She also got her first professional research job in 1894 from France's Society for the Encouragement of national Industry who needed a scientist to investigate the magnetic properties of steel.
Marie Curie's most famous discoveries were made in the late 1890s, during a period of worldwide scientific progress. Every year, discoveries were made that showed flaws in the old ideas of how nature worked. Marie Curie had a great deal to do with overthrowing one of these assumptions. Until the 1890s, scientists thought that atoms were the smallest particles of matter. Scientists did not know how these atoms were connected or how they stayed together to form the rest of matter. They also believed that there was no way to divide an atom into smaller parts. Marie Curie's research provided the first major challenge to this theory. The elements she studied convinced her that atoms could break down into smaller parts. By studying radioactivity, Marie discovered that the atoms of radioactive substance were shooting out tiny pieces of themselves. This action could only mean that there were bits of matter smaller than atoms. Other scientists investigated Curie's theory, and before long, many scientists were using her theory of radioactivity to redevelop models of how atoms were constructed.
Marie Curie also challenged another idea: that women were not capable of original scientific thought. Women during her time formed an extreme minority of scientists in the male-dominated world of science, and even those who did receive their degrees were forced to take positions as assistants to male scientists. Marie Curie fought this mind-set throughout her career. She was accused of building her career on the work of her husband, Pierre, and other male colleagues. And even though she was awarded two Nobel Prizes, Marie was never admitted to the French Academy of Sciences because she was a woman. Curie believed that being a woman was irrelevant to her pursuit of science and in 1903, she became the first woman in France to earn a doctorate in science.