What is the universe made of? Experts weigh in on the mysterious force that shapes our cosmic history

As the Dark Energy Survey (DES) releases its final results, we caught up with two physicists who have been involved with the project since its beginnings. In this Q&A, Josh Frieman, DES co-founder and associate director of the Fundamental Physics Laboratory at the Department of Energy’s SLAC National Accelerator Laboratory, and Risa Wechsler, director of the Kavli Institute for Particle Astrophysics and Cosmology, discuss what this decade-long effort has taught us and how it prepares us for the NSF-DOE Vera C. Rubin Observatory’s 10-year mission to explore some of the greatest mysteries of the universe.