Tom Chang is internationally known for his contributions to the physics of complexity, self-organized criticality, intermittent turbulence, and charged-particle acceleration processes in space plasmas. For thirty-five years, he has led theoretical geo/cosmo plasma research at the Kavli Institute for Astrophysics and Space Research at the Massachusetts Institute of Technology. He is a Senior Fellow of the American Physical Society and has been president of the Society of Engineering Science. He was the editor of the journal Nonlinear Processes in Geophysics and associate editor of Reviews of Geophysics, and he served for many years as an editor of the international journal Plasma Physics. He is the recipient of the National Thompson Award from ASTM and of certificates of recognition from the Society of Engineering Science and the Massachusetts Institute of Technology.