The Joy of Discovery

On a winter evening in Paris, in 1901, Marie and Pierre Curie were eating dinner in their Paris home with their four-year-old daughter, Irène, and,Pierre’s father, Dr. Curie, who lived with them. After dinner, Marie put Irène to bed and Dr. Curie retired to his room. But Pierre was restless. As Marie sat down to her sewing, she sensed his unease and said, “Suppose we go down there for a moment?” Pierre knew exactly where she wished to go: They worked together in a makeshift laboratory, partners in a hunt for something whose existence they believed in but had yet to prove to the world. Every day they put in long hours because they knew they were getting closer and closer to the truth. Their lab was like a magnet that drew them even at the end of a long workday. So they put on their coats and set out, arm in arm, for the five-block stroll to the center of their lives.

Marie and Pierre Curie were scientists who were interested in discovering the basic materials and laws that make up the natural world. By the beginning of the 20th century, the science of chemistry had determined that all the matter on earth was made of elements—solids, liquids and gases that could not be simplified. The smallest particle of an element was the atom. Elements could combine with each other to make more complex materials, called compounds. But chemists knew how to break down compounds to see what elements they were made of. Some of the known elements were gases, like hydrogen, oxygen and nitrogen; some were metals, like gold, silver and tin; some were nonmetals like carbon and sulfur. By 1898, seventy-nine elements had been discovered.

Recently, Marie Curie had become interested in a new kind of energy that was given off by the element uranium—a rare metal. Uranium emitted rays that were similar to light rays, but were invisible to the human eye. They also passed through materials that stopped ordinary light, such as paper or wood. Marie used an instrument invented by her husband to measure the strength of these rays, which she called “radioactivity.” When she measured the radioactivity from uranium ore she discovered that there was far too much radiation to come from uranium alone. Marie guessed that this extra radiation must come from a new and unknown element. She wrote her sister, “You know, Bronya, the radiation that I couldn’t explain comes from a new chemical element. The element is there and I’ve got to find it. We are sure! The physicists we have spoken to believe we have made an error in experiment and advise us to be careful. But I am convinced that I am not mistaken.”

As it turned out the radiation came from two new elements. On that winter evening, the subject of her experiments was the one she called “radium.” She would publish her findings so that other scientists could repeat her experiments and get the same results. The job was harder and took longer than she had imagined when she first started. She shared her dreams of the new element with her husband, dreams that fueled her efforts for almost four years of arduous work.

“I wonder what it will be like, what it will look like….Pierre, what form do you imagine it will take?” Marie speculated to her husband.

“I don’t know,” Pierre answered gently. “I should like it to have a beautiful color….”

That night, as they approached the familiar laboratory, they no longer noticed that it was just a wooden shack in a courtyard; that the skylight roof leaked when it rained, that it was drafty and cold in winter and stifling hot in summer. Pierre put his key in the lock and the door squeaked open. The room was furnished with worn kitchen tables and every surface was covered with tiny glass dishes filled with fluids. The open dishes allowed the fluids to evaporate so that crystals containing their new element would form. “Don’t light the lamps,” Marie said. “Look…look,” she whispered. The dishes glowed in the dark with a strange and beautiful bluish light. These luminous crystals contained their new element radium. Radium was so rare that it was taking a long time to collect enough of it to measure its properties and before publishing their results. Yet its powerful glow was proof that soon they would have enough to do this. At that point, they could publish their results

Marie’s discovery of radium brought her immense joy and satisfaction. It would change the world of medicine and add to our understanding about the structure of the atom. It would bring her fame, though it would not protect her from heartache and disappointment. Marie Curie was a world-class scientist—the first woman to be recognized as such. What did it take to become a scientist? What drove her to spend most of her waking hours in a laboratory, instead of managing a home and family like most women of her day? What is so fascinating about science that it captured her imagination for a lifetime? This book tells the story.