Physical Society Colloquium

Particle Astrophysics at 100: A Century of Adventures and Discovery

Stéphane Coutu

Pennsylvania State University

2012 marks the centennial anniversary of the discovery of cosmic rays by Victor Hess. These harbingers of high-energy phenomena in the cosmos have taught us much about the fundamental constituents of the Universe and their interactions, and about the nature of high-energy processes in our Galaxy and beyond. Their continuing saga is fraught with challenges, requiring the devising of new experimental techniques and theoretical tools to pursue them to ever higher energies, greater sensitivities, improved systematics and the reach for new types of messengers. Modern projects push the state of the art in instrument scales, operational exposures, deployment in remote locations, the need for shielding against backgrounds, and in exploring varied cosmic heralds such as nuclei, electrons, their antimatter counterparts, gamma rays, neutrinos, free neutrons, and as yet undiscovered messengers such as dark matter particles or gravitational waves. We will take a tour through a storied, rich and active field, and highlight recent, continuing and planned efforts.