Scientists have revised the age of the universe

Modern cosmology describes the history of the universe through a model in which dark matter and dark energy play an important role. However, Canadian researchers are developing an alternative theory: according to it, some phenomena that are commonly associated with these components can be explained by changes in fundamental physical constants. Under this hypothesis, the age of the universe reaches 26.7 billion years, almost twice the generally accepted estimate. About what the new model is based on and what questions it still leaves open, see the Izvestia article.

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Physicists from the University of Ottawa Rajendra Gupta and Nikolaos Samaras have tested an alternative cosmological model of CCC+TL. Its name combines two ideas: Covarying Coupling Constants and the hypothesis of "Tired Light." According to this concept, the physical constants that determine the interaction of particles and forces can change together over time, and photons can gradually lose energy as they propagate through space.

The authors suggest that the effects that are explained by dark matter and dark energy in the standard cosmological model may be a consequence of these processes. In this case, it will not be necessary to introduce additional invisible components to describe a number of observed phenomena. The age of the Universe in the CCC+TL model is estimated at 26.7 billion years, while the generally accepted estimate in the framework of the standard ΛCDM model is about 13.8 billion years.

The researchers devoted one of the tests of the alternative theory to primary nucleosynthesis, the process of formation of light chemical elements shortly after the Big Bang. The results are published in the journal Universe. The scientists tested whether the model could reproduce the observed ratios of hydrogen, helium and other light elements. In their calculations, they managed to obtain results comparable to the predictions of standard cosmology, but this required assuming that the rates of nuclear reactions and neutron decay change in concert with the rate of expansion of the universe.

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How scientists tested the new theory

In 2025 and 2026, the researchers compared the predictions of CCC+TL with different astronomical observations. In particular, they used data from cosmic chronometers, a method that makes it possible to estimate the rate of expansion of the universe based on differences in the age of galaxies. The authors also checked the rotation curves of 175 galaxies from the SPARC database. According to their calculations, the model is able to reproduce the observed motion of stars and gas without involving dark matter.

Another object of analysis was the Bullet cluster, a system of colliding galaxy clusters that is often considered as one of the evidences of the existence of dark matter. The researchers claim that in their model, the additional gravitational effect is related to the location of the galaxies, rather than the hot gas that emits X-rays. However, the authors themselves call this test preliminary and requiring further study.

At the same time, the results of various tests cannot yet be considered the final confirmation of the theory. For example, in one of the papers published in the Monthly Notices of the Royal Astronomical Society, researchers tested the model using measurements of the expansion parameter of the Universe and found that with the previously selected parameters, CCC+TL does not reproduce these data as well as the standard model. In another study, on a more limited sample of space chronometers, the models turned out to be statistically indistinguishable. This shows that the conclusions depend on the data used and the calculation parameters.

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An alternative model explains the early galaxies

The authors consider the observations of the James Webb Telescope (JWST) to be one of the arguments in favor of revising the cosmological picture. He discovered galaxies that look unexpectedly massive and developed for such an early period in the history of the universe. Within the framework of the standard ΛCDM model, some of these objects are difficult to explain, since, according to calculations, they had relatively little time to form after the Big Bang.

In the CCC+TL model, the age of the Universe at the same redshift values turns out to be significantly greater. For example, during the cosmic dawn, when the standard model of the universe was about 300 million years old, alternative calculations give about 4.6 billion years. Thus, the galaxies have extra time to grow and form a complex structure. The researchers estimate that the early galaxies in this model may be about 12 times larger in size and mass than predicted by standard cosmology.

The new hypothesis is to be tested by observations.

Future observations of very distant galaxies will be one way to verify CCC+TL's predictions. In particular, the JWST telescope's GLIMPSE program involves searching for objects with a redshift higher than 50. The authors believe that, within the framework of their model, such galaxies could have existed early enough to form. However, the discovery of such objects alone will not prove the whole theory: it will be necessary to compare its other predictions with observations.

The researchers emphasize that the alternative model remains difficult to apply and requires further verification. The standard ΛCDM cosmology still successfully describes many observations, from cosmic microwave background radiation to the large-scale structure of the universe. Therefore, the new theory will have to show that it is capable not only of explaining individual riddles, but also of consistently reproducing the entire array of available data.

At the same time, the estimated age of the Universe at 26.7 billion years remains the result of an alternative theoretical model, rather than a new scientific consensus. Her future fate will depend on how successfully she passes the independent checks.