It’s called a “refinement” to 12.6 billion years, down from 13.77 billion years:
Using known distances of 50 galaxies from Earth to refine calculations in Hubble’s constant, a research team led by a University of Oregon astronomer estimates the age of the universe at 12.6 billion years…
A key calculation for dating is the Hubble’s constant, named after Edwin Hubble who first calculated the universe’s expansion rate in 1929. Another recent technique uses observations of leftover radiation from the Big Bang. It maps bumps and wiggles in spacetime — the cosmic microwave background, or CMB — and reflects conditions in the early universe as set by Hubble’s constant.
However, the methods reach different conclusions, said James Schombert, a professor of physics at the UO. In a paper published July 17 in the Astronomical Journal, he and colleagues unveil a new approach that recalibrates a distance-measuring tool known as the baryonic Tully-Fisher relation independently of Hubble’s constant…
Calculations drawn from observations of NASA’s Wilkinson Microwave Anisotropy Probe in 2013 put the age of the universe at 13.77 billion years, which, for the moment, represents the standard model of Big Bang cosmology. The differing Hubble’s constant values from the various techniques generally estimate the universe’s age at between 12 billion and 14.5 billion years. The new study, based in part on observations made with the Spitzer Space Telescope, adds a new element to how calculations to reach Hubble’s constant can be set, by introducing a purely empirical method, using direct observations, to determine the distance to galaxies, Schombert said.University of Oregon, “New approach refines the Hubble’s constant and age of universe” at ScienceDaily
Our physics color commentator Rob Sheldon writes to say,
The age of the universe is just the inverse of the Hubble constant, H0. This article relates a recent paper recalibrating galaxy distances, and recalculating H0 =75 km/s/Mpc. To recap, all methods that rely on measuring the cosmic microwave background (CMBR), get a value H0=67 +/- 1 km/s/Mpc. All methods that rely on the “distance ladder”, measuring the distance to Cepheid variable stars, then using that to get galaxy distances, then using that to get supernovae distances, get a value H0=73-75 km/s/Mpc.
Initially, there was some hope that reanalysis might bring the two methods into alignment, but CMBR experiments such as COBE, WMAP, then Planck, then ACT all confirmed the 67 number, whereas recalibration of Cepheids stars by Riess and now recalibration of the Tully-Fisher galactic measure are all converging at 74.
So what are we to do? Here’s the conclusion of the paper:
“Our resulting value is on the high side of the different schools of cosmology, signaling that our understanding of the physics of the universe is incomplete with the hope of new physics in the future,” he said.
I have long advocated a rewrite of the Big Bang model that converts the cosmic microwave numbers into a Hubble constant. But strangely, like Darwin’s model in biology, we see few cosmologists willing to kill the sacred cow. They would rather change the laws of physics (“new physics”) than change their model. Models, creations of men, are held in more respect than laws of physics, creations of God.