Paul Dirac's influence on the background to EMR through his exposition of quantum mechanics pervades all modern texts. By using a relativistic treatment for the wave equation he demonstrated the need for a fourth quantum number, spin, ms.
In 1933 Paul Dirac and Erwin Schrödinger were joint recipients of the Nobel Prize for Physics, "for the discovery of new productive forms of atomic theory". The Nobel prize was for his work in quantum mechanics, his seminal book, "The Principles of Quantum Mechanics" was first published in May 1930, and it is still in print!
Dirac invented and introduced bra and ket vectors in "Principles" (p 18), and it is the ubiquitous short hand notation of modern quantum mechanics. In EMR theory it is used by all the main text books, namely <ket|and|bra>
Paul Dirac started his schooling at a Bishopston primary school, just a mile from where this web site is being written!
