Albert Einstein’s general theory of relativity has been one of the cornerstones of modern physics. The German scientists achieved it without any of the technology that researchers have today, and it continues to shape everything in science when it comes to the understanding of gravity and the cosmos. Despite the monumental success, people tried to prove him wrong for over 90 years, and no one succeeded until the discovery of an invisible force pushing the universe forward.
Dark matter and dark energy: What is the difference between the two invisible forces?
Two theoretical concepts have shaped and answered questions about the cosmos: dark energy and dark matter. Dark energy is the force helping the universe expand, while dark matter keeps galaxies together – the same way gravity works. However, recent advancements in observational cosmology have brought a level of complexity to the dark energy concept that scientists did not expect.
The recent study compared Einstein’s predictions with the latest data from the Dark Energy Survey, a tool that scientists created to search for evidence of the invisible force pushing the universe forward. However, what they got back was not what they were expecting, as the research points out a slight discrepancy with the current knowledge. This is transforming everything science knows about the expansion of the universe.
Einstein did it again: Scientists confirmed 100-year-old theory
An international team of scientists has mapped how the structure of the universe has evolved over the past 11 billion years, providing the most precise test yet of how gravity operates on the largest scales. Their results show that, even across these immense distances and times, gravity behaves as Albert Einstein predicted in his 1915 theory of general relativity.
The study focused on dark energy, the mysterious force driving the accelerated expansion of the universe. Researchers analyzed a year’s worth of data from the Dark Energy Spectroscopic Instrument (DESI) at Kitt Peak National Observatory in Arizona, which can capture light from 5,000 galaxies at once. By examining the distribution of galaxies, clusters, and superclusters—forming what is known as the cosmic web—they could see how matter has clumped under gravity over billions of years.
The study went beyond our galaxy: Observed galaxies confirm Einstein’s theory
The DESI team looked at nearly six million galaxies, some of which date back to when the universe was just 20 percent of its current age. Their analysis confirmed that gravity follows the patterns Einstein described, while also suggesting that dark energy may not be constant.
According to astrophysicist Mustapha Ishak-Boushaki of the University of Texas at Dallas, one of the team leaders, the results hint that dark energy is weakening over time. If true, the universe’s expansion might not accelerate forever. Ordinary matter—everything we see and touch—makes up only a small fraction of the cosmos. The rest consists of invisible dark matter, which accounts for roughly 27 percent, and dark energy, which makes up about 68 percent.
Only a portion of all matter is visible: There is more hidden
The new findings strengthen the standard model of cosmology, supporting general relativity, while also offering new insight into how dark energy shapes the universe’s future. Meanwhile, there are also things we can’t see because light hasn’t reached Earth yet, like Einstein anticipated – and some things will remain hidden for eternity, as humans have an expiration date due to the sun’s growth projections.
In the meantime, the DESI collaboration, which includes more than 900 researchers from over 70 institutions worldwide, coordinated by the U.S. Department of Energy’s Lawrence Berkeley National Laboratory, will continue to assist in further discoveries. Their results have been published on the arXiv repository ahead of peer review.