Marie Curie (5 page)

Almost from the beginning, she started calling radioactivity an atomic property. She drew the conclusion that the ability to radiate had to be linked to something in the interior of the atom itself.

A year earlier, the English physicist J. J. Thomson, while pursuing Röntgen’s research, had concluded that certain rays were made up of particles even smaller than atoms. In other words, no longer was the atom the smallest unit in matter, as Mendeleyev and everyone else had insisted. The atom was
not
the end of the story. Thomson was calling the particles “electrons”—the first
sub
atomic particles to be identified.

There was still much more to understand about the atom and its structure. But the doors to modern particle physics—atomic science—had officially swung open.

CHAPTER FIVE

The Legend Begins

P
OLONIUM AND RADIUM. Both of Marie’s monumental discoveries had been based on what she understood to be true from spectroscopic evidence and the intensity of the elements’ rays. Now she felt compelled to go further, to produce actual substances that could be seen and measured, so that she could
prove
her theories on a chemical basis as well.

Thus began her legendary quest to isolate the pure radium that existed in such tiny traces in complex ores.

To do so would require huge amounts of pitchblende. She searched far and wide, locating a uranium mine in Bohemia, now part of the Czech Republic. It supplied potters who made yellow glazes from uranium for the vases and dishes that the area was renowned for. The mine was willing to send the Curies ten tons of pitchblende residue, as long as they paid to have it shipped. To the mine it was waste material, basically worthless. All the uranium was gone from it.

To Marie it was priceless. A wealthy baron donated money for the shipping costs. The next problem was storage. Where do you put twenty thousand pounds of pitchblende residue? Pierre got permission to use a huge shed at the school. This was another gloomy place, freezing in winter, boiling in summer, previously a room for dissections, now too shabby and uncomfortable even for that. Foreign scientists who in later years visited the shed assumed it was some sort of practical joke.
This
was where the famous Madame Curie worked?

In the spring of 1899, bag after bag of brown dust mixed with pine needles started arriving at the shed from Bohemia.

Marie’s mission was to purify known substances out of the pitchblende residue. First she chemically extracted all the elements that weren’t radioactive. Finally she obtained a material that was mostly barium chloride but which also contained radium. At this point she used a delicate process called fractional crystallization to separate the barium from the radium. It was a bit like producing rock candy, which is made by repeated heating and cooling a solution of sugar and water. Again and again, she crystallized and recrystallized—many thousands of times, all the while striving to avoid contaminating her samples with unwanted substances. It was, typically, painstaking work where she couldn’t be too careful. (Later she attributed her success to a very simple rule: “The secret is in not going too fast.”)

The shed was filled with vats of liquids she had to move and pour, stirring for hours at a time. It was dirty work, and mind-numbingly tedious: “I would be broken with fatigue at the day’s end.” She kept track of every detail in notebook after notebook. Accidental contamination and other setbacks occurred often. On the best days, when progress was made, she used as many as nine exclamation points to indicate her giddiness.

Pierre later said that if the decision had been his, he wouldn’t have persisted with the daunting task of isolating radium, or would have done it later when they had a decent lab. But like her mother who’d cobbled shoes, Marie did the hands-on work that needed to be done, knowing it was for a worthy cause. And always the drive to succeed—and get credit—fueled Marie. Pierre was simply not as competitive.

Months passed. Marie worked in her notebooks at the shed and at home. All scientists are recorders of events—think of Leonardo da vinci and his notebooks. Marie was a fanatic recorder. Not just of scientific work. She itemized long lists of expenses (“His” and “Hers”), wrote down recipes (gooseberry jam, with ingredients tallied so precisely it might have been a lab experiment), and especially took note of anything to do with Irène.

Even as a mother, Marie was a scientist. She noted daily measurements of her daughter’s height, weight, the diameter of her little head; her first words (“gogli, gogli, go”); when each tooth came in; every instance of a skinned knee; all of her accomplishments. In some ways, Irène was treated like an experiment in progress. And conversely, Marie referred to radium as “my child.”

Through repeated purifications, the radiation kept getting more intense. Something extraordinary was happening. The substance she had isolated
glowed in the dark
. “It was like creating something out of nothing,” she said.

After her start in 1899, the months piled up into years. Of their days at the lab, she wrote, “A great tranquility reigned. . . . We lived in a preoccupation as complete as that of a dream.” At noon they would break for a simple lunch, perhaps a few bites of sausage with a cup of tea. They had few visitors and participated less than ever in the cultural life of turn-of-the-century Paris.

At night, sometimes the couple would walk the five blocks back to the lab, holding hands, to see in the darkness the eerie blue-green glow of test tubes with radium: “Slightly luminous silhouettes . . . stirred us with new emotion and enchantment . . . like faint fairy light.” In their bedroom they kept a vial of radium salts and marveled at its glow before falling asleep.

What the Curies couldn’t know, not in 1899, was how extremely dangerous radiation exposure is to all living creatures. Its harmful effects weren’t clear for years afterward, and neither of the Curies took precautions while handling it. The excitement of their discoveries was much more on their minds than trivial concerns like a constant burning in their fingers. It was never clear whether the Curies suspected radium’s danger; they were part of a tradition of scientists taking personal risks. The oddest example is perhaps the great Isaac Newton, who while studying optics, nearly blinded himself by poking behind his eyeballs with sharp instruments to see what changes in vision the pressure produced.

After reading of two German professors’ experiments with the effects of radioactivity on the body, Pierre taped radium salts to his arm for ten hours. A blistering sore developed. It healed slowly, but left a permanent gray scar. The Curies took careful notes, disregarding personal injury, thinking only of the meaning for science. “This shouldn’t frighten people,” Pierre stressed.

If radium burned healthy skin tissue, could it be used to destroy diseased tissue? Pierre experimented on animals with cancerous tumors—mice, rabbits, and guinea pigs. Yes, he found out, cancer cells could be destroyed with normal tissue growing back. But then, in a later experiment, he put mice and guinea pigs into confined spaces with radium salts. All the animals died in less than nine hours. Breathing radium, it turned out, destroyed the lungs. So how much exposure to radium was too much? That was the ongoing question.

By the end of 1900, the Curies had written six more papers: two by Marie alone, one by Pierre alone, and three jointly. Other young scientists, excited by the discoveries, volunteered to work for them without pay. One was the chemist André-Louis debierne, one of Pierre’s pupils, who continued as Marie’s trusty assistant for the next thirty-five years.

In 1900, the Paris Exposition—a gigantic world’s fair—drew fifty million people. Surrounding the eleven-year-old Eiffel Tower were pavilions showcasing the latest advances in indoor plumbing, innovations in photography, the brand-new movies, and other wonders of technology. Electric lights were everywhere, and electricity powered a train as well as a moving walkway that took visitors around the whole Expo.

It was an exciting time to be alive. Wireless telegraph service between France and England had just been established, and companies were being formed to sell the relatively new invention of the telephone. People chattered about aeroplanes and horseless carriages. (The Wright Brothers’ first successful flight was only three years away, and Henry Ford’s Model T only eight years away.) A doctor named Sigmund Freud published
The Interpretation of Dreams
, which would revolutionize thinking about the human brain and further popularize psychotherapy.

The Curies were right in the thick of the excitement. As part of the Expo, scientists came in from all over the world for the International Congress of Physics. The biggest draw was the Curies’ presentation of their paper, “The New Radioactive Substances and the Rays They Emit.” It was their longest report so far, giving full credit to similar work going on in England and Germany. Their conclusion: “Spontaneous radiation is . . . a deeply astonishing subject.”

Why?

Because it seemed to violate a fundamental law of nature—that energy could not be created or destroyed. Yet, without diminishing, radium seemed to give off radiation ceaselessly. The Curies made a splash by urging a next step that would solve the mystery. They would locate the source of radiation’s strange energy.

Back in the lab, with Marie’s legendary labor of love approaching an end, she kept on processing her tons of pitchblende. She found out the hard way that a ton produces only a minuscule amount of radium salt. By 1902 she had a piece the size of a grain of rice. Here it was, physical evidence that proved that radium was a new element. Her discovery was now credible to skeptics.

Marie’s work to isolate radium had taken almost four years, during which she lost fifteen pounds and Pierre was constantly ill. Colleagues urged the couple to slow down for the sake of their health. One friend pleaded with them to stop endlessly obsessing about work “every instant of your life, as you are doing. You must allow the body to breathe. . . .
You must not read or talk physics while you are eating.
”

But hard work and sacrifice defined Marie—they were essential parts of her notion of science, and they were essential parts of her very being: “A great discovery does not issue from a scientist’s brain ready-made.” The scientific process was not one of “Eureka” moments but rather a steady, often plodding buildup of knowledge.

At last she was able to calculate the atomic weights of her new elements. Triumphantly she placed radium on Mendeleyev’s chart below barium in the column of alkaline earth metals. It belonged in the same column as similar elements, mostly silver-white, shiny metals.

Also triumphantly, she wrote the news to her ailing father back in Poland. While proud of her, he didn’t quite grasp the magnitude of her accomplishment, writing back, “What a pity it is that this work has only theoretical interest.” He died six days later, incredibly wrong on this particular subject.

Working hard was all the more urgent because the race to learn more about radiation was getting so intense that sometimes mere days separated one person’s discovery from another’s. This was an epic contest to be first to discover major truths about the nature of our universe. Marie was prepared to do whatever it took to win.

One of her chief competitors examining rays was New Zealand physicist Ernest Rutherford, a protégé of J. J. Thomson, the genius who had identified electrons as the first subatomic particles. In 1899, Rutherford published a paper distinguishing two different kinds of particles emanating from radioactive substances. What he called “beta rays” traveled nearly at the speed of light and were able to penetrate thick barriers. “Alpha rays” were more powerful particles, yet were slower and heavier and could be more easily deflected, even by something as simple as a thick layer of aluminum foil.

Rutherford complained, “I have to publish my present work as rapidly as possible in order to keep in the race” against the “best sprinters,” meaning, above all, the Curies.

Meanwhile, the question came up about whether Marie and Pierre would apply for a patent for producing radium. If they kept the secret to themselves, they stood to make a lot of money. No longer on the edge of poverty as they had been during the first five years of their marriage, the Curies were far from rich. All her life Marie saved string, recycled cardboard to write notes on, patched umbrellas to make them last longer, wore dresses until they were threadbare.

But they both vetoed the patent idea. Although aware she was “sacrificing a fortune,” Marie believed it “would be contrary to the scientific spirit.” Early on she theorized that radium’s best use would be medical, and “it seems to me impossible to take advantage of that.” Marie and Pierre believed their findings should be available to everyone.

At the same time they were doing their historic work, the Curies were both teaching in order to bring in money. Pierre began teaching at the Sorbonne. He was a gifted teacher, conveying his enthusiasm and having “the laugh of a child,” according to one student. Marie was appointed to the faculty at the premier school for training teachers, in Sèvres, France. The first woman ever. As the lecturer in physics, she was surprisingly awkward at first. Her speaking style was intense, but monotonous.