Saturday, December 18, 2021

Tough mask mandates linked to fewer COVID-19 deaths, global study finds

By HealthDay News

A global study of 44 countries found those with mask mandates to prevent COVID-19 spread saw a slower increase in deaths from the virus than countries without mandates. File Photo by John Angelillo/UPI | License Photo

Mask mandates work, according to a large international study that linked the laws with a reduction in COVID-19 deaths.

The study included 44 countries with a combined population of nearly 1 billion. Over time, researchers found, the increase in COVID-related deaths was significantly slower in countries with mask laws than in countries without them.

"While several studies before this have looked at the impact of masks on COVID-19 cases, fewer studies were focused on whether mask wearing may reduce COVID-19 deaths, and no study had looked at the data across multiple countries," said lead investigator Dr. Sahar Motallebi of the Department of Social Medicine and Global Health at Lund University in Malmo, Sweden.

"The large sample of culturally diverse countries in this retrospective study covers a large population, giving us more evidence towards the lifesaving potential of masks during the COVID-19 pandemic," she said.

The researchers used countries in the top 50 of a United Nations' development index, which measures life expectancy, education and standard of living.

They excluded six of those countries -- four in the Southern Hemisphere -- because of potential concerns about seasonality, as well as the United States and Canada, where health policy exists at the state or provincial level rather than nationally.

Of the countries studied, 27 had face mask rules and 17 did not.

Between Feb. 15 and May 31, 2020, the countries recorded a combined 2.2 million deaths. They included 1.25 million in countries without mask mandates and nearly 914,000 in countries with mandates.

On average, countries where masks were required had an average COVID-19 death rate of 48.40 per million -- compared to 288.54 per million in countries without mandates.

On average, face mask countries also had a significantly lower daily increase in deaths compared to countries without mandates, even though those countries with no mandates had started with lower COVID-19 death rates, the study found. It was published recently in the American Journal of Preventive Medicine.

"To reach its full potential of saving lives, public health research should be practical and pragmatic," Motallebi said in a journal news release.

"Our primary objective was to assess lessons learned from the pandemic in order to better prepare for future potential epidemics of airborne diseases, before pharmaceutical interventions are available," Motallebi said.

With delays in vaccinations persisting around the world, masks remain an important tool for prevention, the researchers said.

That's even true after full vaccination of a population, they added. Vaccines may reduce death rates across COVID-19 variants, but not necessarily case levels, and face masks protect against rises in both.

"We don't have to choose between these two good policies of vaccination and face masks or substitute one for the other when we can and must do both in parallel," Motallebi said.

More information

The U.S. Centers for Disease Control and Prevention has more on masks.

Copyright © 2021 HealthDay. All rights reserved.



FACT FOCUS: Masks help curb spread of COVID-19 on planes
By JOSH KELETY and ANGELO FICHERA

FILE - From left, American Airlines CEO Doug Parker, Southwest Airlines CEO Gary Kelly and United Airlines CEO Scott Kirby testify before the Senate Commerce, Science, and Transportation in the Russell Senate Office Building on Capitol Hill on Wednesday, Dec. 15, 2021 in Washington. The air transportation executives testified about the current state of the U.S. airline industry during the oversight hearing. 
(Tom Brenner/The Washington Post via AP, Pool, File)

The CEO of a major airline suggested during a congressional hearing this week that face masks provide little value on planes — a claim that was quickly amplified online.

Citing high-quality filtration systems aboard planes, Southwest Airlines CEO Gary Kelly stated that “masks don’t add much, if anything, in the air cabin environment.”

But experts strongly disagree. Here are the facts.

CLAIM: Mask-wearing on planes is unnecessary because advanced air filtration systems sufficiently reduce the risk of COVID-19 transmission.

THE FACTS: While it’s true that the common air filtration and distribution systems used in modern aircraft are highly effective at reducing the risk of COVID-19 transmission among passengers, masks add another layer of protection for air travelers, experts told The Associated Press.

Kelly’s comments came during a Wednesday hearing before the Senate Committee on Commerce, Science, and Transportation. After returning home from the hearing, Kelly tested positive for COVID-19, a Southwest spokesperson confirmed to the AP on Friday.

Kelly made his comment about masks in response to a question from Sen. Roger Wicker, a Republican representing Mississippi, who asked Kelly and another airline CEO if they thought air travel without masks could ever resume.

Kelly said that “99.97% of airborne pathogens are captured” by high efficiency particulate air filters, or HEPA filters, on airplanes, before suggesting that masks are unnecessary during air travel.

“Yeah, I think the case is very strong that masks don’t add much, if anything, in the air cabin environment,” Kelly said. “It’s very safe, and very high quality compared to any other indoor setting.”

American Airlines CEO Doug Parker appeared to agree, saying, “I concur, the aircraft is the safest place you can be.” He noted that all of his company’s aircraft have the same HEPA filters.

The comments were quickly picked up by news outlets and blogs, and spread on social media.

“The CEOs of Southwest and American Airlines both said today in Senate testimony that masks on planes serve no purpose,” said one tweet shared more than 3,500 times.

Both CEOs clarified their comments to say they support the current federal policy requiring masks on flights. On Friday, after returning home from the hearing, Kelly tested positive for COVID-19, Southwest spokesperson confirmed to the AP.

Southwest Airlines provided the AP with a message that Kelly sent to employees in which the CEO apologized for any “confusion” stemming from the hearing, saying Southwest continued to “support the current federal mask mandate at airports and on airplanes.”

Kelly said the airline adopted a mask requirement aboard its flights in May 2020, before the federal government required it, and that employees and customers “have felt it has been an important layer of protection, and I certainly agree with that.” He said the airline would “continue to rely on the advice of our medical experts regarding the necessity of masks.”

Parker later said on social media he “agreed with my fellow CEOs that being onboard a plane is proven to be a safe and healthy indoor environment.” But he said that his statement at the hearing was unclear and that he supported the federal mask mandate “Full stop.”

While HEPA filtration systems are highly effective at reducing the transmission of viruses, they do not completely eliminate risk aboard flights, according to Linsey Marr, an aerosol scientist at Virginia Tech.

“The issue is that they only work on the air as it passes through the filter,” she said in an email. “If you are sitting near someone who is releasing lots of viruses into the air, you could end up inhaling them before they have had a chance to pass through the filtration system.”

Marr said it takes a few minutes for air to completely pass through the filtration system. She said requiring everyone to wear a mask reduces the amount of virus an infected individual can release into the air, and helps reduce the amount of virus someone wearing a mask might breathe in.

Leonard J. Marcus, director of the Aviation Public Health Initiative at Harvard University, agreed.

“Yes, the ventilation system on airplanes are incredible. They’re comparable with what you might find in an operating room,” he said. But “it is the multiple layers, it’s not one thing alone.”

Marcus said that masks are particularly important when people are boarding and exiting airplanes or moving around the aircraft cabin. Rising COVID-19 cases and the threat posed by the omicron variant also make mask-wearing on planes essential, he said.

“People are moving about, people are turning to speak to someone, people are sometimes lifting up their mask to drink,” said Marcus, whose initiative published a report in October that supported a “layered” approach to lowering risk. “If everyone is wearing the mask, there’s going to be much less transmission of the disease.”

The Association of Flight Attendants-CWA, AFL-CIO, a union representing some 50,000 flight attendants, has also called masks a “key component” of safety on flights, noting that not all planes have HEPA filtration systems.

___

Kelety reported from Phoenix; Fichera from Philadelphia.



Nonbelievers across Africa risk freedom and family support
By KWASI GYAMFI ASIEDU

1 of 5
Amina Ahmed, the wife of Muhammad Mubarak Bala, an atheist who has been detained since April 2020, is photograph in her home in Abuja, Nigeria, Sunday, Nov. 21, 2021. Bala was held incommunicado in police custody for so long — eight months — that Ahmed was sure he was dead. “I couldn’t eat. I couldn’t sleep. The emotional torture was too much for me,” she says. (AP Photo/Sunday Alamba)


Muhammad Mubarak Bala was held incommunicado in police custody for so long — eight months — that his wife was sure he was dead.

“I couldn’t eat. I couldn’t sleep. The emotional torture was too much for me,” Amina Ahmed told The Associated Press from her home in Abuja, the capital of Nigeria.

More than a year passed before Bala, an ex-Muslim and president of the Humanist Association of Nigeria, would be charged. Bala is an outspoken atheist in a deeply religious country. His alleged crime: Posting blasphemous statements online.

Bala’s lengthy detention and its traumatic effect on his young family illustrate the risks of being openly faithless in African countries where religious belief pervades social life and challenging such norms is taboo.

“It is generally accepted that to be African is to be religious,” said David Ngong, a Cameroon-born professor of religion who researches African theology and culture at Stillman College in Alabama. “It requires a lot of courage” to opt out.

Atheists are among a growing global group who have no religious affiliation. Also known as “nones,” they include agnostics and those who don’t profess any religion. By 2050, the Pew Research Center estimates, there could be 1.3 billion nones worldwide — about the size of the global Roman Catholic population today.

According to the United States Commission on International Religious Freedom, 25 African nations — nearly half the continent’s sovereign states — have statutes outlawing blasphemy, or offensive behavior against a deity or idea considered sacred.

Punishment can be severe. In Mauritania, for example, Muslims convicted of ridiculing or insulting God face a mandatory death sentence and those renouncing Islam have a three-day window to repent or face capital punishment.

The stiffest penalty in Nigeria’s secular courts is a two-year prison sentence; in the country’s Islamic courts, active in the majority Muslim north, it is death. Shariah law doesn’t apply to non-Muslims without their consent.

Bala grew up Muslim but came out as an atheist in 2014. His family soon checked him into a psychiatric hospital, according to James Ibor, his attorney. Reemerging into public life, he became president of the Humanist Association of Nigeria two years ago and championed the nonreligious on social media.

Prosecutors in the northern state of Kano cited posts on Bala’s popular Facebook account as evidence for charging him in June 2021 in secular court. He faces 10 charges, including alleged insults to Prophet Muhammad and “insulting the religion of Islam, its followers in Kano State, calculated to cause a breach of public peace,” according to court documents provided to AP by Bala’s legal team.

“Muslims are about to start fasting to the God that refused to eradicate their poverty despite the fact that they prayed 17 times every day,” reads one of the posts cited in the complaint. “How I wish Allah exist (sic).”

Denied access to health care and kept in solitary confinement, Bala has been forced “to worship the Islamic way,” according to Ibor, and faces a possible sentence of two years. Prosecutors allege Bala confessed to the charges while in custody; Ibor said Bala had no attorney present at the time.

“Mubarak has been honest with his statements,” Ibor said. “We don’t consider Mubarak’s posts as inflammatory, as offensive or illegal.”

Kano’s attorney general, Musa Lawan, told the AP his agency couldn’t be blamed for Bala’s lengthy detention because it didn’t take over prosecution of his case until a year after his arrest.

Nigeria’s patchwork criminal justice and legal systems are notorious for lengthy pre-conviction detentions. Only 28% of prison inmates have been tried and convicted of a crime, according to the Nigerian Correctional Service.

Bala has already spent almost two-years in pre-trial detention - the maximum secular court sentence for blasphemy charges. Still, Lawan told the AP, “we will look for maximum sentence.”

The faithless often keep a low profile even in African countries where laws against blasphemy and renouncing religion are not on the books or are rarely enforced, such as Malawi in southeast Africa.

“Most of them, they hold their views in hiding simply because they are afraid of social consequences” such as losing jobs or financial support from their parents, said Wonderful Mkhutche, president of the support group Humanists Malawi.

A former church deacon, Mkhutche began to question his Christian faith while pursuing a theology and religious studies degree. He continued to attend worship services for two years to keep up appearances, but stopped in 2013.

Earlier this year he self-published a book on humanism and politics in Malawi, arguing for the abandonment of government-sanctioned religious acts such as national prayers for good rains to help farmers. While his book attracted media attention, he said he is now forced to distribute it himself because many stores won’t stock it.

Leo Igwe, who founded the Humanist Association of Nigeria and researches religion at the University of Cape Town, South Africa, agreed that nones pretending to be believers is common.

“Life is miserable,” Igwe said. “They have to live always looking over their shoulders, and they are forced to live in a very dishonest way.”

To counter the social isolation, Africa’s nones have begun connecting on social media and building support communities, with active online humanist groups in Ghana, Liberia, South Africa, Uganda and Zambia, among others.

In Nairobi, a 21-year-old ex-Muslim woman found the Atheists in Kenya Society on Twitter. The government suspended the group’s legal registration in 2016, saying its activities “generated great public concern which is prejudicial and incompatible with the peace, stability and good order of the republic.” A judge reversed the suspension in 2018.

The woman, who spoke on condition she not be named due to fears she could be targeted for harassment, said the group, which meets online and in-person, provides her with a safe space to speak and feel less lonely.

But she remains closeted, fearful of violence from her conservative Kenyan-Somali family, trapped in what she called a “double life” where she maintains a semblance of adherence to the faith at home while removing her hijab when she goes to school.

“If I pray, I am faking it,” the woman said.

In Nigeria, where Bala remains behind bars, there was widespread condemnation last year led by UNICEF and the head of the Auschwitz museum, after an Islamic court sentenced a 13-year-old boy to 10 years in prison for “disparaging language on Allah.” The sentence was eventually overturned by the secular court.

After 600 days in detention, Ahmed hopes her husband of two years can come home soon, but thinks Nigeria could be a dangerous place to build their lives. She worries about the emotional effect on their son, who was born six weeks before Bala’s arrest.

“He has a lovely son that barely knows him,” she said during a recent visit to Bala’s prison. “My neighbors are home, they are with their husbands and their children. I feel like, ‘Why is mine not like them?’”

___

AP journalist Chinedu Asadu in Lagos, Nigeria, contributed to this report.

___

Associated Press religion coverage receives support from the Lilly Endowment through The Conversation U.S. The AP is solely responsible for this content.
The Culture Corner: Sly and the Family Stone's 'There's A Riot Goin' On' turns 50


Sly and the Family Stone circa 1971.Michael Ochs Archives/Getty Images

Playlist
Sly Stone, "Walking In Jesus Name"
Sly and the Family Stone, "Luv N' Haight"
Sly and the Family Stone, "Just Like a Baby"
Childish Gambino, "Baby Boy"
Sly and the Family Stone, "Family Affair"
There's a Riot Goin' On - YouTube

This month, Sly and the Family Stone's 1971 album There's A Riot Goin' On turns 50. The record was a commercial success, but it was also a big shift for the band – and, it was kind of weird. World Cafe correspondent John Morrison dives into this innovative album, exploring its songs and the unique way it combines genres, from blues to psychedelic rock. And he takes a guess at what Sly might be talking about in "Family Affair." Listen in the player above.
NPR
Episode Playlist
World Cafe 11/29/21

New Zappa book to be published in New Year

Two decades of conversations between Frank Zappa and Zappa expert Co De Kloet to be published in February


(Image credit: Ed Caraeff - Getty)

Two decades of conversations between Frank Zappa and Dutch musician, composer, producer, and radio personality and Zappa expert Co De Kloet are to be published in a brand new book, Frank And Co: Conversations With Frank Zappa 1977-1993, which is to be published by Jawbone Press on February 25.

De Kloet and Frank Zappa were friends for many years, and during that time he recorded nearly every conversation the two men had. They also corresponded frequently—about life, music, politics, and much more besides—and the new book offers a unique chronicle of their friendship, from their first meeting in 1977 to Zappa’s death in 1993.

“This book is somewhat analogous to a documentary movie for your brain,"says Zappa's son Dweezil, who has penned the foreword for the new book. "Whether my father is expressing his views of religion and politics as well his opinions of their ill-advised enmeshment or his bleak opinion about some of his former employees playing his music in public, he gives it to you straight. Well, he gave it straight to Co, and now he’s giving it to you!”

Frank And Co: Conversations With Frank Zappa 1977-1993 also includes Co’s favourite memories of Frank, as well as interviews Zappa alumni Flo & Eddie, Jimmy Carl Black, Pamela Zarubica, and Don van Vliet (aka Captain Beefheart).

(Image credit: Jawbone Press)
Today's best Frank & Co: Conversations with Frank Zappa deals

What is quantum biology? Johnjoe McFadden

Johnjoe McFadden discusses how quantum mechanics principles manifest in the natural world. 00:00 What is quantum biology? 02:16 How revolutionary is it for the life sciences? 02:56 What is quantum/proto tunnelling in DNA? 04:59 How do quantum mechanics principles apply in quantum biology? 06:24 Does quantum biology better explain consciousness? 09:27 What is Occam's razor principle? 13:12 Why is simplicity a good guide? For more talks on quantum biology, quantum mechanics, consciousness and all things science visit at https://iai.tv/debates-and-talks?utm_... Quantum mechanics has long influenced and unalterably changed the world of physics. Yet, biology has taken some time to catch-up. How might our exploration of the quantum influence our understanding of life, consciousness and the natural world? #QuantumBiology #JohnjoeMcFadden #QuantumMechanics Johnjoe McFadden is a scientist, professor and writer at the University of Surrey. He has written many popular science books including Life on the Edge: The Coming of Age of Quantum Biology and Quantum Evolution. To discover more talks, debates, interviews and academies with the world's leading speakers visit https://iai.tv/subscribe?utm_source=Y... The Institute of Art and Ideas features videos and articles from cutting edge thinkers discussing the ideas that are shaping the world, from metaphysics to string theory, technology to democracy, aesthetics to genetics. Subscribe today! For debates and talks: https://iai.tv For articles: https://iai.tv/articles For courses: https://iai.tv/iai-academy/courses

Parker Solar Probe: For the First Time in History, a Spacecraft Has Touched the Sun


NASA’s Parker Solar Probe has now done what no spacecraft has done before—it has officially touched the Sun. Launched in 2018 to study the Sun’s biggest mysteries, the spacecraft has now grazed the edge of the solar atmosphere and gathered new close-up observations of our star. This is allowing us to see the Sun as never before—including the findings in two new papers, which were presented at AGU, that are helping scientists answer fundamental questions about the Sun. Credit: NASA GSFC/CIL/Brian Monroe

For the first time in history, a spacecraft has touched the Sun. NASA’s Parker Solar Probe has now flown through the Sun’s upper atmosphere – the corona – and sampled particles and magnetic fields there.

The new milestone marks one major step for Parker Solar Probe and one giant leap for solar science. Just as landing on the Moon allowed scientists to understand how it was formed, touching the very stuff the Sun is made of will help scientists uncover critical information about our closest star and its influence on the solar system.

On April 28, 2021, during its eighth flyby of the Sun, Parker Solar Probe encountered the specific magnetic and particle conditions at 18.8 solar radii (8.127 million miles) above the solar surface that told scientists it had crossed the Alfvén critical surface for the first time and finally entered the solar atmosphere.


Parker Solar Probe has now “touched the Sun”, passing through the Sun’s outer atmosphere, the corona for the first time in April 2021. The boundary that marks the edge of the corona is the Alfvén critical surface. Inside that surface (circle at left), plasma is connected to the Sun by waves that travel back and forth to the surface. Beyond it (circle at right), the Sun’s magnetic fields and gravity are too weak to contain the plasma and it becomes the solar wind, racing across the solar system so fast that waves within the wind cannot ever travel fast enough to make it back to the Sun. Credit: NASA/Johns Hopkins APL/Ben Smith

As it circles closer to the solar surface, Parker is making new discoveries that other spacecraft were too far away to see, including from within the solar wind – the flow of particles from the Sun that can influence us at Earth. In 2019, Parker discovered that magnetic zig-zag structures in the solar wind, called switchbacks, are plentiful close to the Sun. But how and where they form remained a mystery. Halving the distance to the Sun since then, Parker Solar Probe has now passed close enough to identify one place where they originate: the solar surface.

“Parker Solar Probe “touching the Sun” is a monumental moment for solar science and a truly remarkable feat!”
— Thomas Zurbuchen, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington

The first passage through the corona – and the promise of more flybys to come – will continue to provide data on phenomena that are impossible to study from afar.

“Flying so close to the Sun, Parker Solar Probe now senses conditions in the magnetically dominated layer of the solar atmosphere – the corona – that we never could before,” said Nour Raouafi, the Parker project scientist at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. “We see evidence of being in the corona in magnetic field data, solar wind data, and visually in images. We can actually see the spacecraft flying through coronal structures that can be observed during a total solar eclipse.”


Exciting New Paper Tests a Dark Matter And Black Hole Prediction Made by Hawking

17 DECEMBER 2021

The Universe is too heavy.

According to our measurements of the normal matter in the Universe, there's not nearly enough of it to account for the strength of the gravitational effects we can see.

Whatever is making up the rest of the mass is nothing we can detect directly, and the quest to figure out what it might be is both perplexing and consuming.

The placeholder term for this mysterious mass is 'dark matter', and there are multiple hypothetical candidates. A new paper, however, is making a fresh case for a candidate first proposed in the 1970s by Stephen Hawking and Bernard Carr – primordial black holes.

"Our study predicts how the early Universe would look if, instead of unknown particles, dark matter was made by black holes formed during the Big Bang – as Stephen Hawking suggested in the 1970s," says physicist Nico Cappelluti of the University of Miami. 

"This would have several important implications. First, we would not need 'new physics' to explain dark matter. Moreover, this would help us to answer one of the most compelling questions of modern astrophysics: How could supermassive black holes in the early Universe have grown so big so fast?

"Given the mechanisms we observe today in the modern Universe, they would not have had enough time to form. This would also solve the long-standing mystery of why the mass of a galaxy is always proportional to the mass of the supermassive black hole in its center."

There are several reasons why black holes are not a leading candidate for dark matter. Nevertheless, they are an attractive one (pun absolutely intended); like dark matter, these ultradense objects emit no light, and, if they are hanging about in space not eating anything, they are very hard to detect; you can only do so by observing their gravitational effect on the surrounding space-time.

One of the problems physicists face is the sheer apparent quantity of dark matter. According to our calculations, just 15 percent of the matter in the Universe is made up of normal matter. The other 85 percent is dark matter.

That's extremely challenging to make up with black holes. According to our models, stellar-mass black holes form from massive stars, and there simply aren't enough massive stars out there to even come close to generating that number of black holes. Most of the Universe's stars are titchy red dwarfs.

Primordial black holes, however, are another matter, which is why, in recent years, they have seen something of a revival as a dark matter candidate. As the name suggests, these are black holes that could have formed from overdensities in the primordial plasma that filled the Universe immediately after the Big Bang.

These black holes could be the 'seeds' from which other black holes grew – but others could also have remained small enough to escape detection.

This explanation could also help explain some other conundrums, like how supermassive black holes – ones millions to billions of times the mass of the Sun – get so huge. At the moment, the question is a head-scratcher. According to the team's calculations, these behemoths could have grown in the early Universe by merging with other primordial black holes, and accreting nearby gas and stars.

"Primordial black holes, if they do exist, could well be the seeds from which all the supermassive black holes form, including the one at the center of the Milky Way," says astronomer and physicist Priyamvada Natarajan of Yale University.

"What I find personally super exciting about this idea is how it elegantly unifies the two really challenging problems that I work on – that of probing the nature of dark matter and the formation and growth of black holes – and resolves them in one fell swoop."

Primordial black holes could even help explain a mysterious excess of infrared radiation in the Universe. According to the team, growing primordial black holes would produce the same infrared signature.

While it would certainly be nice to solve so many mysteries in "one fell swoop", there are still some questions that would need answering.

For instance, distant light bends when it has traveled to us through the gravitational field of a black hole, and we simply haven't detected this happening nearly frequently enough to account for all the black holes that would constitute 85 percent of the matter in the Universe.

It's possible that we simply haven't conducted the right kinds of surveys. And this is what the team's paper set out to do: not prove that primordial black holes exist, but to lay out a case for their existence, so we can figure out what we need to look for.

With the James Webb Space Telescope – hopefully, fingers crossed – due to launch soon, we may be able to obtain some answers.

"If the first stars and galaxies already formed in the so-called 'dark ages', Webb should be able to see evidence of them," says astronomer Günther Hasinger of the European Space Agency.

The research has been accepted into The Astrophysical Journal, and is available on preprint server arXiv.

Artistic render of a black hole. (vchal/iStock/Getty Images Plus)

When did black holes form? 

Scientists think right after the big bang

Astronomers explain that black holes existed since the beginning of the Universe ­­and that these primordial black holes could themselves be as-of-yet unexplained dark matter.


India Today Web Desk 

New Delhi

December 17, 2021

black holes existed since the beginning of the Universe ­­and that these primordial black holes could themselves be the as-of-yet unexplained dark matter. (File Pic)

Black holes, the objects with such high gravitational energy that nothing, not even light, can pass through, has always been the most mysterious phenomenon in astronomy and their origin has remained the biggest question. Scientists, now, speculate that supermassive black holes might have formed from the primordial black holes that came into existence right after the big bang.

In an alternative model for how the Universe came to be, a team of astronomers propose that both supermassive black holes and dark matter could be explained by so-called "primordial black holes". Their model suggests that black holes existed since the beginning of the Universe ­­and that these primordial black holes could themselves be the as-of-yet unexplained dark matter.

In a study published in The Astrophysical Journal, the researchers said that if most of the black holes formed immediately after the Big Bang, they could have started merging in the early Universe, forming more and more massive black holes over time.

"Black holes of different sizes are still a mystery. We don’t understand how supermassive black holes could have grown so huge in the relatively short time available since the Universe existed,” explains Günther Hasinger, co-author of the study. Scientists are hopeful that when the future gravitational wave space observatory, LISA, becomes operational it might pick up the signals of those mergers if primordial black holes exist.
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If most of the black holes formed immediately after the Big Bang, they could have started merging in the early Universe. (Photo: ESA)

The study also points to the fact that if supermassive black holes exist, then there might also be very small black holes as well and if they do, they are too small to have formed from dying stars. Small black holes might simply be the primordial black holes that have not merged into larger ones yet.

The European Space Agency, citing the study, said that according to this model, the Universe would be filled with black holes all over. Stars would start to form around these clumps of dark matter, creating solar systems and galaxies over billions of years. If the first stars indeed formed around primordial black holes, they would exist earlier in the Universe than is expected by the standard model.

Co-author Priyamvada Natarajan of Yale University said, "Primordial black holes, if they do exist, could well be the seeds from which all black holes form, including the one at the centre of the Milky Way."

The upcoming James Webb Space Telescope will prove critical in finding answers to questions around the origin of black holes and supermassive black holes. Being dubbed as a cosmic time machine, it will look back over more than 13 billion years, shedding light on this mystery.

“If the first stars and galaxies already formed in the so-called ‘dark ages’, Webb should be able to see evidence of them,” adds Günther.

A black hole is formed from the death of a star with such a high gravitational field that the matter gets squeezed into the small space under it, trapping the light of the dead star. The gravity is so strong due to the matter being squeezed into a tiny space. Since no light can get out, people can't see black holes. They are invisible.

Black Holes Could Be Dark Matter – And May Have Existed Since the Beginning of the Universe

Did Black Holes Form Immediately After the Big Bang?

How did supermassive black holes form? What is dark matter? In an alternative model for how the Universe came to be, as compared to the ‘textbook’ history of the Universe, a team of astronomers propose that both of these cosmic mysteries could be explained by so-called ‘primordial black holes’. In the graphic, the focus is on comparing the timing of the appearance of the first black holes and stars, and is not meant to imply there are no black holes considered in the standard model. Credit: ESA

Did black holes form immediately after the Big Bang?

How did supermassive black holes form? What is dark matter? In an alternative model for how the Universe came to be, as compared to the ‘textbook’ history of the Universe, a team of astronomers propose that both of these cosmic mysteries could be explained by so-called ‘primordial black holes’.

Nico Cappelluti (University of Miami), Günther Hasinger (ESA Science Director) and Priyamvada Natarajan (Yale University), suggest that black holes existed since the beginning of the Universe ­­and that these primordial black holes could themselves be the as-of-yet unexplained dark matter. The new study is accepted for publication in The Astrophysical Journal.

“Black holes of different sizes are still a mystery. We don’t understand how supermassive black holes could have grown so huge in the relatively short time available since the Universe existed,” explains Günther Hasinger.

At the other end of the scale, there might also be very small black holes, as suggested by observations from ESA’s Gaia, for example. If they exist, they are too small to have formed from dying stars.

“Our study shows that without introducing new particles or new physics, we can solve mysteries of modern cosmology from the nature of dark matter itself to the origin of super-massive black holes,” says Nico Cappelluti.

Athena and LISA

Two future missions in ESA’s space science program will investigate some of the most extreme phenomena in the Universe: Athena, the Advanced Telescope for High-ENergy Astrophysics, and LISA, the Laser Interferometer Space Antenna. Currently in the study phase, both missions are scheduled for launch in the early 2030s. Athena will be the largest X-ray observatory ever built, investigating some of the hottest and most energetic phenomena in the cosmos with unprecedented accuracy and depth. Meanwhile, LISA will be the first space-borne observatory of gravitational waves – fluctuations in the fabric of spacetime produced by the acceleration of cosmic objects with very strong gravity fields, like pairs of merging black holes. Credit: ESA – S. Poletti

If most of the black holes formed immediately after the Big Bang, they could have started merging in the early Universe, forming more and more massive black holes over time. ESA’s future gravitational wave space observatory, LISA, might pick up the signals of those mergers if primordial black holes exist. Small black holes might simply be the primordial black holes that have not merged into larger ones yet.

According to this model, the Universe would be filled with black holes all over. Stars would start to form around these clumps of ‘dark matter’, creating solar systems and galaxies over billions of years. If the first stars indeed formed around primordial black holes, they would exist earlier in the Universe than is expected by the ‘standard’ model.

James Webb Space Telescope Artist's Impression

The James Webb Space Telescope is a space observatory to see further into the Universe than ever before. It is designed to answer outstanding questions about the Universe and to make breakthrough discoveries in all fields of astronomy. Webb will observe the Universe’s first galaxies, reveal the birth of stars and planets, and look for exoplanets with the potential for life. Credit: ESA/ATG medialab

“Primordial black holes, if they do exist, could well be the seeds from which all black holes form, including the one at the center of the Milky Way,” says Priyamvada Natarajan.

ESA’s Euclid mission, which will probe the dark Universe in greater detail than ever before, could play a role in the quest to identify primordial black holes as dark matter candidates.

The upcoming NASA/ESA/CSA James Webb Space Telescope, a cosmic time machine looking back over more than 13 billion years, will further shed light on this mystery.

“If the first stars and galaxies already formed in the so-called ‘dark ages’, Webb should be able to see evidence of them,” adds Günther.

Reference: “Exploring the high-redshift PBH-ΛCDM Universe: early black hole seeding, the first stars and cosmic radiation backgrounds” by N. Cappelluti, G. Hasinger and P. Natarajan, Accepted, The Astrophysical Journal.
arXiv:2109.08701

Astronomers just got better at finding 'bright' black holes

Astronomers just got better at finding 'bright' black holes
Seyfert spiral galaxy. Credit: University of Western Australia

Astronomers have a new way of detecting active black holes in the Universe and measuring how much matter they are sucking in.

The technique can be applied to millions of galaxies, searching for bright, supermassive  at the center of the galaxies.

Lead author Jessica Thorne, a Ph.D. student at the University of Western Australia node of the International Centre for Radio Astronomy Research, said active black holes are typically found in the largest galaxies in the Universe.

"The black holes we're looking for are between a million and a billion times more massive than our Sun," she said.

"As they suck in matter from around them, the matter gets super-heated because of friction and becomes very, very luminous."

"And when they're active, these black holes can outshine the rest of the galaxy."

Until now, identifying bright black holes has been challenging, with astronomers having to specifically look for them using complex methods unique to different types of telescopes.

Instead, the new technique works on typical telescope observations that already exist for millions of galaxies.

"We can identify these active black holes and look at how much light they're emitting, but also measure the properties of the galaxy it is in at the same time," Ms Thorne said.

"By doing both at once, we can have a better idea of exactly how the black hole is impacting its host galaxy."

The researchers developed the new technique by using an algorithm called ProSpect to model emission from galaxies and black holes at different wavelengths of light.

They then applied the method to almost half a million galaxies from Anglo-Australian Telescope's DEVILS survey.

They also applied it to more than 200,000 galaxies from the GAMA survey, which brings together observations from six of the world's best ground and space-based telescopes.

ICRAR-UWA astronomer Dr. Sabine Bellstedt said scientists often fail to account for bright black holes in galaxies.

"One of the reasons we've ignored them in the past is because it's hard to find them all," she said.

"We don't really understand these bright black holes to incorporate them into our modeling with sufficient detail."

Dr. Bellstedt said the new technique is easier, more consistent and more thorough.

"It suddenly means we can look for active black holes in so many more places than we were able to before," she said.

"It's going to help us search more galaxies, and look further back in time to the distant Universe."

Supermassive black holes are thought to have a huge impact on how galaxies evolve.

"We think that an active black hole in a galaxy is able to decrease the amount of star formation really quickly and stop the galaxy from growing any further," Thorne said. "It can effectively kill it."

With observations from new telescopes such as the James Webb Space Telescope, the Vera C. Rubin Observatory in Chile, and the Square Kilometre Array in Australia and South Africa, astronomers may be able to apply the technique to millions of galaxies at once.

"It's exciting to think about how many doors this has unlocked for the future," Thorne said.

The research was published in Monthly Notices of the Royal Astronomical Society.

Astronomers discover how to feed a black hole

More information: Jessica E Thorne et al, Deep Extragalactic VIsible Legacy Survey (DEVILS): identification of AGN through SED fitting and the evolution of the bolometric AGN luminosity function, Monthly Notices of the Royal Astronomical Society (2021). DOI: 10.1093/mnras/stab3208

Journal information: Monthly Notices of the Royal Astronomical Society 

Provided by University of Western Australia 

Not all black holes are black – and we have found thousands of the brightest ones


Sometimes materials such as gas, dust or stars that get sucked into the celestial objects heat up and become incredibly bright.
Colour composite image of Centaurus A, revealing the lobes and jets emanating from the active galaxy’s central black hole. ESO/WFI (Optical); MPIfR/ESO/APEX/A.Weiss et al. (Submillimetre); NASA/CXC/CfA/R.Kraft et al. (X-ray), CC BY-SA

When the most massive stars die, they collapse to form some of the densest objects known in the universe: black holes. They are the “darkest” objects in the cosmos, as not even light can escape their incredibly strong gravity.

Because of this, it is impossible to directly image black holes, making them mysterious and quite perplexing. But our new research has road-tested a way to spot some of the most voracious black holes of all, making it easier to find them buried deep in the hearts of distant galaxies.

Despite the name, not all black holes are black. While black holes come in many different sizes, the biggest ones are at the centres of galaxies and are still growing in size.

These “supermassive” black holes can have a mass of up to a billion Suns. The black hole at the centre of our own Milky Way galaxy – called Sagittarius A*, whose discovery received the 2020 Nobel Prize in Physics – is fairly calm. But that is not the case for all supermassive black holes.

If materials such as gas, dust or stars get too close to a black hole, it gets sucked in by the enormous gravitational force. As it falls towards the black hole, it heats up and becomes incredibly bright.

The light produced by these “bright black holes” can span the entire electromagnetic spectrum, from X-rays to radio waves. Another name for the bright black holes at the centre of galaxies is “active galactic nuclei”, or AGN. They can shine trillions of times brighter than the Sun, and can sometimes even outshine all the stars in its galaxy.

Matter swirling into the supermassive black hole at the centre of M87. 
Photo credit: Event Horizon Telescope

Brightest black holes


Some active galactic nuclei violently spew out matter via a jet, which travels millions of kilometres through space and can be seen by radio telescopes. Others produce “winds” at the centre of the galaxy, capable of pushing any gas (the fuel needed for stars to form) out of the galaxy.

VIOLET Violent jets spewing from Hercules A. 
Photo credit: NASA/ESA/NRAO

With such destructive forces in the middle of a galaxy, astronomers are certain this must have a big impact on the galaxy itself. We know most galaxies are slowly turning off their star formation processes and active galactic nuclei might be one of the culprits.

Active galactic nuclei can therefore not only help us to better understand elusive black holes but studying them also teaches us about galaxies themselves.
Finding black holes

Depending on how much a black hole is “eating”, what galaxy it is in and the angle from which we can see it, active galactic nuclei can look very different to one another. Even when looking at the same galaxy, one astronomer with an X-ray telescope may see it glow and discover an active galactic nucleus, whereas another astronomer using a radio telescope might see nothing, if the active galactic nuclei do not happen to produce jets that are visible in the radio spectrum.

Because of this, it was thought they were all different objects, but by looking at the same objects with different telescopes astronomers discovered they had many similarities and realised the benefits of using more of the electromagnetic spectrum to find them.

The relative brightness of a galaxy across different parts of the electromagnetic spectrum is called its “spectral energy distribution”. This can be used to measure how many stars are in a galaxy, how old they are, what they are made of and how much dust is blocking the light

.
Composite picture showing how a typical galaxy appears at different wavelengths. 
Photo credit: ICRAR/GAMA and ESO

In our research, published today in Monthly Notices of the Royal Astronomical Society, we show that this technique can also be used to spot active galactic nuclei. This means we can now measure not just the properties and histories of the stars in the galaxy, but also the brightness of its central black hole.

It is not a simple thing to do. The difference between starlight and the light from an active galactic nucleus is incredibly subtle, so it is possible to confuse young stars for a bright black hole and vice versa.

Here in Australia, astronomers have been using Australian telescopes to make 3D maps of galaxies in specific patches of the sky. These maps let us scour hundreds of thousands of galaxies, spanning 11 billion years of history, for possible active galactic nuclei.

By applying our new method to 700,000 galaxies we identified and quantified more than 75,000 active galactic nuclei to begin understanding how their number has evolved over time and how they have impacted their host galaxies. Astronomers think the number of active galactic nuclei in the universe is linked to the amount of star formation, which we know was almost ten times higher roughly 10 billion years ago. But until we can be certain we have identified all the active galactic nuclei across cosmic time in our galaxy samples, we will not know for sure.

Right now, the astronomical community is still passionately debating the nature of active black holes. While we have not yet answered the questions needed to soothe the debate, we are now one step closer to reliably being able to spot these fascinating objects within galaxies. And that is an important step towards shedding more light on the mystery of black holes.


Jessica Thorne is an Astrophysics PhD Candidate and Sabine Bellstedt is a Research Associate in Astronomy at The University of Western Australia.