Reporters learned from the National Astronomical Observatory of the Chinese Academy of Sciences on the 26th that the cooperation group of Dark Energy Spectral Survey (DESI), jointly established by more than 70 scientific research institutions around the world, released the largest three-dimensional "map" of the universe to the world. This' map 'contains information on nearly 18.7 million galaxies, quasars, and stars. Scientists have created a three-dimensional distribution map of cosmic matter by measuring the redshift of distant galaxies. This provides crucial support for studying dark energy. Dark energy is a mysterious force that accelerates the expansion of the universe, and the sound wave traces left by the Big Bang - baryonic oscillations - can help reveal the characteristics of dark energy. The oscillation of baryonic sound waves forms a fixed scale of approximately 500 million light-years in the distribution of matter, which can be considered as a 'standard scale'. By observing the visual size of this' ruler 'at different times, scientists can calculate the expansion rate of the universe at various stages, thereby deciphering the evolution of dark energy. DESI is an international dark energy experiment involving over 900 researchers from around the world. Under optimal observation conditions, DESI can scan 5000 celestial bodies every 20 minutes and capture over 100000 galaxies overnight. Scientists construct a three-dimensional map of the universe by analyzing the redshift signals generated by the expansion of these galaxies, and then deduce the expansion trajectory and growth process of the universe. The DESI collaboration team tracked the impact of dark energy over the past 11 billion years and, based on a comprehensive analysis of DESI data, cosmic microwave background, supernovae, and weak gravitational lensing, found that the current standard cosmological model is difficult to explain all of these research results, and the model of dark energy changing over time has a higher degree of agreement with these results. Dark energy may evolve over time in unexpected ways, posing a challenge to the current standard cosmological model. (New Society)