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Singlet fission (SF) is an exciton amplification phenomenon in which two triplet excitons are generated from a singlet exciton produced by the absorption of a single photon in chromophores. A team of researchers has demonstrated that SF can be promoted by introducing chirality and controlling chromophore orientation and arrangement. Their innovative study is expected to promote diverse applications in energy science, quantum, and information materials science, photocatalysis, solar cells, and life science.

A new method for determining causality gives scientists a more holistic view of the causal role that contributing factors play within just about any system.

Teams of astronomers used the combined power of NASA's Hubble and James Webb space telescopes to revisit the legendary Vega disk.

Researchers found that a 12-week therapeutic virtual yoga program for chronic low back pain can be a feasible, safe and effective treatment option.

Microplastics have been steadily increasing in freshwater environments for decades and are directly tied to rising global plastic production since the 1950s, according to a new study by an interdisciplinary team. The findings provide insight into how microplastics move and spread in freshwater environments, which could be important for creating long-term solutions to reduce pollution, the researchers said.

Well, I’ll be. The group of interns at the left-wing The Nation have objected to the magazine’s recent endorsement of Kamala Harris and published their gripes. Now why would that happen? We all know that many editors and reporters at the Washington Post objected to the paper’s failure to endorse Kamala Harris, but this kind of reversal is unexpected.  Well, sort of—unless you know how “progressive” young Leftists are beginning to change journalism.

So why the beefing? It’s Israel, Jake!

Here, from the “activism” section of the magazine (!), is the long gripe by The Nation‘s interns (click to read for free):

An excerpt giving the tenor of their rage:

We, The Nation’s current interns, find this endorsement unearned and disappointing. We have a different interpretation of the magazine’s abolitionist legacy, one that says a publication committed to justice must refrain from endorsing a person signing off on genocide. We do not support Donald Trump, but to champion Harris at this moment is to ignore the atrocities that are being carried out with weapons supplied by the Biden-Harris administration.

The Nation’s endorsement notes that on foreign policy the “positive case [for Harris] is harder to make,” adding that “she has failed so far to offer anything more substantive to the millions of Americans…desperate for an end to America’s unconditional support for Israel’s brutal war on Gaza.” Yet it goes on to endorse her anyway—implying that domestic concerns are somehow more important. We disagree. On the grounds of Gaza alone, Harris should not have received The Nation’s endorsement.

In the 12 weeks since she effectively became the Democratic nominee, Harris has failed to differentiate her policies from Joe Biden’s blank-check support for genocide. Instead, she repeats the same bland pronouncements about the need for a ceasefire and uses the same passive-voice support for the idea of Palestinian “freedom and self-determination.” Again and again, she has been asked by Palestinian, Arab, and Muslim voters, along with a broad coalition of Democrats of conscience, to offer an alternative, and again and again she has refused. She would not even allow a pre-vetted Palestinian supporter of hers to speak at theDemocratic National Convention.

We have watched this abdication of moral responsibility by the Democratic nominee with a growing sense of dismay. As young journalists, we think of our colleagues in Gaza. Israel has killed more than 175 journalists in Gaza since last October—and right now, with US support and the Western media’s indifference, Israel is effectively issuing hit lists of reporters in Gaza. During the last year, The Nation has published dispatches from Palestinian journalists, from 14-year-old Lujayn to the journalist Mohammed Mhawish, both of whom have survived air strikes, most likely from US-made weapons. We cannot advocate for a person who is complicit in the murders of fellow journalists and the bombing of colleagues whose pieces we have fact-checked.

Even when they try to leaven  Harris’s position as a perpetrator of genocide with her “good” domestic policies, they can’t resist bringing up Gaza again and again:

Harris, for instance, promises to provide tax credits to families with newborns and to sign a law to restore the right to abortion nationwide. Yet her commitment to the welfare of children doesn’t extend to the more than 17,000 kids killed in Gaza, hundreds of whom died from inadequate postnatal care like incubators. She will fight for reproductive care in the United States, but in Gaza, tens of thousands of mothers have or will give birth without access to doctors, pain relief, hospitals, or food and water.

Harris also pledges to strengthen our healthcare system. But in Gaza, as many as 1,000 healthcare workers have been killed, 30 of 36 hospitals have been damaged or destroyed, and fewer than half are even partially functional. People routinely die from the blockade of basic sanitary equipment, ordinary medicines, and vaccines.

Harris’s plans to relieve the housing crisis in the United States ring hollow next to her support for Israel’s destruction of homes in Gaza, the West Bank, and Lebanon. With the Biden-Harris administration’s full knowledge and aid, 90 percent of Gazans have been forcibly displaced, and hundreds of thousands of homes have been damaged and destroyed. Nor has the administration done anything to stop the demolitions of houses and illegal expansion of settlements in the West Bank.

So who do the interns think the magazine should endorse for President? Nobody, of course. It’s curious that the Washinton Post would get slammed for not endorsing anybody, but the interns haven’t been slammed (or so I’ve seen) for the same action. Of course accusing Israel of genocide is perfectly okay with the “progressive” Left. One more bit from this execrable whine:

There will be people wondering whom we would endorse, if not Harris. Our answer is that we choose not to endorse any party’s candidate for president. We know that a second Trump presidency would be a disaster, but we believe that we cannot vote our way out of this genocide. And while some of us will be voting for president in November—and some of us will not—we all reject the idea that democracy will be safe under a Harris administration.

This is, to my mind, ridiculous, and exemplifies the Jew-hatred that is permeating young people and gradually working its way up into journalism, government, and corporations.  You don’t have to be a rocket scientist to realize that, in fact, the genocide is on the side of Hamas, which put into words (and acts repeatedly on) its desire to eliminate Israel. It is Hamas that deliberately tries to kill Jewish civilians, while Israel does its best to avoid killing civilians (its ratio of civilians killed to terrorist fighters killed is one of the lowest of modern times). Does Hamas warn Israeli civilians to get out of the way when it fires a rocket? No, it wants to kill civilians. It targets civilians, both with rockets and, of course, personally, as the October 7 massacre and subsequent acts of terrorism attest.

And, of course, we all know that part of Hamas’s strategy is to ensure that Gazan civilians get killed as a way of winning the world’s sympathy. They do this by embedding their fighters and rocket launchers among civilians and even in hospitals and humanitarian zones.  That guarantees not only that civilians will die as “collateral damage” (I hate that phrase, since all non-combatant human life should be preserved), but also that journalists, who have to be close to the action, will die as well. As the saying goes—and you know it’s true—”If Hamas put down its weapons, the war would be over. If Israel put down its weapons, all the Jews would be killed and Israel would disappear.” The reason Israel sustains fewer casualties is that it has more weapons than do the Palestinians as well as defense systems against rockets fired by Islamist terrorists.

I regard it as a touchstone of ignorance (willful ignorance, not simply “failure to know”) when someone accuses Israel of genocide when it’s palpably clear that Israel is not engaged in a program of eliminating all Palestinians, whose population has grown rapidly in the last decade. And of course where are the accusations of genocide against Hamas? I haven’t heard any lately, except, perhaps, by Israelis, but even then I can’t think of any.

I can’t print here what I think of these ignorant interns since this is a family-friendly site. Just let me say that I hope to Ceiling Cat that they don’t take over journalism and politics. Harris is already weakening American support of Israel by repeatedly calling for a cease-fire, which if effected now, would simply allow Hamas to regroup and continue perpetrating terrorism. If I were a paper and had to endorse a candidate (of course I don’t think papers should be endorsing candidates), it would of course be Harris. But to withhold that approbation because of a supposed “genocide” is sheer stupidity.

The abiding sin of the interns is their failure to blame Hamas rather than Israel for the deaths of Gazan civilians.  If beginning in 2005, a subset of Palestinians was not intent on killing Jews and getting rid of Israel, Gaza would now be a Mediterranean paradise, rich and full of big-spending tourists and beach resorts.

Alan Turing's theories about computation seem to have a startling consequence, placing hard limits on how fast or slow any physical process in the universe can grow

DNA analysis suggests Pando, a quaking aspen in Utah with thousands of stems connected by their roots, is between 16,000 and 81,000 years old

All day yesterday I was making my way back to Chicago from Ivins, Utah: first, a two-hour drive to Las Vegas, then a two-hour wait in the airport, with the flashing and music of slot machines IN THE WAITING AREA, and finally a four-hour flight back home. I am exhausted. Which is to say: posting will be very light today—if there is any.

But on the way home I read Salman Rushdie’s latest book, Knife: Meditations After An Attempted Murder, which came out in April. Click the screenshot below to go to the Amazon site. I have to say that the cover is wonderfully designed given the contents:

It’s a short (200-page) account of the attempted murder of Rushdie on August 12, 2022 by accused perp Hadi Matar, a Lebanese-American likely trying to fulfill the fatwa issued on Rushdie in 1989 by the Ayatollah Khomeini.  The Ayatollah considered Rushdie’s book The Satanic Verses as anti-Muslim blasphemy, and called for the author’s assassination. A $3 million bounty accompanied the fatwa. Rushdie went into hiding, but several people connected with the book were killed.

Finally, after 33 years, the fatwa was fulfilled when Matar ran at Rushdie as the author was about to address a Chautauqua, New York audience about the need for a “safe space” for politically demonized writers.  Matar apparently stabbed Rushdie 15 times in the neck, eye, chest, and hand, blinding him in one eye and rendering his left hand largely useless. For several days Rushdie hovered between life and death, but thanks to expert trauma care, he survived. His eye remains but its sightless, and his hand is only minimally useful. But, Rushdie avers, he was largely saved by the love of his (fifth) wife, the African-American poet Rachel Eliza Griffiths. In many ways the book is a paean to Griffiths, who was by his side the whole way, and the description of their mutual love is quite moving.

Rushdie, as you see from this book, is back in action, and on to another novel. I have read only one of his, but it was a corker: Midnight’s Children, which I picked up for a pittance in a used-book stall in New Delhi. I was mesmerized by the novel, which won not only a Booker Prize, but the “Booker of the Bookers“, an award for the 25th anniversary of the Prize. In other words, it was judged the best of the 25 Booker winners.  I’ve read a fair number of Booker-Prize winners, and think Rushdie’s award was well deserved. Midnight’s Children is a great classic, a magical-realism account centered on the partition of India in 1947. PLEASE read it if you haven’t.

Sad to say, that is the only novel of Rushdie’s I’ve read, and I must catch up. He’s written about 20 of them, apparently of varying quality, including an earlier autobiography called Joseph Anton, dealing with his post-fatwa journey. But I hear some of the novels are gems, and I must get to them.  He’s a likely future winner of the Nobel Prize for Literature, which I think has been delayed only because Stockholm fears Muslim backlash if Rushdie wins.

As for Knife, it’s a gripping short read and the details of Rushdie’s assault and subsequent recovery make the book one that’s hard to put down. I recommend it highly for a short read and for those interested in Rushdie.  A fair amount of the last part of the book is a fictionalized dialogue between Rushdie and his assailant, which changes the pace of the book substantially. At first I didn’t like this bit, but the more I read it, the more I enjoyed it. It is, I suppose, a way for Rushdie to come to terms with Matar and his attack, trying to suss out why a New Jersey resident would knife the writer after so many years.

Below is a Wikipedia photo of the post-attack Rushdie. He decided not to have his eye removed but rather to hide it with a dark lens in his glasses. He does have macular degeneration in his other eye, and fears above all that he will go blind. But it looks as though they’ve stabilized his condition:

Elena Ternovaja, CC BY-SA 3.0, via Wikimedia Commons

Matar, by the way, is still awaiting trial. They delayed it because his public defender argued that Rushdie’s published account was essential for Matar’s defense.

Just under 5 per cent of the Wikipedia pages in English that have been published since ChatGPT's release seem to include AI-written content

Meanwhile, in Dobrzyn, Hili has a message for us all:

A: What are you thinking about?
Hili: About hope in hopelessness.
A: And what is your conclusion?
Hili: That it requires intelligence, knowledge and craftiness.

Ja: O czym myślisz?
Hili: O nadziei w beznadziejności.
Ja: I jaki wniosek?
Hili: Wymaga inteligencji, wiedzy i przebiegłości.

Light can be directed and steered around bends using a method similar to the way clouds scatter photons, which could lead to advances in medical imaging, cooling systems and even nuclear reactors

From Harlan Ellison to Haruki Murakami, via an intergalactic cooking competition, this month has plenty of science fictional treats on offer

Any doctor who is unabashedly pro-vaccine has already spoken up about the normalization of anti-vaxx quackery within our ranks.

The post If RFK Jr. Turns the CDC Into An Anti-Vaxx Propaganda Outfit, I Don’t Want To Hear a Peep From Some “Respectable” Doctors first appeared on Science-Based Medicine.

David Lusseau always wanted to be a biologist. “Well, either biologist or clown,” he adds, “but I realized there was not much money in clowning.” When Marie the dolphin entered Lusseau’s life, she sealed the deal for him becoming a biologist. A bottlenose dolphin (Tursiops truncatus) who swam in the waters near the village of Cerbère on the border between France and Spain in the late 1980s, Marie set seventeen-year-old Lusseau on a path that would one day lead him to study social networks in her species. “When you look in the eyes of a dolphin, you realize there is a lot going on,” Lusseau says, reminiscing on his time with his cetacean friend. “It is something that is very hard to express or grasp or explain in a factual matter, but spending time with [Marie] got me interested in … trying to understand how dolphins work, [in what] I perceived as another intelligent species on the planet.”

As an undergraduate, Lusseau spent time as a research assistant working with a group studying bottlenose dolphins in Florida. When out in the water, he encountered dolphins swimming on their own or in pairs. On occasion he bumped into a trio, but dolphins always seemed to be doing their own thing, just in the company of one or two others. That view of dolphin sociality, or the lack of it, changed dramatically when Lusseau began his PhD research in the late 1990s at the University of Otago in New Zealand. His dissertation focused on conservation biology in bottlenose dolphins in a fjord called Doubtful Sound, but the social behavior of the dolphins there hit him like a ton of bricks. As soon as he got there, he encountered not lone dolphins, duos, or trios, but groups of thirty or more dolphins schooling and moving about in a coordinated manner. These were very different animals from the solo dolphins and very small dolphin groups he had studied in Florida.

Each day Lusseau rose at 4 a.m., grabbed some breakfast, swatted away an endless barrage of midges, and arrived at Doubtful Sound before the sun rose. He’d board a 14-foot boat, locate a group of dolphins, and do focal animal sampling, cycling through dolphins, each recognizable by natural markings on their dorsal fins, often from shark attacks. Doubtful Sound can be stunningly beautiful, but it is at a latitude called the “roaring forties” because of the strong winds from the west and six- to eight-foot waves at times, which make for rough going when watching dolphins from a boat.

As he spent time with the dolphins, Lusseau began thinking about how to understand their complex social dynamics, but he couldn’t quite figure out the best way to proceed. On one of his stints back at the University of Otago, Lusseau recalls reading a Proceedings of the National Academy of Sciences paper on social networks written by physicist Mark Newman and others. Soon after that, he emailed Newman, telling him, “I think you are doing really cool stuff and I can understand it, because you write so well. Would you like to have a look at what we’re doing?” Newman was interested. It wasn’t long before he and Lusseau were coauthoring papers on dolphin social networks. But before they penned any coauthored papers, Lusseau published a 2003 paper in the Proceedings of the Royal Society of London that is widely regarded as the first study explicitly on social networks in nonhumans.

Unlike animal social network papers in today’s journals, where readers are acquainted with how networks operate, to put readers in the right frame of mind in 2003, Lusseau opened his Royal Society paper using a strategy that Darwin had employed in On the Origin of Species. The idea was to introduce a phenomenon that readers already knew about (in Darwin’s case artificial selection, as in selection of different breeds of pigeons) and then make the case that what followed (natural selection), though it appeared radical, was really just another variety of what he had just discussed. In Lusseau’s paper, the opening sentences read: “Complex networks that contain many members such as human societies … the World Wide Web (WWW) … or electric power grids … permit all components (or vertices) in the network to be linked by a short chain of intermediate vertices.” And before readers knew it, they were learning about such social networks in dolphins.

Lusseau constructed dolphin networks based on thousands of observations, and one metric he looked at was network diameter, which measures the average shortest path between nodes. To introduce network diameter to readers, Lusseau first discussed psychologist Stanley Milgram’s “small world” research from the late 1960s. “The global human population seems to have a diameter of six,” wrote Milgram, “meaning that any two humans can be linked using five intermediate acquaintances.” The party version of Milgram’s small world is the parlor game “six degrees of Kevin Bacon.” The rules are simple: players choose a movie actor and then connect that actor to another that they played alongside in a film, repeating the process over and over, trying to link their original actor to movie star Kevin Bacon—who once quipped “he had worked with everybody in Hollywood or someone who’s worked with them”—in no more than six connections. It turns out the dolphin small world in Doubtful Sound is smaller than the human one (including Kevin Bacon’s), both in the size of the network and network diameter, the latter of which is approximately three, meaning any two dolphins in Doubtful Sound can be linked using two intermediate acquaintances.

Lusseau wondered what would happen if the dolphin network was culled by, for example, shark predation. To do this, using the network data he had collected, he built a computer algorithm that simulated predation, reducing the network size 20 percent by randomly removing 20 percent of the dolphins. The small world of the dolphins, it turned out, was unaffected by such a reduction. But if instead of randomly selecting individuals to remove from the network, Lusseau simulated removal of the 20 percent of dolphins who had the greatest number of ties to others, network diameter increased, which had the effect of slowing information transfer within the network.

As he came to know his dolphins better, Lusseau discovered that some individuals in Doubtful Sound give signals that affect group movement associated with finding new resources, including food. Side flopping, in which a dolphin leaps from the water and lands on its side, is seen only in males when they initiate a move to a new location, while upside-downing, in which an individual rolls onto its ventral side and slaps the water to signal an end to a group move, is seen almost exclusively in females. But only a few males do all the side flopping, and only a few females do all the upside-downing. Lusseau wanted to know if a network analysis would shed light on exactly which males and which females. It did. Males initiating and females terminating travel had higher betweenness— they were key hubs in this traveling/foraging network—than their non-signaling counterparts.

In a few populations of bottleneck dolphins on the other side of the planet, in Brazil, signaling and networking is not sometimes about feeding opportunities—they are always about that. And the dolphins have, rather remarkably, added humans to their feeding networks.

For more than three decades, ethologist Paulo Simões-Lopes has been studying dolphin populations in the lagoon systems along the coastline near Laguna, Brazil, about 800 kilometers south of São Paulo. The dolphins in nine populations along that stretch do something that no other dolphins—and almost no other animals, period— do. They not only network with each other, but cooperate with humans to secure more food for both themselves and their primate partner.

Each autumn, a huge mullet migration takes place in southern Brazil. Both the dolphins and the fishermen see the fish as prize prey. Up to fifty fishers, wading waist deep in very cold water, wait for the chance to cast large circular nylon nets called tarrafa over schools of mullet. The problem for the fishers is that the water is murky, and it is next to impossible to see the fish. The problem for the sixty or so dolphins at Laguna is that compared to their other prey, mullet are large and hard to catch. But dolphins aren’t especially troubled by murky water, as they detect mullet using echolocation, a built-in sonar system that would be the envy of most engineers.

Dolphins produce sound waves in their nasal sacs and focus those waves through fatty tissue and fluid in their foreheads. Once the sound waves are shot out into the water, they travel until they bump into an object, at which point they bounce back to the dolphins, who use their lower jaw as a receiver. From the lower jaw, the waves travel to the inner ear and then to the brain. Objects of different sizes and densities reflect back sound waves of different frequencies, and the dolphins use that information to “see” what is in the water around them. When their sonar detects mullet, dolphins signal fishers that the fish are present by curving their backs and then slapping their heads or their tails on the water surface. The fishers then cast their tarrafa and pull in loads of mullet. The confused mullet who escape the tarrafa often swim right into the mouths of waiting dolphins. It’s the perfect win-win situation.

Laguna newspapers from the late 1890s featured articles about this dolphin-human mutualism, and so Simões-Lopes knows that, at the very least, it has been going on for more than 130 years. And though many dolphins don’t signal fishers, every fisher knows which dolphins do. “It is famous [in southern Brazil],” Simões-Lopes says. “I grew up watching those dolphins … I would sit on a rock in the canal and watch for hours. I knew it was unusual … I knew there were dolphins in a big harbor farther south where dolphins and fishermen don’t interact.”

Today Simões-Lopes has a team of ten working with him, but he began on his own in 1988. Soon thereafter, he entered a PhD program and built his dissertation around his research on the dolphin-human foraging mutualism. Each day he brought a folding chair with him and set it up on a rock, watching the dolphins through his binoculars, taking photos—he had compiled a mug book with photos of all the dolphins in the lagoon—and filling notebook after notebook with data on dolphins signaling fishers.

Simões-Lopes began to know the fishers, and they began to know him. He also was starting to get a good feel for which dolphins at Laguna signaled the fishers and which did not. Not surprisingly, the fishers also kept tabs, telling Simões-Lopes about the “good dolphins” (who signaled fishers) and the “bad dolphins” (who did not). The fishers know not only which dolphins signal, but which dolphin will give which signal: “Each dolphin gives the signal in a different way,” one fisher said, “and we need to know [the different signals] in order to catch the fish.” Another fisher was more of a romantic, telling Simões-Lopes and his colleagues, “This is beautiful. It doesn’t happen everywhere.”

The more that Simões-Lopes thought about those “good” dolphins and “bad” dolphins, the more he wanted to understand them better. Years later Mauricio Cantor joined Simões-Lopes’s team; Cantor had worked with Hal Whitehead, a leader in early social network analysis. Simões-Lopes and Cantor decided that a network analysis might help them delve deeper into the between-species cooperation they observed on a daily basis. In 2008, they contacted David Lusseau, who had done the network studies on bottlenose dolphins in New Zealand, and asked if he would be interested in serving as a sort of conceptual consultant specializing in social networks. Lusseau was more than happy to join their team.

This article appeared in Skeptic magazine 29.3
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Simões-Lopes and his team assumed dolphins learn how to signal humans from other signalers they associate with, so for their social network analysis, they were especially interested in whether signaling dolphins preferred spending time with other signaling dolphins, both when they were chasing mullet into nets and, just as importantly, when they were not. To test whether there were cliques of signalers and cliques of dolphins who didn’t signal, Simões-Lopes’s team looked at clustering coefficients of sixteen cooperators and nineteen dolphins who did not signal and cooperate with fishers.

What they discovered were three cliques within the larger network of the thirty-five dolphins. Clique 1 had fifteen dolphins: each and every one of them cooperated with the local fishers. Dolphins in this clique associated with one another not just during the autumn mullet fishing season but the rest of the year as well. Clique 2 had a dozen dolphins, none of whom cooperated with fishers, and dolphins in this clique were not as well connected to one another as the individuals were in Clique 1. Clique 3 was made up of eight dolphins: seven never cooperated with fishers, but one—dolphin 20—did. And of all thirty-five dolphins in the network, it was dolphin 20 who spent the most time interacting across cliques, acting as what Simões-Lopes and his colleagues call a “social broker” between the signalers and non-signalers.

This behavior is all wonderfully complex, and we humans—and I don’t just mean the artisanal fishers of Laguna—should be grateful to play a role in understanding it.

Excerpted and adapted by the author from The Well-Connected Animal: Social Networks and the Wondrous Complexity of Animal Societies by Lee Alan Dugatkin, published by The University of Chicago Press. © 2024 by Lee Alan Dugatkin. All rights reserved.

About the Author

Lee Alan Dugatkin is an evolutionary biologist and a historian of science in the Department of Biology at the University of Louisville. He is the author of sixteen books and more than 200 articles in such journals as Nature, The Proceedings of the National Academy of Sciences, and The Proceedings of the Royal Society of London. Dr. Dugatkin is contributing author to Scientific American, The American Scientist, The New Scientist, and The Washington Post. His latest book is The Well-Connected Animal: Social Networks and the Wondrous Complexity of Animal Societies.

Is there something strange and alien confined deep inside the Earth? Is it trying to break free and escape into the heavens? No, of course not.

But in a new soundscape from the ESA, it sure sounds like it.

About every 450,000 years, Earth’s magnetic poles flip. North becomes south and vice versa in a phenomenon called geomagnetic reversal. This discovery was shocking since the planet’s magnetic field is such a foundational part of our environment. However, these reversals appear to be mostly harmless to life.

Geomagnetic reversals are chaotic events. Though they occur on average about every 450,000 years, there’s no pattern to them. There have been about 183 of them in the last 83 million years, leading us to the 450,000-year number. But the last one was 780,000 years ago, and some say that we’re overdue for the next one.

Sometimes, the events are excursions rather than full reversals. That’s when the field shifts for several hundred years and then returns to its original orientation, like the Laschamps event about 41,000 years ago. In an excursion, the field reverses in Earth’s outer core while its inner core remains unchanged. These happen more frequently than full reversals, but their exact number and timing are more difficult to determine since their effects aren’t global.

The evidence for these reversals and excursions is found in paleomagnetism. Paleomagnetism measures the orientation of magnetic elements like iron in volcanic rock as it cools. By determining the age of the rock, scientists can determine the orientation of Earth’s magnetic field when the rock solidified. The history of Earth’s magnetic reversals is recorded where new magma cools as the seafloor spreads.

Magnetic stripes are the result of reversals of the Earth’s field and seafloor spreading. The new oceanic crust is magnetized as it forms and then moves away from the ridge in both directions. This diagram shows a ridge (a) about 5 million years ago, (b) about 2 million years ago, and (c) in the present. Image Credit: By Chmee2 – derived from File:Oceanic.Stripe.Magnetic.Anomalies.Scheme.gif, Public Domain, https://commons.wikimedia.org/w/index.php?curid=18557170

During these excursions and reversals, the magnetic field’s strength weakens. During the Laschamps event, which lasted several hundred years, the field weakened to only 5% of its normal strength.

Earth’s magnetic fields deflect cosmic rays away from Earth, and at only 5% of its normal strength, the field lets in far more cosmic rays than usual. Cosmic rays are high-energy particles, usually protons or atomic nuclei, that come from the Sun and from objects both inside and outside of the Milky Way and travel at relativistic speeds. When they strike Earth’s atmosphere, they produce showers of secondary particles.

No matter how often they occur or what causes them, scientists are pretty sure that the Laschamps event was the latest excursion, and the European Space Agency decided it would be good if we knew what it sounded like.

The ESA launched its three-satellite Swarm mission in 2013 to study Earth’s magnetic fields. Swarm measures magnetic signals not only from the core but also from the mantle, the oceans, and all the way up to the ionosphere and magnetosphere. Scientists at the Technical University of Denmark and the German Research Centre for Geosciences used Swarm data and data from other sources to create a soundscape of the Laschamps event.

The scientists used recordings of natural sounds, such as rocks falling and wood creaking, and blended them into alien-like sounds that were both familiar and strange. The result sounds Earthly, subterranean, natural, and creepy all at the same time as if some ancient part of the Earth is writhing around inside the planet, which, in a way, it is.

The first version was created in 2022 and was played as a sort of public art installation in Copenhagen. There were 32 speakers, and each one played the sound represented by changes in the magnetic field at 32 locations around the world.

Check out the ESA’s SoundCloud channel, where they post their audio creations.

The post This is What it Sounds Like When the Earth’s Poles Flip appeared first on Universe Today.

In 1978, NASA scientists Donald J. Kessler and Burton G. Cour-Palais proposed a scenario where the density of objects in Low Earth Orbit (LEO) would be high enough that collisions between objects would cause a cascade effect. In short, these collisions would create debris that would result in more collisions, more debris, and so on. This came to be known as the Kessler Syndrome, something astronomers, scientists, and space environmentalists have feared for many decades. In recent years, and with the deployment of more satellites than ever, the warning signs have become undeniable.

Currently, there is an estimated 13,000 metric tons (14,330 US tons) of “space junk” in LEO. With the breakup and another satellite in orbit – the Intelsat 33e satellite – the situation will only get worse. This broadband communications satellite was positioned about 35,000 km (21,750 mi) above the Indian Ocean in a geostationary orbit (GSO). According to initial reports issued on October 20th, the Intelsat 33e satellite experienced a sudden power loss. Hours later, the U.S. Space Forces (USSF) confirmed that the satellite appeared to have broken up into at least 20 pieces.

While there are no confirmed reports about what caused the breakup, this is hardly the first time a satellite broke up in orbit. In recent years, satellites have been lost through accidental collisions, increased solar activity, or deliberate destruction (during tests of anti-satellite technology). What is known is that the Intelsat 33e satellite, manufactured by Boeing and operated by the multinational satellite services provider Intelsat, has suffered several issues since it was launched in August 2016, especially where its propulsion is concerned.

An artist rendering of the Mission Extension Vehicle docked to an Intelsat satellite.
Credit: Northrop Grumman

The first occurred less than a year after the satellite was launched when it reached its desired orbit three months later than anticipated. This delay was reportedly due to an issue with its primary thruster, which is responsible for controlling the satellite’s altitude and acceleration. Another occurred when it performed a special maneuver that ensures satellites can maintain the right altitude (a “station-keeping activity”). During the maneuver, Intelsat 33e burned more fuel than expected, which reduced the time it would spend in orbit by three and a half years.

In addition, another Intelsat satellite of the same model (a Boeing-built EpicNG 702 MP) failed in 2019. However, they are hardly alone regarding satellites breaking up and producing debris. In July, the Russian commercial satellite RESURS-P1 fractured in LEO, creating over 100 pieces of debris that could be tracked (and likely many more that were too small to detect). That same month, the decommissioned Defense Meteorological Satellite Program (DMSP) 5D-2 F8 satellite broke up in orbit.

On August 9th, 2024, the upper stage of a Long March 6A (CZ-6A) rocket fragmented in orbit, creating a cloud of at least 283 pieces of trackable debris. The geomagnetic storm that took place on February 3rd, 2022, coincided with the launch of 49 Starlink satellites, most of which were lost as a result. It is unclear how this latest incident will affect objects in orbit. Still, astronomers are hopeful that studying the resulting debris will provide insight into the growing problem of space junk.

According to the ESA Space Debris Office, an estimated 40500 objects in LEO are larger than 10 cm (3.9 inches) in diameter. Moreover, there are an additional 1.1 million objects measuring 1 and 10 cm (0.39 to 3.9 inches) in diameter and 130 million objects 1 mm to 1 cm (0.039 to 0.39 inches). Based on the Space Debris Office’s estimates, this adds up to more than 13,000 metric tons, consisting of pieces of spent rocket stages, satellites, and other objects launched into orbit since 1957 – when Sputnik-1 became the first artificial satellite launched into orbit.

In a 2009 paper, Kessler declared that the orbital situation had already reached the point of instability. As he wrote:

“Modeling results supported by data from USAF tests, as well as by a number of independent scientists, have concluded that the current debris environment is “unstable”, or above a critical threshold, such that any attempt to achieve a growth-free small debris environment by eliminating sources of past debris will likely fail because fragments from future collisions will be generated faster than atmospheric drag will remove them.”

In accordance with the 1972 Convention of International Liability for Damage Caused by Space Objects, the country that launched a satellite into space is responsible for its breakup and debris. However, this is only in cases where fault can be proven, and it has been enforced only once in the more than 50 years since it was signed. It is unclear if Intelsat will be fined by the Federal Communications Commission (FCC) for this latest incident. Regardless, this latest breakup highlights the need for a more robust framework for mitigating future collisions and addressing space debris.

In particular, tracking technology will need to evolve so that more objects can be tracked. At present, about 36,860 space objects are regularly tracked by Space Surveillance Networks (SSNs) worldwide and maintained in their catalogs. In addition, active measures to safely track and remove debris from LEO are being researched and developed, some of which have already been deployed. Examples include the ADRAS-J satellite, which launched on February 18th, 2024.

Developed by the Tokyo-based company AstroScale, ADRAS-J is the first mission to approach and survey a piece of space debris. The Clearsat-1 satellite is also being developed by the ESA and Swiss startup ClearSpace Today. NASA is also developing the Active Debris Removal Vehicle (ADRV), a lightweight, single-use vehicle that will remove debris with a mass of 1,000–4,000 kg (1.1 to 4.4 U.S. tons) and at an altitude of 200–2,000 km (124 to 1240 mi).

In the meantime, Intelsat continues to investigate the loss of both of its satellites. According to the latest update issued by the company, which was posted on October 21st, 2024:

“We are coordinating with the satellite manufacturer, Boeing, and government agencies to analyze data and observations. A Failure Review Board has been convened to complete a comprehensive analysis of the cause of the anomaly. Since the anomaly, Intelsat has been in active dialogue with affected customers and partners. Migration and service restoration plans are well underway across the Intelsat fleet and third-party satellites.”

Further Reading: Phys.org, Intelsat

The post Orbital Debris is Getting Out of Control appeared first on Universe Today.

In support of their AI ambitions, tech companies are rapidly expanding US data centres, and this growth is on track to significantly increase US gas demand by 2030

The JWST has found an exoplanet unlike any other. This unique world has an atmosphere almost entirely composed of water vapour. Astronomers have theorized about these types of planets, but this is the first observational confirmation.

The unique planet is GJ 9827 d. It’s about twice as large as Earth and three times as massive, and it orbits a K-type star about 100 light years away. The Kepler Space Telescope first discovered it during its K2 extension. In 2023, astronomers studied it with the Hubble Space Telescope. They detected hints of water vapour and described it as an ocean world.

“This is the first time we’re ever seeing something like this.”

Eshan Raul, University of Wisconsin – Madison

However, the JWST results show that the atmosphere is almost completely comprised of water vapour.

The results are in new research published in The Astrophysical Journal Letters titled “JWST/NIRISS Reveals the Water-rich “Steam World” Atmosphere of GJ 9827 d.” The lead author is Caroline Piaulet-Ghorayeb from the University of Montréal’s Trottier Institute for Research on Exoplanets.

Astronomers have wondered if steam planets can exist. Some thought that life could exist on them in the cooler, higher layers of their atmospheres. Others think it’s extremely unlikely. But there was no evidence to go on until now.

“This is the first time we’re ever seeing something like this,” said Eshan Raul, who analyzed the JWST data of GJ 9827 d as an undergraduate student at the University of Michigan. “To be clear, this planet isn’t hospitable to at least the types of life that we’re familiar with on Earth. The planet appears to be made mostly of hot water vapor, making it something we’re calling a ‘steam world.'”

However, every exoplanet teaches us something. GJ 9827 d and its unique atmosphere will help scientists understand exoplanets better in general.

“If these are real, it really makes you wonder what else could be out there.”

Eshan Raul, University of Wisconsin – Madison

The researchers used transmission spectroscopy to detect the exoplanet’s atmosphere. As the planet passes in front of its star, the atmosphere absorbs certain wavelengths of light in the starlight’s spectrum. Different chemicals absorb different wavelengths and reveal their presence.

The observations show that GJ 9827 d’s atmosphere is more than 31% water vapour by volume and has very high metal enrichment. The observations also show that no hydrogen or helium is escaping.

The exoplanet’s atmosphere may be strange, but in other ways, the planet itself is common. It’s a sub-Neptune, a planet larger than Earth but smaller than Neptune. Sub-Neptunes are the most common type of exoplanet we’ve found in the Milky Way.

This discovery is about more than sub-Neptunes and steam worlds. It’s about one of the key challenges in exoplanet atmospheres: the clouds-metallicity degeneracy.

When astronomers use transmission spectroscopy to examine and characterize an exoplanet’s atmosphere, high metallicity and clouds can produce the same signal. High metallicity can produce smaller spectral features, and clouds can also mute and flatten spectral features. Clouds can also mask the presence of molecular absorbers below the cloud deck. As a result, when scientists see a relatively flat spectrum or muted features, they struggle to determine if they’re seeing a metal-rich atmosphere with intrinsically small features or a low-metallicity atmosphere that’s partially obscured by clouds.

This research has broken the stalemate between clouds and metallicity.

Piaulet-Ghorayeb and her co-authors combined previous Hubble Space Telescope observations of GJ 9827 d with JWST observations. The JWST used its NIRISS (Near-Infrared Imager and Slitless Spectrograph) and SOSS (Single Object Slitless Spectroscopy) to analyze the exoplanet’s atmosphere during two transits. This provided enough wavelength coverage and precision to break the clouds-metallicity degeneracy. This is the first conclusive observation of a high-metallicity and water-rich atmosphere.

“This is a crucial proving step towards detecting atmospheres on habitable exoplanets in the years to come.”

Ryan MacDonald, Astrophysicist, University of Wisconsin This figure from the research shows GJ 9827 d’s two transits observed by the JWST. The broad wavelength coverage and the precision broke the clouds-metallicity degeneracy. Image Credit: Piaulet-Ghorayeb et al. 2024.

Almost all the exoplanet atmospheres that have been characterized are mostly made of the lighter elements hydrogen and helium. These atmospheres are similar to Jupiter and Saturn in our Solar System. They’re nothing like Earth and its life-friendly atmosphere.

“GJ 9827 d is the first planet where we detect an atmosphere rich in heavy molecules like the terrestrial planets of the solar system,” Piaulet-Ghorayeb said. “This is a huge step.”

Though GJ 9827 d isn’t habitable as far as our understanding of life goes, other exoplanets with similar metallicity are desirable targets in the search for life. Now that astronomers have broken the clouds-metallicity degeneracy, it changes our understanding of those planets and scientists’ ability to discern them. It’s all thanks to the JWST and its observing prowess.

Ryan MacDonald is a co-author of the new research and is a U-M astrophysicist and NASA Sagan Fellow. “Even with JWST’s early observations in 2022, researchers were discovering new insights into the atmospheres of distant gas giants,” MacDonald said, referring to the JWST’s spectroscopic characterizations of exoplanet atmospheres.

But those atmospheres were primarily composed of light gases, not heavier metals. These observations take us deeper into the atmospheres of sub-Neptunes. And though they’re the most common type of exoplanet in our galaxy, our Solar System is without one.

“Now we’re finally pushing down into what these mysterious worlds with sizes between Earth and Neptune, for which we don’t have an example in our own solar system, are actually made of,” MacDonald said. “This is a crucial proving step towards detecting atmospheres on habitable exoplanets in the years to come.”

The atmospheric steam didn’t jump out of the JWST observations. JWST produces an enormous amount of data, and to make sense of it, astronomers use modelling tools based on sampling algorithms and machine learning techniques. They typically employ several different models and work with all of the results to arrive at the most likely interpretation of the data.

The process of determining an atmosphere from data is called atmospheric retrieval. A 2023 paper presented a catalogue of 50 different atmospheric retrieval codes used by exoplanet scientists. The lead author of that paper is none other than Ryan MacDonald, a co-author of this new research. MacDonald wrote the software that analyzed and retrieved GJ 9827 d’s atmosphere, and co-author Raul used that software.

Raul generated millions of model atmospheres that matched the JWST observations before settling on the steam world model. In a sense, Raul was the first person to see proof that steam worlds exist.

“It was a very surreal moment,” said Raul, who is now working toward his doctorate at the University of Wisconsin-Madison. “We were searching specifically for water worlds because it was hypothesized that they could exist.”

“If these are real, it really makes you wonder what else could be out there.”

The post Webb Reveals a Steam World Planet Orbiting a Red Dwarf appeared first on Universe Today.

People with stronger autistic trails showed distinct exploration patterns and higher levels of persistence in a computer game, ultimately resulting in better performance than people with lower scores of autistic traits, according to a new study.