Fall 2010

September 3, 2010
"Laser Propulsion: Past, Present and Future" by Dr. John Sinko
3:10 pm
Franklin Miller, Jr. Lecture Hall (RBH 109)
Abstract: Laser propulsion is an emerging propulsion technology that promises to bring about revolutionary changes in the use of space and space assets. Using a high power laser, it may be possible to launch from ground to low earth orbit for as little as 100$/kg, compared to current launch costs of closer to 10,000$/kg. Ground-based laser systems are being studied to remove orbital space debris, which poses a danger to astronauts, satellites and the international space station. In-space laser thruster prototypes have already demonstrated performance competitive with chemical and electric propulsion, and may be applicable to interstellar propulsion. Laser ablation tractor beams have the potential to perform remote control of unpowered satellites, controlled satellite de-orbit and space rescue. In this talk, the international history, underlying physics, likely applications, and current state of this promising technology will be discussed. Reception to follow.

September 10, 2010
"Seeding the Large-Scale Structure of the Universe" by Evan Pease, '11
3:10 pm
Franklin Miller, Jr. Lecture Hall (Hayes 109)
Please join us for Evan Pease's senior honors exercise talk. Abstract: How can we explain the existence of stars, galaxies, and clusters in the context of inflationary cosmology? The current detailed picture of the Cosmic Microwave Background (CMB) and our observations of the large-scale structure of the Universe give measurable hints about how our Universe formed. The theory of cosmological perturbations is a promising explanation of the origin of this structure. This research looks at how the small fluctuations of the vacuum state at the outset of inflation might source the clusters and galaxies that exist throughout the Universe. Key to tracking these perturbations is the evolution of the cosmological scale factor, a(t), through the period of cosmic inflation. I will introduce a specific type of potential-driven inflation with multiple scalar fields known as staggered inflation; and I will explains how the CMB can tell us whether or not this type of inflation occurred. Reception to follow.

September 17, 2010
"Structural Color: From Damselflies to Artificial Sensors" by Frank Peiris, Physics Department
3:10 pm
Franklin Miller, Jr. Lecture Hall (RBH 109)
Abstract: Besides color manifested due to pigmentation, there are many instances in the natural environment where complex biological designs in the fauna or flora reveal brilliant colors. This results in what is termed structural color, a phenomenon that is produced by the interaction of electromagnetic waves with the microstructure of a material. While spending my sabbatical last year in Sri Lanka, a team of students and I explored the structural color mechanism manifested in Gossamerwing damselfly, a species endemic to Sri Lanka, which displays brilliant green-blue iridescent colors. Using optical and atomic force microscopy, as well as x-ray, optical and vibrational experimental techniques, we were able to decipher some of the structure associated with the colored hind-wing of the Damselfly. The simulated reflectivity data were commensurate with experimental data, suggesting that our models were credible. The Damselfly's wing structure will be juxtaposed with some artificial systems we have synthesized in the laboratory, illuminating both the similarities and the complexities between the natural and artificial structures. Reception to follow.

September 24, 2010
"Research and Development in Government and Industry - Some Insights from a Kenyon Grad's Career" by Alan G. R. Bell '74, Clermont Technology Consulting, LLC
3:10 pm
Franklin Miller, Jr. Lecture Hall (RBH 109)
Abstract: Many Kenyon science graduates will pursue research and development (R&D) careers in business, the government, or in academia. R&D is a national investment in our future that affects nearly every aspect of our lives, from maintaining our most basic necessities - the air we breathe, the food we eat, and the water we drink - to advancing our progress and growth by shaping how we communicate, treat disease, and travel within our cities, around the globe, and beyond. This investment also has a major effect on our economy, because entire industries are rooted in R&D and depend on its continuing output. In this talk, I explore what R&D really is, and I "follow the money" to see who the major players are, what they do, and where they do it. I also discuss the outlook for the future of R&D in terms federal science and technology policy, and identify some of the areas that, in my opinion, will be "hot" in the coming years, with an emphasis on career opportunities in the business and government sectors. Throughout this talk, I draw extensively from my own experience as a researcher and senior executive at a mid-sized technology company to show examples of the kinds of R&D projects that a Kenyon graduate might encounter. Reception to follow.

October 1, 2010
FRIDAY AFTERNOON PHYSICS
3:10 pm
Rugby Practice Field
No Physics colloquium this week; however, the SPS Physics Club will be LAUNCHING ROCKETS instead! The group plans to catch the launches on a high-speed camera and then bust out their protractors to figure out the flight height. Meet in the lobby of Hayes at 3:10 pm this Friday to walk down to the rugby practice fields together. Please join us! Faculty, students, friends of faculty and students...all are welcome!

October 15, 2010
"How the Large Angle Properties of the CMB Challenge Concordance Cosmology " by Dr. Glenn Starkman, Director of the Institute for the Science of Origins, Case Western University
3:10 pm
Franklin Miller, Jr. Lecture Hall (RBH 109)
Abstract: The Cosmic Microwave Background Radiation is our most important source of information about the early universe. Many of its features are in good agreement with the predictions of the so-called standard model of cosmology -- the Lambda Cold Dark Matter Inflationary Big Bang. However, the large-angle correlations in the microwave background exhibit several statistically significant anomalies compared to the predictions of the standard model. On the one hand, the largest scales seem to be correlated not just with each other but with the geometry of the solar system. On the other hand, when we look at the part of the sky that we most trust - the part outside the galactic plane, there is a dramatic lack of large angle correlations. So much so that no simple choice of angular power spectrum can explain it.

October 22, 2010
"Measuring Diffusion of Solvent Molecules within the Pores of Biological Crystals," Senior Exercise Talk by Matthew Siewny, '11
3:10 pm
Franklin Miller, Jr. Lecture Hall (Hayes 109)
Please join us for Matthew Siewny's senior exercise talk. Title and Abstract: Understanding diffusion of solvent molecules within the pores of macromolecular crystals has vast applications: for exploiting hindered reaction rates within the crystal for chemical catalysis; for understanding soaking protocols prior to x-ray diffraction studies; and for understanding basic physics of diffusion in confined spaces. In this study, we measure the diffusion of fluorescent dye within crystals using the microscopy technique of fluorescence recovery after photobleaching (FRAP). Crystals of proteins with widely varying known solvent channel size and shape (lysozyme, thaumatin, catalase, and ferritin) were grown in their native solution doped with sodium fluorescein dye. The crystals were irradiated by a broadband, high intensity light through knife slits, leaving a rectangular area of bleached dye within the crystals. By fitting the fluorescence recovery to 3D computational models obtained from the diffusion equation, we were able to obtain the diffusion coefficient within these crystals. We compare the diffusion coefficients to other parameters of the crystal structure: the solvent volume and the size of the pores within the crystal. Reception to follow.

October 29, 2010
"Understanding Global Climate Change: Stories from the Ice" by Ellen Mosley-Thompson, Department of Geology, The Ohio State University
3:10 pm
Franklin Miller, Jr. Lecture Hall (RBH 109)
Abstract: Earth's glaciers and ice sheets preserve long and detailed records that chronicle changes in our climate and environment over thousands of years. Coupled with other observations and climate model results, the ice core data confirm that some observed changes are now outside the range of natural variability for at least the last few thousand years and in some cases for many millennia. Earth is now experiencing a widespread melting of its high mountain glaciers. This threatens the water resources for many highly populated areas that are already prone to drought and will result in the permanent loss of the unique climate histories archived in these glaciers and ice caps. This presentation will include a brief overview of the science of global climate change. Reception to follow.

November 5, 2010
"Nano-magnetism and Micro-transporters: New Tools for Engineering and Medicine" by R. Sooryakumara, Department of Physics, The Ohio State University
3:10 pm
Franklin Miller, Jr. Lecture Hall (RBH 109)
Abstract: One of the major challenges in nano-science, and the advancement of nanotechnology in general, is the development of precision tools for the manipulation and transport of nano-particles and biological entities with directed forces. The difficulty of such manipulation becomes even more pronounced in a native fluid environment when stochastic Brownian motion disrupts targeted activities. We have developed a new approach, based on programmable magnetic signatures patterned on a platform, to create microscopic transporters whose trajectories and functionalities are remotely controlled. Requiring only five tiny electromagnets, a game controller to direct the motion and the power equivalent to a 60W light bulb, tunable directed forces in the femto- to pico-Newton range are utilized to guide, assemble and manipulate magnetic nano-particles and labeled biological cells in a fluid environment. The advantages and challenges of these joystick- and voice-activated approaches will be discussed as we move towards realizing new nano-scale devices and intra-cellular probes. Reception to follow.

November 12, 2010
Senior Exercise Talk by William Koehler '11
3:10 pm
Franklin Miller, Jr. Lecture Hall (Hayes 109)
Please join us for Will Koehler's senior exercise talk. Reception to follow.

November 12, 2010
"Delayed Neutrons as an Avenue for Nuclear Non-Proliferation" by Will Koehler, '11
3:10 pm
Franklin Miller, Jr. Lecture Hall (Hayes 109)
Please join us for Will Koehler's senior exercise talk. Abstract: Over half of the world's Plutonium is stored in spent fuel, and yet, as of today, no method to directly measure the Plutonium content in spent fuel exists. The development of detectors that can quantify nuclide concentration in spent fuel is of great interest to the International Atomic Energy Agency (IAEA) whose responsibilities include alerting the global community if non-weapon states use spent fuel to make nuclear weapons. This talk will look at two different techniques for determining Plutonium content in spent fuel and highlight the integration of these techniques into a single instrument for use by the IAEA. More specifically it will focus on the viability of detecting Delayed Neutrons with a Californium Interrogation of Prompt Neutron (CIPN) detector. The study of the integrated instrument was done completely in modeling space using Monte Carlo N-Particle eXtended (MCNPX). Reception to follow.

December 3, 2010
"Reinventing Discovery: How Online Tools Are Transforming Science" by Michael Nielsen
3:10 pm
Franklin Miller, Jr. Lecture Hall (RBH 109)
Abstract: In this talk I will describe a remarkable transformation now underway in how scientific discoveries are made, a transformation being driven by new online tools that help scientists work together in new ways. I will describe examples that include massively collaborative approaches to solving mathematical problems, citizen science projects that enable large groups of amateurs to make discoveries, and online markets in scientific problems. These and other projects use online tools to amplify our collective intelligence, and so extend our problem-solving ability. This promise is only part of the story, however, for today there are also cultural barriers strongly inhibiting scientists from using online tools to their full potential. I will describe these cultural barriers, and how they can be overcome. Reception to follow.