Paul Ehrenfest asked her to investigate an article on optics by Lord Rayleigh detailing an experiment that produced results Rayleigh had been unable to explain. She was able to explain the results, and also made predictions based on her explanation, which she then verified experimentally, demonstrating her ability to carry out independent and unsupervised research. She published the results in her report on "Some Conclusions Derived from the Fresnel Reflection Formula". In 1906, while engaged in this research, Meitner was introduced by Stefan Meyer to radioactivity, then a very new field of study. She started with alpha particles. In her experiments with collimators and metal foil, she found that scattering in a beam of alpha particles increased with the mass of the metal atoms. She submitted her findings to the Physikalische Zeitschrift on 29 June 1907. This was one of the experiments that led Ernest Rutherford to predict the nuclear atom.