Particle Physics

Particle physics deals with the theory of the fundamental particles of nature, and the book describes it as one of the most active research areas in physics -- theoretically and experimentally alike. It also traces how the field's own idea of 'fundamental' has changed. Initially, the atom itself was thought to be the fundamental entity of matter. In the 1930s it was established instead that atoms are made up of electrons, protons and neutrons. Then, in the 1960s, quarks were discovered, and it was understood that protons and neutrons are themselves made up of quarks -- pushing the 'fundamental' layer one level deeper still. Meanwhile particle-physics research grew exponentially, both theoretically and experimentally, and the book notes it is the field that has received more Nobel Prizes than perhaps any other. It was later found that quarks interact with each other through gluons. Most recently, in 2013, the famous 'Higgs particle' -- also popularly known as the 'God particle' -- was discovered, and Peter Higgs and Francois Englert received the Nobel Prize in Physics for this work. The Higgs particle is significant because it is what gives mass to many other particles, including protons and neutrons themselves. A nested hierarchy diagram accompanies the text, illustrated with a water molecule: a molecule (such as water) is composed of two or more atoms -- here one oxygen atom and two hydrogen atoms; an atom itself consists of electrons revolving around a central atomic nucleus; the nucleus, at the atom's centre, is composed …