With any particle physics experiment, precision is paramount. In experiments with electromagnetic shields, the inherent magnetic field noise from the shield itself can impede the accuracy of high precision experiments. For this research project I designed a model of an electromagnetic shield to find the magnetic field noise of the shield; the results of which can be used to increase the precision of a particle physics experiment being conducted at the University of Washington, searching for a potential source of time reversal symmetry by looking for a permanent electric dipole moment of a specific isotope of mercury (the existence of which would suggest a source of CP-violation). The cylindrical electromagnetic shield was modeled in the finite element analysis application, COMSOL Mulitphysics. The model is initially configured with a single magnetic dipole arranged on the axis of symmetry of the magnetic shield. The accuracy of the model is then compared to an analytic solution found by S.-K. Lee and M. V. Romalis at Princeton University. After refining the model to reflect the analytic solution, the number and orientation of magnetic dipoles is changed, producing the first, second and third derivatives of the magnetic field noise of the shield being used. Accounting for the magnetic field noise will increase the sensitivity of the experiment being conducted.

MML 53 is a system of young stars which, in 2010, was discovered to be an eclipsing binary. A detailed analysis of the brightness changes and velocity variations of an eclipsing binary provides precise measurements of the masses, radii, temperatures, and luminosities of two stars with the same age and chemical composition. Thus, eclipsing binary stars are extremely important astronomical systems that are used to test our understanding of the structure and evolution of stars. Despite their importance, young eclipsing binaries, like MML 53, are rare. We applied the PHOEBE (Physics of Eclipsing Binaries) software to the observed multi-wavelength time series photometry data of MML 53 to derive precise values for the combined radii of the two stars, the effective temperature of the secondary star, and reasonable locations for the starspots on both the primary and secondary stars. Using a Markov chain Monte Carlo analysis (eMCMC Hammer) we ran over 60000 PHOEBE models which has allowed us to explore correlations between various parameters and derive realistic uncertainties on the final fundamental properties of these two young stars.  

Medical diagnostic device development has been, in recent history, focused largely on paper-based diagnostics. Such devices offer incredibly low per patient cost with the downside of poor sensitivity and minimal ability to multiplex, or detect many different compounds simultaneously. New technologies which leverage exceedingly efficient silicon manufacturing have the potential to approach the cost of paper diagnostics with increased sensitivity and extensive multiplexing. This project aims to develop one such technology, silicon photonics. Using existing manufacturing technologies, silicon photonic sensing measures analyte mass accumulation through dielectric shift by taking advantage of the evanescent field of electromagnetic radiation passed through a silicon wafer. Aided by unique binding chemistries, silicon photonic devices are capable of highly specific analyte detection. The current stage in this project is focused on developing tools, the most notable being a rapid prototyping setup for testing chip design. The setup automates the interaction of a variety of necessary hardware components including fluidic pumps, movable stages, a microscope, and an infrared laser. By using such a rapid prototyping setup, it is hoped that a chip design that is extremely condusive to medical diagnostics will be developed and brought to cost effective levels.

Exoplanets are planets outside our solar system, and the current explosion in exoplanet discoveries is revolutionizing our understanding of the potential for extraterrestrial life. This prolific era of detections has stemmed largely from the unprecedented observing capabilities of NASA's Kepler Space Telescope. The Kepler Spacecraft collects high precision time-series photometric data on a fixed group of approximately 160,000 stars. The data are represented by temporal lightcurves (i.e. brightness vs. time) that can be used to detect transiting exoplanets, the topic of our research. Transits are events where an orbiting planet partially eclipses its host star, casting a small shadow on the telescope. To detect transit signals, we rely on the Quasi-Periodic Automated Transit Search Algorithm (QATS). As an automated tool, QATS provides a crucial means to reduce the Kepler dataset to a manageable size. However, since the algorithm is sensitive to stellar variability, eclipsing binary stars, and systematic artifacts of the spacecraft, additional analysis is required to separate true detections from false positives. Determining the best way to do this is the present focus of our work. Concurrently, we are exploring the potential for QATS not only to determine orbital period, but also to constrain transit depth and duration (properties related to the size of the exoplanet and to the density of the stellar host). While this increases the complexity of the QATS algorithm and the amount of output to manage, it provides greater potential for a fully automated transit search process with results that are more descriptive of the exoplanet systems detected.

The discovery of a new particle, which we suspect is the long-sought-after Higgs boson, has opened a wide range of opportunities to explore new physics at the Large Hadron Collider (LHC). One particularly promising direction is the search for "flavor violation" in Higgs decays, where a Higgs decays to a non-matching pair of particles. We focus particularly on decays into a tau and a mu lepton (both of which are heavier relatives of the electron). At present, indirect data from low-energy experiments allows these Higgs-to-tau-mu decays to make up up to 10% of all Higgs decays, while the current Standard Model of particle physics does not expect them to happen at all. The goal of my research is to develop a method for separating these decays out of the other billions of collisions that happen every second in the ATLAS detector, and analyzing them in such a way to make flavor violating decays stand out against background events (which look similar but have different origins). This will allow us to put much stricter limits on the rate at which these decays occur, and if any do occur we will have made a big step into previously-unexplored physics territory.

Acoustic levitation is a method of levitating matter against the influence of gravity using sound waves.  Small droplets of fluid can, for example, be suspended in standing wave fields produced by high-power ultrasonic transducers at locations where the gradients of the sound field potentials counterbalance the gravitational forces acting on the droplets, creating a simulated microgravity environment.  These environments could be useful in simulating and studying how chemical and biochemical reactions might take place in space.  Our research builds on earlier work by J.Santa Cruz and J. Griffith who successfully achieved acoustic levitation at EdCC in 2011.  Santa Cruz and Griffith were able to experimentally demonstrate rough preliminary agreement with Bjerknes theory for levitation stability points in a planar field approximation, but they also observed stable particle orbits completely beyond explanation by the planar theory.  Here, we compare our experimental findings to the more general Gor’kov theory of levitation to explain both one- and two-dimensional levitation stability subspaces.

Video games represent a powerful educational paradigm; nevertheless, strong devotion to convention as well as the highly stigmatized reputation of games as a purely recreational medium, have led to an overarching reluctance to implement them within high-level course curricula. Emerging research on the use of real-time interactive simulations as educational tools consistently shows marked improvement in learning outcomes, however, a rigorous means of quantitative analysis is lacking. To date, all studies correlating learning outcomes with the intrinsic components of video games rely on one of three different methods of data acquisition: surveys, pre-gameplay versus post-gameplay evaluations, or recorded observation of play activity. Each of these methods has its own inherent limitations on the amount and quality of data obtainable. In addition, these methods prohibit researchers from being able to dynamically alter any of the key control variables such as: challenge, contextual motivation, or narrative. This study proposes an alternative model, capable of quantitatively evaluating the educational efficacy of implementing each variable. This is accomplished by embedding the data collection methods and algorithms directly into the framework of the game itself. This would further allow for dynamic alterations of each variable according to the parameter requirements of the inherent statistical methods. We expect the result to be a direct and measurable correlation between student learning outcomes and the modified variables. Also central to this study is the imbedding of real-time data collection functions and processing algorithms, which can automatically save and upload data to a server. This would drastically increase the possible number of participants—thereby increasing the sample size—while simultaneously allowing for greater modularity of data analysis. The primary long-term goal of this research is to develop a model and educational game that implements this framework and affords future studies the tools to overcome the aforementioned limitations in data acquisition.

Orbital spectroscopy provides evidence for the presence of liquid water throughout the history of Mars through analysis of the surface composition. In order to determine surface mineralogy, we use remotely sensed visible/near-infrared spectroscopic data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on board the Mars Reconnaissance Orbiter. We identify minerals by their unique absorptions at specific wavelengths through the examination of CRISM surface reflectance data across 438 wavelengths from 1.0 to 3.9 microns. Spectral datasets like CRISM contain large volumes of data and each spectrum usually covers an area that contains several unique compositions, or spectral endmembers. Factor analysis uses a set of mixed spectra to derive a set of orthogonal eigenvectors and associated eigenvalues. Although physically meaningless, the eigenvectors and eigenvalues can then be used to estimate the number of components present in a mixed system. Target transformation is used to reconstruct endmember spectra using a linear combination of the set of eigenvectors, even if those pure endmembers do not exist in the original data. In practice, the target transformation test is simply a least squares fit of the significant eigenvectors to laboratory spectra. If a laboratory spectrum can be closely matched, then it is a possible endmember present in the system. This methodology can also be used to remove noise and significantly improve the quality of CRISM data. We tested our methodology using CRISM data containing evidence for the presence of carbonates. Target transformation clearly confirmed the presence of Mg-rich carbonates and phyllosilicates in Nili Fossae, a series of extensional faults. We are automating this technique and applying this methodology to test for a variety of minerals across the entire planet. Ultimately, by applying our data analysis technique to the global CRISM dataset, we will have a more detailed understanding of surface composition and aqueous processes on Mars.

Digital planetariums and their software are revolutionizing what can be visualized and hence raising the educational impact to K-12 students and the general public. The ability planetariums offer to present and visualize cutting-edge research of star, planet, and galaxy formation and evolution, in 3-dimensions, has unlocked new discovery space in educators’ ability to communicate and teach science. In order to improve the UW Astronomy department's public outreach programs as well as lay out a model for other Universities and astronomy outreach groups to follow, we assembled a mobile planetarium using new cost-saving methods and have begun designing an innovative curriculum to best implement digital planetariums in high school classrooms. To accomplish this, we used an HST education and public outreach grant (EO-12512) to build the planetarium as well as offset transportation costs to the UW planetarium. The UW mobile Planetarium was developed for less than $18,000, and allows us to increase the number of underserved elementary and high school students the UW Astronomy department reaches. We are beginning to test and evaluate the efficacy of teaching using the mobile planetarium in a high school setting. The mobile nature of the planetarium allows us to develop interesting inquiry-based lessons that incorporate WWT tours.

The unique geography and ice dynamics of the West Antarctic Ice Sheet (WAIS) are believed to make it susceptible to instability and rapid collapse. Predictions of WAIS stability in a warming world rely heavily on ice sheet model simulations; one drawback is that ground truth for these models comes from the last ice age, when the climate was colder. Geologic evidence of ice sheet behavior during warm interglacial periods is currently hidden beneath the Antarctic and Greenland ice sheets. We expect WAIS to have been thinner and less extensive under warmer conditions, and we ultimately plan to determine its past extent with cosmic ray exposure dating of subglacial bedrock. As a prelude to subglacial sampling, during January-February 2013 we collected samples from elevation transects of exposed granitic bedrock at three WAIS nunatak sites: the Pirrit Hills, Nash Hills, and Whitmore Mountains. We also conducted radar reconnaissance surveys to evaluate potential sites for future subglacial rock sampling, which will extend the transects beneath the ice sheet. We have separated out the quartz and potassium feldspar content of our samples for measurement of cosmogenic beryllium-10/aluminum-26, and chlorine-36 respectively. We are using the results of these analyses to determine the history of exposure and ice cover in the past 1-2 million years at each sampled elevation. Based on field observations, we expect our samples to show evidence of prolonged exposure, suggesting that presently subglacial surfaces were also exposed in the past. Ultimately our work will determine whether rock surfaces beneath the WAIS have ever been exposed to cosmic rays, providing clear evidence for or against a thinner ice sheet in the past. Such data will be useful in tuning ice sheet model conditions and establishing WAIS vulnerability to collapse, which is crucial to forecasting future sea level change.

Through the Galaxy Zoo Project, a project that lets public volunteers classify galaxies taken by numerous telescopes, several spiral galaxies were found that appear to be red in color in the visible wavelengths. Typically, only elliptical galaxies are red, so finding spiral galaxies of this color is an oddity. Initial analysis and explanations of these objects claimed that this group of galaxies has no star formation. However, these galaxies seem to be emitting massive amounts of light in the ultraviolet (UV), which might indicate that star formation is actually occurring. For this project, we compared the radial fits of these objects in the optical and ultraviolet using data from GALEX (Galaxy Evolution Explorer) and the SDSS (Sloan Digital Sky Survey) to see if these objects are just regular high mass spirals or galaxies nearing the end of their star formation that have exhausted their gas supply. Preliminary results show that the galaxies are slightly brighter near their center in the optical compared to the UV, but in the disk of the galaxies, the UV images are brighter than the optical images. This could mean that these galaxies indeed have star formation occurring in them.