James Baker, Cornell University
Tue., Jan. 26, 2016, 4:30 PM in Science Center 128
In his 1959 lecture ‘There’s Plenty of Room at the Bottom,’ Richard Feynman posed an “invitation to enter a new field of physics,” and challenged the scientific community to expand their capabilities to observe, measure, and manipulate materials at the nanoscale. While recognition and manipulation have occurred at the nanoscale in biological systems since the origin of life, our ability to observe and characterize these interactions is still emerging. Today’s physicists continue to play a role in this progress, as the application of fundamental physical principals remains vital in the continued development of new measurement approaches for studying nanoscale systems. In this talk, I will discuss two experimental approaches to the detection and analysis of individual biological structures at the nanoscale: nanophotonic resonators and magnetic tweezers. The applications of such developments range from the study of fundamental biophysical interactions to the development of point-of-care medical diagnostics and beyond.
Adam Light, Earlham College
Thu., Jan. 28, 2016, 4:30 PM in Science Center 128
Fluctuations in magnetized plasmas are ubiquitous and complex. Although they often produce detrimental effects, like increasing heat and particle transport in fusion energy devices, fluctuations also provide a diagnostic opportunity. Identification of a fluctuation with a wave or instability gives detailed information about the properties of the underlying plasma. In addition to introducing plasma as a complex system, I will describe imaging measurements of coherent waves in a cylindrical plasma column. Visible light from Ar II line emission is collected at high frame rates (>50,000 frames/second!) using a fast digital camera. Experimental wave-dispersion-relations are constructed using imaging data alone, and can be compared directly with theoretical models. I will discuss the identification of both electron-drift waves and Kelvin-Helmholtz fluctuations, as well as imaging measurements of nonlinear mode coupling.