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The construction of the Vera C. Rubin observatory has just crossed a major milestone with the successful installation of its 3.5 meter diameter secondary mirror. The observatory is now one step closer to first light in 2025, when it will begin the Legacy Survey of Space and Time (LSST): a mission to repeatedly image the entire sky, at high resolution, to create a time-lapse record of the Universe.

The construction of the Vera C. Rubin Observatory (https://rubinobservatory.org/) in Chile has crossed a major milestone with the successful installation of the secondary mirror assembly. The 3.5 meter convex mirror is the first permanent optical component to be integrated into the Simonyi Survey Telescope. Construction is expected to be completed by 2025, when it will achieve first light. In its completed state, it will effectively be the largest digital camera in the world, built to perform the Legacy Survey of Space and Time (LSST), a project to create a ten-year time-lapse view of the entire southern sky.

The mirror is made from Corning® ULE® Glass (Ultra-Low Expansion Glass), and was manufactured by Corning Advanced Optics in Canton, New York. After delivery in 2009, it was stored at Harvard University for five years. After this, L3Harris Technologies, in Rochester, New York, got to work finishing and polishing the mirror. They developed new techniques to work the mirror, as it is very technically challenging to work such a large convex mirror to the necessary precise tolerance. They also designed and built the mirror’s cell assembly, which has adaptive optics capabilities. The cell is built on a stiff steel mounting plate and features 72 axial actuators and six tangent actuators. These allow the supporting structure to constantly adjust as the telescope moves, compensating for the distorting effect of its own weight to keep the mirror at exactly the correct shape at all times.

In 2018, the mirror and cell assembly were shipped to the observatory site in Chile. On arrival, it was given its silver coating. Telescope mirrors are usually coated with aluminum, which is hardier and less prone to tarnishing, and so doesn’t need to be renewed as often. But the Simonyi Survey Telescope in the Vera C. Rubin observatory uses silver (for its superior reflectivity) together with a protective coating to seal it away from atmospheric oxygen and extend the life of the coating. After silvering, it was then sealed back into its container to be stored until construction had reached the point where the telescope would be ready for it. Finally, in July 2024, the complete assembly was installed into the telescope, and integrated with its control electronics.

“Working with the mirror again after five years is extremely exciting because it really feels like we’re in the home stretch,” said Sandrine Thomas, Deputy Director for Rubin Observatory Construction, “Now we have glass on the telescope, which brings us a thrilling step closer to revolutionary science with Rubin.”

The mirrors in observatory telescopes need to be removable, so that they can be cleaned and occasionally resurfaced. But these large mirrors are very heavy, and it would be a disaster if so much glass were to be dropped. That’s why installation and removal is done very carefully, with specialized machinery, following a documented process. To install the secondary mirror assembly, engineers in the summit team loaded it onto a custom-built cart, which rotated the mirror to a vertical position. It was then hoisted up into position on the telescope structure, and carefully bolted into place. Once it was securely attached, the electronics were connected, and the software control system was activated.

“Our 55-year legacy of designing and constructing high-end optical systems for space and ground continues with the world’s largest active secondary mirror system built for Rubin Observatory,” said Charles Clarkson, Vice President and General Manager, Imaging Systems, Space and Airborne Systems at L3Harris. “With this milestone, we are closer to pushing scientific frontiers and charting the Universe like never before, and we look forward to the science that will be discovered.”

The next component to be installed will be the Commissioning Camera (ComCam). This is a temporary camera, meant to be used for testing and integration. At “only” 144 megapixels, it’s only a fraction of the size of the LSST camera. This is not the first time that ComCam has been installed – it is used at various stages of construction to test the various components, ensure that they are properly installed, and that they work together as expected. After ComCam has done its job, the team will get to work on integrating the 8.4 meter primary mirror assembly, followed by the LSST camera.

The Vera C Rubin Observatory was named after the astronomer who first provided convincing evidence of Dark Matter. She and a colleague studied over 60 galaxies to measure how fast they were rotating. In 1978, they found that these galaxies were all spinning too fast: Given the amount of visible matter, they should have not had enough gravity to stop themselves from flying apart. There had to be extra invisible mass, and this work was the first convincing proof of the Dark Matter theory.

The telescope itself is a survey instrument: It is designed to take deep, wide-field images of the sky, very rapidly. The design of the telescope allows it to move very quickly, switching from target to target in short order. With an 8.4 meter primary mirror, it is very sensitive, and can see very faint, distant objects. But it also has a very fast focal ratio of f/1.234, giving it a very wide field of view and allowing it to take much faster exposures.

When the LSST camera is installed, it will capture images covering an area of 9.6 square degrees. Each image will be made from two 15 second exposures, at a resolution of 3.2 gigapixels. At this rate, it will be able to image the entire sky every ten days, and it will repeat this process for ten years. The resulting data will be a ten year time-lapse video of the entire universe, monitoring 20 billion galaxies, 17 billion individually resolved stars, and the orbits of around 6 million objects within our Solar System!

For more information, read the original press release at https://noirlab.edu/public/news/noirlab2419/

The post Rubin's Secondary Mirror is Installed appeared first on Universe Today.

I've long been writing about "alternative cancer clinics" (i.e., quack clinics) that sell false hope in the form of very expensive but ineffective treatments to desperate cancer patients. A recent study demonstrates how they use Google to do this.

The post How Google listings are used by alternative cancer clinics to lure in desperate patients first appeared on Science-Based Medicine.

Researchers have uncovered a more nuanced view of what makes an 'ideal' computer science student, challenging long-held stereotypes of geeky, clever, detail-oriented men, who lack social skills.

Researchers have created Mindful Scroll, a mobile app that helps users transition from doom-scrolling to adding mindfulness into their daily routines.

The movement of radiant heat -- felt when a hot surface warms our bodies and homes -- between buildings and their surroundings at ground level makes buildings with less skyward-facing surfaces harder to cool. A research team has demonstrated a new passive cooling technology that coats walls and windows with materials that can better manage heat movement between buildings and their surroundings at ground level. Findings could reduce the reliance on air conditioning and provide a more environmentally friendly, low-cost and scalable option for low-income communities with limited or no access to cooling and heating systems.

“Today’s science fiction is tomorrow’s science fact.” This quote, attributed to Isaac Asimov, captures science’s intricate relationship with science fiction. And it is hardly a one-way relationship. Whereas science fiction is constantly evolving to reflect new scientific discoveries and theories, science itself has a long history of drawing inspiration from the works of visionary authors, filmmakers, and popular culture. And in some cases, where scientists themselves were the visionaries (like Asimov himself), you had an instance of both!

The relationship between the two was the subject of a recent study by Samuel Boissier, a researcher with the Centre National de la Recherche Scientifique (CNRS) and the director of research at the Laboratoire d’astrophysique de Marseille (LAM). In an age when misinformation, “deepfakes,” and deliberate attempts to obscure scientific truths are at an all-time high, examining the interconnection between science, art, and science fiction is very important. According to Boissier, doing so offers people in the scientific community a way to engage with the public in a way that is relatable and accessible.

The relationship between science fiction and scientific fact is well-documented and has been the subject of academic research. Recent examples (that we have written about) include how exoplanets are depicted, the lives of many professional scientists, and popular depictions of space travel. However, when a concept fails to meet the burden of proof – such as FTL travel using wormholes or the EMDrive – the typical reaction is to label it as “science fiction.” Nevertheless, science fiction authors are often professional scientists themselves or represent science accurately in their stories – hence the term “hard SF.”

This artist’s illustration shows a spacecraft using an Alcubierre Warp Drive to warp space and ‘travel’ faster than light. Image Credit: NASA Inspiring SF (and Vice Versa)

In his paper, Boissier (himself a professional astronomer and astrophysicist) addresses how hard science fiction can be used for educational purposes, particularly in astronomy and astrophysics! What’s more, examples can be found in many forms of popular media, including literature, film, and video games. As he told Universe Today via email:

“Science Fiction is using astronomy to offer to the public blockbusters at the movies (e.g. Interstellar), series or movies in streaming media (Don’t Look Up, The Expanse), many books from classic authors (Isaac Asimov, Arthur C. Clarke) or more moderns ones (Kim Stanley Robinson), comics (the adventures of Valerian and Laureline), or video games (Mass Effect, No Man’s Sky) that have a very large cumulated audience. Astronomers can use Science Fiction to illustrate physics or astronomical facts. It might be a good way to talk about our work and our methods by comparing them to examples with which a large audience is familiar.”

Not only do the following examples contain “hard” science, but they also explore concepts that individuals may not otherwise be familiar with. For instance, the Mass Effect series contains one of the more well-known proposed resolutions to Fermi’s Paradox, the Berserker Hypothesis (or “Killer Probe Scenario”). The Expanse series (the novels and the miniseries adaptation) is renowned for featuring scientific elements that make the story compelling and realistic. Examples include realistic depictions of life on Mars, larger asteroids, and spacecraft, including the effects of low gravity (and microgravity).

In terms of literature, Asimov and Clarke are well-known examples of scientists who used the genre to explore speculative ideas grounded in science. Asimov’s I, Robot series explored how the development of artificial intelligence (AI) would affect our society. Interestingly enough, Asimov wrote the series to address what he felt was the tired and cliched trope of robot uprisings (“kill all humans” and such!). Strangely, the novel was adapted into the 2004 film starring Will Smith, which centered on the premise of a robot uprising (what bitter irony!)

Clarke’s work earned him the nickname “the prophet of the future,” a well-deserved moniker! In Islands in the Sky (1952), he presented the concept of a Space Elevator (named Port Goddard and located in New Guinea) that allows for regular trips to space. Rendezvous with Rama presents readers with the concept of an O’Neill Cylinder traveling between star systems and presents a detailed concept of extraterrestrials. But his most well-known work is arguably 2001: A Space Odyssey, the novel released concurrently with the film in 1968.

The film itself was based on two of Clarke’s short stories, Encounter in the Dawn (1953) and The Sentinel (1948), which were adapted to create the first two parts of the film (The Dawn of Man and Mission to the Moon). These short stories explore the ideas of first contact between ancient humans and extraterrestrials (paleocontact) and the discovery of an alien artifact on the Moon. This became the basis for The Monolith in the film, which is responsible for influencing the evolution of early hominids. These ideas inspired more recent films like Prometheus, Arrivals, and others that explore paleocontact and first contact.

As Boissier explained, these novels and films inspired many to get into astronomy, astrophysics, and STEM. “In a recent study, it was shown that 93 percent of British professional astronomers have an interest in Science Fiction, and 69 percent consider that Science Fiction influenced their career or life choice. I am presenting a similar study made for French astronomers, performed during and just after the 2024 meeting of the French Society of Astronomy and Astrophysics (Journees 2024 de la SF2A).”

But, of course, the relationship between SF and popular media is hardly one-way. After the 2024 SF2A meeting, Boissier met with his colleague, astronomer Frank Selsis, who shared a few examples of how science fiction inspired scientific research. “Selsis told me after the meeting that author Laurence Suhner wrote a short story about an [exoplanet around] TRAPPIST-1 at the same time of its discovery, the observations being announced in the journal Nature at the time.”

Selsis, the research director of the Exoplanets, CLImates, and Planetary Systems Evolution (ECLIPSE) lab at the University of Bordeaux, was part of the consortium that revealed the presence of a potentially habitable exoplanet around Proxima Centauri (Proxima b) in August 2016. As he related to Boissier, he was also a co-author of a study inspired by a conversation with Luvan, a French SF author known for her novel Agrapha. During a presentation last year at the Teich Bird Sanctuary, Selsis spoke on the subject of the relationship between science fiction and exoplanet research (see video above).

Advising SF Writers

As noted, Boissier addresses how science fiction materials can be used as a pedagogical resource. Contrary to what many believe, there are many popular science fiction franchises where professional scientists advised the writers and visual effects departments. “Maybe one of the most famous examples is the imagery of the black hole and its accretion disk [in Interstellar], for which actual computations were performed,” said Boissier. “Kip Thorne was the advisor for the movie. You will find many discussions about it, including a book by Thorne himself.”

Kip Thorne’s computational models (and Interstellar‘s visuals) were confirmed in 2019 when the Event Horizon Telescope (EHT) collaboration released the first image of a supermassive black hole and its accretion disk. In 2021, the EHT released the first image of the SMBHs at the center of the Centaurus A galaxy and the radio jet emanating from it. In 2022, they revealed the first image of Sagittarius A*, the SMBH at the heart of the Milky Way galaxy! Another example that Boissier enjoys citing is the TV series Futurama, where astronomer David Schiminovich of Columbia University helped advise one of the show’s creators.

According to Boissier, this included the 2009 video Into the Wild Green Yonder, which featured a “violet dwarf star.” This was a clear reference to the work Schiminovich did with NASA’s Galaxy Evolution Explorer (GALEX) mission, which observed the Universe between 2003 and 2013 in the ultraviolet wavelength. Also, fans of the series will recall episodes that featured noted scientists like Stephen Hawking, Bill Nye, and noted environmentalist Al Gore. It has also explored concepts ranging from Schrodinger’s Cat, General Relativity, Lorentz Invariance, the “Grey Goo” scenario, and Simulation Theory.

Dr. Kip Thorne’s guidance allowed Nolan to raise science fiction to a new level in the film Interstellar. Credit: Paramount Pictures/Warner Bros. Educating with SF

In addition to recognizing how SF has inspired real-life scientists (and vice versa), Boissier also explores how SF can be used as a pedagogical resource. One of the greatest virtues, says Boissier, is the way SF can make real science accessible to people who might otherwise be intimidated to learn about it:

“I think some people are not confident enough to think they can follow an astronomy lecture or conference, [whereas] they have no problem going to the theatre to watch a Science Fiction movie. If an astronomer is there to say a few words about science after the movie, we can meet with an audience that we would not find in other places. So, to me, it is important to reach more people.”

“I have seen a presentation by Roland Lehoucq in France that was giving shining examples indeed. For instance, using the Star Wars scene in which lightning flashes from the Emperor’s fingers, he showed it is possible to compute the potential difference needed for this effect and how thick the soles of his shoes need to be to avoid electrocution. And he computed how much energy is needed for lightsabers to cut through a metal door (it’s a lot!). Many books explore these types of things, usually starting with “The Science of TITLE HERE”!

Examples include Kip Thorne’s The Science of Interstellar, Kevin R. Grazier’s The Science of Dune, and Lawrence M. Krauss and Stephen Hawking’s The Physics of Star Trek. Moreover, using SF to educate people about science is also a way of combatting misinformation, which is especially important in the “age of the internet,” where fringe theories have become more mainstream. One need look no further than social media platforms to find examples, such as “Flat Earth” theory, Creationism, and conspiracy theories involving vaccinations, election outcomes, and assorted ideas that exploit ignorance and fear.

Scientists at Cornell University have developed a “stillsuit” for NASA spacesuits that could enable longer-duration missions on the Moon and Mars. Credit: DALL-E generated image

To Boissier, this makes educating people about science, astronomy, and the STEMs (and in a way that is accessible) more important than ever. “To me, it is important because too many people are disconnected from science,” he said. “There is a lot of fake news and misinformation, including subjects on which science can help citizens understand the world. Those are opportunities to bring a little bit of science, to talk about the scientific methods that everybody should know about!”

For more information on how SF has inspired science and scientists, check out this list from the Astronomy and Astrophysics Group at the University of Warwick.

Further Reading: arXiv

The post New Study Examines the Links Between Science Fiction and Astronomy appeared first on Universe Today.

Tonight, if the sky is clear and dark in your vicinity, would be a good night for staying up late, going outside, and looking up. Not that it’s an exceptional night for star gazing, necessarily; I wrote “sky-gazing” for a reason. The two phenomena you’re most likely to see are much, much closer than the stars. Both occur in the Earth’s upper atmosphere, and are generated by effects that occur within the solar system (i.e., the Sun, its planets, and their neighborhood.)

The phenomena in question? Meteors, for sure; and auroras, just maybe.

Tonight you will definitely see an unusually large number of meteors (a.k.a. “shooting ‘stars’ “) from the annual Perseid meteor shower. Ordinary meteors are dust-grains and pebbles flying through the solar system that happen to hit the Earth. When these objects enter the Earth’s atmosphere at high speed, they heat up and glow brightly, leaving a track across the sky until they evaporate away entirely. The dust and small rocks are debris from comets, themselves balls of rock, dirt and ice, typically a few miles (kilometers) across, that orbit the Sun on trajectories that are far more elongated than the Earth’s near-circular path. You’ll see more meteors after midnight, but before midnight, the ones you see will often show long trails. However, the moon will drown some of them out before it sets, roughly one hour before midnight; try to go out after moonset if you can. (Meteors will continue to be common for an additional two or three nights, though the number will tend to decrease over time.)

You might also see auroras (a.k.a. the “northern” or “southern ” lights); there’s a moderate chance of them tonight, the more so the higher your latitude. Auroras arise when solar storms create clouds of subatomic particles that cross from the Sun to the Earth. Some of these electrically-charged subatomic particles are steered by the Earth’s magnetic field toward the Earth’s magnetic poles, and when the particles enter the atmosphere, they strike atoms, causing the atoms to glow. The colors seen most often green or red. Last week I wrote about how you can try to guess when they may be occurring. The moon, again, will drown out the colors, so look after moonset, an hour before midnight in most places.

This is not to dismiss actual star gazing. We’re still waiting for stellar event that should be visible to the naked eye: a minor star explosion known as a nova that has been predicted, with moderate confidence, to occur in the next month or so. (But… don’t be too terribly surprised if it is delayed, or doesn’t occur at all. The prediction is empirical and based only on three previous occurrences — and nature doesn’t always follow simple patterns.) I’ve written about this event here.

Again, just to reemphasize: for all of these, you need dark skies! You will barely see anything (except the brightest meteors) from a city, or even from a suburb with parking-lot lights nearby. Get as far from lights as you can — stay away from busy roads where headlights will periodically blind you — and let your eyes adjust to the darkness.

Now here’s something worth contemplating.

• Meteors and auroras typically occur 50-200 miles (100-300 km) overhead — no further than the distance from Boston to New York or from London to Paris.
• The nova explosion, if it occurs, will be more than 10,000,000,000,000,000 miles (km) overhead — a hundred million times further than the Sun is from Earth.

But they’re comparably bright. Just to keep things in perspective.

I highly recommend that you click on the photos to enlarge them.

On Friday we set out to go to the drier part of the Cape Floristic Region, heading from the lusher fynbos to the karoo, a semi-desert which nevertheless harbors a lot of endemic plants and birds.

But the night before we had a big dinner, whipped up by Rita, the night before. It featured lamb chops, sausages, pap (African cornmeal mush) with tomato sauce, salad, garlic bread, and of course the local Shiraz. As you see, we were not gastronomically deprived.

My plate:

Of course there was the wine of the property: a creditable chenin blanc (I’m amazed they can make wine there at all, much less good wine):

At stops along the way to the karoo, we saw several stuffed specimens of local wildlife, which is sad but I’m sure they were shot a while back before trophy hunting became somewhat taboo.

This is a Verreaux’s eagle (Aquila verreauxii), which has a distinction of extreme prey specificity. According to Wikipedia,

Verreaux’s eagle is one of the most specialized species of accipitrid in the world, with its distribution and life history revolving around its favorite prey species, the rock hyraxes. When hyrax populations decline, the species have been shown to survive with mixed success on other prey, such as small antelopes, gamebirds, hares, monkeys and other assorted vertebrates.

The Cape leopard is a subspecies of the African leopard (Panthera pardus pardus), and there’s only one species in toto. Cape leopards are smaller than those further north (the “normal” leopard), perhaps because prey are sparser and so they evolved to do with less food, which means a smaller body.  Some miscreant shot this one, whose stuffed remains we found in a snack bar/restaurant/shop.

It poured the night we left the lovely Driehoek Farm, and we checked in with the managers, who informed us that the rivers were running high and swift, damaging bridges, turning rivulets into dangerous torrents, and even overturning a car (the occupants survived). Martim carefully got maps of all the rivers, which we hoped would have gone down when we crossed what were identified to us as the Three Major Obstacles. Fortunately, we made them all, though the last (where the car overturned) was the diciest.

Obstacle #1–no problem!

Some flowers we saw heading towards the karoo. This one is unidentified, but may be Helichrysum.

Metalasis sp. (African blombos)

Another unknown flower from the daisy family

A must-see in this part of the karoo are the San people’s (previously called “Bushmen”) rock paintings in the Truitjieskrall Reserve of the Cederberg Mountains (see also here).  Although there are fewer paintings than at some other sites, it was accessible with the purchase of a permit (it gives you the code for the lock), and the surrounding rocks, in whose caves and crevices the San clearly sheltered, are fantastic. Below is the rock complex:

. . . and some of the rocks:

You can se that there are many places to shelter here, and although the San apparently didn’t wear anything above the waist (a mystery to me given the cold), they also had fires and plenty of caves and overhangs:

This is the site where all the paintings are; they are exposed to the elements and, sadly, will eventually disappear. Most of the faces of the human figures, depicted in white instead of the usual red ochre pigments, are already gone.

The entrance to the cave, on whose walls the San did their art, is to the right. I can’t say how old these paintings are as it’s been very hard to date them. The oldest in South Africa appear to be 8,000 years old, and the youngest, depicting ships and wagons of the Europeans, are from the 19th century.

This plaque (click to enlarge) tells how they made and used pigments. Painting was sophisticated, often using fine brushes rather than fingers and hands. Curiously, the later paintings appear to be less fine, made without brushes.

The inside of the cave.  You can see one painting in red at the lower right:

This is identified on another plaque as showing “five women clapping and dancing. The men on either side are postures typical of trance healers. The dances were held regularly to allow trained healers to receive power from the spirit world to heal the sick and help the community.”

I presume this is known from observations of San hunter-gatherers (a few still exist) in modern times.

“A line of six female eland. In the San belief system, eland could help people get close to the spirit world where they could access power for healing and making rain.  Many paintings depict spiritual experiences and show associated animals.”

Clearly a man! But his face, originally painted in white, has disappeared as the white pigments didn’t bond as tightly to the rock as did the white ones

More figures and an unknown animal to the right. San paintings in other places showed elephants, but I doubt that the San could bring them down with their spears, though perhaps they killed young ones.

A line of dots; I don’t know what they represent:

An enlargement of the three figures above holding hands.

More of the gorgeous rock formations:

The cylindrical rock must be simply part of the formation:

Obstacle #3!  This is where a car had overturned the night before. When we arrived before lunch it had been removed, but yet another car had been swept off the road into the rushing water. In the picture below this one, a group of people are about to tow the car out of the water. I don’t know if they succeeded.

The Obstacle. After observing several cars go through the stream, Martim, an intrepid driver, essayed the obstacle and we made it!

We celebrated with ribs for lunch, as a woman at the shop where we stopped said her friend made some wicked ribs there. Well, I’m a BBQ maven, and all I can say is that they were just okay. But with some fries and a beer they hit the spot.

This menu shows South African humor as well as their tremendous love of MEAT, something I didn’t know before I came here. (A local joke is that in South Africa, chicken counts as a vegetable.) Just read the part by the asterisk.

More attempts at humor on another menu board:

Oranges are grown in the karoo, making for a strange sight:

This is melkbos (“milk bush”, Euphorbia burmanii), which exudes a viscous and somewhat poisonous sap when you break the stems (see next photo):

Martim said that the San dipped their spear points and arrowheads into the semi-toxic sap to help bring down the animals.

Our next stop was another Afrikaaner farm that doubled as a motel, one with a clear Wild West theme. One room was called “the Jailhouse,” another “sheriff’s office”, while I had the House With No Name (in the desert, they can’t remember the names!).  I called it, in keeping with the theme, “The Bordello.”  In the dining room (here they feed you) there were displays of saddles, Western cowboy hats, and rifles.  The farm offers horseback riding.

The inside of my room, which has a boiler called a “donkey” that you have to turn on by lighting a fire under it. None of us wanted to do that, even though it was bloody cold. And I mean COLD!  It took me an hour to warm up sufficiently to even think about sleeping, even though I was under a comforter and a thick blanket.

But I had an Afrikaans Bible in my room. The faithful insinuate themselves everywhere, even in the frigid karoo!

The best part of this farm was the home-cooked meals. This is dinner for five people (Martim, Rita, their two daughters, and me), and it’s enough food for at least 15 people (we also had beer and soda). Lamb slices, mutton stew, two quiches, potatoes mixed with eggs, vegetables, vegetarian lasagne, and gravy.

Martim is an inveterate hiker, so he got up at 7 a.m. and walked around the property. He found a hole just dug by an aardvark (Orycteropus afer) as a burrow. (“Aardvark” means “earth pig” in Afrikaans.). Aardvarks are shy and are hard to see, but can dig at the rate of one meter every five minutes. Their evening burrows are from 1-6 meters long.

A footprint nearby, almost surely of the aardvark.

A succulent plant (probably from the iceplant family, Aizoaceae) from the dry areas. Lots of people uproot succulents to take them home for decoration. Not good for the environment.

A view of the karoo:

Martim, PCC(E) and Rita in the karoo, photo by one of their daughters.

On the way back to Capetown, we saw several signs saying “Watch for baboons” or “Be careful of baboons”.  The chacma baboon (Papio ursinus) can be either dangerous, boisterous, ravenous, or all three. You don’t want to be around one of these (I took the photo as we passed them in the car) if it’s had experience with human food. In some places they have even learned the noise that a beeper makes when you use it to open a car door, and have learned to rush to the car and open the door (and get inside) when they hear that noise, hoping to ransack the car for food. Martim was once knocked down by a boisterous chacma that jumped on his back.

. . . and the fulfillment of a culinary dream. Ever since I heard of bunny chow, an Indian-inspired workingman’s food in South Africa, I’ve wanted to try one. Yesterday Martim and Rita, while visiting a friend, happened upon a good place to get bunny chow, and phoned me. I asked for a “quarter bunny,” which you’ll see below. From Wikipedia:

Bunny chow, often referred to simply as a bunny, is an Indian South African fast food dish consisting of a hollowed-out loaf of white bread filled with curry and a serving of salad on the side. It originated among Indian South Africans of Durban. Throughout various South African communities, one can find cultural adaptations to the original version of the bunny chow, which uses only a quarter loaf of bread and is sometimes called a skhambane, kota (“quarter”) or shibobo, a name it shares with sphatlho, a South African dish that evolved from the bunny chow.

. . . The traditional Indian meal was roti and beans, but the roti tended to fall apart as a take-away item. To solve this, the centre portion of a loaf of white bread was hollowed out and filled with curry, then the filling was capped with the portion that was carved out.

. . . Bunny chow was created in Durban, South Africa, which is home to a large community of people of Indian origin.

Here’s a quarter bunny with lamb curry. It was terrific, and you can eat it with your hands, as is the custom, sopping up the curry with the bread removed when the quarter loaf is hollowed out to make a bread bowl (you can also get a half bunny).

Sure good eating, I gar-un-tee! (Photos by Martim.)

p.s. From the balcony of the house, we saw a whale disporting itself in the waters of the bay. This was just a few minutes ago (I’m writing at 8 a.m. South African time on Sunday.)

Meanwhile, in Dobrzyn, Hili has her eyes on the future – or the past:

Hili: I’m dreaming about spring. A: It’s summer now. Hili: So what?

Hili: Marzy mi się wiosna.
Ja: Teraz jest lato.
Hili: I co z tego?

Astronomers have confirmed the existence of exoplanets with extremely small orbits around their stars. But what about exoplanets that get close enough to be devoured by their star, and what if it’s an Earth-sized exoplanet? This is what a recent study accepted to AAS Journals hopes to address as an international team of more than 50 researchers investigated an Earth-sized exoplanet with an orbital period of only 5.7 hours, known as “ultra-short-period” (USP) exoplanets, that could eventually experience what’s known as tidal disruption, resulting in its devourment by its star. This study holds the potential to help researchers better understand the processes responsible for this, along with continuing to challenge our understanding of exoplanetary architectures, as well.

Here, Universe Today discusses this amazing research with Dr. Fei Dai, who is an Assistant Astronomer in the Institute for Astronomy at the University of Hawai’i and lead author of the study, regarding the motivation behind the study, significant results, potential follow-up studies, the significance of this exoplanet being Earth-sized, and whether this could occur in our own solar system. Therefore, what was the motivation behind this study?

“Tidal disruption could be a potential fate of rocky planets,” Dr. Dai tells Universe Today, as he notes a March 2024 study published in Nature that he was a co-author of and discusses tidal disruption, which was such a profound study that it was featured on the journal’s cover. “It seems like about 10 percent of sun-like stars might have engulfed their rocky planets. This system TOI-6255 is the best-known progenitor for those planet engulfment events. The tidal disruption of rocky planets allows us to probe their interior composition and compare with Earth.”

For the study, the researchers analyzed TOI-6255 b, whose radius is ~1.08 and mass is ~1.44 of Earth’s and located just over 20.4 parsecs (65.2 light-years) from Earth. However, while being Earth-sized holds promise for life, TOI-6255 b’s 5.7-hour orbit not only make this exoplanet far too hot for life as we know it to exist, but this also means its orbit takes it dangerously close to what’s known as Roche limit. This is the distance a smaller object can orbit a larger object until the larger object’s gravity tears the smaller object to pieces, along with TOI-6255 b also experiencing the aforementioned tidal disruption, which is a common occurrence throughout the cosmos, including black holes. Therefore, what were the most significant results from the study?

Dr. Dai tells Universe Today, “This planet is doomed for tidal disruption in 400Myr which is short on cosmic scale (~13Gyr). The planet is also tidally distorted to be football like in shape (10 percent deviation from sphere), in comparison Earth’s tidal distortion due to the moon is only 1e-7 [0.0000001] level.”

Regarding potential follow-up studies the researchers note they aspire to accomplish with NASA’s James Webb Space Telescope, Dr. Dai tells Universe Today, “Orbital phase curve study of this planet could confirm that it is indeed tidally distorted. We know what the phase curve should look like for a spherical planet, tidally distorted planet has a strong deviation from that. We can also see if the surface of the planet is covered by lava pool as would be expected on a planet this hot.”

USPs are exoplanets whose orbits are less than one day and whose masses are less than 2x the Earth. While intriguing, only about 100 USPs have been discovered with a 2014 study estimating approximately 0.5 percent exist around Sun-like stars and a 2019 study discussing their bulk composition (i.e., mass of its iron core and mantle). As noted, given their extremely short orbit, these worlds are likely too hot for life as we know it to exist, and along with USPs are the familiar “hot Jupiters” who orbit their stars in only a few days and astronomers estimate their population is in the hundreds. As their name literally implies, these worlds are Jupiter-sized or larger gas planets and are also potentially far too hot for life as we know it to exist. But what is the significance of TOI-6255 b being an Earth-sized planet as opposed to a Jupiter-sized planet, or larger?

Dr. Dai tells Universe Today, “Planets similar to Earth in size are most likely rocky i.e. mostly made of iron core and silicate mantle. They show us what terrestrial planets in other planetary systems are made of. Jupiter-sized planets are most certainly covered by thick hydrogen and helium atmospheres. Jupiter-sized planets are unlikely to harbor life.”

While TOI-6255 b isn’t due for disassembly for another 400 million years, watching any exoplanet get ripped to shreds by its host star could provide important insights regarding the planet’s exterior and interior compositions, thus helping us better understand the similarities between exoplanets and planets within our own solar system. These unique worlds and their extremely tight orbits have challenged our understanding of solar system architecture throughout our Milky Way Galaxy, as Mercury is the closest planet to our Sun, and it still takes 88 days to complete one orbit.

For now, one similarity between our solar system and exoplanetary systems is the Roche limit. However, the study also focuses on tidal disruption that is physically distorting TOI-6255 b, with Dr. Dai mentioning above that “Tidal disruption could be a potential fate of rocky planets”. Therefore, what are the chances of tidal disruption occurring for rocky planets in our solar system, and why?

Dr Dai tells Universe Today, “Tidal disruption of planets is minimal in our solar system. However, the rings of Saturn are thought to originate from tidal disruption of satellites around Saturn. Tidal forces are strongly dependent on orbital separation, only objects with the shortest orbital period experience significant tides.”

What new discoveries about tidal disruption on Earth-sized worlds will astronomers make in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

The post Good Thing We Found this Earth-Sized Planet Now. It’s About to Be Destroyed appeared first on Universe Today.

In 1974, astronomers Bruce Balick and Robert L. Brown discovered a powerful radio source at the center of the Milky Way galaxy. The source, Sagittarius A*, was subsequently revealed to be a supermassive black hole (SMBH) with a mass of over 4 million Suns. Since then, astronomers have determined that SMBHs reside at the center of all galaxies with highly active central regions known as active galactic nuclei (AGNs) or “quasars.” Despite all we’ve learned, the origin of these massive black holes remains one of the biggest mysteries in astronomy.

The most popular theories are that they may have formed when the Universe was still very young or have grown over time by consuming the matter around them (accretion) and through mergers with other black holes. In recent years, research has shown that when mergers between such massive objects occur, Gravitational Waves (GWs) are released. In a recent study, an international team of astrophysicists proposed a novel method for detecting pairs of SMBHs: analyzing gravitational waves generated by binaries of nearby small stellar black holes.

The study was led by Jakob Stegmann, a Research Fellow at the Max Planck Institute for Astrophysics (MPA) and the Gravity Exploration Institute at Cardiff University. He was joined by researchers from the Niels Bohr Institute, the Center for Theoretical Astrophysics and Cosmology at the University of Zurich (CTAC-UTZ), and the California Institute of Technology (Caltech). The study that describes the team’s findings, “Imprints of massive black-hole binaries on neighboring decihertz gravitational-wave sources,” recently appeared in Nature Astronomy.

First detected in 2015 by scientists at the Laser Interferometer Gravitational-Wave Observatory (LIGO), Gravitational Waves (GWs) are ripples in spacetime caused by the merger of massive objects like white dwarf stars and black holes. While multiple signals involving binary pairs of merging black holes have been detected, no GW events involving SMBHs have been detected because current Earth-based detectors are not sensitive to the very low frequency these events emit. Much like the issues facing ground-based observatories, scientists hope to remedy the situation by developing space-based instruments.

This includes the proposed Laser Interferometer Space Antenna (LISA), an ESA-led mission that is expected to launch sometime in 2035. Unfortunately, detecting mergers between the largest black holes in the Universe will still be impossible. However, Stegmann and his colleagues propose that binary SMBHs can be detected by analyzing the gravitational waves generated by smaller black hole binaries. Their proposed method leverages the subtle changes SMBHs cause to the GWs emitted by a pair of nearby smaller black holes.

In this respect, small black hole binaries work as a beacon, revealing the existence of larger pairs of merging black holes. As Stegmann explained in a recent UHZ press release:

“Our idea basically works like listening to a radio channel. We propose to use the signal from pairs of small black holes similar to how radio waves carry the signal. The supermassive black holes are the music that is encoded in the frequency modulation (FM) of the detected signal. The novel aspect of this idea is to utilize high frequencies that are easy to detect to probe lower frequencies that we are not sensitive to yet.”

Artist’s impression of the Laser Interferometer Space Antenna (LISA). Credit: ESA

However, the evidence that this proposed method offers would be indirect, coming from the background noise collectively generated by many distant binaries. Furthermore, it will require a deci-Hz gravitational-wave detector, which is far more sensitive than current instruments. For comparison, the LIGO detector measures GWs in the 7.0 kHz to 30 Hz range, whereas the Virgo Observatory can detect waves in the 10 Hz to 10000Hz range. By detecting the tiny modulations in signals from small black hole binaries, scientists could identify merging SMBHs ranging from 10 to 100 million Solar masses, even at vast distances.

As Lucio Mayer, a black hole theorist at the University of Zurich and a co-author of the study, added:

“As the path for the Laser Interferometer Space Antenna (LISA) is now set, after adoption by ESA last January, the community needs to evaluate the best strategy for the following generation of gravitational wave detectors, in particular which frequency range they should target – studies like this bring a strong motivation to prioritize a deci-Hz detector design.”

Further Reading: UZH, Nature Astronomy

The post Scientists Develop a Novel Method for Detecting Supermassive Black Holes: Use Smaller Black Holes! appeared first on Universe Today.

The ESA’s Mars Express orbiter captured an image of the remains of a vast ancient lake on Mars. The remnant lake bed has been weathered and altered by the passing of billions of years. In the planet’s distant past, scientists say, it held enough water to fill Earth’s Caspian Sea almost three times over.

The leading image shows a region on Mars called Caralis Chaos.

At first glance, it just looks like a vague outline of a depression scrambled and scarred by time, with Mars’ ubiquitous impact craters sprinkled throughout the image. But for scientists who study planetary surface features, the image is rife with clues—clues that connect it to Mars’ warm and watery ancient past and to the ensuing episodes of change the planet underwent.

The following topographical map brings clarity.

Red is high elevation, and blue is low elevation. The lakebed boundaries curve up and away from the bottom centre of the frame towards the top right, skirting around the large central crater. This is one of several lakebeds in the region that were once joined into one vast lake named Lake Eridania. Image Credit: ESA/DLR/FU Berlin. Licence: CC BY-SA 3.0 IGO or ESA Standard Licence

The ancient lakebed consists of several basins surrounding and including the Caralis Chaos region. In the distant past, they were all joined into one big lake named Lake Eridania. It had a surface area of about 1.1 million square km. The largest non-ocean body of water on Earth is the Caspian Sea, with a surface area of 389,000 km.

This image puts the Caralis Chaos region into context. It’s from a 2015 paper that focused on two parts of the Eridania Lake system: Atlantis Chaos and Simois Colles. Image Credit: Adeli et al. 2015.

Liquid water was likely abundant on early Mars between about 4.1 and 3 billion years ago during the Noachian and Hesperian Periods. Mars may have even hosted a massive ocean that covered about one-third of its surface. Eridania Lake was likely a single lake until the late Noachian when Mars gradually lost its water. During that period, the lake was fragmented into multiple smaller lakes.

The ancient lakebed is now punctuated with mounds. Scientists think Mars’ dusty winds initially formed the mounds. Later, they were covered by water, then the water disappeared, and they were exposed to the wind again.

This perspective view shows the mounds on the floor of ancient Lake Eridani. Image Credit: ESA/DLR/FU CC BY-SA 3.0 IGO

The floors of all of the basins that comprised Eridania Lake are covered by light-toned materials containing Fe/Mg-phyllosilicates. The region also has chloride, indicating that a playa region once existed here as the water receded. Some of the geological evidence in the region suggests that some surface water may have survived until long after the Noachian.

This diagram shows how volcanic activity may have caused the deposition of minerals on the floor of Lake Eridania. Chlorides were deposited along the shoreline by evaporation. Image Credit: By Jim Secosky chose this image NASA – https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA22060, Public Domain, https://commons.wikimedia.org/w/index.php?curid=63303061

There’s also evidence of volcanic activity. Two large faults called fossae run through the region. Collectively, they’re known as Sirenum Fossae.

This image shows the extent and depth of ancient Lake Eridania. It also shows Sirenum Fossae, two large faults in the Martian surface. Image Credit: By Jim Secosky modified NASA image – https://photojournal.jpl.nasa.gov/figures/PIA22059_fig1.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=63330708

The region between the two faults is called a graben, a depressed portion of the crust. Sirenum Fossae was formed as Mars’ Tharsis region, a vast volcanic plateau that’s home to Olympus Mons and Tharsis Montes, rose up and put enormous pressure on the crust.

This is a perspective view of one of the Sirenum Fossae fault lines. Image Credit: ESA/DLR/FU CC BY-SA 3.0 IGO

These images all come from the ESA’s Mars Express Orbiter. It has been orbiting Mars since 2004, mapping its surface and minerals and studying the planet’s interior, subsurface, and atmosphere. It has been in orbit for more than 20 years. The ESA has extended its mission until at least the end of 2026 and has given it a provisional extension until 2028.

The post An Ancient Martian Lake Was Larger Than Any Lake on Earth appeared first on Universe Today.

Interview with Forrest Valkai; News Items: Mark Edward, Moon Deep Storage, Pursuit of Happiness, Measuring Blood Pressure, First Complex Life on Earth, Life on Venus Update; Who's That Noisy; Your Questions and E-mails: AC vs DC; Science or Fiction

https://traffic.libsyn.com/secure/sciencesalon/mss455_Andrew_Chow_2024_08_10.mp3 Download MP3

As cryptocurrency rose in popularity during the pandemic, new converts bought into the idea that crypto would not only make them rich, but would usher in imminent revolutions across art, finance, politics, and gaming. Cryptocurrency caught the zeitgeist through figures like FTX CEO Sam Bankman-Fried, who only two years later would be convicted of one of the most calamitous acts of financial fraud in U.S. history.

During his meteoric rise, Sam Bankman-Fried outflanked idealists in the movement like Vitalik Buterin, who sought to build fairer, more democratic systems through Ethereum. Bankman-Fried pursued a growth-obsessed, by-any-means approach to crypto, which proved seductive to those who just wanted to get rich. But this Silicon Valley-like approach also drove the creation of a spate of high-risk financial instruments that mirrored those of the 2008 financial crisis. Accused of misleading investors and mishandling funds, Bankman-Fried became a target of prosecutors.

Now, Cryptomania unfolds the tumultuous twenty months inside this male-dominated, overhyped industry that led to its downfall. Drawing on exclusive reporting and an extensive network in the global NFT community, Andrew Chow chronicles the battle for crypto’s soul, and the human toll of its economic meltdown—from the conmen and eccentrics driving the bubble to the victims caught in its burst.

Andrew R. Chow is a correspondent for Time who covers technology, culture, and business. He has written four Time cover stories, including about the impacts of the AI corporate arms race and a prescient profile of Vitalik Buterin months before the 2022 crypto crash. He has previously written for The New York Times, Pitchfork, and NBC News. His first book is Cryptomania: Hype, Hope and the Fall of a Billion-Dollar Fintech Empire.

Shermer and Chow discuss:

• What is money?
• Fiat money without a gold standard
• Cash, coins, and credit cards
• Bitcoin and crypto currencies as the next step in financial transactions
• Crypto’s utopian philosophies
• What triggered crypto’s pandemic-era bull run.
• How the popularity of Non-Fungible Token (NFTs), served as a gateway to crypto, helping to fuel its rise—and then became one of its victims
• How NFTs were originally about the democratization of artistic creation and had the potential to help artists across the globe
• Sam Bankman-Fried’s (SBF) backstory, his interest in “effective altruism” and the “earn-to-give” philosophy, and his early career at a Wall Street trading firm where he developed his obsession with taking huge risks
• Did SBF believe his lies? Was he self-deceived?
• How SBF used his autistic-like behavior to convince people he was a misunderstood genius
• Risk-neutral behavior and crypto
• Effective altruism, utilitarianism, and deontological ethics
• Comparisons of SBF with Elizabeth Holmes
• SBF’s arrest and dramatic trial. Rather than plea guilty and take a deal, Sam, true to his risk-taking nature, gambled it all and took his case to trial
• The parallels between crypto and the problematic financial system it was meant to replace
• While crypto promised to dislodge predatory middlemen, all it did was create new ones, with less oversight and many of the same painful fees
• How the 2022 crypto crash closely mirrored the 2008 financial crisis. The 2008 bubble had been caused by risky mortgage loans repackaged into financial derivatives. The 2022 crypto crash was likewise brought down by hidden, interconnected chains of leverage, in which hedge funds, exchanges, and lenders played dangerous money games because they thought the market might keep expanding forever.

If you enjoy the podcast, please show your support by making a $5 or $10 monthly donation.

The amazing Gaia mission to chart stars in the Milky Way Galaxy is also an expert asteroid hunter. Now, astronomers are reporting its success at spotting more moons of asteroids in our solar system. Once the Gaia data from its release 3 are confirmed, those observations will add 352 more binary asteroids to the known count. That nearly doubles the known number of asteroids with moons and previous Gaia data releases also revealed asteroids in its survey.

The spacecraft’s observations uncovered these possible moons around at least 350 asteroids—making them binary systems. That’s in addition to the known binary asteroids—those objects with companions—that it found with its precise sweeps of the sky. The most recent discoveries come from “blind” astrometric surveys (not necessarily directed at any one part of the sky or specific objects) and show that the collection of asteroids is more complex than we thought.

“Binary asteroids are difficult to find as they are mostly so small and far away from us,” says Luana Liberato of Observatoire de la Côte d’Azur, France, lead author of a new study announcing Gaia’s results. “Despite us expecting just under one-sixth of asteroids to have a companion, so far we have only found 500 of the million known asteroids to be in binary systems. But this discovery shows that there are many asteroid moons out there just waiting to be found.”

The binary near-Earth asteroid 65803 Didymos and its moon Dimorphos. Imaged by the Double Asteroid Redirection (DART) spacecraft. Gaia is finding more such binaries in the Solar System. Courtesy NASA/Johns Hopkins APL. Gaia Astrometry for the Win

Astrometry used to be thought of as a fairly “boring” part of astronomy. It’s the precision study of the positions of objects in space. Not quite as exciting as finding new comets or charting new galaxies. Yet, it’s an important branch because, without it, we’d have more difficulty finding things like planets around stars. Those are notoriously difficult (if not impossible) to detect using imaging techniques. However, a star’s position in space changes thanks to gravitational tugs from its planets. Thanks to precise astronometric measurements made by Gaia and other instruments, astronomers can detect the minute shifts in stellar positions.

It turns out that Gaia’s astrometric abilities are precise enough to detect similar shifts in the positions of asteroids. For example, in one of its data releases, the spacecraft’s survey pinpointed the positions and motions of more than 150,000 asteroids. Those positions were precise enough that researchers could detect very tiny shifts in their positions over time. Those shifts meant that the asteroids had companions influencing their positions and motions in space.

Not only did the instruments onboard Gaia measure those positions accurately, they also allowed scientists to do “asteroid chemistry”. The data it gathered consisted of spectra of the reflected light from each asteroid. The spectra show the fingerprints of an asteroid’s surface composition. Future measurements are expected from the spacecraft in the coming years as part of its data release 4.

A chart of Gaia asteroid science. Courtesy ESA. Why Asteroids?

The Solar System is a collection of objects consisting of one star, multiple planets, moons, rings, comets, and asteroids. Those last two categories sometimes get lumped together as “leftovers of planet formation.” They are, indeed, the materials that didn’t coalesce into planets and moons. As such, they also contain a lot of information about what conditions were like in the original nebula where the Sun and planets formed. That includes insight into the distribution of rocky and icy materials. In addition, as we’re seeing with the Gaia measurements, binary asteroids appear to be a normal part of that population of small rocky/icy bodies that exist throughout the Solar System.

Asteroids are sorted into “families” based on their orbits and other characteristics. The largest collection exists in the Asteroid Belt, which lies between Mars and Jupiter. There are also other collections that orbit the Sun at other distances—such as the near-Earth asteroids. As we see with the discovery of more binary asteroids, not all of these objects orbit alone. Binaries show us that asteroids can collide after formation, re-coalesce, and interact with each other in space. And, the Gaia mission is showing that performing precise astrometric measurements of objects in our solar system is opening up a new avenue of asteroid studies. It should help answer the many questions about asteroids, their moons, and the evolution of their orbits.

The Future of Asteroid Moon Studies

Future studies of these objects (whether binary or singular) lie with Gaia and other telescope observations. Those should help settle some theories in the scientific community about how binary asteroids form. At the moment, there are several ideas, including creating rubble piles of material orbiting together after some catastrophic event. Another theory suggests that asteroids are what’s left after a moon or other body breaks up by collision or gravitational interaction with a larger body. Any fresh insights will depend on more data from Gaia and other studies of these fascinating objects.

So, far from being a boring “bookkeeping” exercise in astronomy, thanks to Gaia, astrometry enables astronomers and planetary scientists to further our knowledge of the solar system and its complex collection of objects.

For More Information

Gaia Spots Possible Moons Around Hundreds of Asteroids
Gaia Mission
Astrometry Overview

The post Gaia Finds Hundreds of Asteroid Moons appeared first on Universe Today.

UPDATE: I looked up Dawkins’s FB account and got this, showing no posts at all, even the ones from 2017 mentioned below:

I received this message from both the UK and US. Apparently Richard Dawkins’s Facebook account, except for two entries dating back to 2017, has been deleted because he criticized the Olympics allowing putative XY boxers, which are likely phenotypically and genetically male, to box against biological women in the Olympics. (See my posts here and here.)

I haven’t been much on the internet since I’m sightseeing and also have only sporadic connection to the world, so I’m not sure how this issue has shaken out. There are debates about whether the two boxers in question were of XY chromosome constitution, had high levels of testosterone (they had previously been disqualified in other competitions), or had genetic disorders of sex development (DSDs).

But regardless, to ban someone’s account for expressing the opinion that genetically male boxers shouldn’t fight against biological women is unconscionable. mRichard said that one of the boxers is “XY undisputed,” and since I’ve been out of touch, that may be the case.  And if that is the case, then there is a real debate to be had.

There’s a general debate to be had about these boxers anyway since, last I heard, people were arguing about every aspect of the two is subject to dispute.

Facebook botched this one very badly, and should restore Dawkins’s account.  What he wrote below is apparently on Twitter.

If some knowledge about these boxers has become generally accepted in the past week, please add it below. I know that Colin Wright has been following the case and wrote a Substack post a week ago called “Fact vs. fiction: Olympic boxer Imane Khelif is male and should not be allowed to fight women.” He also has a new post, which I haven’t yet read, subtitled, “There are no good reasons to doubt the IBA’s claim that both Khelif and Yu Ting have XY chromosomes.”

Richard’s Facebook post

Meanwhile, in Dobrzyn, Hili is becoming demanding, as cats can be:

Hili: You have to renounce your immunity. A: What immunity is that? Hili: The one which protects you from accountability for an empty bowl.

Hili: Musisz zrzec się immunitetu.
Ja: Jakiego znowu immunitetu?
Hili: Chroniącego cię przed odpowiedzialnością za pustą miseczkę.

Supermassive Black Holes (SMBHs) are located in the centers of large galaxies like ours. When they’re actively feeding, they produce more light and are called active galactic nuclei (AGN). But their details are difficult to observe clearly because large clouds of gas block our view.

The JWST was built just for circumstances like these.

New research published in the Monthly Notices of the Royal Astronomical Society (MNRAS) presents JWST observations of an SMBH in a galaxy about 70 million light-years away. The telescope found polar dust surrounding the SMBH. It was outside the expected torus of dust that directly accretes onto the black hole that researchers call the accretion disk. The polar dust is heated, but rather than being heated by the radiation coming from the heated accretion disk, the gas is heated when by energetic shock waves that come from relativistic jets.

The research is titled “Dust beyond the torus: revealing the mid-infrared heart of local Seyfert ESO 428-G14 with JWST/MIRI.” The lead author is Houda Haidar, a PhD student in the School of Mathematics, Statistics, and Physics at Newcastle University in the UK. Houda and her co-researchers are members of GATOS, the Galactic Activity, Torus, and Outflow Survey. According to the GATOS website, GATOS is an international team using the JWST to “crack the enigma that is active galactic nuclei.”

“Having the opportunity to work with exclusive JWST data and access these stunning images before anyone else is beyond thrilling,” said Houda. “I feel incredibly lucky to be part of the GATOS team. Working closely with leading experts in the field is truly a privilege.”

This is the JWST’s first look at the galaxy in question, ESO 428-G14, but it’s not astronomers’ first look at it. They’ve been observing the galaxy—called a Seyfert galaxy because of its high luminosity—for decades. The astronomy community has used several telescopes to examine the galaxy, including ALMA and the Hubble, and that data forms part of this work.

The challenge in observing this AGN, and many others like it, is dust. The thick, extensive clouds of dust and gas that eventually feed the black hole block our view of it. The JWST’s job description is to pierce dust like this and get a clearer look into these obscured regions.

The JWST has four primary science themes, one of which is Galaxies Over Time. A combination of processes drives galaxy evolution, and active galactic nuclei are part of the picture.

Active galactic nuclei can emit relativistic jets of material from their poles that, in some cases, can extend hundreds of millions of light-years into space. ESO 428-G14 is no different; it emits radio jets from its poles. Astrophysicists know that gravitational and magnetic forces are behind these jets, but the exact mechanism behind them is unknown and is an active area of research.

The jets could be the key to understanding SMBHs, how they recycle material in galaxies, and the dust that accumulates around them in a torus. “For decades, the dusty torus has been held responsible for the dichotomy between type?1 and type?2 active galactic nuclei (AGN), forming the keystone of AGN unification,” the authors write.

The unified AGN model states that types 1 and 2 AGN are differentiated by their viewing angles rather than by any fundamental differences between the two. Type 1 is viewed more face-on relative to the dust torus, displays broad emission lines in its spectra, and has visible accretion disks. Type 2 is viewed more edge-on relative to the torus, has narrow emission lines, and has obscured accretion disks.

Some AGN have polar dust that’s separate from their torus dust. Many models predict that this dust is energized by the jets that come out of its poles. “However, little is known about its characteristics, spatial extent, or connection to the larger scale outflows,” the researchers write in their paper. This is “the first JWST/MIRI study aimed at imaging polar dust by zooming on to the centre of ESO 428-G14.”

The JWST found extended Mid-infrared emissions that extended to 650 light-years from the AGN. The structure of this polar dust is co-linear with a radio jet emitted by the AGN. But the dust is perpendicular to a molecular gas lane that’s feeding the AGN and obscuring it. This is important evidence for the presence of polar dust. “Its morphology bears a striking resemblance to that of gas ionized by the AGN,” the authors write.

This figure from the research illustrates some of the results. The left panel is a JWST/MIRI F1000W image showing the MIR structure of the circumnuclear disc along with the small-scale nuclear extensions. The right panel is a Hubble image of the same in optical light. The inset is the radio jet coming from the AGN. Image Credit: Haidar et al. 2024.

This brings us back to the ongoing debate about how AGN energize the gas and dust in their environment. What role do the jets play vs what role does electromagnetic radiation from the AGN play? One line of evidence shows that dust absorbs electromagnetic radiation emitted by the heated dust in the accretion disk.

However, the new JWST images show that much of the polar dust emission is extended and spread out along the jets’ paths. This clearly implies that the jets are responsible for heating and shaping the dust, and radiation from the AGN plays a lesser role. The accretion dust and the polar dust have different temperatures, and that provides clues about how different parts of the AGN are heated differently. Jet-induced shocks could be responsible for the heat differences between the polar dust and the accretion dust.

“There is a lot of debate as to how AGN transfer energy into their surroundings. We did not expect to see radio jets do this sort of damage. And yet here it is!” said Dr David Rosario, Senior Lecturer at Newcastle University and co-author of the study.

The post The JWST Reveals the Nature of Dust Around an Active Galactic Nuclei appeared first on Universe Today.

The covid-19 variant JN.1 may have been able to evade antibodies and spread globally due to one critical mutation to its spike protein

A new artificial intelligence model can predict how different proteins may bind to DNA.