Paul Dirac’s record was almost flawless as an undergraduate. In three years, Dirac nearly managed to be at the top of his class in all subjects, the only flaw being a single Strength of Materials course where he ranked second. After receiving his engineering degree at the young age of nineteen, Dirac went on to Cambridge where he pursued a degree in mathematics.
While Dirac was studying and moving forward in his academics, his older brother Felix had settled in Birmingham working in a machine-testing factory. Charles Dirac had supported Paul in his education, going so far as to give him the money necessary to be sure of solvency in Cambridge. However, Charles Dirac had refused Felix his desire to study medicine as he wished. Felix earned little money as a factory worker and was unhappy with how his life was turning out.
In early January of 1925, Felix left his job, stopped writing to his parents and sister, and began living from his savings. A few months later, in March, Paul Dirac received a letter at Cambridge from his aunt Nell. Felix had committed suicide. Dirac’s feelings about this occurrence are unknown, however, after returning home to his family for a short time, it appears that Dirac went back to work as usual.
It is speculated that the plummet of Dirac’s productivity in the following months was due to grief. Dirac’s focus was also making a shift during these years of study as he was transitioning from working on solvable problems to looking for new, fundamental research problems. In October of 1925, Dirac entered his last year of postgraduate studies. During this year was when Dirac first set out the mathematical basis of quantum theory parallel to the classical theory. Dirac came up with a theory which sought to describe the behavior of all quantum particles in all circumstances throughout all of time.
Only a month later, Dirac had finished writing his paper titled, “Fundamental Equations of Quantum Mechanics”. On December 1st, the same day a historical non-aggression pact between France, Germany, and Belgium called the Treaty of Locarno was signed, Dirac’s paper was published by the Royal Society. This marked the start of when Dirac became recognized in the scientific community. Though part of his results had already been discovered by German physicist and mathematician Max Born, Dirac had become a part of a collection of mathematicians and scientists which sought to crystallize quantum mechanics into a complete theory. A year later, in June of 1926, Dirac would pursue a Ph.D. where he would become the first to write a thesis on matters of quantum mechanics.
Farmelo, Graham, The Strangest Man: The Hidden Life of Paul Dirac, Quantum Genius, Faber and Faber 2009.