Are We Really Made Of Quarks?
Professor Jerry Friedman
The answer to the question, "Are we really made of quarks?", is yes; but physicists did not arrive at this answer easily. The quark model, which embodied a radically new conceptual view of the structure of matter, was fiercely debated and generally rejected by the physics community. Its ultimate acceptance took well over a decade and occurred only after inescapable and compelling experimental evidence. In 1964 quarks were proposed as the basic building blocks of matter. After numerous fruitless searches for free quarks in nature, the great majority of physicists rejected this model. Quarks were finally discovered in a series of high energy electron scattering experiments. In these experiments, the electron beam and the detecting equipment were the equivalent of a very powerful electron microscope that probed the interiors of the proton and neutron. Point-like constituents were observed inside, which were later identified as quarks. The discovery of quarks changed our view of the basic structure of matter and altered the future development of particle physics.