Oct 10 – 11, 2026
William & Mary, Integrated Science Center 4
America/New_York timezone
Registration for PICUP workshop and Zoom attendance still open!

Rediscovering Placentinus and "De Percussione"

Oct 10, 2026, 11:30 AM
15m
William & Mary, Integrated Science Center 4

William & Mary, Integrated Science Center 4

540 Landrum Dr Williamsburg, VA 23185
Talk (15 min) Room 2

Speaker

David Morgan (Richard Bland College)

Description

For several years I have used Descartes's and Huygens's pre-Newtonian collision rules as writing-and-reasoning exercises in introductory physics, asking students two questions: does the rule seem right, and can you show whether it agrees with momentum conservation? While searching for the full-text of Huygens's primary source "Concerning the motion of colliding bodies", I came across a 51-page handwritten Latin treatise with a similar title — De percussione et legibus motus corporum percussorum libellus. The work was attributed to Jacobus Placentinus and cataloged "ca. 1680." Unable to find any Latin translation or discussion of the work in any history of science literature, I let the work sit idle in my files for many years.

I recently rediscovered the treatise and realized it might be possible nowadays to make use of AI/LLM tools to help transcribe and translate the text. In my talk I will describe the context and content of the work itself, my original botched and hallucination-riddled AI translation, and the discovery that the pre-Principia 1680 date given by the Smithsonian library listings for the work was in fact completely wrong. (The work was written after 1706!) In addition to exploring the state of understanding of momentum-conservation in the early 1700s and this work's place among other writing on the topic, I will discuss the promises and pitfalls of using AI/LLM assistants for this sort of linguistic and historical work. I will end with a few introductory physics questions based on Placentinus's understanding of momentum and collisions.

Primary author

David Morgan (Richard Bland College)

Presentation materials

There are no materials yet.