Domain Experts



David Armstrong
David Armstrong, Ph.D.
David S. Armstrong is a Professor of Physics at the College of William and Mary in Williamsburg, Virginia. He received his education in Canada, with degrees in physics from McGill University (B.Sc), Queen’s University (M.Sc.) and the University of British Columbia (Ph.D.). He did post-doctoral research with Virginia Tech, working at the TRIUMF laboratory in Vancouver, and with the University of California (Berkeley), working at CERN in Geneva, before coming to William & Mary. His field of research is experimental nuclear and particle physics; he has conducted research using beams of protons, muons, pions, antiprotons, photons and electrons. Recently, most of his research has been conducted at the Thomas Jefferson National Accelerator Facility, in Newport News, Virginia. He has had the privilege of teaching physics at the undergraduate and graduate level at William & Mary, and mentoring undergraduate and graduate students in nuclear physics research projects. He enjoys reading, sailing, and playing jazz guitar.


Jim Batterson
Jim Batterson
Jim Batterson taught high school physics and mathematics, worked as a scientific programmer for LTV Corporation, and from 1980 until his retirement in 2008, was a research engineer at NASA Langley Research Center. At NASA he was responsible for flight research on the dynamics and control of aerospace vehicles, served as Head of the Dynamics and Control Branch, and later as Deputy Director for Strategic Development. He has also served on a number of community boards including the Newport News (Virginia) School Board and New Horizons Regional Education Center Board. While at NASA, he served on assignments to the Office of Science and Technology Policy, the National Nanotechnology Coordination Office, NASA Headquarters, and most recently, to the Office of Virginia’s Secretary of Education.


Maria Catalina
Maria Catalina teaches mathematics and science at Mar Vista Middle School in the Sweetwater Union High School District. She began researching curriculum in 1995. As the worlds first Teacher to Space Ambassador she turns “Eyes to the Skies” and brings Space down to Earth. Space travel and the universe drive her standards based curriculum as she introduces her students to their technological futures. Miss Catalina knows that our students are the first space faring generation.


George Collison
George Collison, Ph.D.
Dr. George Collison is a nationally known science and mathematics educator. He is one of the founders of the Virtual High School(tm) and lead author of the Seeing Math(tm) video case studies distributed by PBS Teacherline. He has authored courses in algebra, calculus, and physics. George was invited by USAID on several occasions to help science and mathematics planning and write curricula in Africa. His passion lies in crafting clear, highly engaging presentations that build careful bridges from concrete experiences to abstract concepts.


James Dann, Ph.D.
James H. Dann was born and raised in San Francisco. He attended Lowell High school and went on to UC Santa Barbara where he received a B.S. in physics. James then went to grad school at UC Santa Cruz where he joined Alan Litke’s research group at CERN, the largest particle physics lab in the world. James worked at CERN, in Switzerland, for 4 years where his research earned him a Ph.D. in particle physics. James then moved back to San Francisco and lived with his oldest son Aaron, while teaching high school in the city. After seven wonderful years teaching high school, James went on to work as a Senior Engineer for GMW in Silicon Valley. James has since returned to his true passion of teaching high school at Menlo School and lives with his wife, Nisha, and second son Ashaan in the Bay Area.
People’s Physics Book


Nick Fiori
Probability and Statistics


Judy Larson, MA
I was born in Tucson with all its desert beauty and heat! I was delighted to move to Santa Barbara where I attended Westmont College [BA in Chemistry]. I Moved to Taipei, Taiwan for a year; taught in the American HS. Later, my family and I lived in Hong Kong for six years. I Returned to the US; entered Stanford University; [MA in Science Education]. For the past 32 years, I have taught chemistry in private and public high schools in California.


Darryl Morrell
Darryl Morrell, Ph.D.
Darryl Morrell received his B.S., M.S., and Ph.D. degrees in Electrical Engineering in 1984, 1986, and 1988 from Brigham Young University. He is currently an associate professor of engineering at Arizona State University, where he is participating in the design and implementation of a multi-disciplinary undergraduate engineering program using innovative, research-based pedagogical and curricular approaches. He has been actively involved in the development of open educational resources and has authored modules with the Connexions project (an open source curriculum authoring system). His technical research interests include stochastic decision theory applied to sensor scheduling and information fusion, and, more recently, application of research based pedagogy to engineering education.


Richard Parsons, MA
Richard Parsons graduated from San Jose State University in 1967 with a BA in Physical Science with a Chemistry Option and received his MA in 1968 with the same major. He taught high school honors Chemistry, Physics, and Advanced Placement Chemistry for 35 years and was the Science Department chairman for 25 years in the Santa Clara Unified School District. Mr. Parsons retired in 2000, but continued to teach Advanced Placement Chemistry part-time for another 5 years. In the early 80s, he co-authored an in-district course (text, lab book, teacher’s guide) in Integrated Science. The course was taught in all district high schools for 15 years. Mr. Parsons became an author for CK-12 in June 2008 and now serves as CK-12’s Chemistry domain expert.


Geoff Ruth
Geoff Ruth teaches chemistry, AP Chemistry, geology, and environmental science at the Urban School of San Francisco. Before coming to Urban, he taught science at Leadership High School for five years, and wrote chemistry curriculum at Lawrence Hall of Science. Geoff earned a geology degree from Carleton College, and tries to integrate many different science and math topics into his classes. When not teaching, he enjoys bicycling, rock climbing, woodworking, and exploring the Sierra.
Earth Science

Julie Sandeen, MS
Julie Sandeen is CK-12’s Domain Expert for Earth Science and author of several chapters within the Flexbook. She is currently a high school teacher at Woodstock Academy in Connecticut and Adjunct Faculty at Eastern Connecticut State University. She is passionate about Earth Science and loves sharing that joy with her students. She received her Master’s degree in Geology from the University of Connecticut and did her undergraduate work at Smith College in Northampton, Massachusetts.
Earth Science


Sandy Wagner, Ph.D.
For over 20 years Dr. Wagner taught mathematics, science, computer science, and teacher education from 7th grade through college. His other careers have included software manager, mathematics textbook author, and designer of online classes. Recently he was delighted to return to mathematics, his first true love, and to helping teachers explore ways to improve teaching and learning with technology.
Probability and Statistics (Advanced Placement)
Math Analysis


Douglas Wilkin, Ph.D.
Douglas Wilkin, Ph.D. is currently the Chair, Department of Science at Arleta High School in the Los Angeles Unified School District. Prior to teaching high school, Dr. Wilkin held a number of faculty positions at leading research institutions throughout the United States, including the National Human Genome Research Institute of the National Institutes of Health, Cedars-Sinai Medical Center in Los Angeles, and the Federal Bureau of Investigations in Quantico, Virginia. He is extensively published. Biology
Life Science


Bill Zahner
Algebra 1
Math Analysis