Ernest+Rutherford+A+LIGHT

Ernie was the top dog of nuclear physics. Some even describe him as the "Father". He discovered the half-life (used in carbon-dating) and developed the model of an atom that we use today, featuring orbiting electrons around a neutron-proton nucleus. This radically changed everyones perspective on the atom. He also may have done an experiment featuring gold foil at one point to prove that atoms had a nucleus.