Our universe could be twice as old as current estimates, according to a new study that challenges the dominant cosmological model and sheds new light on the so-called “impossible early galaxy problem.”
“Our newly-devised model stretches the galaxy formation time
by a several billion years, making the universe 26.7 billion years old, and not
13.7 as previously estimated,” says author Rajendra Gupta, adjunct professor of
physics in the Faculty of Science at the University of Ottawa.
For years, astronomers and physicists have calculated the
age of our universe by measuring the time elapsed since the Big Bang and by
studying the oldest stars based on the redshift of light coming from distant
galaxies. In 2021, thanks to new techniques and advances in technology, the age
of our universe was thus estimated at 13.797 billion years using the Lambda-CDM
concordance model.
However, many scientists have been puzzled by the existence
of stars like the Methuselah that appear to be older than the estimated age of
our universe and by the discovery of early galaxies in an advanced state of
evolution made possible by the James Webb Space Telescope. These galaxies,
existing a mere 300 million years or so after the Big Bang, appear to have a
level of maturity and mass typically associated with billions of years of
cosmic evolution. Furthermore, they’re surprisingly small in size, adding
another layer of mystery to the equation.
Zwicky’s tired light theory proposes that the redshift of
light from distant galaxies is due to the gradual loss of energy by photons
over vast cosmic distances. However, it was seen to conflict with observations.
Yet Gupta found that “by allowing this theory to coexist with the expanding
universe, it becomes possible to reinterpret the redshift as a hybrid
phenomenon, rather than purely due to expansion.”
In addition to Zwicky’s tired light theory, Gupta introduces
the idea of evolving “coupling constants,” as hypothesized by Paul Dirac.
Coupling constants are fundamental physical constants that govern the
interactions between particles. According to Dirac, these constants might have
varied over time. By allowing them to evolve, the timeframe for the formation
of early galaxies observed by the Webb telescope at high redshifts can be
extended from a few hundred million years to several billion years. This
provides a more feasible explanation for the advanced level of development and
mass observed in these ancient galaxies.
Moreover, Gupta suggests that the traditional interpretation of the “cosmological constant,” which represents dark energy responsible for the accelerating expansion of the universe, needs revision. Instead, he proposes a constant that accounts for the evolution of the coupling constants. This modification in the cosmological model helps address the puzzle of small galaxy sizes observed in the early universe, allowing for more accurate observations.
Reference: Monthly Notices of the Royal Astronomical Society
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