It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Monday, September 13, 2021
VELIKOVSKY WAS RIGHT Venera timeline: The Soviet Union's Venus missions in pictures
The microphones on Venera 13 captured the sounds of the Venusian wind, the first recording of any sound on a planet other than Earth.
The lander, which operated for 127 minutes on the surface — almost three times longer than planned — also sent back color photos and analyzed a sample of Venus' soil, or regolith.
Venera 14
A twin of the Venera 13 spacecraft, Venera 14 landed on Venus on March 5, 1982, four days after its sibling.
It too recorded the sounds of the Venusian wind and sent back images. An attempt at measuring the compressibility of the surface soil accidentally measured an ejected lens cap instead.
Red vs. Blue: Astronomers Nail Down the Origins of Rare Loner Dwarf Galaxies
ByJENNIFER CHU,
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
SEPTEMBER 11, 2021
In this image, the fall of a blue ultra-diffuse galaxy into a galaxy system
and its subsequent ejection as a red ultra-diffuse galaxy, is depicted. Credit: MIT
The results provide a blueprint for finding such systems in the universe’s quieter, emptier regions.
By definition, dwarf galaxies are small and dim, with just a fraction of the stars found in the Milky Way and other galaxies. There are, however, giants among the dwarfs: Ultra-diffuse galaxies, or UDGs, are dwarf systems that contain relatively few stars but are scattered over vast regions. Because they are so diffuse, these systems are difficult to detect, though most have been found tucked within clusters of larger, brighter galaxies.
Now astronomers from MIT, the University of California at Riverside, and elsewhere have used detailed simulations to detect “quenched” UDGs — a rare type of dwarf galaxy that has stopped generating stars. They identified several such systems in their simulations and found the galaxies were not in clusters, but rather exiled in voids — quiet, nearly empty regions of the universe.
This isolation goes against astronomers’ predictions of how quenched UDGs should form. So, the team used the same simulations to rewind the dwarf systems’ evolution and see exactly how they came to be.
The researchers found that quenched UDGs likely coalesced within halos of dark matter with unusually high angular momentum. Like a cotton candy machine, this extreme environment may have spun out dwarf galaxies that were anomalously stretched out.
These UDGs then evolved within galaxy clusters, like most UDGs. But interactions within the cluster likely ejected the dwarfs into the void, giving them wide, boomerang-like trajectories known as “backsplash” orbits. In the process, the galaxies’ gas was stripped away, leaving the galaxies “quenched” and unable to produce new stars.
The simulations showed that such UDGs should be more common than what has been observed. The researchers say their results, published today in Nature Astronomy, provide a blueprint for astronomers to go looking for these dwarfish giants in the universe’s voids.
“We always strive to get a complete consensus of the galaxies that we have in the universe,” says Mark Vogelsberger, associate professor of physics at MIT. “This study is adding a new population of galaxies that the simulation actually predicts. And we now have to look for them in the real universe.”
The team’s search for quenched UDGs began with a simple survey for UDG satellites — ultra-diffuse systems that reside outside galaxy clusters. Astronomers predict that UDGs within clusters should be quenched, as they would be surrounded by other galaxies that would essentially rub out the UDG’s already-diffuse gas and shut off star production. Quenched UDGs in clusters should then consist mainly of old stars and appear red in color.
If UDGs exist outside clusters, in the void, they are expected to continue churning out stars, as there would be no competing gas from other galaxies to quench them. UDGs in the void, therefore, are predicted to be rich with new stars, and to appear blue.
When the team surveyed previous detections of UDG satellites, outside clusters, they found most were blue as expected — but a few were red.
“That’s what caught our attention,” Sales says. “And we thought, ‘What are they doing there? How did they form?’ There was no good explanation.”
Galactic cube
To find one, the researchers looked to TNG50, a detailed cosmological simulation of galaxy formation developed by Vogelsberger and others at MIT and elsewhere. The simulation runs on some of the most powerful supercomputers in the world and is designed to evolve a large volume of the universe, from conditions resembling those shortly after the Big Bang to the present day.
The simulation is based on fundamental principles of physics and the complex interactions between matter and gas, and its results have been shown in many scenarios to agree with what astronomers have observed in the actual universe. TNG50 has therefore been used as an accurate model for how and where many types of galaxies evolve through time.
In their new study, Vogelsberger, Sales, and Benavides used TNG50 to first see if they could spot quenched UDGs outside galaxy clusters. They started with a cube of the early universe measuring about 150 million light years wide, and ran the simulation forward, up through the present day. Then they searched the simulation specifically for UDGs in voids, and found most of the ones they detected were blue, as expected. But a surprising number — about 25 percent — were red, or quenched.
They zeroed in on these red satellite dwarfs and used the same simulation, this time as a sort of time machine to see how, when, and where these galaxies originated. They found that the systems were initially part of clusters but were somehow thrown out into the void, on a more elliptical, “backsplash” orbit.
“These orbits are almost like those of comets in our solar system,” Sales says. “Some go out and orbit back around, and others may come in once and then never again. For quenched UDGs, because their orbits are so elliptical, they haven’t had time to come back, even over the entire age of the universe. They are still out there in the field.”
The simulations also showed that the quenched UDGs’ red color arose from their ejection — a violent process that stripped away the galaxies’ star-forming gas, leaving it quenched and red. Running the simulations further back in time, the team observed that the tiny systems, like all galaxies, originated in halos of dark matter, where gas coalesces into galactic disks. But for quenched UDGs, the halos appeared to spin faster than normal, generating stretched out, ultra-diffuse galaxies.
Now that the researchers have a better understanding of where and how quenched UDGs arose, they hope astronomers can use their results to tune telescopes, to identify more such isolated red dwarfs — which the simulations suggest must be lurking in larger numbers than what astronomers have so far detected.
“It’s quite surprising that the simulations can really produce all these very small objects,” Vogelsberger says. “We predict there should be more of this kind of galaxy out there. This makes our work quite exciting.”
Left: One of the UDGs analyzed in the study, Right: UDG Galaxy DF2, which is almost transparent. ESA / Hubble
After years of research, it has been possible to find out exactly how dwarf galaxies, which appear to be very dim, are born. It is not yet clear why some of these dwarfs were stretched so far, how they formed, and whether the effect of the dark matter is anything special. The portal drew attention to the subject Science Alert.
He is not a dwarf like a dwarf
As he writes With On its web, by definition, dwarf galaxies are tiny galaxies with “only” a few billion stars. However, dwarfs are also giants, and we classify them as dwarf galaxies because of the number of stars, but they are similar to galaxies, such as the Milky Way.
We know these galaxies as Ultra Diffuse Galaxies (UDGs) because they are dwarf galaxies and the stars are spread over a very large area and have only a very low surface brightness. Their brightness is so small that we cannot detect them, the portal warns SciTechDaily.
UDG galaxies, more precisely the “extinct” UDG galaxies, handled by a new study published in the journal Natural astronomy, In which the authors were able to reach really unexpected conclusions. These are in conflict with our model of the formation of these galaxies.
The “extinct” ultra-diffuse galaxy is a rare dwarf galaxy that has stopped forming stars in the gut. However, astronomers involved in new research have identified many such systems through their simulations, finding that these galaxies are not in clusters, but in a large “vacuum”. The “vacuum” in astronomy refers to a large vacuum between large astronomical structures.
This finding contradicts our best assumptions about how such galaxies can form. Further observations and simulations The orbit “backsplash” is from the so-called origin of the “extinct” UDGs, beyond the edges of the host galaxy.
“Backsplash” galaxies are now astronomical objects that appear to be isolated galaxies, but in the past were moons (a satellite galaxy orbiting a large galaxy by gravity), explains co-author Laura Sales.
“Isolated and satellite galaxies have different properties because the physics behind their evolution is completely different.” SciTechDail quotes astronomer Laura Sales. “These backsplash galaxies are interesting because they have the same characteristics of the population of satellites in the system that existed before them, but today they are isolated from it.” Adding.
The researchers used a simulation called TNG50, which in this case acted like a time machine and helped the authors go back in time to observe the evolution of these dwarf systems.
“Extinct” UDGs began to form in the halls of dark matter at unusually high speeds, which could extend these galaxies farther. These UDGs were evolving like other known UDGs in the galaxy cluster, but due to various interventions they were thrown into a more elliptical orbit.
This expulsion into space led to their “backflash” orbits, leading to the loss of gas needed to form stars, causing the galaxies to “extinction” and thus failing to form new stars.
Research suggests that “extinct” UDGs may account for up to 25% of the total UDG population, which means that their incidence is much more common than previously thought. However, it should be noted that this was an identification, or assumption of the existence of galaxies through simulations, so it is still necessary to actually search for them in space.
Because research has helped to better understand the process by which these galaxies form, astronomers around the world can use these results to tune telescopes and identify many of these isolated UDGs.
Nasa will intentionally hit this asteroid to deflect it from 11 million km away
The intercept is scheduled for late September 2022, when the Didymos system is within 11 million kilometres of Earth, enabling observations by ground-based telescopes.
September 13, 2021 A graphical representation of DART heading on a collision course towards 'Dimorphos'. (Photo: Nasa)
Remember the Bruce Willis starred Armageddon, where a group of rag-tag amateur astronauts launched on a mission to deflect an asteroid headed towards Earth? Nasa is now in the final stages of attempting a similar mission, but not with astronauts. The American space agency will begin the countdown for its Double Asteroid Redirection Test (DART) mission as the launch window begins in November.
The DART mission will target an asteroid as engineers and astronomers aim to create a defence system able to deflect potential asteroids headed towards Earth in future. The target asteroid for the mission is Didymos, which will act as the testbed for planetary defence-driven technologies aimed at preventing an impact by a hazardous asteroid.
"The DART mission is Nasa’s first planetary defence test mission and will impact an asteroid to demonstrate a technique that could be used in the future to protect Earth from a potential impact. #CountdownToLaunch on November 24!" Nasa tweeted.
WHAT IS THE DART MISSION?
Dubbed as Double Asteroid Redirection Test mission, DART is managed under the Solar System Exploration Program by Nasa, which will achieve the kinetic impact deflection by deliberately crashing itself into the moonlet (asteroid's moon) at a speed of approximately 6.6 kilometres per second.
DART will launch aboard a SpaceX Falcon 9 rocket. (Photo: Nasa)
The spacecraft will carry a suite of onboard cameras, sophisticated autonomous navigation software to track the developments. Engineers aim to change the speed of the moonlet in its orbit around the main body by a fraction of one per cent due to the collision. "This will change the orbital period of the moonlet by several minutes - enough to be observed and measured using telescopes on Earth," Nasa said.
DART will launch aboard a SpaceX Falcon 9 rocket from Vandenberg Air Force Base, California and will arrive at the target asteroid after journeying through space for a year. The spacecraft will be powered by Roll Out Solar Arrays (ROSA) that will fuel its electric propulsion system.
The intercept is scheduled for late September 2022, when the Didymos system is within 11 million kilometres of Earth, enabling observations by ground-based telescopes and planetary radars. “DART is the first step in testing methods for hazardous asteroid deflection. Potentially hazardous asteroids are a global concern, and we are excited to be working with our Italian and European colleagues to collect the most accurate data possible from this kinetic impact deflection demonstration," said Andrea Riley, DART program executive in a statement earlier.
A MOON-BASED ASTEROID
The Near-Earth Asteroid, which is the target for DART, was discovered nearly two decades ago and scientists found it to have a moon and the binary system was given the name “Didymos", which translates to twins in Greek. The moon system was identified in 2003 when astronomer Petr Pravec, at the Ondejov Observatory in Czechia, was tracking the brightness of a still-unnamed asteroid when he recognised a pattern consistent with a small moon. The DART Mission will intercept with the moon of the asteroid and crash on the surface. (Graphic: Nasa)
According to Nasa, the near-Earth asteroid was originally discovered in 1996 by Joe Montani of the Spacewatch Project at the University of Arizona, but its orbit was needed to be confirmed before it could be named. After confirmation of the Moon, Nasa chose it to be the target of its impact mission and named the Moon 'Dimorphos'.
Dimorphos, 525 feet in diameter and orbit around the larger main body Didymos, which measures 780 meters and because of its proximity to Earth during 2022, astronomers will be able to compare observations from Earth-based telescopes before and after DART’s kinetic impact to determine how much the orbital period of Dimorphos changed.
Researchers have simulated a virtual universe, and you can download it for free
compressed, the simulation takes up 100 terabytes,
so you’ll need some serious hard drive space available.
If you’ve ever wanted to explore the entire universe from the comfort of your computer, now’s your chance. An international team has created the largest and most realistic virtual universe to date called Uchuu (which means “outer space” in Japanese), simulating 2.1 trillion particles in a computational cube which is a mind-bending 9.63 billion light-years wide on each side.
The simulation was created using the supercomputer ATERUI II, which is dedicated to astronomy projects. The supercomputer located in Iwate, Japan, has a peak performance of over 3 Pflops, but even with all this power it still took a whole year to crunch through all of the data and create the simulation.
The Uchuu simulation, the most detailed simulation of the universe to date.Simulation: Tomoaki Ishiyama; Visualization: Hirotaka Nakayama; 4D2U Project, NAOJ
“To produce Uchuu we have used … all 40,200 processors (CPU cores) available exclusively for 48 hours each month,” said Tomoaki Ishiyama, an associate professor at Chiba University who developed the code for the project. “Twenty million supercomputer hours were consumed, and 3 Petabytes of data were generated, the equivalent of 894,784,853 pictures from a 12-megapixel cell phone.”
The simulation looks at halos of dark matter which are huge-scale structures that could tell us about the formation of galaxies and the early universe. The large-scale nature of the simulation makes it a valuable tool for studying how the universe evolved over time, as it shows very distant regions which represent early stages in the life of the universe.
“Uchuu is like a time machine,” said Julia F. Ereza, a Ph.D. student at Instituto AstrofÃsica AndalucÃa in Spain who uses Uchuu. “We can go forward, backward and stop in time, we can ‘zoom in’ on a single galaxy or ‘zoom out’ to visualize a whole cluster, we can see what is really happening at every instant and in every place of the Universe from its earliest days to the present, being an essential tool to study the Cosmos.”
And yes, should you want to experience the wonder of exploring the entire (virtual) universe for yourself, then you can, as the team has made the entire simulation available for free download to anyone who wants it. Though fair warning — even compressed, the simulation takes up 100 terabytes, so you’ll need some serious hard drive space available.
To download the simulation and to find out more about interacting with it, you can head to the Uchuu simulation website and its related GitHub page. The group is also planning to release more data in the future, including catalogs of virtual galaxies and gravitational lensing maps.
Astronomers Capture Detailed Images of Peculiar ‘Dog-bone’ Asteroid Kleopatra, Pics Go Viral
Kleopatra orbits the Sun in the Asteroid Belt between Mars and Jupiter. Astronomers have called it a "dog-bone asteroid" ever since radar observations around 20 years ago revealed it has two lobes connected by a thick "neck".
Asteroid Kleopatra, viewed at different angles as it rotates. (Credit: ESO Twitter)
New York: A team of astronomers has recently obtained the sharpest and most detailed images yet of the asteroid Kleopatra, using the European Southern Observatory’s Very Large Telescope (ESO’s VLT). The observations have allowed the team to constrain the 3D shape and mass of this peculiar asteroid, which resembles a dog bone, to a higher accuracy than ever before. Their research also provides clues as to how this asteroid and the two moons that orbit it formed.Also Read - Asteroid Bigger Than Burj Khalifa Approaching Earth Tonight at a Speed of 94,208 kmph
“Kleopatra is truly a unique body in our Solar System,” said lead researcher Franck Marchis, an astronomer at the SETI Institute in Mountain View, US, as per the study was published in the journal Astronomy and Astrophysics. Also Read - Empire State Building Size Asteroid May Hit Earth, But Not Untill 2100s: Report
“Science makes a lot of progress thanks to the study of weird outliers. I think Kleopatra is one of those and understanding this complex, multiple asteroid system can help us learn more about our Solar System,” Marchis added.
Kleopatra orbits the Sun in the Asteroid Belt between Mars and Jupiter. Astronomers have called it a “dog-bone asteroid” ever since radar observations around 20 years ago revealed it has two lobes connected by a thick “neck”. In 2008, Kleopatra was found orbited by two moons, named AlexHelios and CleoSelene, after the Egyptian queen’s children.
To find out more, the team used snapshots of the asteroid taken at different times between 2017 and 2019 with the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument on ESO’s VLT. As the asteroid was rotating, they were able to view it from different angles and to create the most accurate 3D models of its shape to date.
They constrained the asteroid’s dog-bone shape and its volume, finding one of the lobes to be larger than the other, and determined the length of the asteroid to be about 270 kilometres or about half the length of the English Channel.
Kleopatra’s rubble-pile structure and the way it rotates also give indications as to how its two moons could have formed. The asteroid rotates almost at a critical speed, the speed above which it would start to fall apart, and even small impacts may lift pebbles off its surface, the astronomers explained.
The team believes that those pebbles could subsequently have formed AlexHelios and CleoSelene, meaning that Kleopatra has truly birthed its own moons.
One Lab’s Quest to Build Space-Time Out of Quantum Particles
For over two decades, physicists have pondered how the fabric of space-time may emerge from some kind of quantum entanglement. In Monika Schleier-Smith’s lab at Stanford University, the thought experiment is becoming real.
The prospects for directly testing a theory of quantum gravity are poor, to put it mildly. To probe the ultra-tiny Planck scale, where quantum gravitational effects appear, you would need a particle accelerator as big as the Milky Way galaxy. Likewise, black holes hold singularities that are governed by quantum gravity, but no black holes are particularly close by — and even if they were, we could never hope to see what’s inside. Quantum gravity was also at work in the first moments of the Big Bang, but direct signals from that era are long gone, leaving us to decipher subtle clues that first appeared hundreds of thousands of years later.
But in a small lab just outside Palo Alto, the Stanford University professor Monika Schleier-Smith and her team are trying a different way to test quantum gravity, without black holes or galaxy-size particle accelerators. Physicists have been suggesting for over a decade that gravity — and even space-time itself — may emerge from a strange quantum connection called entanglement. Schleier-Smith and her collaborators are reverse-engineering the process. By engineering highly entangled quantum systems in a tabletop experiment, Schleier-Smith hopes to produce something that looks and acts like the warped space-time predicted by Albert Einstein’s theory of general relativity.
In a paper posted in June, her team announced their first experimental step along this route: a system of atoms trapped by light, with connections made to order, finely controlled with magnetic fields. When tuned in the right way, the long-distance correlations in this system describe a treelike geometry, similar to ones seen in simple models of emergent space-time. Schleier-Smith and her colleagues hope to build on this work to create analogues to more complex geometries, including those of black holes. In the absence of new data from particle physics or cosmology — a state of affairs that could continue indefinitely — this could be the most promising route for putting the latest ideas about quantum gravity to the test. The Perils of Perfect Predictions
For five decades, the prevailing theory of particle physics, the Standard Model, has met with almost nothing but success — to the endless frustration of particle physicists. The problem lies in the fact that the Standard Model, despite its success, is clearly incomplete. It doesn’t include gravity, despite the long search for a theory of quantum gravity to replace general relativity. Nor can it explain dark matter or dark energy, which account for 95% of all the stuff in the universe. (The Standard Model also has trouble with the fact that neutrinos have mass — the sole particle physics phenomenon it has failed to predict.)
Moreover, the Standard Model itself dictates that beyond a certain threshold of high energy — one closely related to the Planck scale — it almost certainly fails.
Monika Schleier-Smith’s lab at Stanford is a dense maze of cables and optical equipment. “But at the end of the day,” she said, “You can make a system that is clean and controlled.” Dawn Harmer/SLAC National Accelerator Laboratory
Physicists are desperate for puzzling experimental data that might help to guide them as they build the Standard Model’s replacement. String theory, still the leading candidate to replace the Standard Model, has often been accused of being untestable. But one of the strangest features of string theory suggests a way to test some ideas about quantum gravity that don’t require impractical feats of galactic architecture.
String theory is filled with dualities — relations between different physical systems that share the same mathematical structure. Perhaps the most surprising and consequential of these dualities is a connection between a type of quantum theory in four dimensions without gravity, known as a conformal field theory (CFT), and a particular kind of five-dimensional space-time with gravity, known as an anti-de Sitter (AdS) space. This AdS/CFT correspondence, as it’s known, was first discovered in 1997 by the physicist Juan Maldacena, now at the Institute for Advanced Study.
Because the CFT has one fewer dimension than the AdS space, the former can be thought of as lying on the surface of the latter, like the two-dimensional skin of a three-dimensional apple. Yet the quantum theory on the surface still fully captures all the features of the volume inside — as if you could tell everything about the interior of an apple just by looking at its skin. This is an example of what physicists call holography: a lower-dimensional space giving rise to a higher-dimensional space, like a flat hologram producing a 3D image.
In the AdS/CFT correspondence, the interior or “bulk” space emerges from relationships between the quantum components on the surface. Specifically, the geometry of the bulk space is built from entanglement, the “spooky” quantum connections that infamously troubled Einstein. Neighboring regions of the bulk correspond to highly entangled portions of the surface. Distant regions of the bulk correspond to less entangled parts of the surface. If the surface has a simple and orderly set of entanglement relations, the corresponding bulk space will be empty. If the surface is chaotic, with all its parts entangled with all the others, the bulk will form a black hole.
The AdS/CFT correspondence is a deep and fruitful insight into the connections between quantum physics and general relativity. But it doesn’t actually describe the world we live in. Our universe isn’t a five-dimensional anti-de Sitter space — it’s an expanding four-dimensional space with a “flat” geometry.
Video: How does gravity work in the quantum regime? A holographic duality from string theory offers a powerful tool for unraveling the mystery.
So over the past few years, researchers have proposed another approach. Rather than starting from the bulk — our own universe — and looking for the kind of quantum entanglement pattern that could produce it, we can go the other way. Perhaps experimenters could build systems with interesting entanglements — like the CFT on the surface — and search for any analogues to space-time geometry and gravity that emerge.
That’s easier said than done. It’s not yet possible to build a system like any of the strongly interacting quantum systems known to have gravitational duals. But theorists have only mapped out a small fraction of possible systems — many others are too complex to study theoretically with existing mathematical tools. To see if any of those systems actually yield some kind of space-time geometry, the only option is to physically construct them in the lab and see if they also have a gravitational dual. “These experimental constructions might help us discover such systems,” said Maldacena. “There might be simpler systems than the ones we know about.” So quantum gravity theorists have turned to experts in building and controlling entanglement in quantum systems, like Schleier-Smith and her team. Quantum Gravity Meets Cold Atoms
“There’s something really just elegant about the theory of quantum mechanics that I’ve always loved,” said Schleier-Smith. “If you go into the lab, you’ll see there’s cables all over the place and all kinds of electronics we had to build and vacuum systems and messy-looking hardware. But at the end of the day, you can make a system that is clean and controlled in such a way that it does nicely map onto this sort of elegant theory that you can write down on paper.”
This messy elegance has been a hallmark of Schleier-Smith’s work since her graduate days at the Massachusetts Institute of Technology, where she used light to coax collections of atoms into particular entangled states and demonstrated how to use these quantum systems to build more precise atomic clocks. After MIT, she spent a few years at the Max Planck Institute of Quantum Optics in Garching, Germany, before landing at Stanford in 2013. A couple of years later, Brian Swingle, a theoretical physicist then at Stanford working on string theory, quantum gravity and other related subjects, reached out to her with an unusual question. “I wrote her an email saying, basically, ‘Can you reverse time in your lab?’” said Swingle. “And she said yes. And so we started talking.”
Swingle wanted to reverse time in order to study black holes and a quantum phenomenon known as scrambling. In quantum scrambling, information about a quantum system’s state is rapidly dispersed across a larger system, making it very hard to recover the original information. “Black holes are very good scramblers of information,” said Swingle. “They hide information very well.” When an object is dropped into a black hole, information about that object is rapidly hidden from the rest of the universe. Understanding how black holes obscure information about the objects that fall into them — and whether that information is merely hidden or actually destroyed — has been a major focus of theoretical physics since the 1970s.
In the AdS/CFT correspondence, a black hole in the bulk corresponds to a dense web of entanglement at the surface that scrambles incoming information very quickly. Swingle wanted to know what a fast-scrambling quantum system would look like in the lab, and he realized that in order to confirm scrambling was taking place as rapidly as possible, researchers would need to tightly control the quantum system in question, with the ability to perfectly reverse all interactions. “The sort of obvious way to do it required the ability to effectively fast forward and rewind the system,” said Swingle. “And that’s not something you can do in an everyday kind of experiment.” But Swingle knew Schleier-Smith’s lab might be able to control the entanglement between atoms carefully enough to perfectly reverse all their interactions, as if time were running backward. “If you have this nice, isolated, well-controlled, highly engineered quantum many-body system, then maybe you have a chance,” he said.
So Swingle reached out to Schleier-Smith and told her what he wanted to do. “He explained to me this conjecture that this process of scrambling — that there’s a fundamental speed limit to how fast that can happen,” said Schleier-Smith. “And that if you could build a quantum system in the lab that scrambles at this fundamental speed limit, then maybe that would be some kind of an analogue of a black hole.” Their conversations continued, and in 2016, Swingle and Schleier-Smith co-authored a paper, along with Patrick Hayden, another theorist at Stanford, and Gregory Bentsen, one of Schleier-Smith’s graduate students at the time, outlining a feasible method for creating and probing fast quantum scrambling in the lab.
That work left Schleier-Smith contemplating other quantum gravitational questions that her lab could investigate. “That made me think … maybe these are actually good platforms for being able to realize some toy models of quantum gravity that are hard to realize by other means,” she said. She started to consider a setup where pairs of atoms would be entangled together, and then each pair would itself be entangled with another pair, and so on, forming a kind of tree. “It seemed kind of far-fetched to actually do it, but at least I could sort of imagine on paper how you would design a system where you can do that,” she said. But she wasn’t sure if this actually corresponded to any known model of quantum gravity. A view of the vacuum chamber at the center of the experiment (left). This view, taken several years ago, is now impossible, as there have been too many elements placed around the apparatus. Inside the control room where researchers control the experiment and analyze the data (right). Carlo Giacommetti; Courtesy of Monika Schleier-Smith
Intense and affable, Schleier-Smith has an infectious enthusiasm for her work, as her student Bentsen discovered. He had started his doctoral work at Stanford in theoretical physics, but Schleier-Smith managed to pull him into her group anyhow. “I sort of convinced him to do experiments,” she recalled, “but he maintained an interest in theory as well, and liked to chat with theorists around the department.” She discussed her new idea with Bentsen, who discussed it with Sean Hartnoll, another theorist at Stanford. Hartnoll in turn played matchmaker, connecting Schleier-Smith and Bentsen with Steven Gubser, a theorist at Princeton University. (Gubser later died in a rock-climbing accident.)
At the time, Gubser was working on a twist on the AdS/CFT correspondence. Rather than using the familiar kind of numbers that physicists generally use, he was using a set of alternative number systems known as the p-adic numbers. The key distinction between the p-adics and ordinary “real” numbers is the way the size of a number is defined. In the p-adics, a number’s size is determined by its prime factors. There’s a p-adic number system for each prime number: the 2-adics, the 3-adics, the 5-adics, and so on. In each p-adic number system, the more factors a number has that are multiples of p, the smaller that number is. So, for example, in the 2-adics, 44 is much closer to 0 than it is to 45, because 44 has two factors that are multiples of 2, while 45 doesn’t have any. But in the 3-adics, it’s the reverse; 45 is closer to 0 than to 44, because 45 has two factors that are multiples of 3. Each p-adic number system can also be represented as a kind of tree, with each branch containing numbers that all have the same number of factors that are multiples of p.
In p-adic geometry, different branches share the same number of factors that are multiples of p. Samuel Velasco/Quanta Magazine
Using the p-adics, Gubser and others had discovered a remarkable fact about the AdS/CFT correspondence. If you rewrite the surface theory using the p-adic numbers rather than the reals, the bulk is replaced with a kind of infinite tree. Specifically, it’s a tree with infinite branches packed into a finite space, resembling the structure of the p-adic numbers themselves. The p-adics, Gubser wrote, are “naturally holographic.”
“The structure of p-adic numbers that [Gubser] told me about reminded me of the way Monika’s atoms interacted with each other,” said Hartnoll, “so I put them in touch.” Gubser co-authored a paper in 2019 with Schleier-Smith, Bentsen and others. In the paper, the team described how to get something resembling the p-adic tree to emerge from entangled atoms in an actual lab. With the plan in hand, Schleier-Smith and her team got to work.
Building Space-Time in the Lab
Schleier-Smith’s lab at Stanford is a dense forest of mirrors, lenses and fiber-optic cables that surround a vacuum chamber at the center of the room. In that vacuum chamber, 18 tiny collections of rubidium atoms — about 10,000 to a group — are arranged in a line and cooled to phenomenally low temperatures, a fraction of a degree above absolute zero. A specially tuned laser and a magnetic field that increases from one end of the chamber to the other allow the experimenters to choose which groups of atoms become correlated with each other.
Using this lab setup, Schleier-Smith and her research group were able to get the two groups of atoms at the ends of the line just as correlated as neighboring groups were in the middle of the line, connecting the ends and turning the line into a circle of correlations. They then coaxed the collection of atoms into a treelike structure. All of this was accomplished without moving the atoms at all — the correlation “geometry” was wholly disconnected from the actual spatial geometry of the atoms.
While the tree structure formed by the interacting atoms in Schleier-Smith’s lab isn’t a full-blown realization of p-adic AdS/CFT, it’s “a first step towards holography in the laboratory,” said Hayden. Maldacena, the originator of the AdS/CFT correspondence, agrees: “I’m very excited about this,” he said. “Our subject has been always very theoretical, and so this contact with experiment will probably raise more questions.”
Hayden sees this as the way of the future. “Instead of trying to understand the emergence of space-time in our universe, let’s actually just make toy universes in the lab and study the emergence of space-time there,” he said. “And that sounds like a crazy thing to do, right? Like kind of mad-scientist kind of crazy, right? But I think it really is likely to be easier to do that than to directly test quantum gravity.”
Schleier-Smith is also optimistic about the future. “We’re still at the stage of getting more and more control, characterizing the quantum states that we have. But … I would love to get to that point where we don’t know what will happen,” she said. “And maybe we measure the correlations in the system, and we learn that there’s a geometric description, some holographic description that we didn’t know was there. That would be cool.”
‘All That Sacrifice Was for Nothing’: Afghans Seethe 20 Years After 9/11
The few good remnants of Afghans’ post-9-11 world — rights for women and a free press — are being ripped away
By JASON MOTLAGH Taliban fighters try to stop the advance of protesters marching through the Dashti-E-Barchi neighborhood, a day after the Taliban announced their new all-male interim government with a no representation for women and ethnic minority groups, in Kabul, Afghanistan, Wednesday, Sept. 8, 2021. Marcus Yam/Los Angeles Times/Getty Images
Nilofar Ayoubi first heard about the 9/11 attacks on the radio, as there was no TV or internet growing up under the Taliban. Within weeks, U.S. warplanes began bombing Taliban and Al Qaeda targets in Afghanistan, and Northern Alliance rebels were blitzing across the plains with support from American special forces. As the fighting drew closer and neighbors fled, Ayoubi and her family hunkered down at home in Kunduz, the Taliban’s last stronghold. Her mother was nine months pregnant, and they decided to leave the city only after her midwife abandoned them. On a frantic drive to safety along a blown-out road, Ayoubi, then 5 years old, remembers tracking American B-52s high in the sky as they pounded Kunduz with bombing runs that ultimately forced the Taliban to surrender. “Everything was destroyed when we returned,” she says.
From the rubble, she and her newborn sister charted a path that would have been inconceivable under the ultraconservative Taliban regime. Ayoubi went to school and joined a foreign-funded theater troupe before moving to Kabul to pursue a university degree. She got involved in the media scene, married a businessman from another ethnic group, and launched several ambitious ventures of her own, including a clothing boutique for working women.
Twenty years after the September 11th attacks changed the trajectory of her life, American forces are gone and the Taliban again reigns supreme. The war’s end comes as a great relief for many rural Afghans who bore the brunt of the suffering in obscurity. But Ayoubi and other beneficiaries of the post-Taliban era now living as refugees or in hiding say they feel betrayed by a reckless U.S. exit that has upended their lives and crushed the values that gave them purpose.
“These past 20 years were like a dream for us, an illusion,” Ayoubi says by phone from a camp in Poland, where she, her husband, and three children arrived two weeks ago after a harrowing escape. “The U.S. said they came to hunt terrorists and now they are roaming freely in Kabul,” she says, referring to the Haqqani faction of the Taliban, designated by the U.S. as a terrorist group and now in charge of securing the Afghan capital. “I cannot make sense of it. Why did they come in the first place, and why did they leave now? What was it all about?”
On one level, it can be summed up easily: The U.S. invaded Afghanistan in late 2001 on a clear-cut mission to defeat the Al Qaeda terrorists behind the September 11th attacks and to oust their Taliban enablers. That objective, fast achieved, then drifted into an ill-defined nation-building project prolonged by career-minded officials at the White House and Pentagon who dissembled and doubled down on the effort despite glaring signs it was failing. Billions of dollars in reconstruction and military aid poured into a government hamstrung by graft, infighting, and ethnic strongmen who operated with impunity. Heavy-handed U.S. counterterrorism tactics frequently killed civilians, deepening resentments among the population. On the home front, the war’s growing unpopularity became a rallying cry for both Republicans and Democrats, borne out by President Biden’s decision to honor the Trump administration’s deal with the Taliban and pull out U.S. forces for good.
Afghan women sit as they study english in a class among male students in Kabul, December 11th, 2001, soon after the Taliban was toppled by the U.S. invasion. “It’s like building a building and tearing it down all at once — we’re back to zero,” says one Afghan woman about the chaotic aftermath of the U.S. withdrawal. WEDA/AFP/Getty Images
But that is the Cliffs-notes version of events, with little perspective into what it has all meant for Afghans. For those who have lived through the post-2001 era, it remade their world, and not always for the better. Over 15 years of reporting around the country, I saw how budding hopes for safer, more prosperous lives gradually hardened into cynicism and despair. While Americans held annual solemn ceremonies for 9/11 victims and built memorials, Afghans continued to bury more and more of their dead. Of the more than 170,000 lives lost during the war, nearly 50,000 were civilians. Urban dwellers enjoyed newfound social freedoms but faced the constant threat of suicide bombings, and people in rural areas prowled by the Taliban lived under the specter of airstrikes and deadly raids. A telecommunications boom improved connectivity and political awareness. But it also served to magnify a widening opportunity gap between cities flush with aid money and neglected, war-battered provinces.
By any number of counts the U.S. intervention in Afghanistan has been an exercise in futility, but American largesse did secure some meaningful improvements, especially in major cities. Girls’ education flourished and women played a prominent role in government and civil society. In a region bereft of press freedom, U.S. grants helped seed a robust media culture that confronted authorities and the Taliban alike for abuses.
But the sudden collapse of the Afghan government and the chaotic U.S. exit has ripped even the best remnants of the post-9/11 legacy away. “It’s like building a building then tearing it down all at once — we’re back to zero,” says Raihana Azad, 38, a former parliamentarian who fled to Turkey last month. A member of the persecuted ethnic Hazara minority, Azad rose from a teenage marriage and motherhood to elected office, where she championed women’s education and entrepreneurship. Though poor and remote, her province, Daykundi, boasted one of the highest female graduation rates in the country. “There were so many real achievements, and still the Americans abandoned us” to the Taliban, she tells me. “They have not changed — they are no better or worse than they were 20 years ago.”
The new Taliban government excludes women and the Hazara minority. And Azad says that all girls’ schools in Daykundi have been closed and women banned from leaving home without a male escort. Contacts told her that 12 surrendering Hazara soldiers and a pair of civilians were executed in late August by the Taliban, a month after nine Hazaras were tortured and killed in another province.
“If you compare the situation now to 20 years ago, the main difference is that we are feeling hopeless,” says Jawad, a reporter and political analyst based in Kabul. “The freedoms we had are being taken away; we are less safe.” Two of his colleagues were beaten up last week for pressing a Taliban official on human rights issues; others have been arrested and brutally flogged for filming demonstrations. Meanwhile, Taliban leaders continue to issue vague directives that media must not violate Islamic law or harm the national interest.
By Jawad’s assessment, the situation today is worse than the aftermath of the 2001 U.S.-led invasion. “The Taliban are much more powerful” thanks to massive U.S. weapons and munitions stockpiles they’ve absorbed from Afghan forces, while the prevalence of more radical groups like the Islamic State-Khorasan could sow greater instability, he says, affirming his belief that Afghanistan could once again become a staging ground for terror attacks beyond its borders. Although Al Qaeda has pledged deference to the Taliban, and the Taliban is the sworn enemy of ISIS-K, having fought them relentlessly in the east of the country, he worries that extremist rivals will try to exploit the vacuum as the Taliban struggles to transition from guerrilla warfare to governance. Indeed, ISIS-K claimed responsibility for the August 26th suicide bombing at the Kabul airport that killed more than 170 Afghans.
In this picture taken on September 8, 2021, Afghan newspaper Etilaat Roz journalists Nematullah Naqdi (L) and Taqi Daryabi show their wounds in their office in Kabul after being released from Taliban custody. Wakil Kohsar/AFP/Getty Images
Among the survivors of the attack was “Fereshta,” a 17-year-old musician from a remote village in the eastern province of Nuristan. Her father was abducted and ransomed three times for supporting her studies, and she found refuge at a music conservatory for disadvantaged children in Kabul. But the new Taliban regime is once more enforcing a ban on live music, as it did during its 1996-2001 rule, and ordered her school shut down. Despondent, Fereshta threw herself into the airport rush and barely escaped the ISIS-K attack. Her goal remains to reach the U.S. to continue her music, if she can find a way out of Afghanistan. As of press time, she was had not yet been able to get out.
For her part, Ayoubi, 26, says she planned to stay in Kabul but fled after learning from a government official that she was on a Taliban hit list. The relief she felt in getting out of the country is tempered by the guilt of leaving her mother and younger sister behind, along with memories of an escape in which Taliban guards broke her nose and her 11-month-old daughter fell unconscious. She has a recurring nightmare that she’s back at the airport gate, fighting to push through, “and then I wake up to this,” she says. “We had good lives, we worked so hard and now we are in quarantine, left with nothing. We have to survive with whatever is given to us.”
In the U.S., the fallout from the withdrawal is measured mainly in terms of its political implications. Pundits debate its potential impact on mid-term elections, how it will tarnish Biden’s presidency, and America’s global standing. For Afghans, it’s a matter of survival. The Taliban takeover has spurred a refugee crisis that could run up to half a million people by next year. More than a million have been displaced internally, and the UN warns that half the population is in dire need of humanitarian aid as basic services break down.
Two decades after 9/11, America’s longest modern war is finally over. But for all those who came of age in that era only to be uprooted or left behind, their plight is far from over.
“When I think of U.S. policy towards Afghanistan, I can only come to the conclusion that no matter what we achieved, no matter how hard we worked, it didn’t matter to them: In the end this was going to happen,” Ayoubi sighs. “And that is the thing that bothers me the most, the part I can’t understand. All that sacrifice, their soldiers and ours, for nothing. This callous betrayal gives a bad image to the U.S. all over the world. It’s going to be written with black ink in American history.”
Democrats are allowing jobless aid to expire just as an eviction ban lapses, which risks leaving 10 million unemployed feeling 'neglected' during the Delta surge
The Delta variant is stymieing the economic recovery, but Congress isn't extending pandemic aid. Samantha Lee/Insider
Joseph Zeballos-Roig Sun, September 12, 2021,
The economy is rebounding, but millions of Americans are still out of work.
The Delta variant threatens to set back the pace of the recovery as jobless aid programs and an eviction freeze end.
"It's like a double hit," economist Claudia Sahm said. "This is the ending that fits the crisis."
The American economy is growing, but it's splitting between flourishing workers and those falling on difficult times.
Indeed, it has recovered from devastating depths it reached last year. Earlier this year, President Joe Biden touted the summer as a time for Americans to declare independence from a pandemic that's held a fierce grip over their lives. Easing restrictions was also supposed to mean a return to normalcy and with it a resurgent economy.
But it hasn't panned out like that since. Millions of Americans remain out of work and unable to land a job even in a rebounding labor market. The rise of the Delta variant is stymieing the speed of the recovery, reflected in a disappointing August jobs report and early signs of Americans pulling back on air travel and spending at restaurants.
On Thursday, Biden outlined steps to mandate swaths of the private and federal workforces to get a COVID-19 shot. He also said in a statement "the Biden plan is working" as weekly unemployment claims tumbled to a new pandemic low.
Resistance from moderate Democrats has doomed any renewal of the federal unemployment programs that expired on Labor Day, along with an eviction moratorium the Supreme Court struck down last month. At least 7.5 million people lost all their federal jobless aid, per an estimate from the left-leaning Century Foundation. Congress and the Biden administration aren't stepping in to provide new aid as virus infections top 150,000 a day and hospitalizations soar. Experts warn it may set the stage for a slower recovery.
"There are enough people in the Biden administration now who should remember this mistake when they were in office under Obama," William Spriggs, a professor at Howard University and economist for the AFL-CIO, said in an interview. "This tendency to want to declare economic victory and take a victory lap is problematic - in part because you're gonna slow the recovery."
Claudia Sahm, a former Federal Reserve economist, said jobless people had been "jerked around" in the pandemic with arbitrary deadlines causing the government to pull the plug on their benefits. "It's like a double hit," she told Insider. "The whole thing has been so tough on the unemployed. This is the ending that fits the crisis."
The White House declined to comment on the record. White House press secretary Jen Psaki has pointed to the child tax credit as an alternative source of federal aid, and administration officials say states can renew federal unemployment programs on their own. None have done so. 'They did it exactly backwards'
The latest jobs report showed the economy recouping 235,000 jobs, a sharp slowdown from the month before when over a million jobs were added. Nick Bunker, an economist at Indeed, noted that leisure and hospitality industry, a sector that had experienced strong growth prior to Delta.
"This has Delta variant written all over it," he wrote on Twitter. The renewed spread of the virus threatens to dent the recovery of the service sector and continuing to sideline workers through school closures or lack of childcare.
"We're heading into winter in the midst of an enormous uncontrolled surge of COVID," Julia Raifman, an associate professor at Boston University, told Insider. "All the people who lost their work in travel and leisure early on in the pandemic are again at risk of not finding work."
Conservatives have assailed the Biden administration's economic response to the pandemic, blaming generous federal benefits from direct payments and jobless benefits in the Democratic stimulus law for a shortage of workers.
"They did it exactly backwards," Casey Mulligan, a former Trump administration economist, said in an interview. "If that's the concern, I'd say take your hand away from the money shovel so you don't destabilize things."
For many unemployed Americans, however, a steady flow of government cash helped them put food on the table, keep up with rent or medical bills and stay housed during a deadly pandemic. In addition, early research indicates the end of federal unemployment benefits didn't lead to a major surge in hiring in GOP states that ended programs this summer. 'I thought the one party in control was for the people'
Aaron Davison, 28, was furloughed from his job as a turnstile attendant at Universal Studios in Orlando, Florida, early last year. Davison had relied on the enhanced unemployment payments to cover the cost of the hotel room where he's lived in with his parents for over a year, along with a GoFundMe he set up. That money is starting to dry up.
He's applied only to remote jobs because he doesn't want to infect his 64-year-old mother Emily, who has multiple sclerosis and diabetes. She's had five hospital visits in the past year, straining their finances as medical bills mount and they struggle to pay them without health insurance.
Aaron Davison alongside his parents. Courtesy of Aaron Davison
The Davison family recently renewed their hotel stay until October 11, but they may have no choice but to move into their compact SUV after that if Aaron can't find work.
Davison said he feels policymakers have ignored jobless people like him as they pivot to other priorities. Democrats are prioritizing the passage of a $3.5 trillion social spending plan this month, full of provisions they hope will transform the economy and help them safeguard their wafer-thin House and Senate majorities ahead of the 2022 midterms.
"Now there's just a push for climate change and other agenda topics, and the unemployed people are neglected," Aaron told Insider. "I thought the one party in control was for the people. I guess I'm wrong because they very well could not be in control in 2022. I think 10 million unemployed Americans will remember they were neglected."
STATE CAPITALI$M REGULATES FOR A FREE MARKET
China Should Curb Tech Monopolies to Ensure Growth, Says PBOC Advisor
“Therefore, starting from the necessity of promoting competition and innovation and protecting consumer rights, the task of preventing and breaking monopolies should not be taken lightly.”
Tom Hancock Sun, September 12, 2021,
(Bloomberg) -- Beijing should strengthen efforts to control the expansion of technology companies because the development of internet platforms leads to a “winner takes all” dynamic, which increases inequality and slows economic growth, an advisor to China’s central bank said.
“The new technological revolution with more prominent properties of increasing returns will inevitably produce an unprecedented tendency toward monopoly,” Cai Fang, a member of the People’s Bank of China’s monetary policy committee, told the state-run Securities Times in an interview.
Cai’s comments are the latest indication that policy makers in Beijing intend to continue a campaign to rein in tech giants such as Alibaba Group Holding Ltd. and Tencent Holdings Ltd., which has rocked equity markets this year. Cai, an economist at the state-run Chinese Academy of Social Sciences, argued that anti-monopoly regulation will increase productivity and help the country’s long-term economic growth.
Now that China has achieved middle-income status, future growth needs to come from productivity gains rather than increasing investment, Cai said. That requires more government action to increase competition between companies and prevent monopolies rather than relying on markets, he added.
The market mechanism “is also the mother and breeding ground of monopoly,” he said. “Market fundamentalism often deliberately downplays the existence and harm of monopoly.” The government should minimize “the obstacles to competition from technological progress and the expansion of enterprises,” he said.
Cai said internet companies were more prone to monopoly as they tend to be larger and have stronger barriers to entry due to their control over data.
“There is a new phenomenon of ‘winner takes all’,” he said. “Therefore, starting from the necessity of promoting competition and innovation and protecting consumer rights, the task of preventing and breaking monopolies should not be taken lightly.”
Cai also commented on redistribution, a topic which has gained prominence following President Xi Jinping’s growing calls for “common prosperity.” He called for the construction of a social security system ensuring that people’s livelihoods are not affected by employment and income shocks, and greater equalization of public services between regions. Large cities should take the lead in improving public services, he added.
The PBOC advisor also called for continued government support for manufacturing, including in large cities such as Beijing and Shanghai.
“Without a manufacturing industry of appropriate size and which continuously upgrades, it is impossible to form a middle-income group of sufficient size,” he said.
