Scientists have unveiled the biggest-ever 3D map of the universe, featuring six million galaxies, prompting questions about the nature of dark energy and the destiny of the universe.
Researchers utilized data collected by the Dark Energy Spectroscopic Instrument (DESI) in Arizona to create a map of galaxies three times bigger than previous efforts, with many having their distances measured for the first time.
The map enabled scientists to accurately determine the universe's expansion rate across different epochs with unprecedented precision, revealing a consistent acceleration rate.
This suggests that dark energy, the enigmatic force propelling this expansion, may not remain constant over time, challenging previous assumptions.
“What we are seeing are some hints that it has actually been changing over time, which is quite exciting because it is not what the standard model of a cosmological constant dark energy would look like,” Dr. Seshadri Nadathur, the study’s co-author and senior research fellow at the University of Portsmouth’s Institute of Cosmology and Gravitation, told The Guardian.
Professor Carlos Frenk, the research co-author from Durham University, suggests that the universe will continue expanding indefinitely if dark energy remains constant over time.
If recent findings are valid then they challenged that theory, implying a need to re-evaluate fundamental physics, the concept of the Big Bang and the universe's future.
The study’s findings, currently in the preprint stage and not yet peer-reviewed, outline the process of creating the 3D map.
Through the analysis of galaxy distribution patterns associated with early universe sound waves known as baryon acoustic oscillations, scientists measured the distances to galaxies.
This enabled precise measurements of the universe's growth over the past 11 billion years, achieving accuracies exceeding 0.5 percent overall and 1 percent between 8 and 11 billion years ago.
“It’s mind-boggling that we can measure anything to a precision of one percent, which is precision you get in the laboratory in physics for high-precision measurements,” Frenk said.
Andrew Pontzen, a cosmology professor at University College London who was not involved in the study, said our knowledge of dark energy mechanics is limited.
Pontzen argued that when the new data is merged with existing measurements, it would not fit with the most basic explanations of dark energy. While he appreciated the study, he cautioned that "there is a huge amount still to understand about this data, and early results should be taken with a healthy grain of salt.”