Sir Mark Oliphant of Adelaide was the main person missing from the film Oppenheimer. 

It was Sir Mark who carried the letter from European scientists to New York to convince the American President that Hitler was trying to make an atomic bomb and needed to be beaten to the chilling quest. It led to the Manhattan Project.

Mark also gave us microwave power, initially to equip planes, later to give us microwave ovens; he helped establish the ANU; was the first President of the Australian Academy of Science and became governor of South Australia.

He was the 'right hand man' of Sir Ernest Rutherford of NZ who revealed the atomic nucleus and won the Nobel Prize in 1916. 

It is often reported that they "split the atom" and so enabled the incredible power therein to be released. 

It was this, as well as the Manhattan Project, that made Sir Mark Oliphant such a voice for peace and tolerance, as this Science Show from 1986 remembers.