Elementary Processes at High Energies

Abstract

The long and fascinating history of the study of light and electromagnetic phenomena (unified through Maxwell’s equations) went through several stages before we reached the contemporary view. Without going into the details of earlier thought, an important founding contribution at the beginning of the 18th century was the publication of Newton’s ideas in his book Opticks (1704), where Newton challenged the accepted view of the nature of light which went back to Aristotle’s time, thus laying the foundations for extensive further debate. Newton defended a mechanistic framework, arguing that light was composed of material corpuscles, basing his scientific deductions on a series of experiments, including his famous example of the chromatic decomposition of light when it passes through a prism. Elementary scattering, absorption and emission processes involving photons are presented with an eye for their application in High-Energy Astrophysics.