A solid-state physicist by training, he is best known for several contributions to the study of the history and philosophy of 20th century science, including the discovery that Albert Einstein once attempted a steady-state model of the expanding universe, many years before Fred Hoyle.

[citation needed] O'Raifeartaigh graduated from University College Dublin in 1988 with a BSc Hons in experimental physics.

A PhD in solid-state physics from Trinity College Dublin in 1994 was followed by Marie Curie Research Fellowships at Aarhus University, Denmark and Trinity College Dublin.

He is a research associate at the School of Theoretical Physics of the Dublin Institute for Advanced Studies and was a research fellow at the Science, Technology and Society Program at Harvard University in 2010–2011.

[citation needed] Cormac is the youngest son of the late Lochlainn O'Raifeartaigh, an Irish theoretical particle physicist.