Professors
Robert E. Thorne
Professor of Physics
B.Sc., 1981, University of Manitoba. Ph.D., 1987, University of Illinois at Urbana. Assistant Professor, Physics, Cornell, 1988-1994. Associate Professor, Physics, Cornell, 1994-2000. Professor, Physics, Cornell, 2000-present. Presidential Young Investigator, 1988-1993. Alfred P. Sloan Fellow, 1988-1990.
Research Areas
Materials physics problems in structural genomics; new technologies for macromolecular crystal growth and crystallography; physics of cryopreservation of biological samples; recovering ancient Greek and Roman inscriptions; physics and nonlinear dynamics of charge density wave conductors; biomass combustion
Current Research
Materials Physics Problems in Structural Genomics:
High-resolution structures of proteins and other biological macromolecules provide insight into molecular function and a basis for rational approaches to the design of new medicines. The bottleneck in determining macromolecular structures by X-ray crystallography is the difficulty of obtaining high-quality macromolecular crystals and of maintaining this quality throughout the data collection process. Our program has been investigating the physical properties of protein crystals; protein crystal disorder and disordering mechanisms; liquid drop pinning and dynamics on surfaces and its application in crystallization technology; radiation damage and its mitigation; crystal cryopreservation; and application of our methods to obtain new and/or improved information about macromolecular structure and function. Techniques used include synchrotron-based x-ray imaging and diffraction, quasi-elastic light scattering, fluorescence microscopy, and microfabrication. Some of our discoveries have been commercialized by Mitegen, LLC.
Physics of Cryopreservation of Biological Samples
Cooling samples to low temperatures is important not only in protein structure determination, but in the long-term preservation of cells and tissues. The basic methods used by biological, medical and veterinary practitioners to freeze and store biological samples have remained largely unchanged for at least two decades, and were arrived at empirically rather than through systematic studies based on understanding of fundamental principles. We are studying both fundamental and applied problems in cryopreservation including the physics of aqueous glass formation, and have developed a method that increases cooling rates by two orders of magnitude over current best practice.
Electronic and Structural Properties of Charge-Density-Wave Conductors:
Low-dimensional electronic materials that undergo transitions to charge or spin-density wave states are among the most remarkable conducting materials ever discovered. They exhibit extremely diverse phenomena having analogs in superconducting, magnetic, and pattern forming systems. Our current projects include fabrication and characterization of
CDW microstructures and characterizing the spatiotemporal dynamics and phase diagram of driven density waves.
Biomass Combustion:
Most biomass energy research in the US has focused on converting biomass to ethanol for use as a transportation fuel. The energy content of the ethanol produced is usually only a small fraction of the available plant energy, and can be comparable to the external energy inputs required for the conversion. Direct combustion of the biomass to generate heat is much more efficient, but this typically involves either high emissions or high capital costs. We are collaborating with a local company and with faculty in Mechanical and Aerospace Engineering on an approach that could yield low emissions, low cost combustion systems, and allow much broader use of biomass energy.
Recovering Ancient Inscriptions:
Although we use "written in stone" to indicate permanence, even this form of archival storage has a finite lifetime. A substantial fraction of all ancient stone inscriptions have been partially or completely eroded, and in many cases their original message remains hidden from us. In collaboration with Kevin Clinton of Cornell's Classics Department and Don Bilderback and Detlef Smilgies of Cornell’s High Energy Synchrotron Source (CHESS), we have reported the first application of X-ray fluorescence imaging to the study of ancient inscriptions. This technique is allowing us to explore the tools and pigments used in the original inscription, and to recover text from eroded regions.
Physics Education:
Future U.S. economic competitiveness depends upon our ability to recruit and train a highly skilled workforce in science, technology, engineering and the health professions. Physics is a critical gateway to all of these disciplines, and provides the foundation for fundamental understanding, analyzing data and solving problems. Following Cornell’s long tradition of innovation in physics education, we have been developing teaching methods and materials that engage students of diverse backgrounds and interests, and that help them to develop both mastery of and a broader appreciation for physics. These methods have had dramatic impacts in our introductory course for life science students, and are now being developed and applied in our engineering sequence.
Physics Teacher Training:
The US has a critical shortage of qualified high school physics teachers. Only one in three US high school students take physics, yet only one in three high school physics teachers has a degree in physics or physics education. The Physics and Education Departments are working together to recruit and train more high school physics teachers at Cornell, with support provided by the Physics Teacher Education Coalition (PhysTEC) and the Provost. A key component is our Undergraduate Teaching Assistant Program, run by our high school physics teacher in residence, which gives Cornell undergraduates with aptitudes and interests in physics the opportunity to experience the practical and intellectual challenges of teaching.
Graduate Students
Matthew Warkentin and Ethan Geil
Postdoctoral Associate
Ahmed Soliman