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I think I’ve already mentioned some things about the giant and fantastic Kruger National Park in NE South Africa, but let’s start with the basics, which means some information and a map from Wikipedia:

Kruger National Park (Tsonga: [ˈkrúːɡà]; Afrikaans: [ˈkry.(j)ər]) is a South African National Park and one of the largest game reserves in Africa. It covers an area of 19,623 km2 (7,576 sq mi) in the provinces of Limpopo and Mpumalanga in northeastern South Africa, and extends 360 km (220 mi) from north to south and 65 km (40 mi) from east to west. The administrative headquarters are in Skukuza. Areas of the park were first protected by the government of the South African Republic in 1898, and it became South Africa’s first national park in 1926.

Here it is below, in red. It’s HUGE! It’s bordered on the east mostly by Mozambique, but we also visited a spot in the north called “Crook’s Corner,” where three countries (South Africa, Mozambique, and Zimbabwe) meet. You can see that spot at the top of the reddish park map below, and it’s where poachers and other criminals used to flee one country to avoid the law by simply stepping across the border (this involves crossing a river) to to one of the other two countries, where they were from from pursuit. Nowadays immigrants from Mozambique cross the river into Kruger seeking a better life in South Africa.

For those who know the park, we entered at the Phalaborwa gate, did a zig-zag heading generally north, often taking dirt roads and taking diversions based on what Isaac heard from his fellow guides and from his own instincts.

We exited the park at the Orpen gate after having stayed four nights in comfortable and inexpensive bungalows: two at Shingwedzi and two at Pafuri. We had about 4.5 days of wildlife watching, at least eight hours a day. I’ll try to reconstruct a map of our travels in the next few days.

Go here to see a good map of the park that includes these locations. If you look at the map, you’ll see that to its west Kruger is surrounded by private game parks and nature reserves. Almost none of these have fences, allowing the animals to transit as they please over a huge area.

But a last meal before I left. A quarter bunny chow in Hoedspruit with beef (the mutton was better but this is still good). It’s filling, cheap, and tasty: a hollowed- out bread bowl (a quarter of a loaf) filled with curry. Note the perfucnctory “salad” to the side.

And the Hoedspruit version of a chocolate milkshake, which was very good:

On to the park. I recommend clicking on the photos to enlarge them.

This is the Phalaborwa gate where you formally enter the park in the north (there are nine entrance gates). You pay by the day on a sliding scale, with South African residents paying about a quarter of what foreigners do, which is fair given the difference in income. The money is for badly needed conservation fees.

Gates are strictly monitored, and open and close at roughly 6 a.m. and 6 p.m. respectively. This is also true of the 12 main “bush camps” where you can stay in well-equipped huts (there are also a couple of fancy private lodges, and “bushveld camps” with fewer facilities). If you are late and the camp is closed, you can still get in (with a reservation), but you have to pay a substantial “fine.”

At the entrance, and throughout the park, there are “sightings boards” showing which charismatic animals have been seen where and when (yesterday or today).  Note that they do NOT post sightings of rhinos because the poachers are, above all, after rhino horns, used in traditional Chinese medicine.

As I mentioned in previous posts. The rangers try to anesthetize all the park’s rhinos and cut off their two horns to prevent the animals from being killed by poachers, but the horns grow back and the process has to be repeated every four years or so.

Our first sighting of animals, apparently a pair of storks. I can’t remember the species.

Our guide Isaac told us that this is a group of social spiders who live in a sac attached to a large, insect-catching web. I believe this is a group of Stegodyphus mimosarum, the African social velvet spider. Individuals in a colony share food and care of the young spiders:

This zoomed-in shot of a raptor with a white chest may be an African hawk-eagle (Aquila spilogaster), but I can’t be sure. Later on we saw and identified a similar-looking species, the booted eagle (Hieraaetus pennatus).

Our first sighting of a mammal that became quite familiar to us, the African bush elephant (Loxodonta africana). (There’s also an African forest elephant in the same genus.) According to a recent census, there are roughly 13,0o0 elephants in Kruger, and the numbers are rising (there were only 725 in 2006).

There is continual debate about whether the increasing population poses a danger to the park, as they knock down trees and displace other species, and for a while they “culled” (i.e., shot) elephants to control the population. Of course big-game hunters in other places shoot them as trophies (an execrable practice), but it’s hard to think about mass killings of these beautiful and highly intelligent creatures when you’ve spent some time watching them.

Here are some small Lala Palms (Hyphaene coriacea). These are small ones, but, as Wikipedia notes,

The spongy pulp of the hard, brown fruit is edible and the fruit is eaten and sold in Madagascar and in eastern Africa; its Swahili name is Mkoma. The flavour has been compared to raisins and raisin bran.

Hippos (Hippopotamus amphibius) are hard to see out of the water, as they prefer spending their days submerged except for their eyes and nose, and generally come out of the water to graze only at night.  (Their skins are very sensitive to sunlight, something you’d think natural selection should remedy.) But on cool days you can see them grazing, always near water.

Here are two. They are considered among the world’s most dangerous animals because they are aggressive, unpredictable, and can run surprisingly fast.  500 people per year are killed by hippos, compared to only 22 for lions, but people are far more scared of lions.

This is a poorly-exposed photo that I included because it’s part of my “animals crossing roads series”.  These are very common antelopes that get no respect because they’re so common in the park: the impala (Aepyceros melampus). They’re everywhere and one tends to overlook them, but they’re very beautiful. Males have horns and females don’t, so these are females.

A larger antelope, the greater kudu (Tragelaphus strepsiceros) with the characteristically spiral horns found only in males. They’re easily identified because both sexes are striped.

Remember, since you’re not allowed to leave your car, all these animals were photographed through open windows in our vehicle. Ergo, most were pretty close to the roadside. Most mammals, save zebras and some antelopes like impala, pretty much ignore cars, although a big bull elephant in the road threatened to charge us after spitting a rare piece of paper at us. Isaac, knowing the signs of elephant aggression (tilting the head sideways is a telling one), backed up the car slowly, and the elephant strode away.

Elephant crossing the road:

A Burchell’s zebra (Equus quagga burchellii) crossing the road. You will see several of these photos in the coming days because it is a ZEBRA CROSSING (in the UK that’s the name for a pedestrian crosswalk).

A rare spot despite its name, here are a few common tsessebe (Damaliscus lunatus lunatus) crossing the road.

A better shot of the tsessebe. In this species both sexes have horns. Horns in males only are a sign of sexual selection, but in some species males have larger horns than females, also indicating sexual selection but likely natural selection as well, giving some reproductive advantage to horned females.

Fun tsessebe facts from Wikipedia:

Several of their behaviors strike scientists as peculiar. One such behavior is the habit of sleeping tsessebe to rest their mouths on the ground with their horns sticking straight up into the air. Male tsessebe has [sic] also been observed standing in parallel ranks with their eyes closed, bobbing their heads back and forth. These habits are peculiar because scientists have yet to find a proper explanation for their purposes or functions

A herd of one of Africa’s most dangerous animals, the African buffalo (Syncerus caffer), a member of the “big five” referred to below; these are animals that are regarded as the most dangerous to hunt and kill with either spear or gun (the other four are lions, rhinos, leopards, and elephants):

One of the “big five” African game, it is known as “the Black Death” or “the widowmaker”, and is widely regarded as a very dangerous animal. African buffaloes are sometimes reported to kill more people in Africa than any other animal, although the same claim is also made of hippopotamuses and crocodiles. These numbers may be somewhat overestimated; for example, in the country of Mozambique, attacks, especially fatal ones, were much less frequent on humans than those by hippos, and especially, Nile crocodiles. In Uganda, on the other hand, large herbivores were found to attack more people on average than lions or leopards and have a higher rate of inflicting fatalities during attacks than the predators (the African buffalo, in particular, killing humans in 49.5% of attacks on them), but hippos and even elephants may still kill more people per annum than buffaloes. African buffaloes are notorious among big-game hunters as very dangerous animals, with wounded animals reported to ambush and attack pursuers.

In male buffalo, the horns grow together, fusing in the middle of the head in a structure known as a “boss.” This one doesn’t have a boss:

Here’s a “boss” male with the fused horns, as well as an oxpecker nibbling at his nose.

Below: the most iconic tree in Africa, the Baobab (Adansonia digitata). I didn’t see it leafed out (that’s during the African summer), but it’s unmistakable because of its large, bulbous trunk (It’s actually classified not as a tree but a succulent.) There are 8 species, but only this one is endemic to mainland Africa (6 others are native to Madagascar and one to Australia.

They can get very old (carbon dating puts an age limit of about 2,000 years). The tree has many uses for man, beast, and bird. Young leaves can be stewed as a vegetable, the roots and fruits are edible, and the seeds can be made into a flour. The bark can be made into fiber and clothes, and, in times of drought, elephants eat the water-rich underbark. And as for birds, see the second photo below.

There are often signs under baobabs in the park, and here’s one of them. What kind of miscreant would throw stones at owl holes?

The lovely impala lily (Adenium multiflorum), native to eastern and southern Africa. It’s a small succulent tree and was blooming everywhere in the dry winter season of our visit. The flowers are gorgeous and trees are planted widely around the camps.

Another baobab. I’d love to see these in the wet summer.

Isaac, the crack spotter, suddenly asked me out of nowhere, “Would you like to see a giraffe lying down?” I said, “Sure,” and asked him if this was an unusual event. He said “yes”.  Sure enough, Isaac had spotted two of them far before I could see them:

You may have wondered if giraffes sleep. The answer is, “Yes, but not much,” probably because they have to keep alert for predators (they can be taken down by lions, leopards, hyenas, and wild dogs, all of whom first go for the legs). Here’s some info about giraffe sleep from one website:

To start, let’s clarify that giraffes only sleep a few hours a day.

Some giraffes don’t even sleep that much. In captivity, adult giraffes have been observed sleeping as much as four and a half hours a day. In the wild, giraffes might only sleep about 40 minutes a day—and only about three to five minutes at a time.

Researches have observed three types of sleep in giraffes: standing, recumbent, and paradoxical. The latter sleep type is similar to REM (rapid eye movement) sleep. Standing sleep is characterized by a giraffe standing up, yet motionless, with its head tilted slightly more forward than it is when awake. This is thought to be essentially a light nap for giraffes and makes up a majority of their sleep.

During recumbent and paradoxical sleep, a giraffe can be observed lying down with their legs folded under them, their neck turned and arched backward and their heads resting on their rumps or the ground—similar to a swan.

When they drink at a waterhole, giraffe splay their legs widely to lower their body, allowing that long neck to reach the water.

A non-napping giraffe:

Zebra crossing!

We crossed the Tropic of Capricorn, where it’s allowed to leave the vehicle. I love official lines like the Equator (which I’ve also straddled) and borders between countries.

The Tropic of Capricorn is explained in the second photo below: it’s the furthest latitude south where the Sun appears directly overhead. That event occurs around December 21, the Winter Solstice in the northern hemisphere. Wikipedia notes that this is “the dividing line between the Southern Temperate Zone to the south and the Tropics to the north.”

Of course I had to straddle it: the line of rocks running between my legs.  Now I can say that I’ve stood astride this line, as well as the Equator. (I can’t remember standing on the Tropic of Cancer; the closest place to Chicago would be in Mexico.)

The explanation:

Two more giraffes. I couldn’t get enough of these majestic and beautiful animals. They’ve evolved, of course, to access leaves high up on trees that other animals can’t reach: an adaptation that comes with several costs.  They give birth standing up and the babies have a long tumble to the ground, which animates them to start their lives.

Here’s a giraffe giving birth in the wild. The baby takes its first wobbly steps within only a few minutes:

I believe I’ve discussed before the phenomenon of “dagga boys”: African buffalo who have been expelled from their herd because they’re old and can’t hold a position in the hierarchy (ca. ten years). They must thus wander, solitary or with a couple of other dagga boys, until they die or are taken down by predators like lions. They often roll in the mud because they have skin conditions, and are especially dangerous because, lacking the defense of their herd, they’re prone to attack.

In a later installment we’ll see the remains of a dagga boy killed by lions. These solitary animals, I think, must be lonely, and I find them ineffably sad. But such is nature.

A lovely male of the Greater Kudu.

And a giraffe sticking out its tongue:

One of the most amazing things we saw on day 1 (and remember, this is only the first of five days) was a huge herd of elephant digging for water in a dry river bed. Apparently elephants have a way of detecting water close to the surface, and when they find it, and are thirsty, they use their legs, tusks, and trunk to excavate a well that can be more than a meter deep. Here’s one female digging for water, and she found it:

This is only a small number of the more than fifty elephants I counted in the vicinity, and they’re all either digging for water or trying to get water from holes dug by others. Naturally the diggers wants a monopoly on their water and try to drive interlopers away, except for mothers who allow their babies to drink with them.  An elephant can take in 100 liters at a time, and about 240 liters per day.

Two photos of a mom allowing her baby to drink:

A bit more than half the group (I couldn’t get them all in one photo):

Finally, a male giving us the stink eye. Notice also that there are impala, kudu, and a single Marabou Stork  (Leptoptilos crumenifer) to the right of the elephant.

That was just Day One. There’s lots to come, but we made camp before closing time and had dinner (there are small and inexpensive restaurants in the camps).

More when I get time, probably tomorrow.

Meanwhile, in Dobrzyn, Szaron gives Hili an enigmatic reply:

Hili: Are you thinking?
Szaron: No, I’m still asleep.

Hili: Czy myślisz?
Szaron: Nie, nadal śpię.

Watching the Olympics recently and the amazing effort of the hammer throwers was a wonderful demonstration of the radial velocity method that astronomers use to detect exoplanets. As the hammer spins around the athlete, their body and head bobs back and forth as the weight from the hammer tugs upon them. In the same way we can detect the wobble of a star from the gravity of planets in orbit. Local variations in the stars can add noise to the data but a team of researchers have been studying the Sun to help next-generation telescopes detect more Earth-like planets. 

To date 5,288 exoplanets have been discovered, that’s 5,288 planets in orbit around other star systems. Before 1992 we had no evidence of other planetary systems around other stars. Since then, and using various methods astronomers have detected more and more of the alien worlds. Techniques to detect the exoplanets range from monitoring starlight for tiny dips in brightness to studying the spectra of stars. Just over 1,000 exoplanets have been discovered using the radial technique making it one of the most successful methods. 

“Icy and Rocky Worlds” is a new exoplanet infographic from Martin Vargic, an artist and space enthusiast from Slovakia. It’s available as a wall poster on his website. Image Credit and Copyright: Martin Vargic.

The local variations in the properties of stars has made it difficult to find smaller planets using the radial technique but a team of astronomers led by Eric B. Ford from the Department of Astronomy and Astrophysics at the Penn State University has just published a report of their findings following observations of the Sun. Observations of the Sun between January 2021 and June 2024 using the NEID Solar spectrograph at the WIYN Observatory have informed their study. 

A gas giant exoplanet [right] with the density of a marshmallow has been detected in orbit around a cool red dwarf star [left] by the NASA-funded NEID radial-velocity instrument on the 3.5-meter WIYN Telescope at Kitt Peak National Observatory, a Program of NSF’s NOIRLab. The planet, named TOI-3757 b, is the fluffiest gas giant planet ever discovered around this type of star.

Across the 3 years and 5 months of observations, the team identified 117,600 features which are not likely to have been caused by the weather, hardware or calibration issues so they could be used for their study. Given that the distance between the Sun and Earth is precisely known the team can use this to analyse solar observations and measure other solar variability. 

Impressively the team have been able to show that the NEID instrumentation is able to measure radial velocity of the Sun accurate to 0.489 m/s-1. Using this data the team conclude that Scalpels algorithm (a technique developed for medicine that uses machine learning to analyse and extract data from images) performs particularly well. It can reduce the root mean square (used to analyse signal amplitude) of solar radial velocity from over 2 m/s-1 down to 0.277 m/s-1! 

The results are significantly better than previous studies at removing solar variability from its radial velocity observations. This suggests that the next generation of exoplanet radial velocity instruments are capable, at least technically at detecting Earth-massed planets orbiting a star like the Sun. This does of course require sufficient observing time which the team estimate would be about 103 nights of observations. 

Source : Earths within Reach: Evaluation of Strategies for Mitigating Solar Variability using 3.5 years of NEID Sun-as-a-Star Observations

The post By Watching the Sun, Astronomers are Learning More about Exoplanets appeared first on Universe Today.

Our Sun is one of the most fascinating objects in the universe and photographing it with specialized equipment to capture its splendor and beauty has become increasingly more common around the world. This is most evident with the work obtained by renowned astrophotographer, Andrew McCarthy (@AJamesMcCarthy), who owns Cosmic Background Studios in Florence, Arizona.

On July 27, 2024, McCarthy posted an image of the Sun on X (formerly known as Twitter) taken with his specialized equipment designed to safely photograph our life-giving star, which revealed active coronal loops and plasma within the solar chromosphere that are some of the many intriguing features of the Sun. However, McCarthy is quick to mention in his post that this image isn’t entirely genuine, but a combination of several attributes.

My recent solar print release drew a lot of questions about some of the features of the sun… particularly in this close up. The second post in this thread features a time-lapse showing how these coronal loops moved over time. pic.twitter.com/AdzVOhr55S

— Andrew McCarthy (@AJamesMcCarthy) July 27, 2024

“This image is a piece of digital art that combines real astrophotos with some rendered features,” McCarthy tells Universe Today. “I captured the solar chromosphere with a solar-modified telescope, designed to block out the photosphere’s light to reveal the faint structure in the Sun’s atmosphere. The corona was captured during April’s total solar eclipse. Between the large-scale and small-scale structures of the photos, there’s a lot going on invisibly with the Sun’s magnetic field. Using some real data of that field as reference, I rendered coronal loops in a plausible way to show a more complete image of the scales of magnetic structure on the Sun.”

The solar chromosphere is the second layer of the Sun’s atmosphere residing above the Sun’s surface, known as the photosphere (4,130 to 6,330 °C), and below the corona (just under 1,000,000 °C). The chromosphere is known for its red color that is observed hydrogen-alpha electromagnetic emissions and extends between 3,000 to 5,000 kilometers (1,900 to 3,100 miles) in height, which is approximately one percent of the Sun’s radius, while exhibiting temperatures ranging between 3,500 to 35,000 °C. It is the solar chromosphere that is responsible for producing coronal loops, which are arch-like structures produced by the Sun’s magnetic field activity, typically occurring from sunspots. In addition to the incredible image, McCarthy also posted an equally incredible 14-second video of these incredible features in action.

You can see the plasma guided back onto the solar chromosphere by the magnetic loops in this time-lapse. Wild!

See the full photo of the sun featuring the solar corona on my website here. I also have limited edition prints available for a short time. https://t.co/jHkqjin72c pic.twitter.com/sBK0N8KFMV

— Andrew McCarthy (@AJamesMcCarthy) July 27, 2024

McCarthy tells Universe Today, “These are an example of the magnetic loops captured authentically by isolating the plasma caught in them. This produces coronal rain, plasma raining back onto the photosphere.”

Our Sun is essentially a giant ball of plasma that is undergoing constant change, both within its interior and on its surface, including radio waves, solar wind, and magnetic field. Studying the magnetic field teaches scientists about 22-year cycles where the poles of the magnetic field flip and then return to their initial position, resulting in increased solar activity occurring over 11-year cycles during each transition. This increased magnetic field activity results in increased solar wind emanating from the Sun, leading to solar storms that can strike Earth, causing auroras near our planet’s poles while also harming satellites in orbit and electronic ground stations. One of the most revered incidents of solar storms on Earth was the Carrington Event, which occurred between September 1-2, 1859, resulting in worldwide auroras and telegraph station fires across the globe, as well.

Scientists who study the Sun and its various features are known as solar physicists who use a combination of ground- and space-based telescopes to obtain data regarding the Sun’s activity on a 24/7 basis. Arguably one of the most successful missions to study the Sun is NASA’s Parker Solar Probe, which was launched on August 12, 2018, and has traveled closer to the Sun than any human-made spacecraft in history, coming within 7.26 million kilometers (4.51 million miles) from the Sun’s surface in September 2023 and again in March 2024. During its mission, the Parker Solar Probe encountered magnetic field switchbacks, which is when the magnetic field reverses its direction, resulting in heating the solar corona.

Examples of ground-based telescopes that study the Sun include the Mauna Loa Solar Observatory, which like McCarthy, uses specialized equipment to safely study the Sun and its various features, providing data and images that can be used for research and public outreach. Therefore, how can McCarthy’s work be used for scientific research, and has his past work been used for scientific research purposes?

“This image is in no way intended for scientific research, but rather a product of scientific research,” McCarthy tells Universe Today. “That said, hydrogen alpha images of the sun offer real insight into the behavior of the sun’s magnetic field and are used by scientists worldwide. Amateurs capturing the sun in detail can complement the data produced by professional observatories on earth and in space and play a role in public outreach that can sometimes be lacking by professional institutions.”

McCarthy has become well-known for capturing incredible images of the Sun and sharing them with the public, including breathtaking images and videos of tornado-like prominences emanating from the solar chromosphere in March 2023, which also captured images of the solar corona. Along with these images, McCarthy provides detailed descriptions of the events occurring in his work with the goal of exciting the public about the Sun and its many incredible features.

“The Sun is unique in that every time I photograph it, it looks completely different,” McCarthy tells Universe Today. “The features are always changing. For that reason, it’s a target I will keep coming back to. While intended purely as a piece of digital art, my goal with this piece was to inspire people to ponder our fragile existence kept in balance by our host star. Hopefully it inspires more people to study it, as it gives us a better understanding of this universe we live in!”

What new discoveries will we make about our Sun in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

Links:

Andrew McCarthy: X (Twitter) & Website

The post Coronal Loops-Digital Art Combination Captures Power of the Sun, Rendered by Andrew McCarthy appeared first on Universe Today.

The Standard Model describes how the Universe has evolved at large scale. There are six numbers that define the model and a team of researchers have used them to build simulations of the Universe. The results of these simulations were then fed to a machine learning algorithm to train it before it was set the task of estimating five of the cosmological constants, a task which it completed with incredible precision. 

The Standard Model incorporates a number of elements; the Big Bang, dark energy, cold dark matter, ordinary matter and the cosmic background radiation. It works well to describe the large scale structure of the Universe but there are gaps in our understanding. Quantum physics can describe the small scale of the Universe but struggles with gravity and there are questions around dark matter and dark energy too. Understanding these can help in our understanding of the evolution and structure of the Universe. 

Enlarged region of the Saraswati Supercluster, the largest known structure in the Universe, showing the distribution of galaxies. Credit: IUCAA

A team of researchers from the Flatiron Institute have managed to extract some hidden information in the distribution of galaxies to estimate the values of five of the parameters. The accuracy was a great improvement on values that were attained during previous attempts. Using AI technology the team’s results had less than half the uncertainty for the element that describes the clumpiness of the Universe than in the previous attempt. Their results also revealed estimates of other parameters that closely resembled observation. The paper was published in Nature Astronomy on 21 August. 

The team generated 2,000 simulated universes after carefully specifying their cosmological parameters. These included expansion rate, the distribution and clumpiness of ordinary matter, dark matter and dark energy and using these the team ran the simulations. The output was then compressed into manageable data sets and this was used to compare against over one hundred thousand real galaxies data. From this, it was possible for the researchers to estimate the parameters for the real Universe. 

The parameters the team managed to fine tune are those that describe how the Universe operates at the largest scale. These are essentially, the settings for the Universe and include the amount of ordinary matter, dark matter, dark energy, the conditions following the Big Bang and just how clumpy the matter is. Previously these settings were calculated using observations from the structure of galaxy clusters. To arrive at a more accurate group of settings observations needed to go down to smaller scale but this has not been possible. 

The full-sky image of the temperature fluctuations (shown as color differences) in the cosmic microwave background, made from nine years of WMAP observations. These are the seeds of galaxies, from a time when the universe was under 400,000 years old. Credit: NASA/WMAP

Instead of using observations, the team used their AI approach to extract the small scale information that was hidden in the existing observational data. At the heart of the approach was the AI system that learned how to correlate the parameters with the observed structure of the Universe – but at small scale. 

In the future the team hope to be able to use their new approach to solve other problems. The uncertainty about the Hubble Constant is an example where the team hope AI can help to fine tune its value. Over the next few years though, and as observational data becomes more detailed both Hubble’s Constant and the Settings of the Universe will become far better understood along with our understanding of the Universe. 

Source : Astrophysicists Use AI to Precisely Calculate Universe’s ‘Settings’

The post Estimating the Basic Settings of the Universe appeared first on Universe Today.

Can you spot the African bush elephant (Loxodonta africana) in this photo? It’s not that hard, but it shows you how well camouflaged they are, although there’s really nothing they need to hide from (the only predators go after babies, who are well protected by their mothers, and of course they’re herbivores.)  In fact, this one’s so easy I don’t think I need to give a reveal.

It was taken in Kruger, and presages my five posts on the five days we spent in the park. Click photo to enlarge.

I’m back in Cape Town, and preparing Kruger Post #1. In the meantime, have another read about college miscreants:

See below. I told you so, but this isn’t rocket science. Anybody with two neurons to rub together could have guessed the protest engine would rev up when classes begin again, for, especially at elite schools, students are more interested in enforcing what they consider Social Justice on others than engaging in learning.

The article below (click to read), written by Judy Lucas four days ago, was published in The Ithaca Voice, the local paper. Click headline to read:

An excerpt:

The spring semester at Cornell University ended with protests, as students erected an encampment on the Arts Quad to oppose the university’s ties to institutions supporting the Israeli state. The war in Gaza raged on through the summer, with reports of thousands of more lives lost. Cornell’s fall semester started much like its last one ended.

A crowd of about 150 student protestors at Cornell University marched into a campus dining hall Monday, the first day of classes, where speakers renewed the call for the university to divest from any institutions supplying weapons and support to the Israeli military in the war against Hamas, among a set of other demands first released earlier this year.

Have a look at the list of demands, especially the “land return” demand (#1) and the usual “and-of-course-we’re-not-to-be-punished” demand (#8).

Twenty minutes into the rally, seven university police officers entered the atrium of Klarman Hall and stood guard near the protestors. At the instruction of lead organizers, students joined arms to form a chain in order to resist interactions with police.

And the kicker: no IDs proferred when asked, and no punishment (bolding is mine, and it’s all bolded because it shows the cowardice of the Cornell administration).

Officers asked protesters to hand over their student identification cards to refer them to the university’s conduct office for potential disciplinary action. None of the protestors followed orders but no arrests were made. 

Have a tweet; this one has three videos and it’s just like the bawling we heard so often last year.

Welcome back! First day of classes, students & activists w/ @cmlcornell were met by 7 @Cornell officers asking for student IDs during a rally calling for the uni to divest in corps supporting Israel in the war against Hamas- atrium @ Klarman Hall- no arrests made. @ithacavoice pic.twitter.com/l1o3kRMvDM

— Judy Lucas (@judy__lucas) August 26, 2024

The unions, by and large all anti-Israel (are there any pro-Israel unions?), were part of the demonstration:

The Coalition for Mutual Liberation (CML), which represents the university’s activist organizations and the group responsible for organizing and maintaining the pro-Palestinian encampment on Cornell’s Arts Quad in April, planned Monday’s demonstration.

They were joined by representatives of the United Auto Workers Local 2300, the union representing about 1,200 university employees, including custodians, cooks and food service workers, who are currently on strike demanding an increase in wages and improved working conditions.

As usual, there’s illegal vandalism:

The morning of the demonstration, graffiti reading “Israel bombs, Cornell pays” and “Blood is on your hands” was found, spray-painted in red, on the front facade of Day Hall, the university’s administrative building. The front door was also shattered.

Cornell’s Vice President for University Relations Joel Malina released a statement on behalf of the university Aug. 26. Malina wrote the administration was “appalled by the graffiti spray painted.”

“Acts of violence, extended occupation of buildings, or property damage (including graffiti) will not be tolerated and will prompt an immediate response from public safety,” Malina wrote. “Cornell Police are conducting a thorough investigation, and those responsible will be subject to suspension and criminal charges.”

Joel Malina is Cornell’s Vice President for University Relations, and if you think that anybody will be suspended or subject to criminal charges, I have some land in Florida to sell you.

Finally, the interim Provost and President sent out an email with dire warnings about what would happen to students who engaged in encampments:

Students involved in encampments would first receive a warning of their violation of the university’s policy. On a second violation, the student would receive a “non-academic temporary suspension.” After a third violation, a student would receive “temporary academic suspension.”

I guess to get a “permanent academic suspension,” you have to shoot someone.

This is only the very beginning. When asked for a comment, the University said bupkes. 

Cornell University has not released a statement or comment regarding the specific demonstration Monday evening during which university police officers were involved.

In response to an email from The Ithaca Voice requesting a statement regarding the protest, a media representative for the university said “We don’t have anything specific regarding yesterday afternoon’s protest.”

Have another tweet with two videos:

Students and activists have entered Klarman Hall from two entrances. I’d guess there are at least 120 people gathered here total— half on the first floor and the other on the second. @cmlcornell @ithacavoice Speakers include Dan Vicente, Director of @UAWregion9. pic.twitter.com/UYx4lBZAgq

— Judy Lucas (@judy__lucas) August 26, 2024

There are more invertebrates in Cornell’s administration than there are in one square meter of the bottom of Cape Town’s Harbour. But there’s one consolation. While Cornell’s administration is demonstrating its spinelessness, I seriously doubt that it will give in to any of the student demands.

h/t: Debi

I think there’s little doubt that the pro-Palestinian and anti-Israel protests will once again roil colleges campuses this coming academic year.  As protestors vow that they’ll continue their activities, legal or not, and as Israel continues to root Hamas out of Gaza, I fully expect more trouble come this fall.

So do colleges, which are at this moment preparing for such trouble by confecting new regulations and policies. We have two articles on this subject, one in the NYT (first below) and the other in the Times of Israel. Click each headline to read; if the NYT is paywalled, you can find the first article archived here.

Note about what’s below: Daniel Diermeier used to be the Provost of the University of Chicago; now he’s the Chancellor (equivalent to the President) of Vanderbilt University, where he’s still carrying out the Chicago Principles, including free expression and institutional neutrality. Indented text is from the press; text flush left is mine. An excerpt from the NYT about Diermeier’s address to this year’s entering class at Vandy:

Less than 10 minutes had passed before Daniel Diermeier, Vanderbilt University’s chancellor, told hundreds of new students what the school would not do.

The university would not divest from Israel.

It would not banish provocative speakers.

It would not issue statements in support or condemnation of Israeli or Palestinian causes.

Before the hour was up on Monday, he added that Vanderbilt would not tolerate threats, harassment or protests “disrupting the learning environment.”

As you see, Diermeier pulls no punches.

This month, Vanderbilt required all first-year undergraduate students to attend mandatory meetings about the university’s approach to free speech, with the hope that clear expectations — and explanations for them — would help administrators keep order after protests rocked American campuses toward the end of the last academic year.

“The chaos on campuses is because there’s lack of clarity on these principles,” Dr. Diermeier said in an interview.

Well, that’s one reason, and I didn’t hear his talk, but the universal hope in all of the new “solutions” to protests is based on the claim that students simply don’t understand how free speech works on campuses, including private ones like Chicago and Vanderbilt. An important difference between “college” free speech and speech in the public arena is that colleges can more easily create “time, place, and manner” restrictions so that while legal speech is allowed, it mustn’t interfere with the mission of the university: no sit-ins or trespassing, no loud megaphones that disrupt classes, no encampments to block access to parts of campus, no deplatforming of speakers.

The problem I see is that the protestors in many places already know about these restrictions, and are determined to violate them anyway. They regard this as a form of civil disobedience—but one that, unlike classical civil disobedience, does not accept any attendant punishment. Indeed, just a handful of protestors who violated university regulations last year received either civil or University punishment, so there’s no incentive to at least go through the motions of obeying free-speech regulations. From later in the article:

Even as some universities have prepared more rigorous rules and procedures, it remains to be seen how strongly or consistently they will be enforced. The lasting consequences of defiance are also murky. Officials nationwide ultimately dropped many of the criminal charges that protesters faced after the spring demonstrations, and school discipline is still pending for many students. Suspensions have often been lifted in the meantime.

This is why universities’ solution to bring more “clarity” to free-speech rules seems hopeless. The solution, I think, is simply to enforce the rules. 

University presidents used summer break to huddle with police commanders, lawyers, trustees and other administrators to rewrite rules, tighten protest zones, and weigh possible concessions to maintain, or restore, order. Many have studied universities that temporarily defused tensions by striking deals with protesters.

But so far, universities are signaling little overt interest in negotiations.

On Monday, the University of California’s president, Michael V. Drake, told campus chancellors to ensure that their policies included bans on unapproved encampments and “masking to conceal identity.” Columbia University, where contentious protests helped drive Nemat Shafik from her 13-month-old presidency on Aug. 14, is limiting campus access. Northwestern University said that students would receive “mandatory trainings on antisemitism and other forms of hate,” with more policy changes coming.

“The question is how do we get more consistent in the way we respond to these issues — and clearer about what the rules are and what the tiered responses will be,” said Richard K. Lyons, the new chancellor at the University of California, Berkeley, a campus with one of the nation’s most robust records of protest. Dr. Lyons estimated that planning for demonstrations had consumed up to 15 percent of the summer for top administrators at Berkeley.

And there have been legal rulings that can force universities’ hands:

A series of recent court rulings, as well as investigations from Capitol Hill and the Department of Education, have created pressure on universities. A federal judge issued a preliminary injunction this month that said the University of California, Los Angeles, could not allow protesters to block Jewish students from campus facilities. (Although U.C.L.A. initially warned that the ruling threatened to “hamstring our ability to respond to events on the ground,” it decided not to appeal and said it would “abide by the injunction as this case makes its way through the courts.”)

Can you believe that UCLA defended the behavior of protestors to keep Jewish students away from their classrooms? Here’s a video of the blocking I remember at the time:

From an article on the UCLA ruling:

The complaint [by three Jewish students] alleges the protesters created a “Jew Exclusion Zone” where in order to pass “a person had to make a statement pledging their allegiance to the activists’ view.” Those who complied with the protesters’ view were issued wristbands to allow them to pass through, the complaint says, which effectively barred Jewish students who supported Israel and denied them access to the heart of campus.

Wristbands! Oy vey!

Our own University, like Vanderbilt, did not divest nor tolerate the encampments for very long, though it did give the encampers what I consider an overly long grace period.

The University of Chicago’s own experience this year suggests that even those deeply held principles do not always prevent turmoil. In May, the university brought in the police to remove an encampment that violated its policy barring unapproved tents.

At any rate, the divisions on campus are now so deep, and the protestors so sure of their moral compass, that I see no rapprochement, no matter how much universities inculcate students with the First Amendment or campus speech regulations.

The solution, which is Diermeier’s is simple, just follow through with campus speech violations by enforcing the rules. In my view, students will be loath to participate in illegal protests if they know that they’re going to be suspended, expelled, or have a punishment noted on their college transcripts. For even more than the students want divestment and a ceasefire, they want their degrees, an untarnished academic record. and jobs. I’m still baffled why many universities are simply letting the protestors off scot-free.

The Times of Israel simply lets us know that more disruptions of campuses are in store (click to read):

An excerpt:

The Student Intifada, a growing coalition of pro-Palestinian, anti-Zionist student groups, is making clear its intention to disrupt the fall semester on school campuses across the United States.

Across dozens of campuses currently opening their fall semesters, there are already calls for masked vigils in support of “Palestine.” Troublingly, many of the groups have gone from calling for demonstrations and encampments to condoning the use of violence and “the total eradication of Western civilization.”

Note that, as some like Douglas Murray have warned, the protestors are not simply anti-Israel, but anti-West and anti-Enlightenment. The article continues.

The Student Intifada’s roots can be traced to the National Students for Justice in Palestine (SJP), founded in 1993 at the University of California Berkeley. However, it’s picked up followers since the war in Gaza and then again with the media attention on Columbia University following last year’s highly-covered student encampment.

It’s worth noting that not a single Columbia student, despite illegal occupation and trashing of a university building faced legal charges (which the Manhattan DA dropped), and nearly none of them (perhaps none at all) faced severe university charges including permanent suspension (many ‘interim suspensions” were rescinded). More:

With the National SJP [Students for Justice in Palestine] as its guide, the movement isn’t limited to local SJP chapters. But it’s not so much the coalition’s reach that troubles some, but rather its refusal to engage with different perspectives.

“The movement is a belief cascade where those in the group compete with each other for acceptance. As they do that, their opinions become more and more extreme,” said William J. Bernstein, author of “Delusions of Crowds: Why People Go Mad in Groups.”

Excuse my cynicism, but I don’t think introductory units on critical thinking, free speech, and civil discussion required for first-year students are going to solve this problem. More:

Across dozens of campuses currently opening their fall semesters, there are already calls for masked vigils in support of “Palestine.” Troublingly, many of the groups have gone from calling for demonstrations and encampments to condoning the use of violence and “the total eradication of Western civilization.”

Yep, all of Western civilization.

The Student Intifada’s roots can be traced to the National Students for Justice in Palestine (SJP), founded in 1993 at the University of California Berkeley. However, it’s picked up followers since the war in Gaza and then again with the media attention on Columbia University following last year’s highly-covered student encampment.

. . . “Expect to see zero compromise”

With the National SJP as its guide, the movement isn’t limited to local SJP chapters. But it’s not so much the coalition’s reach that troubles some, but rather its refusal to engage with different perspectives.

“The movement is a belief cascade where those in the group compete with each other for acceptance. As they do that, their opinions become more and more extreme,” said William J. Bernstein, author of “Delusions of Crowds: Why People Go Mad in Groups.”

“No matter how high their SAT scores were, they don’t have the critical thinking skills they need. They are incapable of putting themselves in other people’s shoes. They are utterly intolerant of other views,” Bernstein said.

. . . University leaders should expect the students to become more strident in their demands this fall, said Lauren Post, an analyst with the Anti-Defamation League’s Center on Extremism.

“They are going to increase their efforts to drive Zionist institutions off campus. They are going to make the average Jewish and Zionist student increasingly uncomfortable. We can expect to see zero compromise from these groups,” Post said.

. . . . In a July 31 Instagram post, the University of Chapel Hill SJP appeared to back the right to use violence.

“We emphasize our support for the right to resistance, not only in Palestine, but also here in the imperial core. We condone all forms of principled action, including armed rebellion, necessary to stop Israel’s genocide and apartheid, and to dismantle imperialism and capitalism more broadly. The oppressors will never grant full liberty to the oppressed; the oppressed must seize liberty with their own hands,” the post said.

The Times of Israel also emphasizes the lack of sanctions for violators, again mentioning my school:

There were an estimated 3,200 people, not all of them students, arrested at colleges and universities last spring, according to the Associated Press. Most of the charges against students have since been dropped.

Other universities, including the University of Chicago and Harvard, withheld degrees from some pro-Palestinian students facing disciplinary measures for their part in encampments and protests. Many of them have since received their diplomas.

About those “nonstudents” demonstrating at many colleges, which also happened at Chicago, it’s a simple matter to ask for IDs, something that students at the U of C must produce on demand.  Then names can be taken and trespassers in unapproved demonstrations given the boot.

Two caveats. First of all, as always I am an exponent of free speech on all campuses, public and private.  I’m even at the extreme of those free-speechers who think that someone shouting “gas the Jews” on campus in a situation that isn’t likely to provoke violence should not be punished.  What I object to is students, with full knowledge, violating campus regulations and, by so doing, impeding the mission of colleges: access to learning. And I object to universities growling about this but doing absolutely nothing to the violators.

There’s a reason why speed traps work: those who speed do so at their own risk (and the risk of others), knowing that they’ll have to get a ticket and a fine. The result: if you know there are speed traps in an area, you slow down.

As an experiement on what happens when deterrence vanishes, read about Montreal’s Murray-Hill Police Strike in 1969. (This is also an object lesson for those who think that you can solve the problem of crime by getting rid of cops and using patrolling by locals.)

Second, I think students deserve a warning when engaged in illegal demonstrations before they’re disciplined.  The encampers in Chicago got several days of warnings before the cops took down the encampment (without a single person hurt) at 4:30 a.m. last May 7.  Those shouting down speakers or occupying buildings should get, say, ten minutes of warnings before the hammer comes down. Finally, there should be no illegal encampments: not a single tent stake should be driven into prohibited college ground without University officials saying, “Sorry, you can’t do that.”

By all means have introductions to free speech and moderated discussions of first-year students to teach them how free speech works, and why we have it. But that’s not enough. I’m stymied by the failure of universities to realize a simple principle of human behavior: if you give people meaningful punishment for doing something that’s prohibited, they will stop doing it. 

A regulation that’s no enforced is a regulation without teeth.

The James Webb Space Telescope (JWST) keeps finding supermassive black holes (SMBH) in the early Universe. They’re in active galactic nuclei seen only 500,000 years after the Big Bang. This was long before astronomers thought they could exist. What’s going on?

Monster black holes like the ones at the hearts of galaxies take a really long time to grow so massive. They could start as smaller ones that gobble up nearby stars and gases, or they can grow by merging with other supermassive black holes. That typically takes billions of years and a lot of material to build up to something as massive as the four-million-solar-mass one in the heart of our Milky Way Galaxy. It’s even longer for the really big ones that contain tens of millions of stellar masses.

A James Webb Telescope image shows the J0148 quasar circled in red. Two insets show, on top, the central supermassive black hole, and on bottom, the stellar emission from the host galaxy.

JWST has spotted many SMBH that already appear “old” and massive less than a billion years after the Big Bang. It’s not an observational fluke—they’re really there.

“How surprising it has been to find a supermassive black hole with a billion-solar-mass when the universe itself is only half a billion years old,” said astrophysicist Alexander Kusenko, a professor of physics and astronomy at UCLA. “It’s like finding a modern car among dinosaur bones and wondering who built that car in the prehistoric times.”

Building Supermassive Black Holes in Ancient Times

So, what built SMBH so early in cosmic history? One obvious process is the death of the first Population III stars that began forming as soon as the infant Universe cooled enough for them to coalesce. These were massive, metal-poor (meaning they had no elements heavier than helium), and short-lived. When they died as supernovae, they formed stellar-mass black holes. It’s possible those early ones merged and got bigger.

Another suggestion is a so-called “gravo-thermal” collapse of self-interacting dark matter halos. That basically means a negative heat transfer inside a system. That can lead to the collapse of a black hole, and from there, it could have grown.

Astronomers have also considered the participation of primordial black holes created in the moments after the Big Bang. These theoretical low-mass black holes could have formed under special conditions when dense areas of space collapsed quickly. How SMBH formed from primordial black holes isn’t understood at the moment. So, is there another formation theory?

Primordial black holes, if they exist, could have formed by the collapse of overdense regions in the very early universe. Some theories suggest these played a role in forming supermassive black holes. Credit M. Kawasaki, T.T. Yanagida.

This is where dark matter comes into play. Kusenko and his colleagues dug into the idea of dark matter-influenced collapse. They found that if dark matter decays, it plays a role in “corraling” a hydrogen gas cloud. It would not fragment (as clouds usually do). Eventually, that could lead to the relatively rapid formation of an SMBH. Since there is evidence of dark matter’s influence in the early Universe, this could explain the monster black holes in the earliest epochs of cosmic history.

From Cloud to Black Hole Formation via Dark Matter?

Of course, the conditions have to be just right for this to happen. “How quickly the gas cools has a lot to do with the amount of molecular hydrogen,” said doctoral student Yifan Lu, the first author on a paper describing the dark matter idea. “Hydrogen atoms bonded together in a molecule dissipate energy when they encounter a loose hydrogen atom. The hydrogen molecules become cooling agents as they absorb thermal energy and radiate it away. Hydrogen clouds in the early universe had too much molecular hydrogen, and the gas cooled quickly and formed small halos instead of large clouds.”

Certain radiation can destroy molecular hydrogen. That creates conditions that prevent cloud fragmentation. The radiation could be from somewhere, and Lu and others suggest an interesting idea in their paper. They state that there’s a possible “parameter space” where relic decaying particles could emit radiation that would spur the collapse. Among other things, they propose an “axion-like” dark matter particle decaying and spurring the eventual coalescence of a cloud of hydrogen into an SMBH.

Mysteries of Dark Matter and SMBH Need Answers

Dark matter itself is a mysterious “stuff” that makes up a very large part of the “stuff” of the Universe. We know about it from its gravitational effects on the objects we can see (called baryonic matter). The form that dark matter takes isn’t understood at all, however. It could be made of particles that slowly decay, or it could be made of more than one particle species. Some could be stable, others could decay at early times. In either case, the product of decay could be radiation in the form of photons, which break up molecular hydrogen and prevent hydrogen clouds from cooling too quickly. Even very mild decay of dark matter yielded enough radiation to prevent cooling, forming large clouds and, eventually, supermassive black holes.

Of course, this idea hasn’t been proven. However, the team points out that the decay of such particles of dark matter can emit light in both the optical and ultraviolet spectrum. That might explain the very precise measurements of the “cosmic optical background” (COB) seen by the New Horizons LORRI instrument. The COB is a visible light background roughly analogous to the cosmic microwave background. Think of it as the sum of all emissions from objects beyond the Milky Way Galaxy. Its presence allows astronomers to diagnose and understand the emissions from all astrophysical objects. There’s still a lot to study and understand about these possible axions (if they make up dark matter).

For More Information

Dark Matter Could Have Helped Make Supermassive Black Holes in the Early Universe
Direct Collapse Supermassive Black Holes from Relic Particle Decay
Pre-print of Paper

The post Dark Matter Could Have Driven the Growth of Early Supermassive Black Holes appeared first on Universe Today.

What's the Word: Bunk; News Items: Starliner Update, Therapeutic Roleplaying, The Search for Gravitons, Dinosaur Footprints, Schools vs Cell Phones; Who's That Noisy; Your Questions and E-mails: Slippery Slope; Science or Fiction

Meanwhile, in Dobrzyn, Hili is peckish:

Hili: I have a feeling that it’s the right time.
A: For what?
Hili: For a little something.

Hili: Mam wrażenie, że to jest właściwa pora.
Ja: Na co?
Hili: Na małe Conieco.

I trust you'll have the intellectual integrity to play videos of these speakers. Anything less, would be misinformation and censorship.

The post An Open Letter to the President of Stanford, Jonathan Levin: Don’t Censor Drs. Scott Atlas, John Ioannidis, Sunetra Gupta, Marty Marky, Monica Gandhi, Jay Bhattacharya, and Vinay Prasad. Amplify Their Voices. first appeared on Science-Based Medicine.

There are four fundamental forces in the Universe; strong, weak, electromagnetic and gravity. Quantum theory explains three of the four through the interaction of particles but science has yet to discover a corresponding particle for gravity. Known as the ‘graviton’, the hypothetical gravity particle is thought to constitute gravitational waves but it hasn’t been detected in gravity wave detector. A new experiment hopes to change that using an acoustic resonator to identify individual gravitons and confirm their existence. 

The four fundamental forces of nature govern the Universe. Gravity is one that many people are familiar with yet we do not fully understand how it works. Its effects are obvious though as the attraction between objects with mass. It keeps the planets in orbit around the Sun, the Moon in orbit around the Earth and us pinned to the surface of planet Earth. One of the earliest attempts to describe it was  from Isaac Newton who stated that gravity was proportional to the mass of objects and inversely proportional to the square of the distance between them. Even at the largest scale of the cosmos it seems to be essential for the structure of the Universe. 

Portrait of Newton in 1702, painted by Godfrey Kneller. Credit: National Portrait Gallery, London

One of the challenges with gravity is that, unlike the other fundamental forces, it can only be explained in a classical sense. Quantum physics can explain the other three forces by way of particles; the electromagnetic force has the photon, the strong nuclear force has the gluon, the weak nuclear force has the W and Z bosons but gravity has, well nothing yet. Other than the hypothesised graviton. The graviton can be thought of as the building block of gravity much as bricks are the building blocks of a house or atoms the building blocks of matter. 

Detectors like LIGO the Laser Interferometer Gravitational-Wave Observatory, can detect gravity waves from large scale events like mergers of black holes and neutron stars yet to date, a graviton has never been detected. That may soon be about to change though. A team of researchers led by physics professor Igor Pikovski from the Stevens Institute of Technology suggests a new solution. By utilising existing detection technology, which is essentially a heavy cylinder known as an acoustic resonator, the team propose adding improved energy state detection methods known as quantum sensing. 

LIGO Observatory

The proposed solution, explains Pikovski “is similar to the photo-electric effect that led Einstein to the quantum theory of light, just with gravitational waves replacing electromagnetic waves.” The secret is the discrete steps of energy that are exchanged between the material and the waves as single gravitons are absorbed. The team will use LIGO to confirm gravity wave detections and cross reference with their own data. 

The new approach has been inspired by gravity wave data that have been detected on Earth. Waves detected in 2017 came from a collision event between two city-sized super dense neutron stars. The team calculated the parameters that would facilitate the absorption probability for a single graviton. 

The team began thinking through a possible experiment. Using data from gravitational waves that have previously been measured on Earth, such as those that arrived in 2017 from a collision of two Manhattan-sized (but super-dense) faraway neutron stars, they calculated the parameters that would optimise the absorption probability for a single graviton. Their development led to devices similar to the Weber bar (thick, heavy 1 ton cylindrical bars) to allow gravitons to be detected. 

The bars would be suspended in the newly designed quantum detector, cooled to the lowest possible energy state and the passage of a gravity wave would set it vibrating. The team then hope to be able to measure the vibration using super-sensitive energy detectors to see how the vibrations changed in discrete steps, indicating a graviton event. 

It’s an exciting time for gravity based physics and we are most definitely getting closer to unravelling its mysteries. Unfortunately though, the super-sensitive detectors are not available yet but according to Pikovski’s team, they are not far away. Pikovski summed it up “We know that quantum gravity is still unsolved, and it’s too hard to test it in its full glory but we can now take the first steps, just as scientists did over a hundred years ago with quanta of light.”

Source : New research suggests a way to capture physicists’ most wanted particle — the graviton

The post If Gravitons Exist, this Experiment Might Find Them appeared first on Universe Today.

Researchers have found a new method to increase both speed and success rates in drug discovery. The study offers renewed promise when it comes to discovering new drugs.

The term ‘habitable zone’ is a broad definition that serves a purpose in our age of exoplanet discovery. But the more we learn about exoplanets, the more we need a more nuanced definition of habitable.

New research shows that vegetation can enlarge the habitable zone on any exoplanets that host plant life.

Every object in a solar system has an albedo. It’s a measurement of how much starlight the object reflects back into space. In our Solar System, Saturn’s moon, Enceladus, has the highest albedo because of its smooth, frozen surface. Its albedo is about 0.99, meaning about 99% of the Sun’s energy that reaches it is reflected back into space.

There are many dark objects in space with low albedoes. Some say that another of Saturn’s moons, Iapetus, has the lowest albedo.

Earth, the only living planet, has an albedo of about 0.30, meaning it reflects 30% of the Sunlight that reaches it back into space. Many factors affect the albedo. Things like the amount of ice cover, clouds in the atmosphere, land cover vs ocean cover, and even vegetation all affect Earth’s albedo.

This image made of satellite data shows the regions of Earth covered by forests with trees at least five meters (16.5 ft.) tall. Image Credit: NASA/LandSat

We live in an age of exoplanet discovery. We now know of more than 5,000 confirmed exoplanets, with many more on the way. Though all planets are interesting scientifically, we’re particularly interested in exoplanets that are potentially habitable.

A team of Italian researchers is examining exoplanet habitability through the lens of vegetation and albedo. Their work is in a paper to be published in the Monthly Notices of the Royal Astronomical Society titled “Impact of vegetation albedo on the habitability of Earth-like exoplanets.” The lead author is Erica Bisesi, a Postdoctoral Researcher at the Italian National Institute for Astrophysics’ Trieste Astronomical Observatory.

“Vegetation can modify the planetary surface albedo via the Charney mechanism, as plants are usually darker than the bare surface of the continents,” the researchers write in their paper. Compared to a dead planet with bare continents, an exoplanet with vegetation cover should be warmer if they’re both the same distance from similar stars.

The Charney mechanism is named after Jule Charney, an American meteorologist who is considered by many to be the father of modern meteorology. It’s a feedback loop between vegetation cover and how it affects rainfall.

In their work, the researchers updated the Earth-like Surface Temperature Model to include two types of dynamically competing vegetation: grasslands and forests, with forests included in the seedling and mature stages.

“With respect to a world with bare granite continents, the effect of vegetation-albedo feedback is to increase the average surface temperature,” the authors explain. “Since grasses and trees exhibit different albedos, they affect temperature to different degrees.”

On Earth, grasslands are found on every continent except Antarctica. They’re one of the largest biomes on Earth. Image Credit: NASA Earth Observatory

Since grasses and trees affect albedo differently, vegetation’s effect on planetary albedo is linked to the outcome of their dynamic competition. “The change in albedo due to vegetation extends the habitable zone and enhances the overall planetary habitability beyond its traditional outer edge,” the authors write.

The researchers considered four situations:

• Complete tree dominance (forest worlds).
• Complete grass dominance (grassland worlds).
• Tree/Grass coexistence.
• Bi-directional worlds

In a bi-directional world, vegetation converges to grassland or to forest, depending on the initial vegetation fractions. In these worlds, seed propagation across latitudes widens the region where forests and grasslands coexist.

The researchers found that vegetation cover lowers a planet’s albedo and warms the climate, nudging the outer limit of the habitable zone. However, they also arrived at more specific results.

They found that the outcome of dynamic competition between trees and grasses affected how vegetation is distributed across latitudes. “The achieved temperature-vegetation state is not imposed, but it emerges from the dynamics of the vegetation-climate system,” they explain.

This figure from the research shows how Earth’s liquid water habitability index is shifted outward by different vegetation regimes. It’s based on Earth’s modern distribution of continents. Image Credit: Bisesi et al. 2024.

The researchers worked with the idea of a ‘pseudo-Earth.’ The pseudo-Earth has a constant fraction of oceans at all bands of latitude, affecting the distribution of continents and vegetated surfaces relative to the equator, where most of the Sun’s energy strikes the planet.

This figure from the research shows how a pseudo-Earth’s liquid water habitability index is shifted outward by different vegetation regimes. It’s based on an equal distribution of oceans at all bands of latitude. Image Credit: Bisesi et al. 2024.

The researchers also worked with a hypothetical dry pseudo-Earth. On this Earth, ocean cover is limited to 30%, while the Earth and the pseudo-Earth both have 70% ocean cover.

The simulated dry pseudo-Earth has less ocean coverage than Earth, meaning there’s more surface area for vegetation to cover. Image Credit: Bisesi et al. 2024.

The team reached some conclusions about vegetation cover, albedo, and habitability.

The more continents a planet has, the greater the climate warming effect from vegetation. When the simulations resulted in a grass-dominated world, the effect was weaker because grass raises albedo. When the simulations resulted in a forest-dominated world, the effect was greater.

The researchers’ key point is that none of this is static. Outcomes are driven by the competition between grasslands and forests for resources, which in turn is driven by the average temperature in each latitudinal band. “In general, thus, the achieved temperature-vegetation state is not imposed, but it emerges from the dynamics of the vegetation-climate system,” they explain.

This is especially pronounced on the dry pseudo-Earth. Because there is so much land cover, vegetation has an even stronger effect on albedo and climate. “However, the ocean fraction cannot be too small, as
in this case, the whole hydrological cycle could be modified,” the researchers add.

Overall, vegetation’s effect on albedo and climate is small. But we can’t dismiss its effect on habitability. Habitability is determined by a myriad of factors.

This issue is very complex. For instance, on a planet where grasslands and forests coexist, external factors like stellar luminosity and orbital variations can be buffered depending on where the continents are and how much their vegetation affects albedo purely by location.

The authors consider their work as a basic first step in this issue. They only included certain types of grasslands and forests, didn’t include the relative availability of water, and didn’t include atmospheric CO2 concentrations.

“The dynamics explored here are extremely simplified and represent only a first step in the analysis of vegetation habitability interactions.” they write. “Future work will also include a simplified carbon balance model in the study of planetary habitability.”

“This endeavour should be seen as a first step of a research program aimed at including the main climate-vegetation feedbacks known for Earth in exoplanetary habitability assessments,” they write.

The post How Vegetation Could Impact the Climate of Exoplanets appeared first on Universe Today.

Entangled particles of light can transmit holographic images that can be selectively erased, allowing for secure communications that can also be deleted

The US military has prioritised deploying high-altitude balloons that can carry out surveillance

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Want a clear view of a supermassive black hole’s environment? It’s an incredible observational challenge. The extreme gravity bends light as it passes through and blurs the details of the event horizon, the region closest to the black hole. Astronomers using the Event Horizon Telescope (EHT) just conducted test observations aimed at “deblurring” that view.

The EHT team collaborated with scientists at the Atacama Large Millimeter/submillimeter Array (ALMA) and other facilities to do the tests. The antennas detected light from the centers of distant galaxies at a radio frequency of 354 GHz, equivalent to a wavelength of 0.87 mm.

A map of the Event Horizon Telescope observatories used in recent test observations at 0.87 mm of distant galaxies, to bump up its resolution. Credit: ESO/M. Kornmesser

This pilot experiment achieved observations with detail as fine as 19 microarcseconds. That’s the highest-ever resolution ever achieved from Earth’s surface. Although there are no images from the tests, the observations “saw” strong light signals from several distant galaxies—and that was only using a few antennas. Once the team focused the full worldwide EHT array on targets, they could see objects at a resolution of 13 microarcseconds. That’s about like looking at a bottle cap on the surface of the Moon—from Earth’s surface!

Sharpening the Event Horizon Telescope

These observational tests are a big breakthrough because it means scientists can make images of black holes that are 50% sharper than previous observations. The EHT’s groundbreaking first observations of M87’s black hole and Sagittarius A* in our galaxy happened just a few years ago, at a wavelength of 1.33 mm. Those images were amazing, but the science teams wanted to do better.

“With the Event Horizon Telescope, we saw the first images of black holes using the 1.3-mm wavelength observations, but the bright ring we saw, formed by light bending in the black hole’s gravity, still looked blurry because we were at the absolute limits of how sharp we could make the images,” said the observation’s co-lead Alexander Raymond of the Jet Propulsion Laboratory. “At 0.87 mm, our images will be sharper and more detailed, which in turn will likely reveal new properties, both those that were previously predicted and maybe some that weren’t.”

The first ever actual image of a black hole, taken in 2019. This shows the black hole at the heart of galaxy M87 Credit: Event Horizon Telescope Collaboration

According to EHT Founding Director Sheperd “Shep” Doeleman, an astrophysicist at the CfA and co-lead on a recent paper about the observations, the recent tests will improve the view of our galaxy’s central supermassive black hole, as well as others. “Looking at changes in the surrounding gas at different wavelengths will help us solve the mystery of how black holes attract and accrete matter, and how they can launch powerful jets that stream over galactic distances,” he said. In addition, the new technique should reveal even more dim, distant black holes than the EHT has already seen.

Creating a Big Radio Eye to Study Black Holes

Think of the Event Horizon Telescope as a giant, Earth-sized virtual radio telescope. Instead of one massive dish the size of our planet, it links together multiple radio dishes across the globe. The technique is called “very long baseline interferometry” with each observatory sending its data to a central processing center. For this test, the array consisted of six facilities, including the Atacama Array. The experiment succeeded in expanding the wavelength range of the EHT. Usually, to get better resolution, astronomers have to build bigger telescopes, but this one’s already Earth-sized. So, goosing the wavelength was the only choice.

The current locations of observatories that make up the full Event Horizon Telescope. (Courtesy EHT)

The test observations at higher resolution mark the first time the VLBI technique was used successfully at a wavelength of 0.87 mm. It’s a challenging measurement to make because water vapor in the atmosphere absorbs more waves at 0.87mm than at 1.3mm. As a result, astronomers worked to improve the EHT’s resolution by increasing the bandwidth of the instrumentation. Then, they had to wait for good observing conditions at all the test sites.

The improvements should allow astronomers to get high-fidelity “movies” of the event horizon around a black hole. Of course, astronomers want more upgrades to the existing EHT arrays. Planned improvements include new antennas, as well as improvements to detectors and other instruments. The result should be some pretty spectacular images and animations of material trapped in the extreme gravitational clutch of a black hole.

Revisiting Old Black Hole Friends

Future observations will include return observations of the supermassive black holes in M87 and the heart of the Milky Way Galaxy. Both are surrounded by accretion disks full of material swirling into the black hole. Once that material crosses the event horizon (the gravitational point of no return), it’s gone forever. So, it’s important to track that kind of action around a black hole. That’s where the EHT comes in handy.

Researchers using the Event Horizon Telescope hope to generate more and better images like this of supermassive black hole Sag. A’s event horizon. Image Credit: EHT.

According to Shep Doeleman, the details should be amazing. “Consider the burst of extra detail you get going from black and white photos to color,” he said. “This new ‘color vision’ allows us to tease apart the effects of Einstein’s gravity from the hot gas and magnetic fields that feed the black holes and launch powerful jets that stream over galactic distances.”

With this in mind, he added that the Collaboration is excited to reimage M87* and Sgr A* at both 1.3mm and 0.87mm and move from detecting black hole “shadows” to more precisely measuring their sizes and shapes, which can help to estimate a black hole’s spin and orientation on the sky.

If all that happens as they hope, the 400-member EHT consortium will certainly be able to fulfill its founding aim. That’s to provide the most detailed radio images of the mysterious beasts that lurk in the hearts of most galaxies.

For More Information

EHT Scientists Make Highest-resolution Observations Yet from the Surface of Earth
Event Horizon Telescope Main Page
First Very Long Baseline Interferometry Detections at 870 µm

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