We have long known that the Sun is active. It “flares” quite often, sending huge amounts of energy off in a certain direction - sometimes directly at Earth. But we also know that, compared to other Sun-like stars, it seems relatively quiet, and not capable of producing the “superflares” we sometimes see in its stellar equivalents. That sounds like great news for humanity, and some scientists have even argued that lack of superflares was a critical impetus for the development of complex life on Earth. But a new paper from Natalie Krivova of the Max Planck Institute for Solar System Research and her co-authors in the journal Philosophical Transactions A calls the assumption that our Sun is incapable of such dramatic outbursts into question. That also means that, eventually, our highly technological society could bear the brunt of one of them.

Scientists have been collecting data on the Sun for decades, and one of the most interesting features they watch out for are solar flares. These massive outbursts of energy occur when the twisted magnetic fields located in what are known as the Sun’s “Active Regions” (ARs) snap and reconnect, releasing a huge amount of stored energy. Commonly known as “sunspots”, ARs also leave behind a residual glowing area known as “flare ribbons” that occur after their high-power snap-back.

Using data collected by NASA’s Solar Dynamics Observatory between 2010 and 2016, the authors analyzed what they believed to be a critical relationship - between the total area of an Active Region, the size of its resultant flare ribbons, and the total energy released during their creation. They found a very accurate statistical correlation that also makes sense intuitively - the larger the active region, the larger the ribbon area, and the more maximum potential flare energy. And critically, they found the flare energy scales exponentially with the ribbon area...

The Human Genome Project was launched in 1990, preceded by decades of breakthroughs in genetics. It eventually gave us a sequence of the human genome. Yet, while the physical rules behind the genome's organization remain an active area of research, many questions are still largely unanswered. Among these is the impact of an omnipresent force influencing life on Earth: gravity.

A new study, which appears in the journal Science Advances, addresses some of these weighty questions by using an innovative technique: creating a zero-gravity, or microgravity, environment to reveal gravity's impact on a human cell.

The method serves two purposes: isolating gravity's impact on the genome by removing it as a factor in experiments while, at the same time, showing how the genome functions in outer space, where gravity is nonexistent.

"On Earth, the role of gravity is intriguing—it is a constant mechanical stress on everything," explains Alexandra Zidovska, an associate professor in New York University's Department of Physics, who led the study.

"We wanted to know what gravity's role is in the genome's organization and function here on Earth. To uncover it, you have to remove gravity as a force, so we simulated zero gravity in our experiments."

"Beyond Earth, the question of lack of gravity is also compelling: How will the human genome be affected when in outer space?" she continues.

"We think our findings can be useful in better understanding how space travel affects us."

The human genome has a complex and compact hierarchical organization. It is a one-dimensional sequence encoded in 2 meters (6.6 feet) of DNA molecules packed in three dimensions inside a cell nucleus barely 10 micrometers in size—or about the width of a silk fiber.

Its structure is directly linked to its function, and deviations from it can lead to human diseases, such as cancer and developmental afflictions. Despite their significance, the physical principles governing the genome's organization are not well understood.

"We do not know if or how the presence of gravity affects this organization and if the absence of gravity would cause genomic aberrations," observes Zidovska...

The human brain is terrible at healing itself from injury or disease. But some animals can harness their own cellular abilities not only to repair injuries but also to regrow their brains entirely. Researchers from the University of Georgia have pinpointed several of the genes that make brain regeneration possible in one type of flatworm.

"Big picture: We would like to come up with ideas for how to better empower the human brain to regenerate itself," said Rachel Roberts-Galbraith, corresponding author of the study and an associate professor in UGA's Franklin College of Arts and Sciences.

"The understanding of brain regeneration that we can develop using simple animals gives us a reason to be optimistic. It's not an inherent property of brains that makes them bad at regeneration. It's something specific to humans."

Flatworm and human brains are both made up of networks of specialized cells called neurons. These cells communicate with each other by sending electrical or chemical signals. Some neurons react to stimuli, such as light or touch, while others control movement.

Flatworms use stem cells to replace neurons after injury. Humans also have stem cells, but they are unable to transform into new neurons effectively enough to heal injuries. The new study sheds light on how shared genes work in flatworms and lays the groundwork for researchers to investigate similar pathways that might be activated in humans to design better therapies for traumatic brain injuries or diseases.

Some flatworms can regrow tissues, muscles and even their brains
Planarians can be found in freshwater, saltwater and even on land. They don't have circulatory or respiratory systems. But they do have stem cells that can change into whatever their body needs at a given time, making them valuable animals for brain and cognitive research.

Using stem cells, planarians can regrow their entire body from just a sliver of a body fragment. They can rebuild tissues, muscles and even their brains.

But how do these tiny creatures know what type of cell to make and where to send it?

The hydrogen in your body and present in every molecule of water came from the Big Bang. There are no other appreciable sources of hydrogen in the universe. The carbon in your body was made by nuclear fusion in the interior of stars, as was the oxygen. Much of the iron in your body was made during supernovas of stars that occurred long ago and far away. The gold in your jewelry was likely made from neutron stars during collisions that may have been visible as short-duration gamma-ray bursts or gravitational wave events. Elements like phosphorus and copper are present in our bodies in only small amounts but are essential to the functioning of all known life. The featured periodic table is color coded to indicate humanity's best guess as to the nuclear origin of all known elements. The sites of nuclear creation of some elements, such as copper, are not really well known and are continuing topics of observational and computational research.

Image Credit: NASA's GSFC, SVS

Unlike electric charge, as far as we know all mass is positive, and positive masses attract one another. Could negative mass exist, and if so, what would be the ramifications?

Antigravity between a positive mass and a hypothetical negative mass has received a fair bit of attention in both physics and science fiction over the years. For example, in 1901's "First Men in the Moon" author H. G. Wells imagines a substance he calls "cavorite" which creates a negative force of gravity and thus acts as a gravity shield. In Newton's theory of gravity, negative mass would effectively appear as his same equation but with the gravitational constant G replaced by -G. But Einstein's version of gravity, general relativity, is not so kind, and does not seem to consistently allow anti-gravity.

In a new paper in Physics of the Dark Universe, Shin'ichi Nojiri from Japan and S.D. Odintsovc from Spain dig deeper into the possibility of negative mass objects (NMOs) and conclude that the idea may not be as exotic as is thought. Using theoretical tools, they show that negative mass "does not always lead to any inconsistency."

Where negative mass could arise
Mass comes from a particle's interaction with the Higgs field, and most of a particle's mass is actually binding energy (remember Einstein: m=E/c²) between its constituents. Protons, 1,836 times more massive than electrons, are composed of three quarks and gluons bound together. The quark masses are only about 9% of the proton's mass, according to lattice gauge theories of quantum chromodynamics. The rest comes from the field energy of gluons that mediate the dynamics inside the proton...

Scientists built a swallowable paper battery that can power medical devices inside the body and then gradually break down after its job is done.

So far, the battery has been tested only in pigs, in which it powered devices for up to three days. If proven safe and effective in people, the battery could someday power temporary devices inside the gut while avoiding surgery to retrieve a conventional battery from the body when the device is no longer needed.

"I'm very excited about this work," said Reza Ghodssi, a professor of electrical and computer engineering at the University of Maryland who was not involved in the study. "The battery is one component that takes up most of the space in an ingestible device, so anything that can provide the required power while reducing the size of the capsule is very promising."

Examples of ingestible medical devices include those that detect bleeding, dispense medicines, or stimulate specific tissues or organs.

How does the battery work?
Conventional batteries used in ingestible devices are not only large; they also need to stay sealed to prevent their internal materials from leaking into surrounding tissue and causing damage. The new battery, described Monday (Sept. 21) in the journal Nature Chemical Engineering, is made from materials that gradually dissolve in the acidic gastrointestinal tract and can then be safely absorbed without leaving behind harmful fragments or toxic byproducts...

Two decades ago, scientists seemed on the verge of understanding biology in a new, quantum way.

Life unfolds over an incomprehensible span of scales, from our planet-enveloping biosphere at one end, to individual cell-building biomolecules at the other. Even at its most microscopic, though, biology doesn’t really reach down to the quantum realm, in which particles act like waves, become entangled with one another, and exist in superpositions of multiple states at once. But scientists in the field of quantum biology are searching for ways that organisms might be able to push quantumness into the space, time, and temperature domains relevant to life, to make use of its strange properties.

In photosynthesis, for example, organisms use specialized pigments and proteins to harvest light with nearly perfect quantum efficiency; they convert almost every incoming photon into useful chemical energy. In 2007, new evidence suggested that life might accomplish this feat by taking advantage of a quantum effect called coherence. The result buoyed the controversial idea that, despite being a warm, wet, and decidedly classical environment, a living cell could maintain — and even exploit — fragile quantum states.

Gregory Scholes, a chemist at Princeton University, was initially enthusiastic about the result. He and colleagues followed up with experiments on photosynthesizing proteins and pigments and came away with similar conclusions. But today, Scholes is skeptical that quantum effects play a role in life. In fact, he’s convinced that the way forward for quantum biology might not be quantum at all. Rather than taking advantage of genuine quantum effects, Scholes proposes, life might be imitating them instead. In several papers published over the past three years, Scholes and colleagues have shown that complex networks of classical objects can conspire to produce phenomena that mathematically mimic quantum objects.

Don’t be fooled: The states that these networks produce are not truly quantum; they’re only “quantumlike.” They arise when many interacting, oscillating parts add up to a collective whole whose behavior obeys the same mathematics that makes predictions about the quantum world.

Fusion-powered space travel has long held the promise of rapid trips across the solar system: Mars in weeks, Saturn in months, Pluto in years.

For decades, such possibilities have remained theoretical, like something plucked out of a science fiction novel. But several companies are now working to build practical nuclear fusion propulsion engines, with significant milestones being hit.

Pulsar Fusion, a U.K.-based startup, hopes to launch a demonstration mission to space in 2027, while Princeton University and Helicity Space in the U.S. are continuing their own work on fusion drives.

If any of these efforts prove successful, missions across the solar system for robots and humans could be unlocked like never before, turning us into a true spacefaring species.

"If we continue on the current trajectory, everything we know about space travel is going to change within a decade," Stephane Lintner, CEO and co-founder of Helicity Space, told Live Science.

But is it too good to be true? Can the dream of nuclear fusion propulsion ever be fully realized, or will it remain a sketchbook fantasy? After decades of dreaming, we might be on the cusp of finding out...

In the early 1960s, a worker extracting minerals at Jebel Irhoud, in Morocco, uncovered a skull with strikingly human features.

Named Irhoud 1, the fossil was initially identified as an African Neanderthal variant about 40,000 years old.

Later dating studies pushed the age of the find back, to between 100,000 and 200,000 years in 1991 and to about 160,000 years in 2007.

In 2017, two studies reclassified Irhoud 1 and associated remains as Homo sapiens and gave them an age of roughly 315,000 years, making them the oldest known representatives of the species.

“In 2017, the Max Planck Institute for Evolutionary Anthropology (MPI-EVA) publicly released image and video data regarding the three-dimensional digital reconstruction of the Jebel Irhoud skull,” said corresponding author Dr. Johari Yap Abdullah, a researcher at the Universiti Sains Malaysia and Saveetha University, and his colleagues.

“The three-dimensional model in question constitutes a composite skull, structured through the spatial integration of multiple specimens excavated from the same stratigraphic unit.”

The MPI-EVA model is dominated by the Irhoud 1 fossil, the original 1961 find, which supplies the braincase and upper face.

A mandible from another individual, Irhoud 11, and fragments from other specimens fill the gaps...

A new company has a plan to make the dirty gas turbines powering data centers more efficient: liquid carbon dioxide.

American Supercritical came out of stealth Wednesday, announcing $8 million in funding. It wants to retrofit inefficient gas turbines that many data centers rely on for power with units that can generate more power, without adding more emissions (though the gas-fired turbines will continue to emit carbon pollution). The technology can also theoretically be used on a wide variety of energy sources at a time when power demand is skyrocketing.

“We want to start with gas turbines but eventually expand beyond that,” says cofounder Simon Shuham.

Most large gas-fired power plants in the United States use an array of heat engines in what’s known as a combined-cycle process: First, turbines generate electricity from burning compressed air and natural gas, then a separate engine uses the hot exhaust to make steam and create additional energy. But for a variety of reasons, data centers across the US have opted to power their operations with what are known as simple-cycle turbines, and exclude the steam component.

These turbines are much less efficient than combined-cycle plants. Usually, only about 35 percent of the energy from simple-cycle turbines is converted to electricity, while the rest escapes as exhaust. (In combined-cycle plants, that figure hovers closer to 60 to 65 percent.) That exhaust includes greenhouse gases, making plants that run on simple-cycle turbines a much worse choice for the environment than combined-cycle plants.

The size of some of these plants combined with their inefficiency is a recipe for climate disaster. A massive data-center power plant in Texas that Amazon is building with just simple-cycle turbines, for instance, is permitted to emit more than 33 million tons of greenhouse gases per year—more than the annual total of some small countries.

But all these small, inefficient turbines could be a great match for supercritical CO2 technology, American Supercritical’s founders say. Carbon dioxide becomes supercritical when it’s pressurized and held at a certain temperature. In this state, it gets the density of liquid but still behaves like a gas, meaning it can move energy more efficiently through much smaller amounts of equipment.

American Supercritical wants to attach its units to small gas turbines and help generate more energy. While the turbines themselves would still use gas, the supercritical CO2 unit can use the hot exhaust generated from those turbines to create additional electricity. Instead of using that heat to boil water and create steam, the heat is transferred directly by the pressurized CO2 to generate additional energy with no additional emissions.

“We’re essentially building miniature combined-cycle plants,” says Shuham.

Using supercritical CO2 also can eliminate or greatly reduce water use in the power generation process—something that’s drawn intense scrutiny when it comes to data centers. Importantly, the CO2 involved operates in a closed-loop system, meaning that it doesn’t have to be refilled. Cofounder Matthew Carlson, who researched supercritical CO2 for more than a decade, likens it to refrigeration systems that circulate CO2 to facilitate cooling.

Researchers in Japan have switched on "Shunkai," a neutral atom quantum computer that scientists hope to scale into a 10,000-qubit behemoth by March 2031.

Shunkai is the first full-stack system of its kind in Japan, meaning it features the software, control and hardware layers needed to read user inputs and return a result — not unlike a conventional PC. In theory, that means it should be easier for researchers to get some meaningful use out of the machine, with the team behind Shunkai planning to open it up to external users over the coming years.

In a statement, project lead Kenji Ohmori, a professor of photo-molecular science at the Institute for Molecular Science, said researchers' use of Shunkai would "lead to ripple effects on various fields in industry, academia, and government around the world."

The team behind the new machine plans to integrate it into an existing shared supercomputing facility to create a quantum-GPU hybrid computing center.

Quantum computers: Powerful but impractical
Unlike traditional, or "classical," computers, quantum computers operate according to the strange laws of quantum physics. In quantum systems, qubits — in the form of superconducting circuits, trapped ions or photons (among other modalities) — represent the fundamental building blocks of quantum information. These can exist as a 1, 0, or a "superposition" of both states at once...