In this book I want to tell the story of gauge fields, the messengers
that transmit signals among elementary particles, enabling them to
interact. They work in the quantum realm of quarks, the deepest
level of the structure of matter we have reached so far.
The basic interaction at this level percolates upwards, through
hierarchies of organizations, to the everyday world we live in.
On its way, the interaction appears in different guises — nuclear
interaction, atomic interaction, and the classical electromagnetic interaction that rules our everyday world. But these are facets of the
same basic interaction.
The idea of “gauge” first appeared in electromagnetism. At the
level we speak of, however, it is inextricably tied with the “quantum
phase”, that abstract attribute that distinguishes the microscopic
world from the macroscopic, and that, incidentally, empowers new
technologies of the 21st century, such as atom lasers and quantum
computing.