How Quarks Inside Protons Rewrote the Rules of Matter
At the heart of matter lies a hidden world of tiny particles and forces. These building blocks shape everything from atoms to the pull of gravity. Decades of experiments have slowly uncovered how they work—and how they hold the universe together.
In 1967, researchers at the Stanford Linear Accelerator Center (SLAC) began a series of deep inelastic scattering experiments. Physicists Jerome Friedman, Henry Kendall, and Richard Taylor shot high-energy electrons at protons and neutrons. The way these particles scattered suggested that nucleons were not solid but made of smaller, point-like objects. These were later named quarks.
The experiments at SLAC opened a window into the subatomic world. They confirmed that protons and neutrons are built from quarks and gluons, held together by the strong force. Mesons and pions keep atomic nuclei stable, while photons and gravitons govern forces on a larger scale. Together, these particles and interactions form the foundation of all matter and energy in the cosmos.
