Latest news with #IndranilBanik
Yahoo
2 days ago
- Science
- Yahoo
Scientists Say Earth May Be Trapped Inside a Huge, Strange Void
Astronomers who examined the sound waves from the Big Bang say that the Earth — and the entire Milky Way galaxy we call home — could be trapped in a huge void billions of light years across. Their study, which was just presented at the Royal Astronomical Society's National Astronomy Meeting in the UK, could solve one of cosmology's greatest mysteries: the Hubble tension, or why the older universe appears to be expanding more slowly than younger regions. "The Hubble tension is largely a local phenomenon, with little evidence that the expansion rate disagrees with expectations in the standard cosmology further back in time," Indranil Banik, a cosmologist from the University of Portsmouth who led the research, said in a statement about the work. "So a local solution like a local void is a promising way to go about solving the problem." Our universe is expanding at an accelerated rate, but precisely what rate is a matter of intense debate. When astronomers analyze the cosmic microwave background, the light leftover from the Big Bang and the oldest light in the universe, the rate is slower compared to that derived from observations in the nearby universe of Type Ia supernovas and luminous, pulsing stars known as Cepheids. The discrepancy has become undeniable, and its implications are so profound that it's been dubbed a "crisis in cosmology." Is our understanding of the universe wrong? Is there some new physics we are yet unaware of? But this latest research could pump the brakes a little. If the Earth happens to be near the center of a low density "void" in space, approximately a billion light years in radius and roughly 20 percent below the universe's average density, that could neatly explain the discrepancy. Banik explains that such a region "would cause matter to be pulled by gravity toward the higher-density exterior of the void, leading to the void becoming emptier with time." "As the void is emptying out," he continues, "the velocity of objects away from us would be larger than if the void were not there. This therefore gives the appearance of a faster local expansion rate." The idea of a local void has been floated before. But this latest work adds credence to the theory by analyzing baryon acoustic oscillations (BAO), or as the researchers call it, the "sound of the Big Bang" — emanations produced as the uniform sea of hot matter that formed from the Big Bang repeatedly contracted and then expanded in a tug of war with gravity, before eventually cooling. "These sound waves traveled for only a short while before becoming frozen in place once the universe cooled enough for neutral atoms to form," Banik said, allowing astronomers to use them as a "standard ruler" to measure cosmos. If this void exists, Banik argues, then it would distort the BAO in a way that we could measure. After analyzing all BAO measurements taken over the last 20 years, that's exactly what Banik says he's found. The biggest problem that this theory runs into, however, is that it defies our understanding of the universe's structure: at the largest scales, it should appear uniform and evenly distributed. A region billions of light years across that's somehow less dense than everything around it is quite clearly in violation of that. Nonetheless, Banik plans to test his local void model with other methods of estimating the universe's expansion. More on space: Mysterious Object Headed Into Our Solar System Is Coming From the Center of the Galaxy
Yahoo
3 days ago
- Science
- Yahoo
Sound of The Big Bang Suggests Our Galaxy Floats Inside a Void
Sound waves 'fossilized' in the arrangements of galaxies across the Universe support the theory that the Milky Way galaxy floats adrift in a giant void in space. If this is the case, we could be teetering at the brink of solving one of the biggest problems in cosmology: the Hubble tension, a heretofore irresolvable discrepancy between measurements of the rate at which the Universe is expanding. The Hubble tension exists because different ways of measuring how fast the Universe is expanding – a rate known as the Hubble constant – give us different results. Measurements based on features of the early Universe, including the cosmic microwave background and baryon acoustic oscillations, tell us that the Hubble constant is around 67 kilometers per second per megaparsec. Measurements based on things closer, like Type Ia supernovae and Cepheid variable stars, give us a Hubble constant of around 73 kilometers per second per megaparsec. Related: This Is The Most Exciting Crisis in Cosmology "A potential solution to this inconsistency is that our galaxy is close to the center of a large, local void," says cosmologist Indranil Banik of the University of Portsmouth in the UK. "It would cause matter to be pulled by gravity toward the higher-density exterior of the void, leading to the void becoming emptier with time. As the void is emptying out, the velocity of objects away from us would be larger than if the void were not there. This therefore gives the appearance of a faster local expansion rate." A void in intergalactic space is pretty much what it sounds like. Matter isn't completely evenly distributed in the Universe; it tends to clump together, creating regions of higher and lower density. Astrophysicists have put forward the idea that the Milky Way is in just such a void as an explanation for the Hubble tension, with measurements of local space suggesting that our galaxy exists in a bubble about 2 billion light-years across that is 20 percent less dense than the average volume of space. However, this explanation is far from proven. To investigate the possibility of a local void, Banik and his colleagues turned to baryon acoustic oscillations, or BAO. When the Universe was just a wee baby, full of nothing but sloshing plasma, gravity and radiation combined to form waves of pressure that could shake their way through the compressed material. When space grew too diffuse for vibrations to propogate, the pressure waves remained preserved as vast spherical arrangements of cosmic structures, with higher densities of matter at their edges. This is the 'sound of the Big Bang', a buzz trapped in time across the Universe that is visible to us as ring shapes we call BAO. Because these rings froze at the same size – about 1 billion light-years in diameter – we can determine pretty much exactly how far away they should be. According to the researchers' calculations, the presence of a local void should distort BAO in a way that ought to be measurable, especially since that distortion would increase at greater distances. They carefully reexamined 20 years' worth of BAO observations, and found a deviation from what we would expect from the standard model of cosmology, consistent with the distortion invoked by a local void. Related: "A local void slightly distorts the relation between the BAO angular scale and the redshift, because the velocities induced by a local void and its gravitational effect slightly increase the redshift on top of that due to cosmic expansion," Banik explains. "By considering all available BAO measurements over the last 20 years, we showed that a void model is about one hundred million times more likely than a void-free model with parameters designed to fit the CMB observations taken by the Planck satellite, the so-called homogeneous Planck cosmology." The researchers say their void model results in a reduction in the Hubble tension from 3.3 sigma to 1.1 to 1.4 sigma. It's going to require some rigorous testing, but it suggests that at least part of the solution to this burning problem may at least partially be found in nothingness. The team plans to embark on this testing regime, looking at objects in local space to see if these observations hold up to the notion of a local void. The research has been published in the Monthly Notices of the Royal Astronomical Society, and presented at the Royal Astronomical Society National Astronomy Meeting 2025. Dying Star's Strangled Jets Solve 50-Year-Old X-Ray Mystery Alien World Discovered Provoking Its Own Hellish Apocalypse Impact That Gave Us a Moon Could Explain Why Earth Now Has Life
Yahoo
4 days ago
- Science
- Yahoo
Researchers claim Earth, Milky Way are trapped in cosmic void
July 10 (UPI) -- Fresh evidence claims that the Earth and the surrounding galaxy are suspended inside a cosmic void based on echoes from the Big Bang. Research presented at the Royal Astronomical Society National Astronomy Meeting on Wednesday showed that data found by analyzing the sounds from the Big Bang, known as "baryon acoustic oscillations," suggest that the Milky Way Galaxy is floating in a region that is less dense than average. The 2 billion light-year region that scientists have dubbed the "Hubble Bubble" is 20% less dense than the average matter density throughout the universe. If proven correct, the findings can help settle an issue known as the "Hubble Tension" created by conflicting measurements of the expansion of the universe and could help reveal its true age. The first measurement is based on small changes in the cosmic microwave background, which is "cosmic fossils" of the first light produced by the universe 380,000 years after the Big Bang, while the second measures distances between type la supernovas or variable stars and their host galaxies. The first method found the universe expanded at a rate of 67 kilometers per second per megaparsec, while the second found a higher rate of 73.2 kilometers per second per megaparsec. The study posits, however, that if the Milky Way is sitting in a "Hubble Bubble", it would be expanding faster than a higher-density cosmos. "A potential solution to this inconsistency is that our Galaxy is close to the center of a large, local void," the study's lead author, Indranil Banik, said in a statement. "It would cause matter to be pulled by gravity towards the higher density exterior of the void, leading to the void becoming emptier with time." That would make local expansion inside the void faster than it is in denser, more distant regions of the cosmos, he added. The local void theory would mean the Earth would have to sit about in the center of the low-density "Hubble Bubble." Banik and his team used the sounds of the Big Bang to bolster previous research from the 1990s, which found fewer galaxies in the local universe than previously believed. "These sound waves traveled for only a short while before becoming frozen in place once the universe cooled enough for neutral atoms to form," Banik explained. "They act as a standard ruler, whose angular size we can use to chart the cosmic expansion history." The researchers found that it is 100 times more likely that we live in a cosmic void than a region of average density. Banik and his team's next step will be to compare their void model to other models to reconstruct the universe's expansion history. They will also explore tweaks to the standard model of cosmology.
UPI
4 days ago
- Science
- UPI
Researchers claim Earth, Milky Way are trapped in cosmic void
Fresh evidence claims that our Milky Way galaxy is suspended inside of a giant cosmic void, researchers shared on Wednesday. NASA/UPI | License Photo July 10 (UPI) -- Fresh evidence claims that the Earth and the surrounding galaxy are suspended inside a cosmic void based on echoes from the Big Bang. Research presented at the Royal Astronomical Society National Astronomy Meeting on Wednesday showed that data found by analyzing the sounds from the Big Bang, known as "baryon acoustic oscillations," suggest that the Milky Way Galaxy is floating in a region that is less dense than average. The 2 billion light-year region that scientists have dubbed the "Hubble Bubble" is 20% less dense than the average matter density throughout the universe. If proven correct, the findings can help settle an issue known as the "Hubble Tension" created by conflicting measurements of the expansion of the universe and could help reveal its true age. The first measurement is based on small changes in the cosmic microwave background, which is "cosmic fossils" of the first light produced by the universe 380,000 years after the Big Bang, while the second measures distances between type la supernovas or variable stars and their host galaxies. The first method found the universe expanded at a rate of 67 kilometers per second per megaparsec, while the second found a higher rate of 73.2 kilometers per second per megaparsec. The study posits, however, that if the Milky Way is sitting in a "Hubble Bubble", it would be expanding faster than a higher-density cosmos. "A potential solution to this inconsistency is that our Galaxy is close to the center of a large, local void," the study's lead author, Indranil Banik, said in a statement. "It would cause matter to be pulled by gravity towards the higher density exterior of the void, leading to the void becoming emptier with time." That would make local expansion inside the void faster than it is in denser, more distant regions of the cosmos, he added. The local void theory would mean the Earth would have to sit about in the center of the low-density "Hubble Bubble." Banik and his team used the sounds of the Big Bang to bolster previous research from the 1990s, which found fewer galaxies in the local universe than previously believed. "These sound waves traveled for only a short while before becoming frozen in place once the universe cooled enough for neutral atoms to form," Banik explained. "They act as a standard ruler, whose angular size we can use to chart the cosmic expansion history." The researchers found that it is 100 times more likely that we live in a cosmic void than a region of average density. Banik and his team's next step will be to compare their void model to other models to reconstruct the universe's expansion history. They will also explore tweaks to the standard model of cosmology.
NDTV
5 days ago
- Science
- NDTV
Is Earth In A Giant Cosmic Void? Why New Research Could Change Everything
In a discovery that could upend our understanding of the cosmos, scientists believe that Earth, along with the entire Milky Way, may be drifting near the centre of a massive cosmic void, an area unusually empty of galaxies and matter. Presented at the Royal Astronomical Society's National Astronomy Meeting, new research led by Dr Indranil Banik from the University of Portsmouth proposes that this "void", also known as an underdensity, could help solve one of astrophysics' biggest puzzles: the Hubble Tension, a long-standing discrepancy in measurements of the universe's rate of expansion. 'We showed that a void model is about one hundred million times more likely than a void-free model,' Dr Banik said, explaining that their data was based on 20 years of measurements of baryon acoustic oscillations – faint, frozen ripples in matter left over from the Big Bang, often described as the "sound" of the early universe. If true, this theory means we're sitting inside a cosmic bubble roughly a billion light-years wide and about 20% less dense than the average universe. This sparsity of matter could distort our view of how quickly galaxies are racing away, essentially tricking us into thinking the universe is expanding faster than it actually is. The idea of a local void is not new; scientists have debated it for decades, but it has remained controversial because it challenges the principle that the universe should be evenly spread out at large scales. However, Dr Banik's model, which incorporates redshift measurements and the latest Planck satellite data, offers compelling evidence that could shift mainstream scientific opinion. If confirmed, the implications are profound: not only would it reshape our understanding of cosmology, but it could also suggest that the "heat death" of the universe, when all energy is evenly spread and nothing happens anymore, might be much further in the future than previously believed. The research team plans to compare their void model with other measurements to further test its validity.
