He received his PhD in Plasma Physics at Princeton University in 1998, working with Russell Kulsrud on magnetic reconnection, and then held postdoctoral positions at the University of Chicago (1998-2001) and at the Kavli Institute for Theoretical Physics in Santa Barbara (2001-2004). In 2004 he moved back to Princeton as a research stuff member in the Department of Astrophysical Sciences there, and in 2009 joined Physics faculty at the University of Colorado in Boulder. He is now on a sabbatical at the Institute for Advanced Study in Princeton this academic year.