Elaine Loft, Staff Writer
On January 17, AT Physics hosted Dr. Steven Kuhlmann, a retired astrophysicist. Kuhlmann had a long career at the Argonne National Laboratory, which was born out of the University of Chicago’s work on the Manhattan Project in the 1940s. He has recently retired to NH and reached out to Derryfield to see if he could share his research and knowledge in the field of subatomic particles and dark matter. Long-time Derryfield physics teacher Jeffrey Cousineau welcomed the opportunity for his students to learn from an expert in the field.
Prior to his visit, Kuhlmann shared eight “explainer” videos created by high school students he had worked with in Illinois. The Derryfield students then submitted questions for Kuhlmann to elucidate during his visit. Kuhlmann began the discussion with a review of protons, neutrons, molecules, and quarks. The students learned that “size matters”—quarks are 10000th the size of a proton. The class started to work through their list of questions, including “Do quarks have a substructure?” Kuhlmann noted this very issue was the topic of his PhD dissertation, some 40 years earlier. The quark model was first proposed in 1964, but there was little evidence for their physical existence until experiments at the Stanford Accelerator Center in 1968. The conversation eventually led to the topic of accelerators, which are used to measure quark energy. Kuhlmann described in detail the Large Hadron Collider (LHC), the most powerful particle accelerator in the world, which is located at CERN, in Geneva, Switzerland.
One level of discussion quickly led to another, with Kulhmann augmenting his slides and explanations with videos and “explainers” from other experts in the field. Cousineau welcomed the opportunity for his class “to learn from someone who has vast and firsthand experience in the field of astrophysics.”

Pictured in Photo from L-R: Upper School Science Faculty Jeffrey Cousineau and Retired Astrophysicist Dr. Steven Kuhlmann.