Infant Universe Images Refine Age and Expansion Rate, Confirming Standard Cosmological Model

New images from the Atacama Cosmology Telescope (ACT), taken before its 2022 decommissioning, provide the clearest view yet of the universe's infancy. These images capture the cosmic microwave background (CMB), the first light emitted approximately 380,000 years after the Big Bang. The ACT data refines the estimated age of the universe to 13.8 billion years with a 0.1% uncertainty. It also confirms the standard cosmological model and provides precise measurements of the universe's expansion rate in its early stages. The images reveal subtle variations in the density and velocity of early gases, showing the movement of hydrogen and helium as they were pulled by gravity. This process marks the initial steps toward forming stars and galaxies. The ACT's high resolution and sensitivity allowed for direct observation of the faint polarization signal, distinguishing it from previous telescopes like Planck. Despite these advancements, the ACT data did not resolve the "Hubble tension," a discrepancy in the measured expansion rate of the universe. The team explored alternative models but found no evidence to support a faster expansion rate. The new data is publicly available on NASA's LAMBDA archive.