Research

Current Role

I am currently a Senior Data Science Fellow and Director of Open Software at the University of Washington eScience Institute. In this role, I spend much of my time facilitating connections between researchers across UW's campus, as well as teaching and advocating for open and reproducible research practices. Additionally, I invest time in supporting, developing, and maintaining various open source scientific and data science packages in the Python world. Through all of this, I enjoy working on the statistical and computational methodologies that are helping push forward astronomical research in the era of ever-growing datasets.

Background

After completing my undergraduate studies in Physics at Calvin College, I took a few years off before returning to academia. In those years I lived in Sendai, Japan, where I taught English at a non-profit student center, then returned to the US and spent two years as an outdoor educator with Mount Hermon Outdoor Science School (just outside Santa Cruz, CA) and Summit Adventure (just outside Yosemite). Those two years working and teaching outdoors among the Redwoods, Sequoias, granite peaks, and dark skies rekindled my interest in science in general, and Astronomy in particular. I began my doctoral studies at the UW in 2006, finishing in 2012, after which I had two short post-doc appointments before joining the eScience Institute in 2014. When not working on my research, I enjoy growing food in my garden, eating that food in large quantities, traveling, experiencing the world through my daughter's eyes, and occasionally escaping to the mountains for long trail-runs.

Past Projects

• Type Ia Supernovae
  After beginning my graduate studies, I quickly became involved in the SDSS-II supernova team. The project had the advantage of being very sensitive to events in the so-called "redshift desert" between z=0.05 and z=0.4. Under the guidance of PI Rick Kessler, we used the first-year results as a background to do the first serious comparison of systematic effects of the two of the leading light-curve fitters.
• Machine Learning/Open Source Software
  In 2008 I began exploring a nonlinear dimensionality reduction technique called Locally Linear Embedding (LLE). LLE has been broadly studied in various fields relating to computer perception, and we showed that it is useful in processing galaxy spectra. In particular, the dimensionality reduction is sensitive to nonlinear effects that are lost by more familiar techniques such as PCA. I ended up submitting a version of this code to the open source scikit-learn project, and have remained involved. I've since invested a lot of energy into other open source Python projects in the realm of machine learning, data mining, and visualization, and have co-authored a textbook on these subjects, focusing on applications to astronomy and astrophysics.
• Weak Gravitational Lensing
  My PhD dissertation work was in the area of Weak Gravitational Lensing. Working with Andy Connolly at UW, as well as Bhuvnesh Jain and Mike Jarvis at University of Pennsylvania, I explored ways in which data compression and noise filtration algorithms similar to PCA could be used in generating mass maps and computing cosmological constraints from weak lensing shear catalogs.
• Observational Probes of Scalar/Tensor Gravity Theories
  In collaboration with collaborators at the University of Pennsylvania, I've published several papers exploring small-scale effects of modifications to General Relativity (GR) which might be behind the accelerated expansion of the universe. To be consistent with Solar System observations, these theories must allow any fifth-force effects to be somehow screened within our own galaxy so that GR is recovered. These screening mechanisms lead to some interesting dynamical and morphological consequences in the case of isolated dwarf galaxies. We've been exploring observations which might constrain the strength of these modifications.
• Astronomy Education: UW Planetarium
  During my graduate career, I was involved in the University of Washington Planetarium in a variety of positions. For two years, I oversaw our K-12 outreach program, providing free planetarium shows to school groups from the greater Seattle area. Later, I spent two years managing and coordinating the installation of a new digital projection system in the planetarium, built upon World Wide Telescope in collaboration with Microsoft Research (see a feature on the project here). Through these opportunities, I had the chance to facilitate hands-on exploration of the universe with thousands of people both in Seattle and around the country.
• NSF Fellowship
  During 2013, I was a post-doctoral fellowship through the NSF's Transformative Computational Infrastructure program (CI-TraCS), and worked at UW jointly between the Computer Science department's Database Group, and the Astronomy department's survey science group. I worked primarily on ways to utilize advances from the field of database research to enable new approaches to data-intensive areas of Astronomy and Astrophysics.