Physicist challenges dark matter existence, doubles universe's age

According to the most popular theory, the Universe consists essentially of ordinary matter, dark matter, and dark energy, and is believed to be about 13.8 billion years old. However, a physicist from Ottawa has introduced a new theory in a recent publication, challenging this model by disputing the existence of dark matter and dark energy, and suggesting that the Universe is actually much older.

Last year, Rajendra Gupta, a theoretical physicist at the University of Ottawa, proposed that the Universe is 26.7 billion years old, nearly double the previously estimated age. He believes this could explain the unexpected maturity of some galaxies, which, according to current theories, should have existed for only about 300 million years. Gupta has now expanded on his theory, arguing against the presence of dark matter in the Universe. His study was published in "The Astrophysical Journal."

**Dark Matter and Dark Energy**

In cosmology, dark matter is thought to be matter that does not interact with light or electromagnetic fields, or can only be inferred through gravitational forces. Its exact composition, whether unknown particles or waves, is still a mystery, but it is believed to permeate throughout the Universe.

The evidence for dark matter comes from indirect observations, such as its gravitational effects on galaxy rotation and movement within galaxy clusters. Without dark matter, current models cannot explain these phenomena.

It is theorized that dark matter serves as a cosmic glue, holding galaxies together, while dark energy drives the Universe's expansion. However, despite extensive searches, direct evidence of dark matter and energy remains elusive.

**New Concept**

Gupta combined the tired light theory with a variation of the current Lambda-CDM model in his research. The tired light concept, originally proposed by Fritz Zwicky in 1929, suggests that light loses energy over great distances, appearing redshifted. This redshift is observed as light from faraway galaxies shifts towards longer wavelengths, a key measurement used in astrophysics to estimate the age of celestial objects.

Zwicky's hypothesis faced criticism and was largely set aside for the expansion of space theory to explain redshift. However, Gupta also incorporates the idea, proposed by Nobel laureate Paul Dirac, that the forces of nature and possibly physical constants change over time. This allows for a longer timeline for the formation of early galaxies.

By merging these two theories, Gupta claims to provide a better explanation for various observations, challenging the conventional belief in dark matter and dark energy.

"Our previous work, suggesting the Universe is 26.7 billion years old, led us to conclude that dark matter is not necessary," Gupta explains. He proposes that the observed accelerated expansion of the Universe is due to the weakening of natural forces over time, not dark energy.

Gupta's theory also accounts for the distribution fluctuations of ordinary (baryonic) matter caused by acoustic waves in the Universe's early history. He believes that his work, while questioning the existence of dark matter, remains consistent with key cosmological observations, offering a new perspective on the Universe's fundamental properties.

Source: University of Ottawa, Science Alert