Professor Antonia is distinguished for his contributions to the field of turbulent flow. His early work was concerned with the response of turbulence flows to small perturbations in surface roughness. Later work has been focused on small-scale turbulence and the statistics of small-scale motion. His papers on this topic had a strong influence on the field and are highly cited. He has also made significant contributions to instrumentation and measurement of turbulent flows, and large-scale organization in shear flows. His work is characterized by a deep appreciation of the mathematical difficulties of the subject, coupled with formidable experimental skills. He is in the top 100 cited authors in engineering, internationally.