Professor and Interdisciplinary Chair in Science; Department of Physics
320 Regents Hall
Telephone: (202) 687-6594
Prof. Urbach completed his B.A. in Physics at Amherst College (1985), his Ph.D. at Stanford University (1993), and a Postdoctoral Fellowship at the University of Texas at Austin (1993-1996). He joined the Physics Department at Georgetown University as an Assistant Professor in 1996 and was promoted to Professor of Physics in 2006. He served as chair of the Physics Department in 2000-01, 2004-07 and from 2016 to 2020, as the co-Director of the Program on Science in the Public Interest from its founding until 2011, and the Director of the Institute for Soft Matter Synthesis and Metrology from its founding in 2011 until 2015. In 2009-10, he served as a AAAS Science and Technology Policy Fellow at the Department of Energy. Prof. Urbach’s research interests include complex dynamics and biophysics. He has received a Sloan Foundation fellowship and the Presidential Early Career Award for Scientists and Engineers, and research funding from the National Science Foundation, the National Institutes of Health, NASA, the Air Force Office of Scientific Research, NIST, the Petroleum Research Foundation, the Research Corporation, and the Whitaker Foundation.
Prof. Urbach and his collaborators study complex dynamics in a variety of systems, ranging from shaking sand to cytoskeletal proteins to migrating neurons. Using the techniques of statistical physics and nonlinear dynamics, together with advanced imaging techniques, image processing, and computer simulations, they are trying to develop quantitative, testable descriptions of multifaceted, interacting, ever changing systems that might at first glance seem like a complicated mess. For more specifics, visit the Dynamics Imaging Lab website.
Rathee, V., Miller, J., Blair, D. L. & Urbach, J. S. Structure of propagating high-stress fronts in a shear-thickening suspension. Proc National Acad Sci 119, e2203795119 (2022).
Rathee, V. et al. Role of particle orientational order during shear thickening in suspensions of colloidal rods. Phys Rev E 101, 040601 (2020).
Rost, B., Stimatze, J. T., Egolf, D. A. & Urbach, J. S. Effective aspect ratio of helices in shear flow. Physical Review E 102, B (2020).
Rathee, V., Blair, D. L. & Urbach, J. S. Localized transient jamming in discontinuous shear thickening. J Rheol 64, 299–308 (2020).
Rathee, V., Blair, D. L. & Urbach, J. S. Localized stress fluctuations drive shear thickening in dense suspensions. Proceedings of the National Academy of Sciences 114, 8740–8745 (2017).
Arevalo, R. C., Kumar, P., Urbach, J. S. & Blair, D. L. Stress Heterogeneities in Sheared Type-I Collagen Networks Revealed by Boundary Stress Microscopy. PLoS ONE 10, e0118021 (2015).
Koch, D., Rosoff, W. J., Jiang, J., Geller, H. M. & Urbach, J. S. Strength in the Periphery: Growth Cone Biomechanics and Substrate Rigidity Response in Peripheral and Central Nervous System Neurons. Biophysj 102, 452 460 (2012).
Sisan, D. R., Yarar, D., Waterman, C. M. & Urbach, J. S. Event Ordering in Live-Cell Imaging Determined from Temporal Cross-Correlation Asymmetry. Biophysj 98, 2432 2441 (2010).
Olafsen, J. S. & Urbach, J. S. Two-Dimensional Melting Far from Equilibrium in a Granular Monolayer. Phys Rev Lett 95, 098002 (2005).
Rosoff, W. J. et al. A new chemotaxis assay shows the extreme sensitivity of axons to molecular gradients. Nature Neuroscience 7, 678 682 (2004).