Über den anschulichen Inhalt der quantentheoretischen Kinematik und Mechanik is published which outlines Heisenberg's findings and research. The most notable of which is the Uncertainty Principle. Heisenberg stated that it was impossible to know the exact position and momentum of a particle at any given time. To formulate this principle he used research of prior physicist as well as experiments he did himself. In one expirement he tried to measure the position of an electron with a microscope. he observed that the light used to observe the electron caused it to move. He realized the more precisely you tried to measure the position of an electron the more uncertain the momentum would become. In his paper he also published the first complete and correct definition of quantum Mechanics through his use of Matrices.