In this podcast episode, MRS Bulletin’s Laura Leay interviews Kento Katagiri, a postdoctoral scholar at Stanford University, about the propagation speed of dislocations in materials. Using an X-ray free electron laser to collect data from single-crystal diamond, Katagiri and colleagues have determined the velocity of wave propagation to be in the transonic region. Katagiri’s work is most applicable to extreme shock events such as missile strikes and shuttle launches where pressures of one terapascal or more might apply. The results are relevant to a type of nuclear fusion known as Inertial Confinement Fusion, which uses intense lasers to compress the fuel. This work was published in a recent issue of Science.