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.
Approaches to date the Big Bang, which gave birth to the universe, rely on mathematics and computational modeling, using distance estimates of the oldest stars, the behavior of galaxies and the rate of the universe’s expansion. The idea is to compute how long it would take all objects to return to the beginning.
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. 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.
Schombert’s team recalculated the Tully-Fisher approach, using accurately defined distances in a linear computation of the 50 galaxies as guides for measuring the distances of 95 other galaxies. The universe, he noted, is ruled by a series of mathematical patterns expressed in equations. The new approach more accurately accounts for the mass and rotational curves of galaxies to turn those equations into numbers like age and expansion rate.
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.