Astronomy is always so fascinating
“Another hallucinating change”: new data suggest that the mysterious dark energy is evolving
by Ashley StricklandCNN
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New clues from one of the most extensive studies in the cosmos to date suggest that the mysterious dark energy may be evolving in a way that can change the way astronomers understand the universe.
Dark energy is a term scientists use to describe an energy or force that accelerates the expansion of the universe. But while representing 70% of the cosmos’ energy, researchers still have no idea what dark energy is, says Mustapha Ishak-Bosshaki, professor of physics and astrophysics at the University of Texas, Dallas, USA.
Ishak-Bosshaki is co-president of a working group for the collaboration of the dark energy spectroscopic instrument known as Desi. The instrument, now in its fourth year of heaven observation, can observe the light of 5000 galaxies at the same time. When the project is over next year, it will have measured the light of about 50 million galaxies.
Collaboration, which includes more than 900 researchers, allowed data to share the first three years of Desi observations. Among the findings include measurements of about 15 million galaxies and quasars, some of the most brilliant objects in the universe. Ishak -Bosshak helped lead the analysis of the latest Desi data, which suggest that dark energy – long designated as “constant cosmological,” as astronomers thought it was unchanging – they are behaving unexpectedly and may even be weakening over time.
“The discovery of dark energy for almost 30 years was the biggest surprise of my scientific life,” says David Weinberg, professor of astronomy at Ohio’s state university, who contributed to the analysis of Desi. “These new measurements offer the strongest evidence so far that dark energy evolves, which would be another hallucinating change to our understanding of how the universe works.”
The findings place astronomers closer to unmasking the mysterious nature of dark energy, which may mean that the standard model of how the universe works may also need an update, scientists say.
A deep look at the universe
The dark energy spectroscopic instrument is at the top of the four -meter Nicholas U. Mayall telescope of the National Science Foundation at the National Kitt Peak Observatory in Tucson, Arizona, USA. The 5,000 fiber optic “eyes” of the instrument and its extensive observation capacity are allowing scientists to build one of the largest 3D maps in the universe and to follow the way dark energy has influenced and shaped the cosmos over the last 11 billion years.
The light of celestial objects such as galaxies takes some time to reach Earth, which means that Desi can effectively see what the cosmos like at different times, from thousands of millions of years to the present.
“Desi is different from any other machine in terms of its ability to observe independent objects simultaneously,” says John Moustakas, professor of physics at Siena College and coordinator of the data publication.
The latest discoveries include data on more than twice the cosmic objects that were analyzed and presented less than a year ago. These 2024 revelations first suggested how dark energy may be evolving.
“Our goal is to let the universe tell us how it works and perhaps the universe is telling us that it is more complicated than we thought,” says Andrei Cuude, a post-doctoral researcher at the US Department of Energy Berkeley National Laboratory, which manages the Desk’s Lyman-Alpha de Desi. “It’s interesting and it is more confident to see that many different lines of evidence are pointing in the same direction.”
Increasing cosmic evidence
Desi can measure what scientists call the scale of the acoustic oscillation of the barium, or Bao – essentially the way the events that occurred at the beginning of the universe left behind patterns in the distribution of matter in the cosmos. Astronomers look at the Bao scale, with separations of about 480 million light years, such as a standard ruler.
“This separation scale is like a gigantic ruler in space that we can use to measure distances and use the combination of these distances and redshifts (speed to which objects move away from us) to measure the expansion of the universe,” says Paul Martini, coordinator of analysis and astronomy teacher at Ohio’s state university.
Measuring the influence of dark energy throughout the history of the universe shows how a dominant force has been.
Researchers have begun to note that when they combined these observations with other light measurements throughout the universe, such as the explosion of stars, the light distorted by the severity of distant galaxies and the light left of the early days of the universe, called Cosmic Microwave Background, the DES data show that the impact of dark energy may be weakening over time.
“If this continues, dark energy will eventually cease to be the dominant force in the universe,” says Ishak-Bosshak. “Therefore, the expansion of the universe will cease to accelerate and will remain at a constant pace or, in some models, it may even stop and collapse again. Of course these futures are very remote and will lead thousands of millions of years to happen. For 25 years I work with the issue of cosmic acceleration and my perspective is that if the evidence continues to increase, and it is likely to happen, then it will be a big event for the big event for cosmology and all physics. “
Resolve a lasting mystery
There is still not enough evidence to declare an innovative discovery that definitely states that dark energy is evolving and weakening, but this may change within a few years, it considers Ishak-Bosshak.
“My first big question is whether we will continue to see proof of the evolution of dark energy as our measurements are improving,” Paul Martini says. “If we get to the point where the tests are overwhelming, then my next questions will be: How does dark energy evolve? And what are the most likely physical explanations?”
The publication of new data can also help astrophysicists better understand the evolution of black galaxies and holes and the nature of dark matter. Although dark matter has never been detected, it is believed to constitute 85% of the total matter of the universe.
The scientists involved in collaboration are eager to improve their measurements using Desi.
“Whatever the nature of dark energy, it will shape the future of our universe,” says Michael Levi, director of the Desi and Scientist of the National Laboratory Lawrence Berkeley. “It is remarkable that we can look to heaven with our telescopes and try to answer one of the greatest questions that humanity ever raised.”
A new experience called Spec-S5, or Stage 5 Spectroscopic Experiment, could measure more than 10 times more galaxies than Desi to study both dark energy and dark matter, says Martini.
“Spec-S5 would use telescopes in the northern and southern hemispheres to map galaxies throughout the sky,” explains Martini. “We are also enthusiastic about how the Vera Rubin Telescope will study supernovae and provide a new and uniform set of data to study the history of the expansion of the universe.”
Other spatial observatories, such as Euclid space telescope and Nancy Grace Roman space telescope, which is expected to be in 2027, will also contribute to more important measurements of dark matter and dark energy in the coming years, which can help fill the gaps, says Jason Rhodes, an observational cosmologist of the NASA jet propulsion lab in Pasadena, California. Rhodes, who is not involved in Desi, is Euclid’s scientific leader in the US and the main researcher of NASA’s Euculid Dark Energy Scientific team.
Rhodes, who considers the results intriguing, states that the data show a slight but persistent tension between the measurements of the early days of the universe and those of the posterior universe.
“This means that our simplest model of dark energy does not allow the primitive universe we observe to evolve to the late universe we observe. The results of the Desi – and some other recent results – seem to indicate that a more complex model of dark energy is preferable. This is truly exciting because it may mean that a new, unknown physics, governs the evolution of the universe. cosmology. ”
