Simons Foundation | Center for Computational Astrophysics | 2020 Jul 16
Observations by the Atacama Cosmology Telescope suggest that the universe is 13.8 billion years old.
From a mountain high in Chile’s Atacama Desert, astronomers with the National Science Foundation’s Atacama Cosmology Telescope (ACT) have taken a fresh look at the oldest light in the universe. Their new observations plus a bit of cosmic geometry suggest that the universe is 13.77 billion years old, give or take 40 million years.A portion of a new picture of the oldest light in the universe taken by the Atacama
Cosmology Telescope. This part covers a section of the sky 50 times the moon’s width,
representing a region of space 20 billion light-years across. The light, emitted just
380,000 years after the Big Bang, varies in polarization (represented here by redder
or bluer colors). Astrophysicists used the spacing between these variations to calculate
a new estimate for the universe’s age. Credit: ACT Collaboration
The new estimate matches the one provided by the standard model of the universe and measurements of the same light made by the Planck satellite. This adds a fresh twist to an ongoing debate in the astrophysics community ... In 2019, a research team measuring the movements of galaxies calculated that the universe is hundreds of millions of years younger than the Planck team predicted. That discrepancy suggested that a new model for the universe might be needed and sparked concerns that one of the sets of measurements might be incorrect. ...
The age of the universe also reveals how fast the cosmos is expanding, a number quantified by the Hubble constant. The ACT measurements suggest a Hubble constant of 67.6 kilometers per second per megaparsec. That means an object 1 megaparsec (around 3.26 million light-years) from Earth is moving away from us at 67.6 kilometers per second due to the expansion of the universe. This result agrees almost exactly with the previous estimate of 67.4 kilometers per second per megaparsec by the Planck satellite team, but it’s slower than the 74 kilometers per second per megaparsec inferred from the measurements of galaxies. ...
The Atacama Cosmology Telescope: DR4 Maps and Cosmological Parameters ~ Simone Aiola et al
- arXiv.org > astro-ph > arXiv:2007.07288 > 14 Jul 2020
Microwave Background Power Spectra at 98 and 150 GHz ~ Steve K. Choi et al
- arXiv.org > astro-ph > arXiv:2007.07289 > 14 Jul 2020