Latest news with #MonthlyNoticesoftheRoyalAstronomicalSociety
Yahoo
19-04-2025
- Science
- Yahoo
Universe may revolve once every 500 billion years — and that could solve a problem that threatened to break cosmology
When you buy through links on our articles, Future and its syndication partners may earn a commission. In 1929, astronomer Edwin Hubble published a paper demonstrating that the universe is expanding. It gave rise to the Hubble constant, the number that describes how fast the universe is expanding. But it eventually created a puzzle, called the Hubble tension, because this cosmic expansion differs depending on what cosmic objects are used to measure it. A new mathematical model could resolve the Hubble tension by assuming the universe rotates. Related: After 2 years in space, the James Webb telescope has broken cosmology. Can it be fixed? The new research, published in March in the journal Monthly Notices of the Royal Astronomical Society, suggests that our universe completes one revolution every 500 billion years. This ultraslow rotation could resolve the discrepancy between different measurements of the Hubble constant. "The standard concordance cosmological model has some wrinkles," study co-author István Szapudi, an astronomer at the Institute for Astronomy at the University of Hawai'i at Mānoa, told Live Science in an email. "A slow rotation of the universe could solve the Hubble puzzle." Astronomers measure the universe's rate of expansion in a few ways. One involves looking at supernovas — the explosive deaths of giant stars — and measuring how quickly these supernovas recede. The other method utilizes the cosmic microwave background, the radiation present 380,000 years following the Big Bang. However, these two measurements differ by about 10%. The idea of a rotating universe isn't new; mathematician Kurt Gödel introduced the idea in a 1949 paper published in the journal Reviews of Modern Physics. Other researchers, like Stephen Hawking, have also explored this theory. In the new study, the team applied the rotation to the Hubble tension. Because all celestial objects — including planets, stars, galaxies and black holes — rotate, this behavior naturally extends to the universe as a whole, the study authors proposed. "Much to our surprise, we found that our model with rotation resolves the paradox without contradicting current astronomical measurements," Szapudi said. RELATED STORIES —Scientists may have finally found where the 'missing half' of the universe's matter is hiding —Rare quadruple supernova on our 'cosmic doorstep' will shine brighter than the moon when it blows up in 23 billion years —Scientists discover smallest galaxy ever seen: 'It's like having a perfectly functional human being that's the size of a grain of rice' The proposed glacial speed at which the universe may rotate is too slow to detect, but it would still affect the universe's expansion rate and does not require new physics. However, the model only incorporated some of the physics thought to be at play. "We use Newtonian physics with some input from General Relativity," Szapudi said. "A complete [General Relativity] treatment would be desirable." He also explained that their work assumes the universe is uniform and did not vary in density as it evolved. In future investigations, the team will contrast the rotating-universe model against other cosmological models.
Yahoo
17-04-2025
- Science
- Yahoo
The universe isn't just expanding—it may be spinning
The prevailing consensus in astrophysics is that the universe has spent the past 13-or-so billion years expanding outward in all directions, ever since the Big Bang. It's expanding at this very moment, and will continue to do so until… a number of possible theoretical endings. Meanwhile, the specific rate at which the universe is growing remains a longstanding point of contention known as the 'Hubble tension.' However, there may be a way to finally ease that tension—you just need to put a slight spin on everything. In simplest terms, the rate at which the universe expands on paper doesn't match actual astronomical observations. That speed—called the Hubble Constant—is measured in units of kilometers per second per megaparsec (km/s/Mpc), with a megaparsec measuring about 300,000 light years. The most widely accepted theoretical model, the Lambda/Cold Dark Matter model (ΛCDM), says the universe is growing at 67-68 km/s/Mpc. But what astronomers see through their equipment is a little faster, at about 73 km/s/Mpc. And therein lies the Hubble tension. In a study published in the April issue of the Monthly Notices of the Royal Astronomical Society, a team of researchers including experts at the University of Hawai'i's Institute for Astronomy argue that introducing a miniscule amount of rotation to standard mathematical model of the universe may provide the way to align both expansion theories.'Much to our surprise, we found that our model with rotation resolves the paradox without contradicting current astronomical measurements,' study co-author and astrophysicist? István Szapudi said in a statement. 'Even better, it is compatible with other models that assume rotation.' In addition to its mathematical compatibility, the concept also doesn't break any of the known laws of physics. The problem is detecting this spin, given just how slowly the universe may be turning. But while it is difficult to discern with current tools, the spin is still fast enough to influence the expansion of space over the eons. Szapudi and their colleagues' new model indicates the universe finishes a single rotation once every 500 billion years—meaning there's still quite a bit of time before the universe completes its first full circuit. 'To paraphrase the Greek philosopher Heraclitus of Ephesus, who famously said 'Panta Rhei' (everything moves), we thought that perhaps 'Panta Kykloutai,' everything turns,' said Szapudi. Looking ahead, astronomers hope to construct a full computer model of the universe based in part of their new theory. From there, they will hopefully be able to pinpoint signs of cosmic spinning to search for among the stars.
Yahoo
21-03-2025
- Science
- Yahoo
A terrifying fate may lurk inside the Milky Way
All good things come to an end—even the Milky Way. Our home galaxy's demise isn't estimated to occur for at least another 4 or 5 billion years, when astronomers believe it will start colliding with its neighbor Andromeda. However, a new analysis of a more distant galaxy is hinting at another dramatic outcome. Instead of being annihilated from without, the Milky Way's cosmic destruction could begin from within. The spiral galaxy 2MASX J23453268−0449256 is located nearly 1 billion light-years away from Earth, and measures about three times the size of the Milky Way. Like our own galaxy, a supermassive black hole lurks at its center. But while our Sagittarius A (Sgr A*) currently exists in very cosmically quiet, dormant conditions (for a black hole), the one inside J23453268−0449256 spews chaotic, 6 million light-year-long jets of energy. That's what an international team has discovered using data collected by the Hubble Space Telescope, the Giant Metrewave Radio Telescope, the Atacama Large Millimeter Wave Array, and multi-wavelength analyses. According to their study published March 20 in the journal Monthly Notices of the Royal Astronomical Society, these findings are challenging conventional notions of how galaxies operate, and what forces they are capable of unleashing. Simply put, experts previously believed a galaxy like J23453268−0449256 couldn't survive under its own conditions. The roiling gamma, cosmic, and X-rays documented coming from its black hole are almost only seen in elliptical galaxies. Based on traditional theory, these powerful radio jets should be disrupting the spiral galaxy's comparatively delicate structure. However, that's not the case at all for J23453268−0449256. The galaxy appears pretty stable, with well-defined spiral arms, an untroubled stellar ring, and a bright nuclear bar. 'This discovery is more than just an oddity—it forces us to rethink how galaxies evolve, and how supermassive black holes grow in them and shape their environments,' Joydeep Bagchi, a study lead author and astronomy professor at India's CHRIST University, Bangalore, said in a statement. One difference appears to be its ability to form new stars. Although the galaxy is surrounded by a halo of X-ray-emitting gas needed to make them, the supermassive black hole's energy jets act like a deep space oven. This appears to prevent the halo from cooling enough to form new stars. Despite this stellar anomaly, J23453268−0449256 already hosts an untold number of stars. 'If a spiral galaxy can not only survive but thrive under such extreme conditions, what does this mean for the future of galaxies like our own Milky Way?' wondered Bagchi. This type of scenario could begin if the Milky Way's black hole Sgr A* ever begins devouring a star, gas cloud, or even a smaller dwarf galaxy. Previously documented in other galaxies, these Tidal Disruption Events (TDEs) are as dramatic as they are powerful. But depending on their direction, there are scenarios in which any future life on Earth wouldn't survive the experience. If a hypothetical Milky Way TDE's cosmic rays lined up with the solar system, the effects would cause almost incomprehensible devastation. The energy beams could strip planetary atmospheres, irradiate DNA enough to cause genetic mutations, as well as destroy the Earth's ozone and kick off dinosaur-level mass extinctions. While astronomers believe that the Milky Way hosted those kinds of radio jets in the past, the chance of it occurring any time in the near future is pretty slim. Regardless of the Milky Way's ultimate celestial fate, discovering and studying unique neighboring galaxies like J23453268−0449256 allows astronomers to learn more about our surprising, complex universe. 'Understanding these rare galaxies could provide vital clues about the unseen forces governing the universe—including the nature of dark matter, the long-term fate of galaxies, and the origin of life,' said study co-author and PhD candidate Shankar Ray. 'Ultimately, this study brings us one step closer to unraveling the mysteries of the cosmos, reminding us that the universe still holds surprises beyond our imagination.'
