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Yahoo
4 days ago
- General
- Yahoo
The Big Bang's Glowing 'Echo' May Be Something Else Entirely
Part of the reason scientists have settled on the Big Bang theory as the best explanation of how the Universe came into being is because of an 'afterglow' it emits – but a new study suggests we may need to rethink the source of this faint radiation. Technically, this afterglow is known as Cosmic Microwave Background (CMB) radiation, and it's been traveling through space for more than 13 billion years, since soon after the Big Bang first went bang. It can be picked up by our most advanced telescopes. Now, researchers from Nanjing University in China and the University of Bonn in Germany have run calculations suggesting we've overestimated the strength of the CMB. In fact, it might not even be there at all. The rocking of the cosmological boat, as it were, is driven by new evidence of early-type galaxies (ETGs). Recent data from the James Webb Space Telescope suggests these ETGs might account for some or even all of the CMB, depending on the simulation used. "Our results are a problem for the standard model of cosmology," says physicist Pavel Kroupa, from the University of Bonn. "It might be necessary to rewrite the history of the Universe, at least in part." Scientists already know plenty about ETGs, which are usually elliptical in shape. What's new is that recent studies, and this latest interpretation of them, point to these types of galaxies having formed even earlier than previous models accounted for. If that timeline shifts, then so does the pattern of radiation spreading out across the Universe. In simple terms, the Universe may have moved through its initial phase of gas surges and galaxy formation quicker than we imagined. "The Universe has been expanding since the Big Bang, like dough that is rising," says Kroupa. "This means that the distance between galaxies is increasing constantly." "We have measured how far apart elliptical galaxies are from one another today. Using this data and taking into account the characteristics of this group of galaxies, we were then able to use the speed of expansion to determine when they first formed." This earlier estimate for the formation of these ETGs means that their brightness could emerge "as a non-negligible source of CMB foreground contamination", the researchers write. We should bear in mind that this research is still in its preliminary stages. It's not time yet to start pulping scientific textbooks – or whatever the modern equivalent is. Rewriting Wikipedia, perhaps? But this research certainly raises some big questions. Given the almost unimaginable timescales and distances involved, it's difficult for astrophysicists to always be precise. The researchers suggest anywhere from 1.4 percent to 100 percent of the CMB could be explained by their new models. What's certain is that as our space telescopes and analysis systems get more sophisticated, we're learning more about the surrounding Universe than ever before – and that in turn means some previous assumptions may have to be readjusted, including those about the very formation of the Universe itself. "In the view of the results documented here, it may become necessary to consider [other] cosmological models," write the researchers in their published paper. The research has been published in Nuclear Physics B. A Serious Threat May Be Lurking in The Orbit of Venus, Says Study We Now Know What Switched The Lights on at The Dawn of Time Light Travels Across The Universe Without Losing Energy. But How?
Newsweek
13-05-2025
- Science
- Newsweek
Cosmic Afterglow Revelation May 'Rewrite the History of the Universe'
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. Findings from a new study into the cosmic "afterglow" may rewrite the history of the universe, according to researchers. This afterglow—the "cosmic microwave background" (CMB), the relic radiation left behind by the Big Bang—has given astronomers insights into the birth of the universe and helped shape the standard model of cosmology. However, new research has calculated that the strength of this afterglow may have been overestimated—a fact that would call the standard model into question. "According to our calculations," explained paper author and University of Bonn astrophysicist professor Pavel Kroupa in a statement, "it could be that this background radiation doesn't exist at all. "At the very least, we are convinced that its strength has been underestimated." Artist's impression of the Big Bang. Artist's impression of the Big Bang. coffeekai/Getty Images In their study, Kroupa and his colleague Eda Gjergo, an astrophysicist at China's Nanjing University, studied elliptical galaxies, which are known to have been the first galaxies to form in the universe's infancy. "We considered multiple well-established properties of massive early-type (elliptical) galaxies, and without altering them, we reconstructed their luminosity evolution," Gjergo told Newsweek. He added: "These galaxies formed rapidly, with extremely high star formation rates, producing vast numbers of massive stars." In fact, the duo explain, the process that saw vast volumes of gas accumulate into hundreds of billions of stars in these earliest galaxies only last a few hundred million years—this, Gjergo notes, "is relatively short on a cosmological time scale." Gjergo told Newsweek that elliptical galaxies are "already among the brightest objects in the universe. However, their current luminosity comes primarily from ancient, low-mass stars, which are intrinsically very bright." (In contrast, massive stars shine bright and die young.) Gjergo continued: "We find that at the peak of their formation, elliptical galaxies must have been 10,000 times brighter than their counterparts today. We came up with the analogy of seeing 'embers in the ashes of ancient cosmic bonfires.' " By measuring how far apart elliptical galaxies are today, and factoring in the rate at which the universe is thought to be expanding, the researchers were able to determine when exactly it was that elliptical galaxies first formed. "The light these stars in all these galaxies emitted whilst forming is still around today as a background seen in all directions, and this background light essentially happens to more or less coincide with the observed CMB," Kroupa told Newsweek. "Our most conservative estimate tells us that at least one percent of the CMB is from these stars in the forming elliptical galaxies." "Since the fluctuations in the CMB are merely one thousandth of a percent, this means that the currently understood physics of the CMB is completely incorrect." Previous research concluded that the CMB has small, localized differences in intensity—a fact which had been interpreted as proof that gas was not uniformly distributed across the burgeoning cosmos after the Big Bang. Read more Spinning universe could solve long-standing astronomy puzzle Spinning universe could solve long-standing astronomy puzzle The new findings beg the question of how reliable such interpretations can be if elliptical galaxies account for at least 1.4 percent of the total measured radiation previously attributed to the CMB. This, Kroupa said in a statement, may present "a problem for the standard model of cosmology. "It might be necessary to rewrite the history of the universe, at least in part." He told Newsweek that the unexpected result "upsets the usual interpretation of the nature of the CMB. It essentially means that we do not have solid evidence for a hot big bang. Taking the observed CMB and subtracting this foreground leaves too little for the hot big bang to be real." (The "hot big bang" refers to how the universe started in a hot, dense, state and has been cooling and expanding ever since.) Kroupa added: "This shocking result means that we now need to revisit the very foundations of everything we know about cosmology, gravitation and the evolution of the Universe and how galaxies came to be." According, the researchers reported, they are now developing an entirely new model—which they dub the "Bohemian Model of Cosmology"—which has no hot big bang, no dark matter, no dark energy and no inflation. This, Kroupa said, is "a significantly simpler and, it seems, better and much improved representation of the observed universe." Gjergo added: "With this work, we identified the problem. Next, we aim to model the detailed imprint that we expect this early galaxy radiation must have left behind. "What type of spectral features did these galaxies have during their prime? And how did they evolve to the present?" Do you have a tip on a science story that Newsweek should be covering? Do you have a question about cosmology? Let us know via science@ Reference Gjergo, E., & Kroupa, P. (2025). The impact of early massive galaxy formation on the cosmic microwave background. Nuclear Physics B, 1017.
