David Matzen Close

Dr. David Matzen Close, 84, of Johnson City, TN, passed away on April 8, 2026, after a brief hospitalization. Born in Plainfield, NJ, on March 9, 1942, his early years were spent, by his own account, running amok with a loyal group of friends during the post-WWII American heyday. Told at one point that he wouldn't amount to anything, Dave promptly proved otherwise, earning acceptance to Franklin & Marshall College in Lancaster, PA, where he studied physics. He went on to receive a Master of Science degree from West Virginia University and a PhD in Physics from Clark University in Worcester, MA. It was at Clark that he met his wife, Nancy Fischman, during a volleyball match between the physics and geography departments. The two spent two years at the University of Connecticut in Storrs, CT, and four years at the University of Rochester in Rochester, NY, where Dave completed postdoctoral appointments. Dave's advisor told him it was time to go find a real job, so he accepted a faculty position at East Tennessee State University in 1978.

Dave spent the next 44 years teaching physics to generations of ETSU undergraduate and graduate students, many of whom remember him as patient, quietly funny, and deeply committed to making sure they actually understood the material. He was also known to offer extra credit for the advanced academic skill of remembering to write your name on your exam. When not teaching, he could often be found in his Brown Hall basement lab (or "lair," depending on who you asked) conducting research on the effects of radiation damage on the basic building blocks of DNA. From 1967 to 2019, Dave authored or co-authored 131 papers in scientific journals, which were cited more than 3,400 times. He was a Distinguished Fellow of the Radiation Research Society and served on its committees and board for many years. His work, often in collaboration with colleagues around the world, advanced understanding of both the molecular and real-world impacts of radiation exposure on individuals, communities, and the environment.

Dave's greatest contribution may well have been his decades of service as a consultant and board member of the Institute for Energy and Environmental Research (IEER), a think tank dedicated to providing the public with accurate and accessible information on environmental and energy issues, particularly nuclear energy and waste. At IEER's intensive five-day technical training workshops, Dave's principal role was to explain radiation and its health impacts to community leaders concerned about nuclear waste, plutonium, and exposure risks, many of whom were from communities directly affected by weapons facilities or nuclear waste storage sites. He had a rare gift for translating complex science into language that was clear, engaging, and often very funny. Those who attended these workshops returned home better equipped to advocate for their communities, contributing to the shutdown of numerous polluting and unsafe facilities across the country and around the world. Closer to home, Dave supported the community coalition that successfully defeated a 2002 effort to locate a uranium enrichment plant in Unicoi County.

In his final months, Dave was not well enough to join the latest local effort opposing the proposed BWXT facility in Washington County. He cared deeply about this work and the health of the community he called home. In lieu of flowers, his family asks that those who wish to honor his memory consider supporting ongoing efforts to protect our region from a major source of uranium pollution: etncc.org/donate.

He is survived by his wife, Nancy Fischman of Johnson City; two daughters, Alexis "Lexy" Close (eldest) and Maren Close (tallest), both of Johnson City; two grandsons, Oscar and Sidney; and his sister, Katherine Close Watkins of Yucaipa, CA. Dave was preceded in death by his parents, Herbert Schock Close and Dagmar Matzen Close of Plainfield, NJ-as well as a long line of beloved fat orange cats, notably Ginger, Jasper T. Armbuster, Fritz the Cat, and Jean-Clawed Kitty.

A celebration of life will be held on Saturday, May 23 at 5:00 p.m. at the Fischman Gallery in Johnson City. Attendees are encouraged to bring their favorite Dave Close stories to share.

Memories and condolences may be shared with the family via www.morrisbaker.com

Morris-Baker Funeral Home and Cremation Services,
2001 E. Oakland Ave., Johnson City, is serving the Close family. (423) 282-1521.