He briefly trained as a concert pianist at the London College of Music, before switching to philosophy.
During a two-year postdoctoral fellowship at the University of Calgary in 2005, he worked on the application of complex systems theory to population health.
His doctoral dissertation, Quantum Gravity in Philosophical Focus (published as a book in 2007[3]), set the foundations for his oft-quoted work within history of string theory[4][5][6][7] and as well as deepening our understanding of the foundations and history of quantum gravity more generally with a series of studies[8][9][10] and interviews,[11] culminating in his book Covered in Deep Mist: The Development of Quantum Gravity, 1916-1956 (Oxford University Press 2020).
Other philosophical papers include econophysics,[12][13] public health[14] and musicology,[15] as well as deeper issues such as the question of Why there is anything at all[16] In a 2012 collaboration with Huw Price, he developed the John Templeton Foundation project New Agendas for the Study of Time: Connecting the Disciplines.
[17] Rickles was president of Australian Association for the History, Philosophy, and Social Studies of Science and Society (AAHPSSS) during the period 2012–2014.