The Mystery of Dark Matter in the Universe

This public lecture from the APS Global Physics Summit 2025 explores the enigmatic nature of dark matter, which along with dark energy constitutes 95% of the universe while ordinary atoms make up only 5%. Delve into the historical journey of dark matter research, from its initial proposal in the 1930s to Vera Rubin's groundbreaking galaxy observations in the 1970s, and continuing to today's sophisticated detection efforts using underground laboratories, space satellites, and the Large Hadron Collider. Learn about leading theoretical candidates for dark matter including WIMPs, axions, fuzzy dark matter, and primordial black holes—particles that pass through our bodies by the billions yet exert enough gravitational force to control galactic rotation and bend light. Presented by Katherine Freese from the University of Texas at Austin, the lecture also covers Dark Stars—early stellar objects powered by dark matter that may have been detected by the James Webb Space Telescope. Recorded live in Anaheim, California, this comprehensive presentation illuminates how solving the dark matter puzzle represents a pivotal milestone in humanity's understanding of the cosmos.