HEP - ASTRO SEMINAR | Direct Cosmic-Ray Measurements: Tickling the Knee

The fast plummet of cosmic-ray rates with energy has been a constant frustration in accumulating enough experimental statistics to unravel the highest-energy physical processes in the universe. With recent and current advances in detector design and long exposures through space-borne or Antarctic balloon flights, unprecedented direct cosmic-ray and gamma-ray measurements are providing glimpses of energetic processes closing in on the cosmic-ray "knee," the well-known kink in the all-particle energy spectrum a little above 1015 eV. We will review recent and ongoing efforts and summarize the state of knowledge at the direct energy frontier.