Scientists Explained The Merger Of Two Black Holes

Scientists may have solve the mystery of an "impossible" merger between black holes that was detected via ripples in space-time called gravitational waves back in 2023.

The collision occurred around 7 billion light-years away and involved a smashup of two black holes that seemed to be forbidden, because of their enormous masses and the incredible rate at which they were spinning.

These black holes — with masses of 100 and 140 times that of the sun, and spinning at near the speed of light — shouldn't exist according to current theories of how "stellar mass black holes" form when massive stars collapse and explode as supernovae.

Researchers from the Flatiron Institute's Center for Computational Astrophysics (CCA) in New York tackled this puzzle by performing simulations that recreated this system's evolution through the lives of the progenitor stars, all the way to their supernova deaths. This revealed a simple factor that hadn't been properly considered in the process before: magnetic fields.

"No one has considered these systems the way we did; previously, astronomers just took a shortcut and neglected the magnetic fields," team leader Ore Gottlieb, an astrophysicist at the CCA, said in a statement. "But once you consider magnetic fields, you can actually explain the origins of this unique event."

The gravitational waves from this collision of "forbidden" black holes were "heard" by the Earth-based detectors LIGO, Virgo, and KAGRA on Nov. 23, 2023, as Space.com reported in July this year. Analysing this signal, designated GW231123, astronomers were immediately puzzled by the existence of such massive and rapidly spinning black holes.

That's because the stars that could die to leave behind stellar mass black holes as massive as these should end their lives with a specific type of supernova called a "pair-instability supernova" that's so violent that nothing remains, not even a black hole."As a result of these supernovae, we don't expect black holes to form between roughly 70 to 140 times the mass of the sun," Gottlieb explained. "So, it was puzzling to see black holes with masses inside this gap."

Black holes can exist within that mass gap as the result of a previous merger between black holes, but researchers ruled this out for the black holes involved in the collision that sent the signal GW231123 rippling through space. That's because mergers are disruptive to the spin of the created "daughter" black hole, but the two black holes involved in this merger were still spinning at near the speed of light, at the maximum speed at which black holes can rotate. Thus, researchers concluded that something other than prior mergers must account for the tremendous masses of the progenitor black holes.

Gottlieb and colleagues began investigating what this mechanism could be by first simulating a giant star with a mass of around 250 times that of the sun, which they tracked through its evolution right up until its supernova death. They found that, by this end stage, the star had burned through so much of its fuel that it had "slimmed down" to 150 solar masses. That left it small enough to leave behind a black hole after it went supernova.

The team then ran another, more complex simulation, factoring in magnetic fields that play a role in the aftermath of the supernova. This second model began with supernova remnants in the shape of a cloud of leftover stellar material intertwined with magnetic fields. At the heart of this wreckage sat a black hole.

Prior to this research, scientists had assumed that the entire mass of this remnant material would be consumed by the newborn black hole. As a consequence, the mass of that black hole would grow to match the mass of the massive progenitor star. However, the team's simulations showed something different happening.

What Gottlieb and colleagues observed instead was that, after the collapse of a nonrotating star to form a black hole, leftover material does indeed quickly fall into the black hole. But if the progenitor star is spinning rapidly, this stellar wreckage forms a rotating, flattened cloud around the newborn black hole that causes it to spin faster and faster as more and more material is fed to it.

In the presence of magnetic fields, the disk of debris experiences pressure strong enough to blast some of the leftover matter away from the black hole at nearly the speed of light.

This outflow of material reduces the mass of the disk feeding the black hole, and the stronger the magnetic fields involved, the more rapidly this platter of stellar material is carried away from the black hole. If the magnetic fields are powerful enough, half of the star's initial mass can be blasted away. The net result: a weak magnetic field results in less deprivation of matter and a final black hole that sits within the mass gap.

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Why Are There 5,200 Holes In Peru?

Hundreds of years ago, someone took great pains to carve thousands of holes into a long ridge-top strip in the Andean foothills.

Just who built the structure known as Monte Sierpe, and why, has baffled the world since 1933, when the National Geographic Society published Robert Shippee's aerial photographs of the strange site. Now, archaeologists think they know the answer.

An analysis of plant material found inside the holes suggests that it may have initially functioned as a market and later as an accounting system, says a team led by archaeologist Jacob Bongers of the University of Sydney in Australia.

"Why would ancient peoples make over 5,000 holes in the foothills of southern Peru? Were they gardens? Did they capture water? Did they have an agricultural function?" Bongers says.

"We don't know why they are here, but we have produced some promising new data that yield important clues and support novel theories about the site's use."

Humans don't tend to undertake major construction works unless there's a purpose, and Monte Sierpe is a monumental work of landscape engineering. The long strip of holes measures 1.5 kilometers (0.93 miles) long and around seven or eight holes wide. It consists of some 5,200 holes excavated from the sediment, some deliberately reinforced at the sides using stones.

It would have required significant planning and time, which leads to the obvious questions: Who, and why? Proposed explanations have ranged from gardening to fog collection.

Bongers and his colleagues built on previous work that proposed the site was used as a system of taxation by the Inca. The archaeologists conducted extensive fieldwork, mapping the site with drones and testing sediment samples from inside the holes to determine which materials, if any, may have been placed there, and how long ago.

The Inca empire moved into the region around 1400 CE, so scientists have been operating under the assumption that Monte Sierpe is an Inca site. However, the Inca culture wasn't the first to live there; before their expansion into the region, the Chincha culture had lived there for hundreds of years.

Radiocarbon dating of charcoal from one of the pits revealed it was deposited around 1320 to 1405 CE – a timing that suggests the material predates the Inca. If so, it suggests the Chincha likely built and used the site well before the Inca arrived. Pottery fragments found on the surface support the same timeframe.

The most significant revelation, the researchers say, is the contents of the holes. Their microbotanical analysis of sediments from 19 holes yielded starch and pollen grains of maize (corn), Amaranthaceae (the plant group that includes quinoa, spinach, beets, and chard), Pooidae (the grass subfamily that includes cereals such as oats, wheat, and barley), and Cucurbita (squash).

"This is very intriguing," Bongers says.

"Perhaps this was a pre-Inca marketplace, like a flea market. We know the pre-Hispanic population here was around 100,000 people. Perhaps mobile traders (seafaring merchants and llama caravans), specialists (farmers and fisherfolk), and others were coming together at the site to exchange local goods such as corn and cotton."

Yet aerial imagery of the site revealed a pattern that is not as apparent from the ground. The holes are arranged in blocks that, the researchers say, are remarkably similar to an Inca khipu, a knotted-string counting device recovered from the same Andean valley.

This suggests that the later Inca repurposed the holes for tax collection, using them as a tribute register to ensure the appropriate levies were collected.

"There are still many more questions – why is this monument only seen here and not all over the Andes? Was Monte Sierpe a sort of 'landscape khipu'? – but we are getting closer to understanding this mysterious site. It is very exciting," Bongers added.

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Scientists Drilled 1,500 Feet Into Antarctic Ice And Discovered Something

More than half a mile beneath the surface of Antarctica's Kamb Ice Stream, scientists have uncovered a slow-moving river of water that's been hidden for millennia. This latest discovery is offering fresh insight into how Antarctica melts from below, and it could have big implications for the future of coastal towns and cities.

So, what is really happening here?

In a recent expedition, researchers drilled more than 1,600 feet into the West Antarctic Ice Sheet and discovered a subglacial river flowing beneath the Ross Ice Shelf, per Earth.com.

The river, about as tall as a 30-story building and as wide as a city block, is a blend of freshwater and seawater, slowly making its way toward the ocean.

"We struck water at the end of the borehole and with the help of our camera, we even discovered a school of lobster-like creatures — 400 kilometers from the open ocean," expedition leader Huw Horgan said.

The research team believes the river surges about once every decade when nearby lakes empty into it, like a massive underground plumbing system.

These surges may be carving out channels in the ice, accelerating melt, and moving nutrients that sustain hidden ecosystems.

Think of the Ross Ice Shelf like a giant bottle stopper — it holds back inland ice and helps keep sea levels in check.

But when rivers like this one thin that shelf from beneath, it makes it easier for land-based ice to slip into the ocean, speeding up sea-level rise.

When sea levels rise, it can mean higher tides during extreme weather, more flooding in coastal neighborhoods, and added pressure on food systems and public health. Some scientists even warn of increased disease spread as rising waters alter how pathogens move through our communities. While extreme weather events have always occurred, human-caused pollution is now supercharging them, making storms, floods, and droughts more destructive. Understanding how these hidden systems work helps us better prepare for what's ahead and make smarter decisions today.

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One Genetic Tweak May Have Allowed Humans To Walk

There were two small changes in human DNA that was believed to have played a big role in helping our ancestors walk upright, researchers say.

The study, recently published in the journal Nature, found that these tweaks changed how a key hip bone developed. This allowed early humans to stand, balance and walk on two legs instead of moving on all fours like other primates.

One change caused the ilium -- the curved bone you feel when you put your hands on your hips -- to rotate 90 degrees.

This shifted how muscles attached to the pelvis, transforming a structure once used for climbing into one built for upright walking.

The other genetic change slowed down how the ilium hardened into bone, giving it more time to expand sideways and form a short, bowl-shaped pelvis.

These changes were "essential for creating and shifting muscles that are usually on the back of the animal, pushing the animal forward, to now being on the sides, helping us stay upright as we walk," study co-author Terence Capellini, an evolutionary biologist at Harvard University, said.

The researchers examined samples of developing pelvic tissue from humans, chimpanzees and mice, pairing microscopic samples with CT imaging.

They found that in humans, pelvic cartilage grows sideways rather than vertically as it does in other primates, and that it hardens later, allowing the structure to widen as it forms.

Further analysis revealed that the difference came from subtle changes in gene regulation -- the "on-off switches" that control how and when certain genes are active.

In humans, cartilage-forming genes switched on in new regions, prompting horizontal growth, while bone-forming genes activated later, slowing the hardening process.

Because primates share most of the same developmental genes, researchers believe these changes appeared early in human evolution, after our lineage split from chimpanzees.

"What Terry and his lab's work has shown is that it's not just a rotation, it's a different way of growing," University of Missouri anthropologist Carol Ward, who was not involved in the study, told Science News.

"One of the most significant things about this change is it shows how critical it was to establish the ability to stand on one foot at a time, which lets us walk on two feet," Ward said.

Interestingly, this research didn't start as an evolutionary study. Funded by the National Institutes of Health, researchers originally set out to understand how the pelvis forms to improve treatments for hip disorders.

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Scientists Discovered Multiscale Coupling In Plasma

Researchers in Korea have made a massive discovery that could change the way we approach nuclear fusion and our understanding of the universe.

According to Interesting Engineering, scientists at Seoul National University's Department of Nuclear Engineering, led by Hwang Yong-Seok, PhD, have discovered that microscopic magnetic turbulence can cause magnetic reconnection, which causes a cascade effect that reorganizes plasma on a macroscopic scale. In other words, it is the first experimental confirmation of multiscale coupling in plasma.

Plasma is a fourth state of matter separate from solids, liquids, and gases. As the news source detailed, it is a superheated, ionized gas made up of positively charged atomic nuclei and free-moving electrons, and it is an essential part of the process of nuclear fusion. Plasma allows the nuclei to overcome their mutual repulsion and fuse, thereby releasing massive amounts of energy, per Interesting Engineering.

However, one of the big risks involved in fusion is flaring, when energy shoots out from the primary source of plasma and can cause serious damage in a reactor setting.

The experiment showed that microscopic events can set off large-scale structural changes in the plasma, helping researchers understand magnetic reconnection, which is the phenomenon behind things like solar flares, according to the news source. The breakthrough could help to further stabilize fusion reactors and push fusion research forward, as well as reshape our understanding of how stars work.

If researchers are able to scale fusion technology, it can provide significant amounts of affordable energy without the risks of harmful pollution that comes from burning coal, oil, or natural gas, and with far less nuclear waste than one might see with a traditional fission reactor.

The promise of fusion is immense; it's why countries like Great Britain have fast-tracked research on it. China's "portable sun" fusion reactor is making massive strides in fusion technology as well, and researchers may have found a way to contain the massive amounts of energy produced in fusion reactions.

"This outcome was only possible through countless discussions and debates between experts in fusion and theoretical physics, who started from different interests but ultimately arrived at common ground," Park Jong-Yoon, PhD, an assistant professor at the university, said, per Interesting Engineering.

Fusion is the next big energy frontier. Companies and nations alike are pouring money into researching it to find a way to make it viable as a source of massive amounts of clean energy. While the technology is still in its infancy, more and more breakthroughs are pushing that technology closer and closer to viability.

"We hope this research will not only expand the framework of interpretation in plasma physics but also serve as a foundation for the development of new fusion technologies," Yoon Young Dae, a theoretical physicist at the Asia Pacific Center for Theoretical Physics and co-researcher on the project, said, per Interesting Engineering.

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