Professor Murphy specialises in the spectra of quasars, particularly the absorption lines imprinted on them by very distant galaxies between the quasars and Earth. Using this technique, he has made significant contributions to the field of measuring the fundamental constants of nature in the distant, early universe.
Together with collaborators at UNSW, Professor Murphy won the 2012 Eureka Prize for Scientific Research. From 2003 to 2005 Professor Murphy was a research fellow at the Institute of Astronomy at the University of Cambridge and took up a PPARC Advanced Fellowship (now known as an STFC Ernest Rutherford Fellowship) from 2005 to mid-2007. He also held an Australian Research Council QEII Fellowship at Swinburne from 2008 to 2012. Professor Murphy is a Fellow of the Australian Institute of Physics, a Fellow of the Astronomical Society of Australia (FASA) and a member of the International Astronomical Union.