In standard use, the S-matrix can be calculated if you understand the forces in the interaction region - for example, in the nucleus of an atom. But what if you don’t know those internal interaction forces? Heisenberg sought a way to...

Discovery of the Proton and Neutron

Backgro
und:
• J.J. Thomson's 1897 discovery of the electron led to the development of atomi
c models.
• Ernest Rutherford's Gold Foil Experiment (1911) revealed the presence of...