Riess collaboration

The Riess collaboration, led by astronomer Adam Riess, is a scientific group that measures how fast the universe is expanding. They do this by observing distant supernovae—exploding stars—that act as cosmic distance indicators. By carefully analyzing these observations, they determine the rate of expansion, known as the Hubble constant. Their work is crucial for understanding the universe's age, size, and ultimate fate, and has helped refine our knowledge of cosmology. The collaboration’s precise measurements have also highlighted ongoing questions about potential differences between early and late universe expansion rates, sparking further research in physics and cosmology.