The photons of Planck, Einstein, and Bohr

Chapter 3 reviews the traditional historical, schoolbook notions of thermal radiation quanta found in the work of Planck, the traveling and absorbed quanta of Einstein, the spectroscopic evidence associated with the atom transitions of Bohr, and the scattering evidence of Compton – experiments that resulted in seemingly conicting views of photons as particles and as waves. It comments on revisionist views that have made these four experimental works no longer the definitive evidences for photons that they once were regarded.

Manipulating photons

Chapter 7 discusses ways of creating, altering, and subsequently detecting single photons – possibilities for ultimately demonstrating the quantum nature of particular radiation sources and putting those properties to work.

The photons of Dirac

Chapter 4 presents the joining of quantum theory to electromagnetism and radiation associated with Dirac, particularly noting the variety of photons that are consistent with the choice of radiation field modes that still form the working definition of photons for many physicists, and which ofiers a possible resolution to the seeming paradox of wave-particle duality.

Introduction

The introductory chapter sets the stage for the narrative discussion by defining terminology and commenting on several basic concepts often taken for granted in expositions, but essential for any understanding of a technical subject: operational definitions and the scientific method; the difierence between physics, technology and engineering; the connection with art and philosophy; and the goals in modeling of physical phenomena with systems and observables.

Finale

The brief chapter 9 lists some useful references and acknowledgements.

Overview; Ways of regarding photons

Chapter 8 overviews some of the ways in which photons are usefully defined, including the Feynman picture and the photons with slow speeds that occur in dense matter. It notes alternatives to photons, denials of photons, and evidence for photons.

Photon messengers

Chapter 6 examines notions of messaging and information and overviews the ways that photons serve that purpose, starting with the remarkable views they brought to astronomers in the 1950s. It comments on the involvement of photons in teleportation, correlation and entanglement.

Photons as population changers

Chapter 5 presents the views of photons that have accompanied experimental uses of lasers to manipulate the quantum states of atoms and other systems. It discusses not only the Einstein rate equations appropriate for incoherent radiation but also the Rabi oscillations that accompany coherent excitation, and the Jaynes-Cummings model that demonstrates the discreteness of photons.

Basic background: Everyday physics and its math

Chapter 2 introduces portions of mathematics that underly the physics of ordinary objects and experience, leading to discussions of atoms and electrons as elementary particles, to aggregates that exhibit ows and waves, to concepts of force, vectors, energy and their equations of change. It notes the defining properties of light beams, distinguishes coherent and incoherent sources, and raises the question of radiation granules as photons.