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Noble gases have a reputation for being unreactive, inert elements, but more than 60 years ago Neil Bartlett demonstrated the first way to bond xenon. He created XePtF6, an orange-yellow solid. Because it's difficult to grow sufficiently large crystals that contain noble gases, some of their structures -- and therefore functions -- remain elusive. Now, researchers have successfully examined tiny crystallites of noble gas compounds. They report structures of multiple xenon compounds.

Between July and November of 2022, NASA's Perseverance rover collected seven samples of sediment from an ancient alluvial fan in Jezero crater. While onboard analysis gave researchers some information about their origins, only detailed analysis on Earth can retrieve evidence of when water flowed on Mars and whether life arose there. Geophysicists had hoped to get these samples back by 2033, but NASA's sample return mission may be delayed beyond that date.

Using nighttime lightdata from NASA, remote sensing, official outage records and census information, a study reveals notable differences in power-restoration rates between urbanized and rural areas and between disadvantaged and more affluent communities after Hurricane Michael in Florida's Panhandle. Block groups with higher proportions of minorities, multi-family housing units, rural locations, and households receiving public assistance experienced slower restoration of power compared to urban and more affluent neighborhoods.

Research revealed how the use of ChatGPT to cheat on general chemistry multiple-choice exams can be detected through specific statistical methods.

Scientists report that rock samples from Mars' Jezero Crater contain minerals that are typically formed in water. While the presence of organic matter is inconclusive, the rocks could be scientists' best chance at finding remnants of ancient Martian life.

Researchers simulated social norms with a supercomputer. Their findings contribute to a deeper understanding of the evolution of social norms and their role in fostering cooperative behavior.

A new implantable sensor could reverse opioid overdoses. The device rapidly releases naloxone when an overdose is detected.

Researchers discover that while artificial intelligence (AI) tools can make accurate diagnoses from textbook-like descriptions of genetic diseases, the tools are significantly less accurate when analyzing summaries written by patients about their own health. These findings demonstrate the need to improve these AI tools before they can be applied in health care settings to help make diagnoses and answer patient questions.

For decades, the oceans have absorbed much of the excess heat caused by greenhouse gases. The latest observations suggest they are reaching their limits, so how worried should we be?

The nearest source of the altar stone at the centre of Stonehenge has finally been identified – and it is at least 750 kilometres away in north-east Scotland

The South American lungfish has a whopping 180 gigabases of DNA in each cell, compared with 6 gigabases in human cells

Yesterday morning, with anxiety-provoking storms threatening, I managed to get an early flight from Capetown up to Hoedspruit, a small (pop. 3,157) town in NE South Africa that is the gateway to many natural wonders, not least among them Kruger National Park, one of the world’s finest game reserves, and the Blyde River Canyon. I’ll be visiting both of them.

My e-friend Rosemary, who kindly helped me make these arrangements independently, lives in Hoedspruit, where she helps run a conservation organization called Global March for Elephants and Rhinos.

Here’s Hoedspruit on a Wikipedia map:

Below: the location of Kruger National Park. Kruger is also surrounded by private game reserves that have no fences, so the wildlife roam free throughout the region. I’ll be staying a few days at one of the private reserves, which is spiffy and takes you for two long game drives per day.  (This is what’s known to visitors as a “safari camp.”) After that I visit Blyde, and after that I’ll be visiting Kruger with a driver and Rosemary, traipsing around the park for four days looking for wildlife.

Kruger is in red:

Htonl, CC BY-SA 3.0, via Wikimedia Commons

But there’s plenty of wildlife to see in the fenced community in Hoedspruit where I’m staying for two nights before heading to the private reserve. Foremost among them is OZY, my beloved common warthog (Phacochoerus africanus)—there’s nothing common about him!—whom I’ve been assisting from afar.  And here he is. He’s big, dominant, and loves to roll around in the dirt and mud. There are many other warthogs of both sexes and all sizes here, but Ozy is the King of them All:

Ozy: “Gaze on my warts, ye mighty, and despair.”

Here I am communing with my beloved pig. Short video by Rosemary Alles:

Another pig grooming a juvenile:

Two ways of looking at a southern red-billed hornbill (Tockus rufirostris):

After a quick look at the pigs, it was time for lunch. There’s a good Indian restaurant in town, and of course I got a mutton bunny chow (spelled “chao” there). This was a spiffy one, very spicy and delicious. If I lived in this country, I’d seek out the best bunny chow, just as I seek out the best BBQ in the US. I wonder if there’s a Guide to the Bunny Chows of South Africa  (I doubt it).

This is the perfect street food, though messy. It originated in the largely Indian city of Durban, South Africa, as a way for workers to have a quick, filling lunch that could be carried to the job (the top was usually plugged with the inside of the bread that had been scooped out). From Wikipedia:

Bunny chows are popular amongst Indians and other ethnic groups in the Durban area. Bunny chows are commonly filled with curries made using traditional recipes from Durban: mutton or lamb curry, chicken curry, trotters and beans curry, and beans curry. Other varieties found across the country using less traditional Durban-Indian food include chips with curry gravy, fried sausage, cheese, eggs and polony. These are all popular fillings; the original bunny chow was vegetarian.

This was an excellent specimen (note the scooped-out bread to the left.) You can barely make out the quarter loaf of white bread which holds the curry.

Rosemary had a fish curry with naan.

On the way back to my room, I came across one of the most beautiful and friendly antelopes I’ve seen: a nyala (Tragelaphus angasii). This is a young male; females don’t have horns. They’re herbivores and live in social groups, though older males (see below) tend to be solitary.  I love the white patches on thee face. This one came right up to me:

Somehow it came across a piece of bread, which it’s chewing below:

A close-up of its beautiful face. Look at those eyes!

A female with nice stripes:

A Crested Francolin (Ortygornis sephaena). It’s a ground-dwelling bird that’s considered a delicacy.

A group of helmeted guineafowl, (Numida meleagris), widespread in sub-Saharan Africa. They have lovely crested turquoise-and-red heads and spotted feathers:

Here’s a better photo from Wikipedia:

Bob, CC BY 3.0, via Wikimedia Commons

A gorgeous female nyala that came right up to me. I fell in love with these antelopes. Look at her eyelashes!

And a big old male, clearly dominant to the others.  They are very sexually dimorphic, not only with horns, but a blackish coat:

The antlers are wicked sharp, and the male threatens by lowering his head and pointing the horns at another bothersome individual. This one had a standoff with Ozy, who did a threat display, but Ozy fled when this male lowered his head.

Me communing with my distant relative, the nyala bull above (photo by Rosemary):

We also saw a pair of shy duiker and, on a night drive through the area, and two groups of majestic impala. And these are just within a fenced residential area that serves itself as a wilelife reserve. It’s not part of Kruger, just a small patch of forest in which people live.

More from today: a drive around the wildlife estate and stuff we saw while communing with Ozy.

Two baby warthogs, brothers, sleep together in the yard:

Ozy, King of All Hogs. We found him by himself this afternoon and thus were able to feed him a large amount of grass pellets without interference from other hogs. Note that he, like all warthogs, dines while resting on his front knees:

Ozy sleeping (two photos). He enjoys his naps in the shade:

My first impala (Aepyceros melampus):  a young male at one of the waterholes (the estate keeps several of these ponds in good condition):

. . . and my first zebra, a Burchell’s zebra (Equus quagga burchellii):

Another antelope new to me: a female waterbuck (Kobus ellipsiprymnus). She was also drinking at the water hole.

Rear view. Waterbucks are identifiable by the white ring around their butt, reminiscent of a toilet seat (thus making the name easy to remember):

A giraffe zebra footprint near the waterhole (see comments.)

The estate puts out large amounts of hay and other greenery for the animals, as it has been a dry year and forage is scarce. Here some warthogs chowing down:

And finally, resting while observing Ozy an hour ago, we heard a crunching in the bushes and Rosemary excitedly pointed out that there was a giraffe in the back yard, about twenty meters away.  It was HUGE, towering above the treetops.  I crept out to photograph it but it was easily spooked, so here’s a photo. I’ll get more in the game parks:

There is much more wildlife to come. . .when I go to the Manyalete Game Reserve tomorrow.

Lab-reared German cockroaches are susceptible to consumer insecticide sprays, allowing manufacturers to pass US regulatory tests, but insects taken from real-world infestations are able to shrug off the products

The Hyde Park Herald reports that the University of Chicago, which previously withheld diplomas from eleven students for participating in our encampment, has given them back. This means that although the students were warned that being in the encampment was illegal, they, along with all the encampers, suffered no penalty for breaking University rules. The encampment was the fifth violation of University regulations by protestors that went unpunished. 

This seems to be the general trend in most universities. Now that the tumultuous year has ended, universities are experiencing a wave of forgiveness—a wave that will come back to haunt them this fall.  As far as I can see, no students were disciplined by the city of Chicago or by the University despite multiple and clear violations of both the law and University regulations. (This includes the Ciry of Chicago dropping trespassing charges against 24 students and two faculty who were arrested for violating University regulations for sit-ins in University buildings.}

In April I recounted the sad story of how remiss Chicago has been in punishing pro-Palestinian protestors who violated University regulations. As far as I know, the only puniahment levied the entire year, as described above, is a simple warning to the Students for Justice in Palestine that they had better desist from illegally disrupting and deplatforming opponents:

Official Warning – An official warning indicates the organization has violated University policies or regulations and will be placed on file. If the organization engages in any additional misconduct, the appropriate disciplinary body will be informed of this official warning, the related circumstances, and must consider the warning in determining further sanctions.

No that’s really going to deter illegal protests, isn’t it? As noted below, the protestors are proclaiming they’ll return this fall resuming their disruptions. Why wouldn’t they, when they know there’s no penalty for doing so?

Click below to read the Hyde Park Herald’s account of the restoration of diplomas:

An excerpt:

The last of the disciplinary cases against 10 University of Chicago students for their involvement in the pro-Palestine campus encampment was dismissed this week, student activists announced Monday.

Among those facing disciplinary cases were four graduating seniors and a graduate student, whose diplomas were withheld pending U. of C. investigations into potentially “disruptive conduct” at the encampment, which was erected on the Main Quadrangle in early May to protest the institution’s investments in weapons manufacturers arming Israel in its war on Gaza. Most of these cases – including those for another six undergraduate students – were dismissed last month, and the final one, the case of the graduate student, was dismissed and the degree conferred on August 12.

Youseff Hasweh, one of the four graduating seniors, said Monday that this final dismissal after months of pressure from students, alumni and faculty “tells UChicago that we’re never going to back down.”

“Students are even more fired up to join the movement and to let UChicago know that this wasn’t okay, that everything they’ve done this past year,” he said.

In addition to tearing down the encampment, U. of C. police officers arrested more than two dozen students and two faculty members during a November sit-in demanding divestment in the Israel-Hamas war and that the U. of C. cut ties with Israel altogether. U. of C. officers also arrested one person during a commencement walkout this June.

As I said, the City dropped all charges against the two dozen students and two faculty members.  I don’t know why this happened, but surely some punishment should be meted out by the University (as did Vanderbilt–see link above) for illegal sit ins, even if it’s only a note on the student’s transcript.

University regulations that aren’t enforced are regulations that are toothless and can be violated with impunity. I predict that the whole brouhaha will begin again this fall, as there’s simply no way the conflict between Israel and Hamas will be resolved by then. I’ll add this: those calling for a cease-fire in Gaza, including candidate Kamala Harris, realize that, by leaving Hamas in power, such a move will ensure that Israel will be forever subject to Palestinian terrorism—until the Jewish state is destroyed by an Iranian nuke.

As for my University, the paper says this:

Administrators for the U. of C. could not be reached for comment regarding the alleged photos as of press time.

That, of course, means they have no comment.

Get ready for fall—it will be a bumpy ride.

Most rational people, I believe, are opposed to academic boycotts: those political movements that try to prohibit the exchange of scholars or academic information with countries deemed unacceptable on ideological grounds.  These boycotts not only stem the free flow of information among countries that is the lifeblood of academia—especially of science—but also punish those who can contribute to this knowledge even though those people rarely have any influence with their government. Indeed, as in the case of Israel (surely the reason for the dropping of the boycott prohibition), many scholars are opposed to the government’s policies.

Inside Higher Ed (click below to read) reports on the ending of boycotts by the influential organization the American Association of University Professors, an organization that should know better. Click to read:

The report:

The American Association of University Professors (AAUP) has dropped its nearly 20-year-old categorical opposition to academic boycotts, in which scholars and scholarly groups refuse to work or associate with targeted universities. The reversal, just like the earlier statement, comes amid war between Israelis and Palestinians.

In 2005, near the end of the second intifada, a Palestinian uprising, the AAUP denounced such boycotts; the following year, it said they “strike directly at the free exchange of ideas.” That statement has now been replaced by one saying boycotts “can be considered legitimate tactical responses to conditions that are fundamentally incompatible with the mission of higher education.” The new statement doesn’t mention Israel, Palestine or other current events—but the timing isn’t coincidental.

The new position says that “when faculty members choose to support academic boycotts, they can legitimately seek to protect and advance the academic freedom and fundamental rights of colleagues and students who are living and working under circumstances that violate that freedom and one or more of those rights.”

Note that the AAUP never prevented individual professors from deciding not to cooperate with faculty from other countries. Rather, they used to aver that systematic academic boycotts were not approved by the organization.   Now that’s all changed: systematic boycotts are okay.  But o its credit, the University of Chicago, under the late President Bob Zimmer, opposed academic boycotts in a 2013 statement, and our opposition remains intact:

“The University of Chicago has from its founding held as its highest value the free and open pursuit of inquiry. Faculty and students must be free to pursue their research and education around the world and to form collaborations both inside and outside of the academy, encouraging engagement with the widest spectrum of views. For this reason, we oppose boycotts of academic institutions or scholars in any region of the world, and oppose recent actions by academic societies to boycott Israeli institutions.”

That’s the way a gutsy university handles such matters. Sadly, the AAUP punted (read its statement at the link).  The AAUP’s statement was also heartily approved by a group participating in the BDS (Boycott, Divestment, and Sanctions) movement, an antisemitic initiative whose goal is to eliminate Israel as a Jewish state. Click to read:

An excerpt:

The Palestinian Campaign for the Academic and Cultural Boycott of Israel (PACBI) commends the American Association of University Professors (AAUP) for dropping its biased, unethical policy opposing academic boycotts, which was primarily aimed at shielding Israeli universities from accountability for their egregious human rights violations.

PACBI salutes all those who worked tirelessly to push the AAUP to change its position, as well as the conscientious academics, students, and progressive academic associations that have for years advocated for ending US academic institutional complicity with Israel’s 76-year-old regime of settler-colonialism and apartheid and, in the process, challenging AAUP’s hypocrisy. Without their persistent protests and intellectual challenges, without the student-led encampments reenergizing campus campaigns for academic boycott and divestment in response to Israel’s Gaza genocide, the AAUP would not have reversed its ethically and logically untenable policy.

. . . Scrapping its unethical policy, which was, arguably by design, used to suppress academic freedom of many calling for BDS against Israel, the new AAUP position recognizes the obvious. It finally accepts that academic boycotts targeting institutions deeply implicated in grave human rights violations can be legitimate “to protect and advance the academic freedom and fundamental rights of colleagues and students who are living and working under circumstances that violate that freedom and one or more of those rights.”

The PCBI’s only beef is that the AAUP didn’t go far enough and denounce Israel specifically:

. . . AAUP’s failure to now endorse the Palestinian call to boycott complicit Israeli universities, which it finally recognizes as legitimate, even as Israel’s violence culminates in the world’s first livestreamed genocide, which has included scholasticide, domicide and engineered famine, is a profound ethical failure to make amends for the harm the AAUP’s racist policy has done to Palestinians and to our struggle for emancipation from colonial subjugation.

It’s clear from all this, as Inside Higher Ed notes, that the AAUP’s change of policy was to legitimize academic boycotts of Israel.  The coincidence of timing is too strong to imply otherwise.

Invasive cane toads have decimated native freshwater crocodile populations in northern Australia, as the predators don't know they should avoid the toxic amphibians

We have often stated here on SBM that vaccine programs are the most effective, and most cost-effective, public health measures in human history. They save lives, prevent disease, and save money. These benefits are all well researched and copiously documented. A recent CDC study adds to the literature on the benefits of vaccines and vaccine programs, focusing on the effects of the […]

The post Vaccines for Children Program Works first appeared on Science-Based Medicine.

This month we’re in an Italian cave with a bellissimo fossil. If I was giving a live talk, at this point I would ask for a show of hands: have you heard of Altamura Man? Since it was new to me, I’m going to guess that most of you will be unfamiliar with it. Which is peculiar, because it’s an astonishing specimen. To find Altamura Man you would need to travel to Puglia (also known as Apulia) in southern Italy: if you think of Italy as looking like a boot, Puglia is the heel. Much of it is karst, a landscape where water draining through bedrock creates sinkholes, springs and caves – including Lamalunga cave near the town of Altamura. In early October 1993, local researchers were exploring Lamalunga cave when they stumbled upon human bones, including a skull. They alerted anthropologists including Eligio Vacca and Vittorio Pesce Delfino at the nearby University of Bari Aldo Moro, who arrived the following evening. It was immediately obvious that the skeleton was in excellent condition. As the researchers wrote later that year, it was “one of the most extraordinary paleontological discoveries in Italy and in Europe”. However, it was also obvious that the skeleton was going to be hard to study. Not only is the cave difficult to operate in, but, as the team wrote the following year, “All the bones are partly covered with, or embedded in, calcareous concretion while others are visible but lined with a calcareous shell of varying thickness.” Bluntly, the skeleton is embedded in rock. It’s 31 years later and the skeleton is still there, still entombed. Thanks to some ingenious researchers, we know more about it than we did in 1993 – but its secrets remain largely untapped because of its fragility and inaccessibility. That’s vexing, but on the plus side, nobody has done anything egregiously stupid. As a result, Altamura Man remains intact. Altamura Man The central problem for anyone wanting to study Altamura Man is that it’s embedded in a speleothem. To answer your immediate question, a speleothem is any rock formation that gradually forms in a cave, often as a result of water flowing through. Stalactites are an example where water dripping from the ceiling leaves behind tiny particles of minerals, which accumulate over the years into dangling pillars. In the case of Altamura Man, the skeleton is smothered in cave popcorn. These speleothems are small nodules of calcite sometimes known as “coralloids”, because they look like the corals that make up a reef. You might think researchers could carefully remove the cave popcorn from the skeleton, but there’s another complication. The bones are not fully fossilised, probably due to the conditions in the cave: the temperature varies a lot and fresh air often blows in. As a result, the bones are fragile. So we have a perfect storm: a cave that’s difficult to get into containing a skeleton that’s both fragile and trapped in hard rock. The solution lies in virtual palaeoanthropology. Over the past decade, researchers have used digital imaging equipment and other advanced technology to study Altamura Man without physically interfering with it. To find out more, I emailed with Costantino Buzi at the Catalan Institute of Human Paleoecology and Social Evolution in Tarragona, Spain, the lead author of the latest study of Altamura Man. Buzi describes the skeleton as “like Godot” – the titular character of Samuel Beckett’s play Waiting for Godot, who famously never shows up – as it’s “often in the conversation but no one can actually see it”. Despite the difficulties in studying Altamura Man, some tantalising snippets have emerged. A 2004 study by Vacca and Pesce Delfino used miniature video cameras to photograph the bones, concluding that the skeleton belonged to an adult male. Five years later, researchers removed a single bone from a small chamber behind the main skeleton, using a procedure inspired by keyhole surgery. The bone, a scapula or shoulder blade, yielded a lot of information. In a 2015 analysis, the researchers dated the specimen to between 172,000 and 130,000 years ago. The shape of the scapula suggests Altamura Man was a Neanderthal – as does the DNA the team extracted. The following year, the palaeoartist brothers Alfons and Adrie Kennis produced a detailed reconstruction of Altamura Man’s face. CAN WE GET THE IMAGE? https://www.kenniskennis.com/altamura-man/ More recently, Buzi and his colleagues have used laser scanning and 3D analysis of photos to study the skeleton. In 2023, they produced a virtual reconstruction of Altamura Man’s cranium. This painted an intriguing picture: although clearly Neanderthal, his skull had some features that are not seen in most Neanderthals, but are found in older specimens from Atapuerca in northern Spain that are thought to be the ancestors of Neanderthals. It may be that the Neanderthals living in southern Italy were isolated from other populations, and as a result retained some older features that Neanderthals elsewhere lost.     Extracting the skeleton This is all gleaned from one shoulder blade and scans of the skull. Imagine what we could learn if we got our hands on the whole skeleton. Buzi says research into Altamura Man is stuck in first gear. “There have been only limited observations with traditional methods, and the works published struggled in getting attention,” he says. “For this reason, Altamura has been quite overlooked.” He wants to work towards a way to safely remove the skeleton. “In my opinion, extraction would be the best way to both study and keep the skeleton in the ideal conditions for its preservation,” he says. This presents a twofold problem: getting the skeleton out, and preserving it. The second problem is arguably easier, says Buzi, because we already have ways to preserve delicate specimens like Ötzi the iceman, who is kept at the South Tyrol Museum of Archaeology in Bolzano, Italy. “It is more difficult to envision the protocols for a safe removal,” says Buzi, but he thinks it’s achievable with “sufficient technical expertise” and funding. Arguably, there has been “an excess of caution” around Altamura Man, says Buzi, but he says that is understandable because “the context is so unique”. Certainly, it’s preferable to the alternative. On the same day Buzi’s latest study was published, the journal it appeared in also released a study of the Juukan 2 rock shelter in Western Australia. Researchers led by Michael Slack at Scarp Archaeology found that Aboriginal Australians had repeatedly visited the site over the past 47,000 years. These people processed bush potatoes as food and left behind a variety of stone artefacts. A piece of braided hair revealed that the ancient visitors were closely related to the Puutu Kunti Kurrama and Pinikura peoples that live in the area today. I mention this because Juukan 2 is not there anymore. It was blown up in 2020 by the Rio Tinto corporation, as part of a mining project. This was, I want to emphasise, permitted under Australian law. It was legal to destroy 47,000 years of Aboriginal Australian heritage. A 2023 paper found a host of flaws in the ways Australian heritage law operates. For instance, there was no way for the traditional owners of Juukan 2 to appeal the decision to allow the destruction, even when the archaeologists found new information about its significance. The deck was stacked in favour of the mining company and against Aboriginal Australian cultural heritage. The contrast with the fate of Altamura Man could hardly be more stark. Some of this is sheer luck – Buzi points out that the area around Lamalunga cave doesn’t contain any valuable mineral resources. Furthermore, the cave is in the pre-existing Alta Murgia National Park, so Altamura Man was already protected before anyone knew he existed. “Luckily, Italy has an old history of protection and management of natural and cultural heritage,” says Buzi. Like Buzi, I would like to see more work done on Altamura Man and Lamalunga cave. If it can be done safely, I would love to see the skeleton extracted from its rocky tomb so its secrets can be plumbed. He has sat in the shadows long enough. But I’m also relieved that this extraordinary specimen has been treated with such care over the past three decades.

Meanwhile, in Dobrzyn, Hili is suspicious:

Hili: This leaf looks like a small animal. A: But it is a withered leaf.

 

Hili: Ten liśc wygląda jak małe zwierzątko.
Ja: Ale to jest zeschnięty liść.

Primordial black holes formed during the earliest stages of the evolution of the universe. Their immense gravity may be playing havoc in stellar systems. They can transfer energy into wide binary systems disrupting their orbits. Like celestial bullies their disruption might lead to extreme outcomes though like the ejection of a star, only to be replaced by the black hole itself! A new paper studies the interactions of systems like these and looks at ways we might be able to detect them. 

It’s been theorised that during the earliest moments after the Big Bang, black holes may have formed. They are not the result of supermassive stars having collapsed but instead have formed out of fluctuations in the density of matter. Regions with great density would simply collapse under their own gravitational influence forming what have been dubbed primordial black holes (PBHs). They are thought to vary in size from subatomic to some that are more massive than the Sun. 

Whether primordial black holes really do account for dark matter in the universe is still up for debate. Among the astronomical community it is generally accepted that they cannot account for all dark matter but probably account for up to 10% of dark matter in the planetary mass range (10-7 to 10-3 solar masses.) Whether this is PBHs account for any of the dark matter in the universe requires further analysis.

Researchers are making progress mapping dark matter, but they don’t know what it is. This is a 3D density map of dark matter in the local universe, with the Milky Way marked by an X. Dots are galaxies, and the arrows indicate the directions of motion derived from the reconstructed gravitational potential of dark matter. Image Credit: Hong et al., doi: 10.3847/1538-4357/abf040.

If large scale is taken into account then PBHs are indistinguishable from a background of particle dark matter. At small scales the distribution of PBHs is not uniform across the universe relative to the background of particle dark matter and so we are forced to look for a unique and new theory. Observing PBHs to understand how close the model is to reality is difficult but it is possible to study their interactions with star systems. 

In a paper published by Badal Bhalla from the University of Oklahoma and a team of astronomers they explore the way PBHs can lose energy when interacting with stellar binary systems. These interactions can result in any one of 5 possible outcomes; 

1: Hardening – the two bound objects lose energy to the third free object causing their separation to decrease;

2: Softening – the free body transfers energy to the bound system causing their separation to increase but remain bound;

3: Disruption – the free body transfers enough energy to the bound system that the components become unbound and all objects continue unbound;

4: Capture – the bound objects capture the free object;

5: Exchange – the free object transfers enough energy to unbind one of the bound objects and in doing so loses sufficient energy to become bound to the remaining one. 

Previous studies have explored softening and disruption in PBH and binary interactions as has the capture model. The team propose that hardening is also unlikely and so explore the possibility of the exchange model. They find that the exchange model should lead to a population of PBH binaries in the Milky Way and indeed some observations hint that they may exist. The team also suggest it may be possible to detect PBHs in binary systems with a sub-solar mass PBH by the properties of the system. Observations are now needed to validate the model. The discovery of black holes in a binary system may be detectable and go some way to support the findings.

Source : Dancing with invisible partners: Three-body exchanges with primordial black holes

The post Primordial Black Holes Could Kick Out Stars and Replace Them. appeared first on Universe Today.