons of rock mined out of the earth.
She established that one mole of radium had a mass of 226 grams. On most
days, she worked over a large vat outside her laboratory shed. On rainy
days, she had to move inside though the lab room was cold and drafty. The
latter turned out to be a blessing in disguise since noxious radon gas was
being produced, and everything in the lab was contaminated. One science
historian has estimated that Marie was exposed to about 1 rem ( a unit of
radiation) per week. By today's standard, a much smaller amount of .03 rem
is considered dangerous.
"Just at present, the world has run raving mad on the subject
which has excited our credulity precisely as the apparitions at Lourdes
excited the credulity of Roman Catholics."
- G.B. Shaw, introduction to his play The Doctor's Dilemma
After the Curies won their first Nobel Prize, the popular press around the
world declared radium a miracle drug. Marie kept a glass vial of radium
salts on the stand next to her bed at home. She was enchanted with the soft,
blue glow it produced in the dark. Both Marie and Pierre were swept along
by all the publicity, and they played down the negative health effects they
experienced. For example, their finger tips were permanently scarred, hardened,
and in constant pain from handling radioactive samples. Pierre, Marie, and
Becquerel had all suffered accidental burns on their skin when they carried
samples of radium salts in their clothing for a few hours. Marie was always
tired "without being exactly ill," and she lost more than 15 pounds.
Today, it is well-established that fatigue and depression are side-effects
of radiation over-exposure. The worst tragedy occurred when, after giving
birth successfully to Irene (her first child), she suffered a miscarriage
in her fifth month in1903 probably due to radiation exposure. She had not
felt well during either pregnancy. Marie was very disappointed, and this
dampened whatever satisfaction she got from obtaining her doctorate earlier
in the year.
What the Curies and the world did not know, although the evidence was mounting,
is that radium and other radioactive substances give off a powerful, invisible
light energy called gamma rays. These gamma rays are very destructive to
animal and human body tissues because they can penetrate anything except
lead. In December of 1903, neither Pierre or Marie felt well enough to travel
to Stockholm to receive their Nobel medals in person. Their physician, however,
could find nothing wrong with them. Marie's lungs were checked for TB, and
they were clear. Perhaps the Curies had more down-to-earth problems on their
minds. One of the few things they bought with their Nobel prize money was
a modern bathroom with a toilet for their home. In 1900, two out of three
French residences did not have indoor plumbing.
The Radium Institute / Pierre's Death / The Langevin Affair