Henry Way Kendall coauthored measurements of deep inelastic scattering that exposed structure inside the proton. Measuring the scattered electron's energy and direction determines the energy and momentum transferred to the target. The extracted structure function showed approximate scaling under the paper's stated assumptions, providing evidence for pointlike constituents. The test depended on systematic comparisons across collision kinematics rather than a visual image of a quark.[ref]
Observed Behavior of Highly Inelastic Electron-Proton Scattering by M. Breidenbach and others. 1969 abstract: scattering at six and ten degrees, structure function and scaling conditions
Portrait of Henry Way Kendall
. Tom Frost; source Yosemite Climbing Association; existing Commons crop. CC BY-SA 3.0, via Wikimedia Commons. Source. Articles by others on the same topic
Henry Way Kendall (1926-2015) was an American physicist and a prominent advocate for the promotion of science and education. He is best known for his work in experimental physics, particularly in the field of particle physics. Kendall made significant contributions to the understanding of the structure of protons and neutrons through deep inelastic scattering experiments at the Stanford Linear Accelerator Center (SLAC).