Chinese fish fossils help researchers understand human evolution

According to a series of investigations published in Nature on September 28, 2022, scientists in southern China have uncovered fossil fish dating back more than 400 million years. This graphic, provided by Heming Zhang, portrays Xiushanosteus mirabilis. Photographed by Heming Zhang and released by the Associated Press.

Scientists say that new information provided by 440 million-year-old fish fossils discovered in China is "filling some of the crucial gaps" in understanding how humans evolved from fish.

In 2019, researchers unearthed two fossil fish beds in Guizhou, in southern China, and Chongqing, in the southwest.

The fossils "assist to trace many human body structures back to ancient fishes, some 440 million years ago, and fill some crucial gaps in the evolution of 'from fish to human,'" according to experts from the Chinese Academy of Sciences' Institute of Vertebrate Paleontology and Paleoanthropology (IVPP).

Fish fossils dating back more than 400 million years have been discovered in southern China, as depicted in this picture by Heming Zhang and published in a series of articles in Nature on September 28, 2022. Photos by Heming Zhang for the Associated Press.

As they put it, their findings "give further solid proof to the evolutionary path," and four publications detailing their research were published in Nature on Wednesday.

Acanthodians, a type of fish found in the Chongqing fossil deposit, are thought to be the origin of all animals with jaws and a backbone, including humans.

In 2013, researchers claimed to have discovered a fish fossil in China that dated back 419 million years, casting doubt on the hypothesis that modern animals with bony skeletons (osteichthyans) originated from shark-like creatures with a cartilage frame.

The scientists concluded that the newly discovered organism, Fanjingshania, lived roughly 15 million years before this ancient fish fossil.

"This is the oldest jawed fish with known anatomy," said Zhu Min, the study's principal researcher.

According to the authors, "the new data allowed us to... acquire much-needed information regarding the evolutionary pathways leading to the origin of crucial vertebrate adaptations like jaws, sensory systems, and paired appendages (limbs)."

Fish fossils dating back more than 400 million years have been discovered in southern China, as seen in this picture by Heming Zhang for the September 2022 issue of Nature. (H. Zhang via AP)

The statement added that the Chongqing fossils are the only ones in the world that date back about 440 million years and "preserves whole, head-to-tail jawed fishes," providing an extremely rare glimpse into a period considered the "birth of fishes."

"It's truly an extraordinary, game-changing combination of fossil findings," said John Long, the former president of the Society of Vertebrate Paleontology and a professor at Australia's Flinders University.

It completely rewrites the textbook on the origins of jawed animals.

NASA Spots New Island As Underwater Volcano Erupts

According to NASA, islands formed by undersea volcanoes are often "short-lived,"; therefore, the newly formed island may not be here to stay.

The Home Reef volcano was still active and spewing lava as of Monday.

Hours after an undersea volcano erupted not far from Australia; a new baby island appeared in the southwest Pacific Ocean.

The Home Reef volcano in the Central Tonga Islands has recently begun erupting, discolouring the surrounding sea with its lava, steam, and ash. According to NASA Earth Observatory, which obtained satellite imagery of the island, it erupted above the water's surface just eleven hours after the eruption.

According to a NASA press release, the infant island expanded rapidly. Scientists from Tonga Geological Services determined the island's dimensions on September 14. They determined that it covered an area of 4,000 square metres (1 acre) and rose 10 metres (33 feet) above sea level. The researchers reported the island's expansion to a total area of 24,000 square metres on September 20. (6 acres).

According to the US space agency, the new island can be found on the seamount of Home Reef in the Central Tonga Islands, which is southwest of Late Island. However, it also mentioned that the infant island might disappear in the future.

NASA said that submarine volcanoes "typically result in short-lived islands, though they occasionally survive for years," NASA said.

A 12-day eruption of the adjacent Late'iki Volcano in 2020 formed an island that washed away two months later, although an earlier island built by the same volcano in 1995 lasted for 25 years.

Meanwhile, the Tonga Geological Services reported Monday that the Home Reef volcano continued to erupt. In a statement, officials noted that there had been 21 separate volcanic episodes at Home Reef Volcano in the last 24 hours, indicating that the volcanic activity is progressive. However, they noted that the Aviation Community and the people of central Tonga Vava'u and Ha'apai islands have only a "minimal risk" from the volcano's ongoing activity.

Scientists Discover Chromosome Fluidity

Outside of their replication and division phases, chromosomes were found to be pliable, if not liquid.

The ability to move chromosomes around inside living cells proves they are malleable.

Scientists from the French National Center for Scientific Research (CNRS), the Curie Institute, and the Sorbonne University have successfully performed the first direct physical manipulation of chromosomes in living cells. When they subjected chromosomes to varying stresses using magnets, they discovered that, outside of cell division phases, chromosomes are remarkably malleable, nearly liquid. This research was just released in the highly-regarded journal Science.

Chromosomes are pliable, albeit not liquid, substances when not undergoing cell division. The first time that chromosomes in a living cell's nucleus have been directly mechanically manipulated has allowed for this breakthrough finding.

Chromosomes, extremely long DNA molecules, were formerly depicted as tangled like loose balls of yarn, producing a gel-like substance. The findings of this new publication paint an entirely different image. A cell's chromosomes are mobile and can rearrange themselves without interference from the other components of the nucleus.

Scientists from the Nuclear Dynamics, Physical Chemistry and Cell Biology, and Cancer laboratories at CNRS, the Curie Institute, and Sorbonne University, in collaboration with scientists from the Massachusetts Institute of Technology, attached magnetic nanoparticles to a small portion of a chromosome in a living cell and published their findings in Science. The chromosome was then stretched using an external micro-magnet to apply varying tension. By taking this method, the groups could quantitatively evaluate how a chromosome reacts to external pressures for the first time in a living cell.

These studies demonstrated that the range of stresses exerted naturally in the nucleus, such as by enzymes copying DNA, is sufficient to alter a chromosome's conformation significantly. Located at the crossroads of physics and biology, this groundbreaking finding modifies the standard depiction of chromosomes. It also enriches our knowledge of biological mechanisms, chromosome biophysics, and genome structure.

The NASA spacecraft is closing in on the target of a crucial test to deflect asteroid collisions

On September 26th, NASA will attempt to do the impossible by intentionally crashing a spacecraft into an asteroid to alter its orbit slightly. (AFP)

• At around 23,000 kilometers per hour, on September 26th, the spaceship is scheduled to crash into the asteroid moonlet Dimorphous.
• The Dimorphos are not directly dangerous to Earth, but this research is necessary in case a similar situation arises.

WASHINGTON: Surely, the dinosaurs would have appreciated this idea.

As a crucial test of our ability to prevent cosmic objects from destroying life on Earth, NASA will attempt a task humanity has never before accomplished on Monday: purposefully smashing a spacecraft into an asteroid to divert its orbit gently.

The California-launched Double Asteroid Redirection Test (DART) spacecraft is rapidly closing in on the asteroid. It will strike at an estimated 14,000 miles per hour (23,000 kph).

Neither the little asteroid Dimorphos nor the larger asteroid Didymos, which it circles, pose any danger to Earth as they travel around the Sun and zoom past at a distance of about seven million miles.

NASA, however, believes it is necessary to experiment regardless of whether or not a future need arises.

NASA planetary defense officer Lindley Johnson told reporters on Thursday, "This is an exciting time, not only for the agency but in the history of space and the history of humanity, quite frankly."

At 7:14 pm Eastern Time (23:14 GMT), if all goes according to plan, the car-sized spacecraft will collide with the 530-foot (160-meter, or two Statue of Liberty-tall) asteroid, and the whole thing will be broadcast live on NASA's website.

NASA expects that by crashing into Dimorphos head-on, it will be pushed into a more compact orbit, decreasing the time it takes to orbit Didymos from 11 hours and 55 minutes to 10 hours and 45 minutes. This will be observable by ground-based telescopes in the days following the impact.

The proof-of-concept experiment will bring to life an idea previously only explored in science fiction, most notably in films like "Armageddon" and "Don't Look Up."

The primary camera system, dubbed DRACO, will begin transmitting the first images of Dimorphos as the craft accelerates itself into space, flying autonomously for the final leg of the mission like a self-guided missile.

In a recent briefing, Nancy Chabot of the Johns Hopkins Applied Physics Laboratory (APL), which hosts mission control, predicted that the object would appear as a "tiny point of light" before rapidly expanding to fill the entire field of view.

The planetary scientist continued, "These visions will persist until they don't."

A toaster-sized satellite named LICIACube, which split out from DART a few weeks ago, will make a close flyby of the spot minutes later to take pictures of the collision and the ejecta, or the crushed rock thrown off by the impact.

LICIACube's image will be transmitted back in the coming weeks and months.

An assortment of Earth-based and space-based telescopes, including the newly operational James Webb, is keeping an eye on the event in the hopes of catching a glimpse of a brightening cloud of dust.

When a European Space Agency mission called Hera arrives in four years, we'll have a much clearer picture of the system's appearance than we do now. Hera will survey Dimorphos's surface and quantify its mass, which is presented simply as estimated.

Only a minuscule percentage of the solar system's billions of asteroids and comets threaten Earth, and none will for at least 150 years.

NASA's chief scientist, Thomas Zurbuchen, has remarked, "I guarantee you that if you wait long enough, there will be an object."

We know this because of evidence found in geological records, such as the six-mile-wide Chicxulub asteroid that crashed into Earth 66 million years ago, causing a global cooling that ultimately resulted in the extinction of the dinosaurs and seventy-five percent of all other species.

In contrast, even if an asteroid the size of Dimorphos would have more destructive power than any nuclear bomb in history, its effect would be limited to a local area, such as the destruction of a city.

Researchers are also anticipating learning something new that will improve their understanding of asteroids in general.

What DART can do in terms of momentum transfer to Dimorphos depends on whether or not the asteroid is composed of solid rock or more like a "rubbish pile" of boulders bonded by mutual gravitation.

NASA engineers are optimistic that DART's SmartNav guidance system will successfully navigate to the target asteroid. However, they don't know whether the asteroid is shaped like a dog bone or a doughnut.

NASA has another chance in two years to try again; the spacecraft has just enough fuel for one more pass.

But if it works, Chabot says, it will be the first step toward a world that can protect itself from a potentially existential threat.

Undersea volcanic eruption in Tonga was a "once-in-a-lifetime event," scientists believe

Scientists are still trying to decipher the effects of January's underwater volcano eruption in Tonga.

Hunga Tonga-Hunga Ha'apai, the volcano responsible for the study published on Thursday in Science, is said to have released millions of tonnes of water vapor into the atmosphere.

Scientists believe the eruption, which was far more potent than the atomic bomb on Hiroshima, increased the amount of water in the stratosphere (the second layer of the atmosphere, high above the range where humans live and breathe) by about 5%.

Scientists are currently attempting to predict how much this water will affect the atmosphere and whether or not it will cause global warming in the coming years.

According to the primary author and climatologist at Colorado's National Center for Atmospheric Research, Holger Voemel: "This was a once-in-a-lifetime event."

Earth generally cools after significant eruptions. The majority of volcanoes spew massive quantities of sulfur into the sky, which blocks the sun's rays, according to Matthew Toohey, a climate researcher at the University of Saskatchewan who was not involved in the study.

The Tongan explosion was much wetter than average as it began its life beneath the sea and sent a plume of water into the air at a much higher concentration than usual. Since water vapor is a greenhouse gas that traps heat, Toohey predicts that the eruption will have the opposite effect of what was hoped for: a rise in global temperatures.

The extent to which the climate may warm is unknown.

N.O.A.A. climate scientist Karen Rosenlof, who was not involved in the study, said she anticipates the effects to be minor and transient.

This increase "could warm the surface a modest bit for a short time," Rosenlof wrote in an email.

According to scientists who reported this in August, it injected enough water vapor to fill 58,000 Olympic-sized swimming pools, setting a new "all-time record" since satellites began capturing such data.

Toohey predicted it would take several years for the water vapor to descend from the upper into the lower atmosphere. Meanwhile, Rosenlof added, the additional water may hasten ozone depletion in the atmosphere.

However, since experts have never witnessed an eruption quite like this one, it is difficult to determine for sure.

According to Voemel, the stratosphere is the region about 7.5 and 31 miles above Earth, where the air is typically relatively dry.

Voemel's group used a system of devices dangling from weather balloons to calculate the size of the volcano's plume. Voemel said that typically, such instruments are incapable of detecting even trace amounts of water in the stratosphere.

Scientists from another organization kept an eye on the explosion via a NASA satellite. Their analysis, released earlier this summer, suggested that the eruption was much more massive, adding roughly 150 million metric tonnes of water vapor to the stratosphere. This is three times as much as Voemel's study found.

Based on the research results, experts have concluded that the great plume may have a short-term impact on Earth's global average temperature.

Voemel conceded that the satellite imagery could have seen features of the plume that the balloon instruments missed, increasing the accuracy of its assessment.

As he put it, the Tongan blast was unlike anything witnessed in recent history, and researching its aftermath could reveal hitherto unknown aspects of our environment.

 NASA completes crucial Artemis 1 rocket fuel test successfully.

September 27 may see the next attempt to launch the Artemis 1 mission.

NASA

Since NASA has accomplished everything necessary to call the fuel test for its rocket a success, the next Artemis 1 launch attempt could come as soon as next week. After a second launch attempt was canceled in late August, NASA needed to confirm the modifications it made by testing the addition of super-cooled fuel to the Space Launch System's tanks. After discovering a persistent hydrogen leak in one of the SLS's fuel lines, the ground crew at Kennedy Space Center attempted to fix it three times that day. The expedition was ultimately postponed since the team proved unsuccessful.

A few days later, the crew found that a slight over-pressurization of the SLS rocket's core booster tank had set off the leak. Filling the rocket's tank with propellants is a delicate process that requires gradual changes in temperature and pressure to avoid the fast fluctuations that led to the last leak. After finding a slight indentation in one liquid hydrogen seal that may have contributed to the leak, the team's engineers replaced all the seals on the rocket.

The engineers discovered another hydrogen leak during the fuel test, but after some investigation and adjustment, the leak was brought down to "within allowed rates." Because of this, the pre-pressurization test could be carried out, which involved increasing the pressure within the liquid hydrogen tank to simulate conditions shortly before liftoff.

According to Artemis 1 launch director Charlie Blackwell-Thompson, the test went "very well," and the crew achieved all of their goals. Next, NASA will examine the test results to determine if they are sufficient to proceed with a launch attempt on the initially planned date of September 27.

 Breakthrough in Superconductors: Scientists Discover an Invisible Phenomenon.

The discovery makes superconductivity more accessible.

Understanding the connection between spin liquids and superconductivity may lead to the creation of room-temperature-operating superconductors, which would have far-reaching implications for our daily lives.

High-speed hovertrains, magnetic resonance imaging equipment, efficient power lines, quantum computing, and other technologies could all benefit significantly from using superconductors. Superconductivity necessitates shallow temperatures. However, its application is constrained. Their complex and expensive needs make it challenging to incorporate them into current technology.

Unlike regular metallic conductors, whose electrical resistance decreases gradually as temperature is lowered, even down to near absolute zero, superconductors have a critical temperature beyond which it rapidly drops to zero.

Current efforts in superconductivity research are primarily focused on finding superconductors that do not necessitate these shallow temperatures. No one knows how these superconductors work, which is the biggest mystery in this area. More uses could be found for superconductivity if the method by which it is created at high temperatures could be better understood.

Researchers from Israel's Bar-Ilan University have made strides toward solving this enigma with their recent work published in the journal Nature. The researchers took pictures of an otherwise unseen occurrence using a magnetic microscope scanning SQUID (superconducting quantum interference device).

When high-temperature superconductors were first discovered, scientists were taken aback. Researchers expected to find materials with high superconductivity in metals. The best superconductors are, surprisingly, insulating ceramic materials.

Exploring shared characteristics across these ceramics could lead to insights into their superconductivity's origin and better regulation of the critical temperature. For example, the electrons in these materials exhibit high levels of mutual repulsion. Therefore, they are restricted in their mobility. Instead, they are imprisoned within a lattice that repeats at regular intervals.

Electric current is caused by electrons' charge traveling around, and electrons' spin is the other distinguishing feature. Electrons' magnetic characteristics can be attributed to their quantum property, spin. Each electron has the magnetic force of a small bar magnet. Standard materials have electrons with charge and spin that are "built-in" and cannot be removed.

However, a peculiar event occurs when electrons interact in certain quantum materials termed "quantum spin liquids," splitting each electron into a particle with charge (but no spin) and a particle with spin (and no charge). The existence of quantum spin liquids in high-temperature superconductors has been proposed as a possible explanation for the excellent superconductivity observed in such materials.

The difficulty arises from these spin liquids being "invisible" to the majority of currently available measurement techniques. Now, no experiment can confirm or investigate the Nature of a material's suspicion to be a spin liquid. It's hard to detect since it doesn't interact with light like dark matter.

This work is essential in creating a method to analyze spin liquids. It was undertaken by Professor Beena Kalisky and Doctoral Student Eylon Persky of the Physics Department at Bar-Ilan University, together with their collaborators. Scientists put a spin liquid in contact with a superconductor to investigate its peculiarities. They employed a synthetic material composed of superconductors and liquid spin candidate atomic layers.

In contrast to signal-free spin liquids, Superconductors have easily measurable magnetic fingerprints. As a result, "we were able to examine the properties of the spin liquid by monitoring the minor changes it created in the superconductor," as per Persky's explanation. Scientists looked at the heterostructure's characteristics using a scanning SQUID, a magnetic sensor sensitive enough to detect both magnetism and superconductivity.

We have witnessed the formation of vortices in the superconductor. These whirlpools represent swirling electric currents and hold one quantum of magnetic flux each. However, in our situation, the vortices formed independently without needing a magnetic field, as Kalisky explains. This finding demonstrated that the material itself produced a magnetic field. Unexpectedly, this field did not manifest itself in a straightforward experiment. Kalisky chimes in, "Surprisingly, we found that the material's magnetic field was invisible to a direct magnetic measurement."

The results indicated the presence of a "hidden" magnetic phase that was revealed by contact with the superconducting layer in the experiment. The researchers, who worked together from Bar-Ilan University, the Technion, the Weizmann Institute, the University of California, Berkeley, and the Georgia Institute of Technology, found that the magnetic phase was likely caused by the interaction between the liquid spin layer and the superconducting layer. The spin-charge separation in the spin liquid is responsible for the latent magnetism. Without an external "actual" magnetic field, the superconductor will respond to this magnetic field, creating vortices.

This is the first time the connection between the two states of matter has been seen directly. The features of the enigmatic spin liquids, such as the interactions between electrons, are now accessible thanks to these findings. Moreover, the results pave the way for further research into the connection between superconductivity and other electronic phases by building additional layered materials. More investigation into the relationship between spin liquids and superconductivity could lead to the development of room-temperature-operable superconductors, which would have far-reaching implications for our daily lives.