Category: English

Source: The Conversation – USA – By Mojtaba Akhavan-Tafti, Associate Research Scientist, University of Michigan

Weather forecasting is a powerful tool. During hurricane season, for instance, meteorologists create computer simulations to forecast how these destructive storms form and where they might travel, which helps prevent damage to coastal communities. When you’re trying to forecast space weather, rather than storms on Earth, creating these simulations gets a little more complex. To simulate space weather, you would need to fit the Sun, the planets and the vast empty space between them in a virtual environment, also known as a simulation box, where all the calculations would take place.

Space weather is very different from the storms you see on Earth. These events come from the Sun, which ejects eruptions of charged particles and magnetic fields from its surface. The most powerful of these events are called interplanetary coronal mass ejections, or CMEs, which travel at speeds approaching 1,800 miles per second (2,897 kilometers per second).

To put that in perspective, a single CME could move a mass of material equivalent to all the Great Lakes from New York City to Los Angeles in just under two seconds – almost faster than it takes to say “space weather.”

When these CMEs hit Earth, they can cause geomagnetic storms, which manifest in the sky as beautiful auroras. These storms can also damage key technological infrastructure, such as by interfering with the flow of electricity in the power grid and causing transformers to overheat and fail.

To better understand how these storms can wreak so much havoc, our research team created simulations to show how storms interact with Earth’s natural magnetic shield and trigger the dangerous geomagnetic activity that can shut down electric grids.

In a study published in October 2025 in the Astrophysical Journal, we modeled one of the sources of these geomagnetic storms: small, tornado-like vortices spun off of an ejection from the Sun. These vortices are called flux ropes, and satellites had previously observed small flux ropes – but our work helped uncover how they are generated.

The challenge

Our team started this research in summer 2023, when one of us, a space weather expert, spotted inconsistencies in space weather observations. This work had found geomagnetic storms occurring during periods when no solar eruptions were predicted to hit Earth.

Bewildered, the space weather expert wanted to know if there could be space weather events that were smaller than coronal mass ejections and did not originate directly from solar eruptions. He predicted that such events might form in the space between the Sun and Earth, instead of in the Sun’s atmosphere.

One example of such smaller space weather events is a magnetic flux rope – bundles of magnetic fields wrapped around each other like a rope. Its detection in computer simulations of solar eruptions would hint to where these space weather events may be forming. Unlike satellite observations, in simulations you can turn back the clock or track an event upstream to see where they originate.

So he asked the other author, a leading simulation expert. It turned out that finding smaller space weather events was not as simple as simulating a big solar eruption and letting the computer model run long enough for the eruption to reach Earth. Current computer simulations are not meant to resolve these smaller events. Instead, they are designed to focus on the large solar eruptions because these have the most effects on infrastructure on Earth.

This shortfall was quite disappointing. It was like trying to forecast a hurricane with a simulation that only shows you global weather patterns. Because you can’t see a hurricane at that scale, you would completely miss it.

These larger-scale simulations are known as global simulations. They study how solar eruptions form on the Sun’s surface and travel through space. These simulations treat streams of charged particles and magnetic fields floating through space as fluids to reduce the computational cost, compared with modeling every charged particle independently. It’s like measuring the overall temperature of water in a bottle, instead of tracking every single water molecule individually.

Because these simulations are computational phenomena that happen across such a vast space, they can’t resolve every detail. To affordably resolve the vast space between the Sun and the planets, researchers divide the space into large cubes – analogous to two-dimensional pixels in a camera. In the simulation, these cubes each represent an area 1 million miles (1.6 million kilometers) wide, tall and across. That distance is equivalent to about 1% of the distance from Earth to the Sun.

The search begins

Our search began with what felt like hunting for a needle in a haystack. We were looking into old global simulations, searching for a tiny, transient blob – which would signify a flux rope – within an area of space hundreds of times wider than the Sun itself. Our initial search did not yield anything.

We then shifted our focus to the simulations of the May 2024 solar eruption event. This time, we specifically looked at the region where the solar eruption collided into a quiet flow of charged particles and magnetic fields, called the solar wind, ahead of it.

There it was: a distinct system of magnetic flux ropes.

However, our excitement was short-lived. We could not tell where these flux ropes came from. The modeled flux ropes were also too small to survive, eventually fizzling out because they became too small to resolve with our simulation grid.

But that was the type of clue we needed – the presence of flux ropes at the location where the solar eruption collided with the solar wind.

To settle the issue, we decided to bridge this gap and create a computer model with a finer grid size than those previous global simulations used. Since increasing the resolution across the entire simulation space would have been prohibitively expensive, we decided to only increase the simulation resolution along the trajectory of the flux ropes.

The new simulations could now resolve features that spanned distances six times Earth’s 8,000-mile (or 128,000-kilometer) diameter down to tens of thousands of miles – nearly 100 times better than previous simulations.

Making the discovery

Once we designed and tested the simulation grid, it was time to simulate that same solar eruption that led to the formation of those flux ropes in the less fine-grained model. We wanted to study the formation of those flux ropes and how they grew, changed shape and possibly terminated in the narrow wedge encompassing the space between the Sun and Earth. The results were astonishing.

The high-resolution view revealed that the flux ropes formed when the solar eruption slammed into the slower solar wind ahead of it. The new structures possessed incredible complexity and strength that persisted far longer than we expected. In meteorological terms, it was like watching a hurricane spawn a cluster of tornadoes.

We found that the magnetic fields in these vortices were strong enough to trigger a significant geomagnetic storm and cause some real trouble here on Earth. But most importantly, the simulations confirmed that there are indeed space weather events that form locally in the space between the Sun and Earth. Our next step is to simulate how such tornado-like features in the solar wind may impact our planet and infrastructure.

Watching these flux ropes in the simulation form so quickly and move toward Earth was exciting, but concerning. It was exciting because this discovery could help us better plan for future extreme space weather events. It was at the same time concerning because these flux ropes would only appear as a small blip in today’s space weather monitors.

We would need multiple satellites to directly see these flux ropes in greater detail so that scientists can more reliably predict whether, when and in what orientation they may affect our planet and what the outcome may be. The good news is that scientists and engineers are developing the next-generation space missions that could address this.

Mojtaba Akhavan-Tafti is the Principal Investigator of Space Weather Investigation Frontier (SWIFT). He receives funding from NASA.

W. Manchester is a Co-Investigator of Space Weather Investigation Frontier (SWIFT). He receives funding from NASA and the National Science Foundation (NSF).

– ref. ‘Space tornadoes’ could cause geomagnetic storms – but these phenomena, spun off ejections from the Sun, aren’t easy to study – https://theconversation.com/space-tornadoes-could-cause-geomagnetic-storms-but-these-phenomena-spun-off-ejections-from-the-sun-arent-easy-to-study-266567

Source: The Conversation – USA – By Kelling Donald, Professor of Chemistry, University of Richmond

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to CuriousKidsUS@theconversation.com.

---

“What is radium and why is it dangerous?” – Aurora, 10, Laredo, Texas

---

The element radium can be found in extremely tiny amounts in the Earth’s crust and oceans, and in its pure form it is a soft silvery metal. To an untrained eye, a small piece of radium may look like a chip off a regular gray rock. But radium can invisibly emit radiation – energy and small fragments of itself – that you can’t feel, see or smell. And that invisible radiation can hurt you, without you even noticing right away.

What’s going on with this silent threat that can stealthily damage your body in ways that can take years to reveal themselves?

As a chemist, I’m interested in what makes different elements safe to handle or hazardous. This dangerous release of radiation is called radioactivity, and even though its source may look unassuming, it can burn you or even give you diseases that don’t manifest for years.

Atoms and isotopes

Everything you see around you – your skin, rocks, the pages of books – is all made up of different combinations of extremely small particles called atoms.

An atom has a small, dense center called the nucleus. Negatively charged particles called electrons move around the nucleus. Inside the nucleus, there are two types of particles: positively charged protons and neutral neutrons.

All atoms with the same number of protons in their nuclei are the same element. Besides radium, some elements you may have heard of are carbon and oxygen. All carbon atoms have six protons and all oxygen atoms have eight protons. Radium atoms are much heavier – all radium atoms have 88 protons.

Interestingly, it is possible for atoms of the same element to have different numbers of neutrons. Atoms of the same element with different numbers of neutrons are called isotopes. For instance, two carbon atoms would each have six protons, but one might have six neutrons while another could have seven or eight.

The number of protons and neutrons packed together in the nucleus determines whether the nucleus of an isotope is stable or not. If the nucleus is not stable, problems can arise.

Radioactive decay

The nucleus of each atom wants to be stable, but only certain arrangements of protons and neutrons make that possible. The number of protons and neutrons do not have to be equal, but some combinations make for a happy, or stable, coexistence in the nucleus while others don’t.

A nucleus with an unhappy mix of protons and neutrons might break down or deteriorate in some way. That process is called radioactivity or radioactive decay.

That radioactive decay process releases some form of radiation from the nucleus. This radiation can take the form of tiny particles moving rapidly or high-energy electromagnetic waves emerging from the nucleus. It is that radiation – the high-energy particles and waves shooting out from the nucleus of unstable atomic nuclei – that can make you sick.

There are different types of radioactive decay. In one case, an atom decays by kicking out a small fragment of itself that is made up of two protons and two neutrons. Since the number of protons determines what element we have, decay that changes the number of protons in an atom turns it into a different element.

Radioactive decay can be quite slow, though. It can take thousands of years for one element to decay into a different one.

The case of radium

All radium atoms are unstable and radioactive. Many of these isotopes decay very quickly, but Ra-226, which has 138 neutrons and 88 protons and is the most common, decays the slowest. It takes 1,600 years for half a sample of Ra-226 to decay.

As Ra-226 decays, it loses two protons and two neutrons, which turns it into an isotope of radon. Then the radon decays, and the atom eventually reaches a stable form as the element lead. Each step in that decay series releases more nuclear radiation.

Some other elements in nature with no stable isotope are technetium, polonium, actinium and uranium.

Effects on the human body

The nuclear radiation emitted when radium and other elements decay can damage the cells in the human body. It can lead to cancers or other health problems.

Whether you’re exposed to a lot of radiation quickly, like making the mistake of walking around for a few hours with radioactive material in your pocket, or you’re exposed to just a little over a long time, the high-energy particles and electromagnetic waves from nuclear radiation can lead to serious health problems, including burns and cancers.

Remarkably, even though radioactivity is a threat to life, scientists can control and use it to diagnose and treat diseases – including cancers. If the radiation is delivered precisely to where cancer cells are, the radiation can destroy those rogue cells wreaking havoc in the body.

People who work professionally with radioactive materials need to follow strict guidelines and procedures to protect themselves. They use special shields and radiation detectors, and they minimize the amount of time they’re exposed to any radioactivity.

Pierre and Marie Curie, who discovered radium in 1898, suffered some of the negative effects of radioactivity. Pierre experienced radioactive burns, and Marie died from a blood disease likely caused by chronic radiation exposure. Over 100 years later, her notebooks are still radioactive.

---

Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to CuriousKidsUS@theconversation.com. Please tell us your name, age and the city where you live.

And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.

Kelling Donald does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Why are elements like radium dangerous? A chemist explains radioactivity and its health effects – https://theconversation.com/why-are-elements-like-radium-dangerous-a-chemist-explains-radioactivity-and-its-health-effects-262923

Source: The Conversation – USA – By James T. Stroud, Assistant Professor of Ecology and Evolution, Georgia Institute of Technology

We are lizard biologists, and to do our work we need to catch lizards – never an easy task with such fast, agile creatures.

Years ago, one of us was in the Bahamas chasing a typically uncooperative lizard across dense and narrow branches, frustrated that its nimble agility was thwarting efforts to catch it. Only when finally captured did we discover this wily brown anole was missing its entire left hind leg. This astonishing observation set our research down an unexpected path.

That chance encounter led us to collaborate with over 60 colleagues worldwide to document what we suspected might be a broader phenomenon. Our research uncovered 122 cases of limb loss across 58 lizard species and revealed that these “three-legged pirates” – the rare survivors of traumatic injuries – can run just as fast, maintain healthy body weight, reproduce successfully and live surprisingly long lives.

To be clear, most lizards probably do not survive such devastating injuries. What we’re documenting are the exceptional cases that defy our expectations about how natural selection works.

This discovery is startling because lizard limbs represent one of biology’s most studied examples of evolutionary adaptation. For decades, scientists have demonstrated that even tiny differences in leg length between individual lizards can mean the difference between life and death – affecting their ability to escape predators, catch prey and find mates.

Since subtle variations matter so much, biologists have long assumed that losing an entire limb should be catastrophic.

Yet our global survey tells a different story about these remarkable survivors. Working with colleagues across six continents, we found limb-damaged lizards across nearly all major lizard families, from tiny geckos to massive iguanas.

These animals had clearly healed from whatever trauma caused their injuries – likely accidents or the failed attempts of a predator to eat them. Perhaps most remarkably, we documented surviving limb loss even in chameleons, tree-climbing specialists whose movements seem to require perfect limb coordination.

Thriving, not just surviving

The body condition of these lizards was most surprising. Rather than appearing malnourished, many limb-damaged lizards were actually heavier than expected for their size, suggesting they were successfully finding food despite their handicap. Some were actively reproducing, with females found carrying eggs and males observed successfully mating.

These findings force us to reconsider some basic assumptions about how evolution might work in wild populations. Charles Darwin envisioned natural selection as an omnipresent force, “daily and hourly scrutinizing” every feature.

But perhaps selection is more episodic than constant. Maybe sometimes limb length matters tremendously, while during other times – such as when food is abundant and predators are scarce – limb length matters less and three-legged lizards can flourish.

These lizard survivors showcase the incredible solutions that millions of years of evolution have built into their biology. Rather than being passive victims of their injuries, these lizards may survive by actively choosing safer habitats or hunting strategies, using smart behavior to avoid situations where their disability would be a disadvantage.

Biological engineering in action

Our research combines old-fashioned natural history observations with cutting-edge, biomechanical analysis.

We use high-speed cameras and computer software that can track movement frame by frame to analyze running mechanics invisible to the naked eye. This combination of field biology and laboratory precision allows us to understand not just that these lizards survive, but how they accomplish this remarkable feat.

When we tested the three-legged lizards’ athletic performance, the results defied expectations. Some animals were clearly impaired in their sprinting capabilities, but others actually ran faster than fully-limbed individuals of the same size across a 2-meter dash during our “Lizard Olympics.”

High-speed video analysis revealed their secret: The speedy survivors compensate through creative biomechanical solutions. One brown anole missing half its hind limb dramatically increased its body undulation during sprinting, using exaggerated snakelike movements to compensate for the missing leg.

By documenting the unexpected – the seemingly impossible survivors – we’re reminded that nature still holds surprises that can fundamentally change how we think about life itself.

Jonathan Losos receives funding from the National Science Foundation.

James T. Stroud does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. 3-legged lizards can thrive against all odds, challenging assumptions about how evolution works in the wild – https://theconversation.com/3-legged-lizards-can-thrive-against-all-odds-challenging-assumptions-about-how-evolution-works-in-the-wild-262467

Source: The Conversation – USA – By Ryan Kennedy, Timashev Chair of Data Analytics and Professor of Political Science, The Ohio State University

A series of recent events has sparked alarm about rising levels of political violence in the U.S. These episodes include the assassination of political activist Charlie Kirk on Sept. 10, 2025; the murder of a Democratic Minnesota state legislator and her husband in June 2025; and two attempts to kill Donald Trump during the 2024 presidential campaign.

Some surveys have reported that a large number of Americans are willing to support the use of force for political ends, or they believe that political violence may sometimes be justified.

My research is in political science and data analytics. I have conducted surveys for almost 25 years. For the past three years, I have studied new techniques that leverage artificial intelligence to conduct and analyze interviews.

My own recent surveys, which use AI to ask people about why they give their answers, show that the surprisingly high level of support in response to these questions is likely the result of confusion about what these questions are asking, not actual support for political violence.

A failure to communicate

Why would multiple surveys get the answers to this important question wrong? I believe the cause is an issue called response error. It means that respondents don’t interpret a question in the way the researcher thinks they will.

As a result, the answers people provide don’t really reflect what the researcher thinks the answers show.

For example, asking whether someone would support the use of force to achieve a political goal raises the question of what the respondent thinks “use of force” means in this context. It could be interpreted as violence, but it could also be interpreted as using legal means to “force” someone to do something.

Such response errors have been a concern for pollsters ever since survey research began. They can affect even seemingly straightforward questions.

What did you mean by that?

To avoid this problem, I used an AI interviewing system developed by CloudResearch, a well-known survey research company, to ask respondents some of the same questions about political violence from previous surveys. Then I used it to ask what they were thinking when they answered those questions. This process is called cognitive interviewing.

I then used AI to go through these interviews and categorize them. Two short reports that summarize this process as applied to both polls are available online. These analyses have not been peer-reviewed, and the results should be considered very preliminary.

Nonetheless, the results clearly demonstrate that respondents interpret these questions in very different ways.

Nuance matters

For example, in my survey, about 33% of Democrats agreed with the statement that “use of force is justified to remove President Trump from office.” However, when asked why they agreed, more than 57% gave responses like this: “I was not thinking physically but more in the sense that he – the president – might need to be ‘fired’ or forced out of office due to rules or laws.” Still others were envisioning future scenarios where a president illegally seizes power in a coup.

Once you account for these different interpretations of the question, the AI only coded about 8% of Democrats as supporting use of force in violent terms under current conditions.

Even here, there was substantial ambiguity – for example, this type of response was not unusual: “The language ‘use of force’ was a bit too broad for me. I could not justify killing Trump, for example, but less extreme uses of force were valid in my eyes.”

Similarly, 29% of Republicans agreed that “use of the military is justified to stop protests against President Trump’s agenda.” However, almost all of the respondents who agreed with this statement envisioned the National Guard interceding nonviolently to stop violent protests and riots. Only about 2.6% of Republicans gave comments supporting use of the military against nonviolent protests.

Almost all those who agreed that use of the military was justified expressed thoughts like this: “I see the military coming and acting as a police force to stop or prevent the demonstrations that become violent. Peaceful protesters must be allowed to exercise their right to free speech.”

When is political violence justified?

Even questions that explicitly ask about political violence are open to wide interpretation. Take, for example, this question: “Do you think it is ever justified for citizens to resort to violence in order to achieve political goals?”

The lack of a specific scenario or location in this question invites respondents to engage in all kinds of philosophical and historical speculation.

In my survey, almost 15% of respondents said violence could sometimes be justified. When asked about the examples they were thinking of, respondents cited the American Revolution, the anti-Nazi French Resistance and many other incidents as a reason for their responses. Only about 3% of respondents said they were thinking about actions in the U.S. at the current time.

Moreover, almost all respondents stated that violence should be a last resort when all other peaceful and legal methods fail.

One respondent illustrated both problems with one sentence: “The (American) colonists tried petitions and negotiations first, but, when those efforts failed, they resorted to armed conflict to gain independence.”

A call for understanding

Even these numbers likely overestimate Americans’ support for political violence. I read the interviews, checking the AI system’s labeling, and concluded that, if anything, it was overestimating support for violence.

Other factors may also be distorting reports of public support for political violence. Many surveys are conducted primarily online. One study estimated that anywhere from 4% to 7% of respondents in online surveys are “bogus respondents” who are selecting arbitrary responses. Another study reported that such respondents dramatically increase positive responses on questions about political violence.

Respondents may also be willing to espouse attitudes anonymously online that they would never say or do in real life. Studies have suggested that “online disinhibition effects” or “survey trolling” can impact survey results.

In sum, my preliminary research suggests that response error is a substantial problem in surveys about political violence.

Americans almost universally condemn the recent political violence they have witnessed. The recent poll results showing otherwise more likely stem from confusion about what the questions are asking than actual support for political violence.

Ryan Kennedy does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Far fewer Americans support political violence than recent polls suggest – https://theconversation.com/far-fewer-americans-support-political-violence-than-recent-polls-suggest-266113