ACT Reveals Universe's Infancy in Unprecedented Detail, Reinforcing Standard Cosmological Model

An international team of astronomers using the Atacama Cosmology Telescope (ACT) has produced the clearest images to date of the universe's infancy. These images, capturing light from the cosmic microwave background (CMB) after traveling over 13 billion years, reveal the universe as it was approximately 380,000 years after the Big Bang. The ACT collaboration's research displays both the intensity and polarization of this early light with exceptional clarity, showing the formation of ancient hydrogen and helium clouds that evolved into the first stars and galaxies. Analysis of the CMB has allowed researchers to confirm a simple model of the universe, ruling out many alternative theories. The data refines the estimate of the universe's age to 13.8 billion years, with an uncertainty of only 0.1%. The team's measurements also support a lower value for the Hubble constant, aligning with CMB-derived measurements of 67-68 kilometers per second per megaparsec. ACT completed its observations in 2022, and the team is now focusing on the Simons Observatory, a new CMB project located in Chile.