Charting the Dark Unknown: Jaco’s Fellowship Journey
When Jaco reflects on his path into science, it begins on a farm in the rural Netherlands. Surrounded by open skies and endless fields, he developed a curiosity about the universe that would carry him far beyond those quiet beginnings. Jaco made his way to Amsterdam, where he studied both physics and philosophy and started to explore the deeper question of why we think the way we do.
By the time Jaco embarked on his master’s thesis, he turned his curiosity into a focused research interest in the history of dark matter. In the process, he crossed paths with AIP who gave him a Grants-In-Aid to begin early work on dark matter’s history at the Niels Bohr Library & Archives. That visit left a lasting impression.
A decade later, the AIP Helleman Postdoctoral Fellowship opened for applications. The position felt tailor-made. Jaco quickly applied, and soon after, began a fellowship that would become a defining chapter in his career.
As a Helleman Fellow, Jaco had the rare freedom to dive deeply into the intellectual history of dark matter — tracing how scientists in the 1970s and 1980s wrestled with the idea of “missing mass” in the universe. The fellowship supported extensive travel to archives and gave him the opportunity to conduct oral history interviews, gathering firsthand insights into how ideas about dark matter evolved.
One of the fellowship’s most rewarding aspects was the chance to work under David Kaiser at MIT, a scholar Jaco had long admired. That mentorship, combined with the intellectual space the fellowship provided, helped him sharpen his research and expand its reach.
Most importantly, the fellowship culminated in a milestone achievement: Jaco secured a contract to publish a book on the history of dark matter. For any historian of science, a book contract is a crowning accomplishment — and for Jaco, it validated years of inquiry into how scientists conceptualize the unseen forces shaping our universe.
From a farm in the Netherlands to the archives and lecture halls of leading research centers, Jaco’s journey is a testament to curiosity, persistence, and the power of asking bold questions. Thanks to the Helleman Fellowship, his work will now help shape how future generations understand one of the greatest mysteries of modern science.