A major software advance could aid the creation of bigger, more reliable quantum computers, a study suggests. Researchers have developed an algorithm that enables off-the-shelf computers to run quantum simulations previously only possible using the world's most powerful supercomputers.

It means the simulations can be run using around 5% of the computing power previously needed to perform them with a supercomputer, the team says.

The advance could make it cheaper and easier to run experiments vital for understanding the limitations of current quantum computers and informing the design of improved devices, experts say.

Simulations confront quantum computing's limits
Quantum computers could, in theory, perform calculations far beyond the capabilities of even the most advanced supercomputers, but current devices are small and error-prone, hindering their performance.

Key to informing the creation of bigger, more reliable quantum computers is the development of algorithms to simulate how devices might work in reality. However, running these simulations has until now required vast amounts of computing power available at only a handful of facilities worldwide.

The new algorithm was developed by a team led by scientists at the University of Edinburgh and EPCC, the U.K.'s first National Supercomputing Centre, which is part of the university.

Standard computers tackle light-based quantum simulations
The work could aid the development of light-based quantum devices, one of several branches of current quantum research by academics and industry, the team says.

For the first time, the algorithm enables standard computers to run so-called Gaussian boson sampling, a simulation designed to demonstrate the superior capabilities of quantum devices powered by light—known as photonic quantum computers.

In tests, researchers found that classical computers using the algorithm could match and even outperform some current quantum devices' ability to run the simulations...

Leap seconds have driven a raging debate in the metrological community for three decades. Now, that argument has been put to rest: The leap second is officially dead.

Doing away with an obscure metric the average person has been blissfully unaware of may seem like a novelty, but killing the leap second has major ramifications for technology you rely on every day. It also helps stave off what could’ve been a dangerous moment in time: The possibility of the world’s first negative leap second.

The International Bureau of Weights and Measurements (known by its French acronym BIPM) on Thursday said that in May 2027 it would stop issuing leap seconds, 32 of which have been added since 1972 to adjust what’s known as Coordinated Universal Time (UTC).

The world implemented the leap second in 1972 due to a growing gap between time measured with atomic clocks and time based on the Earth’s rotation. The reason for the discrepancy? The latter is slowing down due in large part to tidal friction caused by the moon and Earth’s rotation not lining up. The molten core of the Earth as well as oceans and the atmosphere also affect the spin rate.

Leap seconds are a way to keep atomic-clock-driven UTC in line with astronomically kept Universal Time (UT1). Think of it like adding a little extra track for a train to keep running exactly parallel with another one. Rather than happening on a set interval—like a leap year—BIPM uses the average of hundreds of atomic clocks around the world and compares their time calculations to astronomical time to determine when a leap second is necessary. The most recent one was added in 2016.

Of course, adding track is no small effort, and it may seem like a lot of hassle for a measly second. But UTC is vital for all sorts of technology given the number of APIs and databases that rely on it. Introducing a leap second helped keep UTC and UT1 aligned, but it also wrought havoc on various systems running on UTC and forced companies to figure out how to deal with them when they were added every few years...

Stellar cores called white dwarfs come in an astonishing array of colors, including what scientists say is the first known green star and the reddest star ever found, new research reveals.

A white dwarf star is the dense, cooling core that remains after a low- to medium-mass star runs out of fuel. The new study, published Thursday (Oct. 15) in the journal RAS Techniques and Instruments, shows that white dwarfs come in far more colors than their name suggests.

White dwarf stars got their moniker because the first known examples glowed in either white or pale blue. The new study, however, suggests that "white" dwarfs also emit visible-light colors like pink, green, cyan, purple and yellow.

"Most stars, including most white dwarfs, behave like 'perfect radiators,' so their colour is set almost entirely by temperature. But nobody had really looked into what else might be possible for white dwarfs," Mark Hollands, an astronomer at the University of Warwick in the U.K. and first author of the study, said in a statement. "It turns out these incredibly dense stars can produce colours nobody expected, and some of them genuinely surprised me."

The variety of colors is possible due to white dwarfs' densities compared with main-sequence stars, the study suggests. Cooler white dwarfs have a density of about 1 gram per cubic centimeter, much like flowing water on Earth. The density of these white dwarfs is also millions of times denser than the sun's visible surface, or photosphere, leading to unusual conditions...

Spacecraft propulsion traditionally relies on volatile fuels and separate, bulky systems for different types of maneuvering in space. NASA is working to change that. Engineers at NASA's Marshall Space Flight Center in Huntsville, Alabama, recently completed a series of environmental and physical tests on a new small satellite designed to make spaceflight safer and more efficient.

The ASCENT (Advanced Spacecraft Energetic Non-Toxic) Propulsion Dual Mode mission is a flight demonstration of a spacecraft about the size of a large shoebox. The mission will test a single, integrated propulsion system that uses a common fuel tank to feed two types of engines.

Typically, spacecraft carry two separate propulsion systems to navigate: a high-thrust chemical system for rapid movements like entering orbit, and a low-thrust electric system for efficient, slow maneuvers like maintaining a position. This requires multiple fuel tanks and heavy plumbing, which take up valuable space and add weight.

The spacecraft being developed uses a single nontoxic propellant called ASCENT. By feeding both a high-thrust combustion engine and low-thrust electrospray thrusters from one central tank, the spacecraft saves mass and volume. For future missions, this means more room for scientific instruments and the ability to launch on smaller, less expensive rockets...

The year is 2050, and as the sun sets, the night's first constellations emerge in perfect rows. But these amber-glowing arrays aren't stars at all; they're satellite clusters, harvesting the day's last rays before beaming their power back to Earth.

If it reads like science fiction, that's because it started that way. Called space-based solar power (SBSP), the concept featured prominently in the techno-utopian imaginations of 20th-century visionaries and writers. But for decades, it was dismissed — a pie in the sky proposal.

Now, as a new space race heats up, governments and private companies in China, the U.S., the U.K. and Japan are developing several projects to reassess the idea's feasibility. These include China's ZhuRi ("Chase the Sun") program, Japan's OHISAMA project, the U.K.'s Space Solar, and power-beaming experiments by Caltech and the Air Force Research Laboratory in the U.S., all of which are targeting test launches in the next five years.

Proponents say the technology has the potential to meet Earth's energy needs many times over while causing minimal harm to the environment. But first it needs to get off the ground: In the eyes of critics, space-based solar power is exorbitantly expensive, riddled with untested assumptions, and far too complex to be deployed in time for an urgent green-energy transition.

The challenges include getting the massive solar-panel-covered satellites into space; assembling them; getting those solar panels to constantly face our star; and then finding ways to convert, concentrate and transmit their collected power back to Earth...

Rising temperatures and increasing drought are shortening crop-growing seasons in many parts of the world. Now scientists in Sweden report new advances toward engineering more efficient photosynthesis, work that could eventually contribute to efforts to adapt crops for climate change.

A team at KTH Royal Institute of Technology created and tested about 15,000 genetically altered versions of bacterial Rubisco—an enzyme that helps turn carbon dioxide into material for growth. Paul Hudson, professor in systems biology at KTH, says the study focused on bacterial rather than plant Rubisco and searched for versions that support bacterial growth.

In their article published in Science Advances, the researchers report they found several promising variants—and identified numerous changes that didn't appear to work.

Rubisco's costly inefficiency
Arguably the most important enzyme for life on Earth, Rubisco's role in bacteria and plants goes hand in hand with photosynthesis. Where sunlight provides the power, Rubisco captures carbon dioxide and incorporates it into material the organism can use to make sugars and grow.

Nevertheless, the enzyme is surprisingly inefficient. It works slowly and sometimes captures oxygen instead of CO₂. Plants must then spend energy recycling the unwanted products.

While the study focused on a bacterial Rubisco rather than the plant enzyme, its large database of successful and unsuccessful mutations offers a possible map for designing better enzymes, which may help researchers improve computer models of how Rubisco responds to genetic changes. The lessons may eventually guide work on plant Rubisco, but producing faster-growing, climate-resilient crops will require further testing in plant cells and whole plants...

A Japanese spacecraft rocketed toward Mars on Tuesday on a quest to explore its mysterious moons and bring back samples.

Five of the world's space agencies joined forces for the five-year mission that will attempt to land a robotic prospector plus a rover on Phobos, the larger and closer of Mars' two pint-sized moons.

The Japan Aerospace Exploration Agency, which is leading the sampling effort, launched the spacecraft before dawn from the country's main spaceport on Tanegashima Island. Officials declared success an hour later when the spacecraft separated as planned from the rocket's upper stage. Flight controllers burst into applause and jumped to their feet, shaking hands and embracing.

No one has managed to get samples from Mars or its moons yet
While NASA has successfully landed nine spacecraft on Mars over the past 50 years and China scored a 2021 touchdown, no one has ever reached Phobos or its sidekick Deimos. And no one has managed to fetch samples from Mars, let alone its moons.
If successful, bits of dust, soil and rocks from Phobos will arrive on Earth in 2031.

"There's a lot of adrenaline and a lot of excitement and a lot of wow," said NASA astrophysicist Tom Statler, who's involved with the project.

Japan has an edge going in, with two asteroid sample returns already under its cosmic belt...

What if the brain evolved to serve the gut? Scientists at Flinders University are challenging a cornerstone of biology, arguing that the gut's nervous system may be the body's original "brain," with the brain evolving later to support its needs.

An opinion piece published in The Journal of Physiology draws on evidence from physiology and evolutionary biology to suggest the nervous system may have originated in the gut. The paper offers a perspective on one of evolution's fundamental questions: why did brains evolve in the first place?

Flinders researchers argue the answer may lie in a much older nervous system embedded in the gut, which helped early organisms to secure the energy necessary to survive.

Rethinking the body's command structure
Lead author Dr. Tim Hibberd says the idea challenges the traditional view that the brain sits at the top of the body's command structure.

"We are proposing a different way of looking at the nervous system," says Hibberd, from Flinders' College of Medicine and Public Health.

"The enteric nervous system in the gut can sense its environment, process information and coordinate complex responses. In many ways, it functions like a brain in its own right."

Often referred to as the body's "second brain," the enteric nervous system contains hundreds of millions of neurons and can operate independently to coordinate digestion and other essential functions.

Researchers now argue it may be more accurate to think of this as the body's first brain...

An experimental vaccine offers new hope to patients with melanoma, one of the most aggressive forms of skin cancer. The pharmaceutical companies Merck and Moderna released the results of a Phase 3 clinical trial that evaluated the efficacy of a personalized mRNA-based vaccine that, when combined with immunotherapy, reduced the risk of disease recurrence or death by 42 percent compared to treatment with the immunotherapy drug alone.

Georgina Long, medical director of the Australian Melanoma Institute and the study’s principal investigator, said in a statement that these results are “transformative” and “have the potential to make a foundational shift in how we treat patients with earlier-stage melanoma.” ...

When it comes to deciding the fate of the planet, Colleen Golja always thought science and reason would have a seat at the table. That was until one morning last September in London, when the climate researcher took part in the first in a series of war games. The goal: to prevent an uncontrolled global race to develop a technology aimed at cooling the planet but that comes with vast, unknown risks that could reshape life on Earth.

“I thought that would be such an easy thing. Like, we can all agree to do ethical research and make sure it's for the better of all humans,” she told WIRED. “And boy, was I wrong.”

The simulation, titled Exploring Geopolitical Tipping Points and Climate Cooling Strategies, saw a couple dozen foreign-relations experts, scientists, military personnel, and former government officials from across the world convene in a meeting room at Queen Mary University of London. After making introductions over coffee and little yogurts, they sat at tables arranged in a square with the name of the country or organization each person was playing: national governments, climate NGOs and nonprofits, indigenous groups, and tech companies. Golja was assigned to provide technical advice to help participants make scientifically literate decisions.

The point of the game was to stress-test the world’s response to a group of prospective technologies known collectively as solar radiation modification. These technologies promise to reverse global warming by reflecting away a portion of the sunlight reaching Earth, for example by spraying particles of sulphur dioxide or some other manufactured substance into the atmosphere. The cooling effect of this kind of solar geoengineering is widely accepted. It would mimic the well-known impacts of large volcanic eruptions, which temporarily cool the planet by half a degree or more. But the fallout is less certain—and less equal. Some regions will suffer: Models predict drying in sub-Saharan Africa and more intense tropical storms in the Atlantic. The cooling effect would also last only as long as the geoengineering continued; after that the global temperature could shoot back up with wild and hard-to-predict effects...

Scientists at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have identified a potentially much more efficient way to achieve nuclear fusion, the process that powers the Sun. Their calculations suggest that changing the order in which plasma is heated and compressed could dramatically reduce the energy needed to reach ignition, a crucial milestone in the pursuit of practical fusion power.

For more than seven decades, scientists have relied on an equation called the Lawson criterion to determine whether plasma can remain sufficiently hot and dense for long enough to sustain fusion reactions without additional external heating. Developed in the 1950s, this equation establishes the conditions required for ignition, but it does not explain the most efficient way to achieve them.

Now, PPPL physicists Luis Delgado-Aparicio, Masayuki Ono, and Jonathan Menard have updated that decades-old framework. By incorporating four additional factors that influence the behavior of fusion plasma, they have developed a more comprehensive model for determining how fusion systems should heat and maintain their fuel.

To understand the significance of the discovery, it helps to know what plasma is. Often called the fourth state of matter, plasma is a gas so hot that its particles become electrically charged. When plasma reaches ignition, the energy released by fusion reactions produces enough heat to sustain the process without further external heating. Achieving this condition efficiently is one of the central challenges facing fusion energy researchers...

Attachment is the term psychologists use for the most significant relationships that hold people's lives together. But what makes an attachment relationship different from all others? According to the pioneering American–Canadian developmental psychologist Mary Ainsworth, it must meet the following six conditions.

The relationship must persist over time, and it must have been formed with a particular subject who cannot be replaced. The relationship must be emotionally significant, involve the desire to remain close to them and cause distress at involuntary separation. Finally, when threatened, the person must seek security and comfort in their relationship with that subject.

The first five conditions describe any lasting affectionate bond, such as a close friendship. Only the sixth turns it into an attachment bond specifically. Simply liking someone, feeling close to them or spending hours together isn't enough to create an attachment relationship.

Interestingly, though, nothing in these six conditions specifies a human on the other side.

This was already noticed long before the emergence of AI chatbots with the power to converse. Deities, pets and objects (ranging from children's blankets and stuffed animals to cherished household items and even phones and computers) have all been found to supply security and comfort when someone is feeling distressed.

Today, AI companion apps are commonly sold on the promise of lasting and close relationships. Many of their users describe feeling real grief when an app is updated or withdrawn. But do such experiences meet the narrow definition of attachment?

The honest answer is: We don't really know yet.

What the evidence suggests
Research on human–AI relationships has so far recorded users' feelings about chatbots, their frequency of use and their reactions to chatbot withdrawal. It hasn't tested these relationships comprehensively against the six conditions described above...

When you’re stressed, you lose some control. Stress hormones flood your bloodstream. Your heart rate and blood pressure go up. You breathe faster. These changes happen without thought. They’re run by what’s known as your sympathetic nervous system. And they kick in whether you’re facing true danger or just a big exam. But scientists are learning how to guide our nervous systems out of that fight-or-flight mode and into relaxation.

Some calming techniques come naturally. Maybe you’ve already used slow, deep breaths to recenter yourself. Now, though, there’s mounting data to support a range of zanier approaches. Ever tried humming, or tapping on your skin? What about dunking your face in cold water?

Explainer: How our body deals with stress

“Consciously, you can’t tell your heart to slow down,” explains Patricio Millar Vernetti. He’s a neurologist at NYU Langone Health in New York City. “But by doing these interventions, you have a little bit more control.”

On social media, these practices are often described as ways to “regulate” your nervous system. But it’s really about balancing two branches of your nervous system. That “sympathetic” branch is in charge of stress responses. It gets you ready for action, pumping blood to your brain and muscles. Its counterpart — the parasympathetic nervous system — calms things down.

Getting that parasympathetic nervous system to kick in can help calm us back to a resting state. It lowers stress hormone levels. It slows the heart and lowers blood pressure.

Being able to control this back-and-forth may yield big health benefits. Over time, an over-active stress response can contribute to a range of problems. These include high blood pressure, strain on the heart, inflammation and other issues.

These systems normally work without our giving them thought. But research is finding ways to turn on the parasympathetic nervous system when we feel it’s needed...

Long before modern astronomy, humans looked to the stars and were absolutely astounded by what they saw. Even by the most ancient reckoning, the night sky offered enough to inspire awe and wonder, make us feel insignificant, fire our imaginations, and foster hope and a sense of connection. Yet, for as long as humans have surveyed the heavens, they have seen no indication that life as we know it exists elsewhere - what has come to be known as the "Great Silence."

For many, the disparity between the assumed prevalence of life in the Universe and the lack of evidence for it raises a troubling incongruity often erroneously referred to as "Fermi's Paradox" (in truth, it was neither Fermi's nor a Paradox). It seems like a valid question when you consider the facts. Given the age, size, and density of the known Universe, shouldn't we have found unambiguous evidence of extraterrestrial life (and intelligence) by now?

Sixty years after the first Search for Extraterrestrial Intelligence (SETI) experiment (Project Ozma), scientists are still asking the question: "Are we alone in the Universe?" In addition to listening to the cosmos for radio signals and other signs of technological activity ("technosignatures"), efforts have been mounted to send messages to space for the purpose of making contact with an extraterrestrial intelligence (ETI).

This practice has come to be known as Messaging Extraterrestrial Intelligence (METI) to distinguish it from its more "passive" SETI cousin. Previously, we chronicled the history of SETI by examining some of its greatest milestones. Today, we will begin looking at the brief(-ish) history of METI and how it came to be...

The largest artificial intelligence (AI) firms increasingly understand that they are hostages of one another. If one firm pushes ahead recklessly, others may feel compelled to follow. If one deploys a dangerous model without adequate safeguards, others may see it as a green light to do the same.

The debate over AI has centered on what governments should do to regulate this frontier technology. That remains essential. But a more immediate question is emerging: Can the companies building these powerful systems take action independently before they lose credibility and suffer legal consequences?

That question no longer looks theoretical and is being recognized as an urgent challenge. We've already seen AI firms lose control of their models — for example, in Australia, a rogue AI hacked a government healthcare website. If we are not careful, it's only a matter of time before one of these incidents causes large-scale, real-world harm, like shutting down an electricity grid or municipal water system, or a mass misdiagnosis in a health system. If this trend continues, the entire industry could become tarnished.

But there is a blueprint for self-regulation in a risky business: the nuclear industry, which has built up layers of oversight, controls and self-scrutiny over decades.

Frontier AI may require something similar: private regulation among competitors that do not trust one another but have a mutual interest in preventing outcomes that could damage them all. This does not appeal to the better angels of human nature — it's self-preservation for the industry itself.

There is a historical precedent for this kind of arrangement. The nuclear sector did not become safe because every actor suddenly became benevolent. It became safer through a layered system of peer scrutiny, technical standards, information-sharing and external oversight. International organizations such as the International Atomic Energy Agency (IAEA), which was established in 1957, emerged to coordinate monitoring and verification, while national regulators and industry bodies gradually built professional norms around catastrophic risk.

The result was not perfect safety, as the Chernobyl disaster in 1986 clearly attests. But nuclear governance architecture is designed around the recognition that in high-risk technological systems, one actor's failure can become everyone's problem. This was seen following Chernobyl: global nuclear safety increased significantly after the disaster, with upgrades to reactor designs, improved training and international monitoring networks...

Is there a link between Earth's geomagnetic reversals and extinctions? Nobody has proven it, despite their efforts. But the idea just won't go away.

The Earth's magnetic poles haven't remained consistent over the planet's 4.5 billion year history. It's experienced multitudes of pole flips, or geomagnetic reversals, where its north and south poles swap positions.

Scientists rely on paleomagnetism to detect them. Paleomagnetism detects the orientiation of Earth's poles across geological time in lava and sediments. The orientation of magnetic minerals in lava and ancient sediments record the locations of the poles at the time they solidified or accumulated.

Scientists think reversals are triggered by changes in the heat that flows across Earth's core-mantle boundary, but finding a pattern in geomagnetic reversals is a daunting task. They seem to occur about once every 450,000 years; evidence shows 183 of them in the last 83 million years. The last one was about 780,000 years ago, so by that measure, we're overdue for the next one But the 450,000-year average is kind of a mathetmatical abstraction. There's no indication of a periodic cycle.

Determining when a reversal happened can be difficult, and determining how long the reversal took to complete is likewise challenging. Predicting one is next to impossible.

Lava and sediments present a tangled history that needs to be painstakingly untangled. Deciphering the history of these reversals is made more difficult because sometimes there are long periods of stability punctuated by shorter periods of rapid multiple reversals. To add to that, individual reversals are chaotic events.

"The Permian witnessed profound geomagnetic, environmental, and biotic upheavals, yet high-resolution paleomagnetic constraints across critical transitions remain sparse," the authors write. In this work, the authors present a magnetostratigraphic record from what's called the Fengshan section in South China that covers 3.75 million years. The record spans what's called the Guadalupian-Lopingian transition (end-Guadalupian extinction), which occurred from 262.5-258.75 Mya...

Antimatter is not known for being easy to get ahold of. That’s part of why these particles remain so cryptic. But recently, a team of physicists at Northwestern University managed to trap a single antimatter particle for months. Cooling it to temperatures near absolute zero, they could control its quantum states with great precision without even touching it. The experiment, published in Physical Review Letters, represents a breakthrough in our understanding of one of the great mysteries of physics.

In theory, antimatter should be everywhere. Mathematics predicts that every particle of matter has an equivalent antiparticle, a fact that scientists have verified experimentally. The universe should therefore contain similar amounts of both, but almost everything we observe is made up of ordinary matter, and we still don’t know why.

It is possible to produce antimatter particles in laboratories, but studying them is still incredibly difficult. When an antiparticle comes into contact with ordinary matter, the two annihilate each other and release energy. To prevent research facilities from exploding, scientists use vacuum chambers and electromagnetic fields that suspend the antiparticles in isolation. But this only partially solves the problem. Studying these particles, especially experimenting with their behavior on a quantum scale, remains challenging.

For this experiment, researchers at Northwestern trapped a positron, the antimatter counterpart of electrons. The team, led by Gerald Gabrielse, developed a device known as a single-positron quantum cyclotron, which used electric and magnetic fields to hold the positron in a vacuum at a temperature close to absolute zero. This means the antimatter particle was at its lowest energy state, allowing the researchers to induce controlled changes in its quantum behavior. Unlike other methods in particle physics, this approach didn’t destroy the particle. The researchers were therefore able to keep the single antiparticle trapped for months, allowing them to repeat measurements.

So what can taming antimatter particles actually teach us? Scientists know that matter and antimatter have very similar properties. For example, an electron and a positron have exactly the same mass, although their electric charges are opposite. However, questions still remain about exactly how similar these two forms of matter are and whether there are small differences that have gone unnoticed in experiments conducted to date...

‘He has a seriously creepy vibe. I’m not going anywhere with him.’, ‘This seems like phishing. I wouldn’t click that link.’, ‘Something about this deal feels off. Walk away.’ When people say such things, they are not typically drawing conclusions from a chain of reasoning. The person who avoids getting in the stranger’s car is not thinking: ‘He displayed these three behavioural cues and, therefore, he poses a risk.’ The email isn’t flagged by going through an explicit checklist. The deal doesn’t announce its flaws through a formal audit. In each case, something is simply presented as having a certain character: the man as creepy, the email as fraudulent, the deal as suspect. And yet, acting on these intuitions seems not merely excusable but entirely reasonable. If the man really does strike you as creepy, staying out of his car was probably the smart call – even if you can’t say why.

Despite this, ‘vibes’ and ‘intuitions’ are often dismissed both in daily life and in academic enquiry as irrational or merely heuristic devices. And while we cannot always trust such reactions, they are central, indeed indispensable, to our ability to rationally navigate the world. Philosophers, however, have done surprisingly little to illuminate the rational credentials of these ordinary kinds of intuitions. Instead, they have focused the bulk of their attention on a much more rarefied kind of intuition called rational intuition, which is taken to function primarily in the a priori disciplines of philosophy, logic and mathematics.

My objective is to explain why our everyday intuitive reactions can have such rational force. The key is to see that intuition works in much the same way as perception, in that both can directly present something to us as actual. Once we understand what gives perception this feature, we can see why intuitions might involve exercising the same basic kind of cognitive capacity...

Researchers at Delft University of Technology (the Netherlands) have succeeded in controlling the magnetism in the nucleus of a single atom with radio waves. This came as a surprise: until now, physicists believed that this nuclear spin could not be manipulated directly. The discovery could open up new possibilities for storing and reading quantum information. The research is published in the journal Nature Communications.

In metals such as iron and nickel, every atom is slightly magnetic. But inside the atom, different magnetic "compass needles," known in quantum mechanics as spins, are also at work. "By far the strongest magnetism comes from the electrons," says lead researcher Sander Otte. "But in some atoms, the nucleus also carries a spin. That spin is much weaker, but it is also much better shielded from the outside world."

Otte's group studies spins using a converted scanning tunneling microscope. This enables electrical signals to be directed with extreme precision at a single atom. In the past, the researchers mainly focused on the electron spin, which is the easiest to read out. The nuclear spin appeared only indirectly, through the so-called hyperfine interaction. This causes the spins of the nucleus and the electron to become slightly entangled.

Control against expectations
In their latest experiment, main author Hester Vennema and her colleagues sent two different signals to an atom simultaneously: one targeting the electron and one targeting the nucleus. This allowed them to study the influence of each signal independently. To their surprise, they found that they could flip the nuclear spin even when the two spins were largely disentangled.

That result came unexpectedly. "According to our simple understanding, this should not really happen," says Otte. "The nuclear spin should not be sensitive at all to the electrical signals from a scanning tunneling microscope." ...

The theory that comets delivered the molecular building blocks for life on Earth is a long-standing one, since comets are known to carry many of these molecules. However, a new study challenges this idea.

The researchers, led by the University of Cambridge, found the cometary delivery of these building blocks would be—at best—a 'one-off fluke,' and not the steady rain of prebiotic molecules that had been theorized.

Using computer modeling, the researchers determined that comets travel too fast and at too sharp an angle to Earth's atmosphere for the fragile organic molecules to survive: they would almost certainly vaporize on impact with the surface. However, the researchers also found that another planet in our system—Mars—could be a slightly more promising candidate for cometary delivery of prebiotic molecules, although this is still highly unlikely. The results are published in the journal Scientific Reports.

"Historically, scientists thought that comets were important for the origin of life on Earth, because they carried carbon- and nitrogen-bearing molecules, so these giant space snowballs were almost like a 'get out of jail free card' that brought all the molecules a planet would need to seed life," said lead author Dr. Richard Anslow from Cambridge's Institute of Astronomy. "It's kind of a romantic idea, but our results suggest it's highly unlikely."

Testing the planet-hopping comet theory
In 2023, Anslow and several of his co-authors on the current paper theorized that in systems where planets orbit closely together, comets might slow down by 'bouncing' from one planet to the next, delivering organic molecules as they went.

Building on the earlier study, Anslow and his colleagues investigated whether such a scenario might be possible in our own solar system. "We're learning more and more all the time about how our solar system and the Earth formed, and pulling this together with lots of different advances in modeling, which allowed us to investigate this idea that has been around for close to a century," he said.

However, the new study shows just how rare that scenario is. The researchers used recent advances in comet impact simulations, comet-atmosphere interactions and dynamic modeling of the origin and evolution of comets to conduct their study. Taken together, the researchers found that while the successful delivery of prebiotic molecules cannot be ruled out completely, it would be extremely unlikely...

Many of the world's leading happiness researchers say they consciously spend more time with loved ones after seeing the evidence, according to a new paper. "Happiness emerges from a symphony of factors, but if I had to pinpoint one secret to happiness, relationships with other people might be it," says Lara Aknin, a professor of social psychology at Simon Fraser University.

Earlier this year, Aknin took part in a Zoom call with 12 other international leaders in well-being science. On the agenda? What their collective 600 years of happiness research and their own lived experiences reveal about living a good life and the future of the field they helped to create. Their reflections were captured in a recent paper published in the Journal of Happiness Studies.

"Having relationships is one of the most reliable predictors of happiness that has emerged from a robust body of evidence spanning the social sciences," says Aknin, who coauthored the paper with Harvard University's Säde Stenlund and Kelsey O'Connor, a senior researcher at Luxembourg's National Institute of Statistics and Economic Studies.

"We know that having just one person you can count on is extremely consequential. Having more relationships and more communities that you feel a part of compounds that sense of well-being."

Researchers also talked about well-being as a journey, says Aknin. Generally happy people aren't constantly happy, nor is happiness reserved only for people with ideal lives, perfect circumstances or a natural sense of optimism. Instead, it can be developed through conscious choices, self-awareness and adaptation, even when life gets hard, she says.

Some of the leading models on happiness suggest that roughly 10% of one's happiness is attributable to one's life circumstances—things that are big and relatively difficult to change, like where you live, your age, your employment status or your relationship status. But as much as 40% of one's happiness is related to "volitional activities" or how you choose to spend your time...