Marie Curie was able to begin work. Their mutual passion for science brought them increasingly closer, and they began to develop feelings for one another. Eventually Pierre Curie proposed marriage, but at first Skłodowska did not accept as she was still planning to go back to her native country. Curie, however, declared that he was ready to move with her to Poland, even if it meant being reduced to teaching French. Meanwhile, for the 1894 summer break, Skłodowska returned to Warsaw, where she visited her family. She was still laboring under the illusion that she would be able to work in her
Pierre Curie that area. Pierre Curie studied ferromagnetism, paramagnetism, and diamagnetism for his doctoral thesis, and discovered the effect of temperature on paramagnetism which is now known as Curie's law. The material constant in Curie's law is known as the Curie constant. He also discovered that ferromagnetic substances exhibited a critical temperature transition, above which the substances lost their ferromagnetic behavior. This is now known as the Curie temperature. The Curie temperature is used to study plate tectonics, treat hypothermia, measure caffeine, and to understand extraterrestrial magnetic fields. Pierre Curie formulated what is now known as the "Curie Dissymmetry Principle": a physical