NASA’s Artemis II mission will take an astronaut crew around the Moon – a space policy expert describes the long road to launch

Source: The Conversation – USA – By Scott Pace, Professor of the Practice of International Affairs, George Washington University

NASA’s Space Launch System rocket will launch a crewed capsule into orbit and then on a mission around the Moon. AP Photo/John Raoux

NASA is once again shooting for the Moon, for the first time since the 1970s. As soon as April 2026, NASA will launch its Artemis II mission, using the Space Launch System heavy lift rocket to send a crewed spacecraft, called Orion, into orbit. From there, the crew will journey to and circle around the Moon over 10 days.

In this episode of The Conversation Weekly podcast, we spoke to Scott Pace, the director of the Space Policy Institute at George Washington University. Pace worked with the George W. Bush administration in space policy, and from 2017 served for four years as the executive secretary of the National Space Council during Donald Trump’s first term as president.

In the first paragraph, it makes it sound like the spacecraft is landing on the moon. “From there, the crew to orbit around the Moon over 10 days”

Four astronauts in orange space suits with their helmets off.
The crew members of the Artemis II mission are, counterclockwise from left NASA astronauts Christina Hammock Koch, Reid Wiseman and Victor Glover and Canadian Space Agency astronaut Jeremy Hansen.
NASA

We’re about to send humans in orbit around the Moon again. What’s had to happen to get to this point?

Pace: Let’s go back to the 1980s and 1990s. After the space shuttle Challenger accident, a lot of people were thinking, “What do we do next?”

The space shuttle program was not an economic success. The recurring cost per flight was very expensive. So there was a lot of thinking about different vehicles that could be the shuttles’ successor. NASA pursued some of the higher-risk options, thinking that if they didn’t work out, they could still extend and use the shuttle. Some of those higher-risk ideas were things like single-stage-to-orbit space planes. When they didn’t work, it was OK because NASA was still working on the shuttle.

And then we had the 2003 space shuttle Columbia accident. NASA figured they could either stop for a decade or so and then try to restart a human spaceflight program once they had better technology, or try to transition the infrastructure and industrial base they had with the space shuttle to a new system.

When the second shuttle accident happened, we examined what we had to build a new system with, and we had solid rocket boosters and external tanks. To make something safer, we needed to build crew capsules. A capsule with an escape system onboard was one of the few immediate ways you could increase the likelihood of a crew’s survival.

If your eventual goal is Mars, you’ll then need a really heavy-lift vehicle to launch more crew and a heavier load. All that deliberation led to the current Space Launch System and the Orion capsule.

Four astronauts will be sent on a 10-day mission orbiting the Moon. What’s exciting to you about this mission, and what will you be looking out for?

Pace: The first thing is the performance of the solid rocket boosters on launch. Boosters are very reliable, but if they go bad, they go bad pretty quickly. The next thing is a checkpoint in Earth’s orbit when they’re going to make a decision about whether to do a translunar injection. During the translunar injection, they fire the engine to escape Earth’s orbit and get on the right path to orbit around the Moon.

Before they decide, they’re going to check the environmental control and life support system to make sure the passengers are safe and healthy inside the vehicle. Once you make the commitment to head for the Moon, that life support system is going to be essential. And they haven’t yet done a full flight test on Orion of the environmental control and life support system.

The translunar injection is actually fairly straightforward. In many ways, this is less risky than Apollo 8, which went to the Moon and then fired its engines to get into a stable orbit around the Moon. Then, it fired the engines again to come home.

Artemis II is more like Apollo 13. They’re going up, looping around the Moon and using its gravity to whip around and then come back. In some ways, it’s a less risky trajectory than Apollo 8 because you don’t have to fire the engines as much.

When the crew vehicle comes back, we’re going to look at its heat shield performance. The heat shield has had a long and complicated history. It looks like it’ll be safe, but this is a flight test. And so we’re going to look at how it reenters the atmosphere and how it handles the heat load put on it.

The SLS does come with challenges. One is the high cost. Every time you build one of these vehicles, it costs several billion dollars. The other problem is flight rate.

A conical spacecraft with the NASA worm logo in space, with Earth and the Moon shown in the background.
NASA’s Orion spacecraft had a view of both Earth and the Moon during the Artemis I mission.
NASA via AP

Some people will argue that beating China to the Moon is really important. Does that matter to you?

Pace: It matters to me if China is the only one showing up and they drive all the standards and the operating norms on the Moon. But the issue of beating China back in the near term doesn’t quite seize me as much as the longer term.

This is part of the problem I have with the term “race.” The U.S. had a space race in the past, but what we have now with China is a long-term competition.

Space is not yet contentious in the way the South China Sea is, or border disputes with India are. But I can see why some people are worried by looking at China’s behavior in other areas.

Part of the stated goal for Artemis is to secure a lasting presence on the lunar surface. Do you think there’s a rationale for nations to stay permanently on the Moon now?

Pace: Humanity’s future in space depends on two sub-questions. First: Can you live off the land and use local resources, or are you always dependent upon Earth? Second: How are you paying? Are you also financially dependent upon Earth – for example, supported by taxpayers?

If you can both use local resources and do something economically useful, then you can build space settlements and get permanent human activity beyond the Earth.

If the answer is no on both counts, then space is like Mount Everest: It’s a place of adventure and symbolism. People can go there and take pictures. But nobody really lives there.

If you can do something useful in space and generate an economic return, but still have to come home to Earth because the environment can’t support life long term, then space is like a North Sea oil platform. It’s a dangerous and difficult place, but a place where you can go for economic reasons.

If you still have to depend on taxpayer money, space may be similar to Antarctica – like going to McMurdo Station. You can do science there and have a human presence, but it’s a constrained environment.

Part of the purpose of exploration is to find out which of these futures is feasible. Some people have faith that space settlements are possible. But we really don’t know.

If it turns out there are economically useful things to do on the Moon, there may be an eventual transition. Activity on the Moon would go from a government-led effort to one led by private sector activities, including mining helium-3 or shipping water back to refueling stations.

If it turns out that none of that really makes sense, we’d still have some science presence there, but we would press on to Mars. I think there’ll be some sort of scientific presence regardless – but its size will depend on economics and markets that we, frankly, don’t understand yet.

The world today in space is much more globalized, much more democratized. Many more countries and entities are involved in space. While the U.S. wants to be the leader in this effort, it knows that simply doing it with a NASA logo is really not sufficient. The Artemis program is meant as an international and commercial partnership effort with others to voluntarily shape what space looks like.

The Conversation

Scott Pace is an advisor for Sierra Space and is a member of the Board of Trustees for the Planetary Science Institute, and the Board of Advisors for the National Security Space Association. He was a political appointee in the Administrations of George W. Bush (2002-2008) and Donald J. Trump (2017-2020). He is the Director of the Space Policy Institute at the Elliott School of International Affairs, at George Washington University, Washington, D.C.

ref. NASA’s Artemis II mission will take an astronaut crew around the Moon – a space policy expert describes the long road to launch – https://theconversation.com/nasas-artemis-ii-mission-will-take-an-astronaut-crew-around-the-moon-a-space-policy-expert-describes-the-long-road-to-launch-274481

Scientists may be overestimating the amount of microplastics in the environment – and the culprit is lab gloves

Source: The Conversation – USA – By Anne McNeil, Professor of Chemistry and Macromolecular Science and Engineering, University of Michigan

Gloves used in the laboratory that led to microplastic overestimation. Madeline Clough

It seems like every day a new study finds tiny plastic particles called microplastics where they should not be: in our bodies and our food, water and air.

Yet finding and identifying microplastics is extremely challenging, especially given their small size. One microplastic can range from as large as a ladybug to as small as an eighth of a red blood cell.

In addition, it can be hard for researchers to avoid unintentionally contaminating their samples, because these plastics are practically everywhere. As a result, much of this research may be overestimating the number of microplastics.

In a new study published in March 2026, our team found that, even when following established protocols, using certain methods to measure environmental microplastics can potentially contaminate the results.

Microplastics are tiny plastics shed from plastic waste. They are found in the environment, waterways and even the human body.

The study

We are chemists at the University of Michigan working in a collaborative team. We set out to understand how many microplastics Michiganders were inhaling when outside, and whether that depended on where they lived.

When preparing our samples, we followed all the standard protocols while conducting our research – we avoided plastic use in the lab, wore nonplastic clothing and even used a specialized chamber to reduce potential contamination from the laboratory air.

Despite these precautions, we found plastic counts in the air that were over 1,000 times greater than previous reports. We knew these numbers didn’t seem right, so what happened?

The culprit: Lab gloves

After a long path to pinpointing the contamination source, we found that laboratory gloves, which the scientific community recommends using as a best practice, can transfer particles to the surface of our samples – in this case, small metal sheets used to collect material depositing from the air. Moreover, the particles led to an overestimation of microplastic abundance in our study.

Here’s how: The particles, which we identified as stearate salts, are used to help the gloves cleanly release from their mold during the manufacturing process. When gloves are used to handle laboratory equipment, the particles are transferred to anything they touch. Stearate salts are similar to soap molecules – if you eat a lot of them, they’re probably not good for you, but they’re not harmful in the environment in the same way that microplastics are.

While not microplastics themselves, stearate salts are structurally similar to polyethylene, the type of plastic most often found in the environment. This structural similarity makes it difficult to distinguish them using the most common tools scientists use to determine whether a particle is plastic.

Researchers use vibrational spectroscopy to identify microplastics, which entails measuring how the particle interacts with light to produce what scientists call a chemical fingerprint.

Because polyethylene and stearate salts have very similar structures, they also interact with light in a similar way.

As a result, at least some of the time, the particles from gloves are incorrectly identified as microplastics. As more researchers rely on automated methods to speed up their analyses, glove residue may be increasingly mistaken for microplastics, leading to higher reports of microplastics in the environment than in reality.

How widespread is this contamination?

To investigate how prevalent this contamination might be, we looked at different glove types. We mimicked the touch between seven types of gloves while handling laboratory equipment and counted the number of microplastics we would incorrectly attribute to the environment if we followed the most common approaches.

We found that gloves can contribute over 7,000 particles per square millimeter that are misidentified as microplastics. This finding means that researchers could be unknowingly overestimating microplastic abundance in the environment when handling their samples with gloves.

Even more concerning, we found that the particles were largely less than 5 um in size. Microplastics in this size range have larger impacts on human and ecosystem health because they can more easily enter cells. By inflating microplastic counts in this size range, using laboratory gloves may jeopardize the studies that inform future policies and regulations.

A diagram showing particles coming off gloves from contact, where it causes a signal similar to a microplastic during scientific analysis.
How handling samples with gloved hands leads to an overestimation of plastics.
Madeline Clough

Moving forward

To avoid contamination, we suggest scientists avoid glove use while conducting microplastic research. If that is not possible – for example, with biological samples where the researchers must wear gloves to protect themselves – we recommend a glove made without stearates, such as those designed for electronics manufacturing. To recover older, potentially contaminated datasets, we have developed methods to help differentiate the chemical fingerprints.

Science is an iterative process. New areas of research, including environmental microplastics, introduce new challenges to the scientific community. In addressing these new challenges, we will encounter setbacks, such as unforeseen contamination.

While we had to discard our initial dataset, we expect the lessons we learned about glove contamination to reach other scientists. In addition, we plan to continue our research on Michigan’s atmospheric microplastic contamination – but this time without gloves.

It’s important to note that even if the microplastic abundance in the environment is lower than researchers originally thought, any amount of microplastics can be troublesome, given their negative effects on human health and ecosystems.

The Conversation

Anne McNeil receives funding from the National Science Foundation, the Department of Energy, the Vinyl Institute, the University of Michigan, and the State of Michigan Economic Development Corporation.

Madeline Clough receives funding from the University of Michigan Rackham Graduate School and the University of Michigan College of Literature, Science, and The Arts. She is affiliated with the Michigan Microplastics Coalition.

ref. Scientists may be overestimating the amount of microplastics in the environment – and the culprit is lab gloves – https://theconversation.com/scientists-may-be-overestimating-the-amount-of-microplastics-in-the-environment-and-the-culprit-is-lab-gloves-258545

Vagus nerve stimulation shows promise as a way to counter Alzheimer’s disease- and age-related memory loss

Source: The Conversation – USA – By Elizabeth Riley, Lecturer in Psychology, Cornell University

The vagus nerve, which carries information between the brain and heart, lungs and other organs, might regulate the activity of a tiny brain region called the locus coeruleus. Sebastian Kaulitzki/Science Photo Library via Getty Images

Most people think of Alzheimer’s disease as an illness of aging. But in fact, the brain changes that characterize it begin much earlier – sometime around the third decade of life.

In the earliest of these changes, a tangled version of a protein called tau starts building up in a tiny region deep in the brain involved in sleep, attention and alertness, called the locus coeruleus. Tau later spreads to the rest of the brain.

Developing tau tangles doesn’t mean a person has Alzheimer’s disease – in fact, it happens to nearly everyone to varying degrees. But because these changes start in the locus coeruleus, some brain researchers – myself included – see this area as a canary in the coal mine for developing Alzheimer’s disease

We are exploring whether stopping or slowing down tau tangles in this brain region, or otherwise maintaining its health, may be a way to interrupt how the disease ultimately unfolds and to prevent other aspects of cognitive aging.

Emerging research from my lab and others is investigating the idea that a therapy called vagus nerve stimulation, which is already widely used for other health conditions, could be one way of keeping the locus coeruleus functioning properly.

The locus coeruleus and Alzheimer’s disease

The locus coeruleus sits in the brain stem, the lowest part of the brain. Its name, “blue spot,” comes from a pigment called neuromelanin that its cells produce.

The locus coeruleus plays a crucial role in multiple aspects of basic human functioning. It makes virtually all of the brain’s norepinephrine, a chemical critical for sleep, alertness, focus, learning and even immune function. And it receives inputs from nerves originating throughout the brain and body – including from the vagus nerve, which carries information to and from the heart, lungs and other organs.

My research explores this brain region’s structure, how nerve cells pass messages within it and how it connects with other brain regions. I also investigate how those features change throughout life and affect thinking and memory.

Alzheimer’s disease destroys memory and thinking skills, but researchers don’t yet understand how or why.

Studies suggest that starting in middle age, nerve cells in the locus coeruleus may get damaged by tau buildup, and that damage may correlate with declines in memory. Tau buildup, cell death and loss of function in the locus coeruleus precedes and predicts Alzheimer’s diagnosis and symptoms.

This has led researchers to hypothesize that keeping the locus coeruleus healthy could be a way to protect the rest of the brain, too.

Vagus nerve stimulation and brain health

The vagus nerve carries information between the brain and organs in the chest and abdomen, such as the heart and intestines, helping the brain monitor and regulate many of the body’s essential organs. It is responsible for sending rest and digest messages throughout the brain and body, stimulating digestion and promoting cellular repair.

In the 1980s and 1990s, researchers discovered that stimulating the vagus nerve can help ease epilepsy. They also found that doing so often also had other benefits, such as improving mood and thinking.

Today, vagus nerve stimulation is approved by the Food and Drug Administration not just for treating epilepsy, but also for migraine and depression, as well as to aid with stroke rehabilitation.

Vagus nerve stimulation for epilepsy and depression generally involves implanting an electrical stimulator in the left side of a patient’s chest, where the vagus nerve passes. Noninvasive devices for treating headaches deliver gentle pulses of electricity to certain places on the neck or ear where the vagus nerve is very close to the surface of the skin.

Even before the discovery of locus coeruleus’s link to Alzheimer’s disease, researchers hypothesized that vagus nerve stimulation might help mood and thinking in people with the condition. That’s because vagus nerve stimulation might work in part by raising brain levels of norepinephrine – and people with Alzheimer’s have too little norepinephrine in their brains.

Keeping the pace

Neuroscientists still don’t know exactly how or why vagus nerve stimulation might be beneficial for the brain, but one leading theory is that it helps regulate the activity of nerve cells in the locus coeruleus, enabling it to function properly.

Too much locus coeruleus activity could potentially make people too alert, causing them to feel stressed or even panicked. In fact, a hyperactive locus coeruleus fuels some symptoms of post-traumatic stress disorder. Conversely, too little could cause depression or memory problems.

A scan of the brain with the locus coeruleus lit up in the brain stem
The locus coeruleus, which means ‘blue spot,’ is located in the brain stem, the lowest part of the brain.
Elizabeth Riley, CC BY-SA

Some forms of vagus nerve stimulation neither turn up nor turn down locus coeruleus activity. Instead, they seem to affect the timing and pace of firing in its neurons. Other forms of vagus nerve stimulation seem to increase norepinephrine in the brains of rats, and researchers hypothesize that this may also be how vagus nerve stimulation treats epilepsy.

These different findings have led researchers to suggest that vagus nerve stimulation could act as an effective regulator for the locus coeruleus, enabling it to establish just the right level of activity for optimal functioning.

Can vagus nerve stimulation counter memory loss?

Intriguing hints are emerging that vagus nerve stimulation may help the aging brain.

A handful of studies have found that vagus nerve stimulation can prevent memory from worsening, or even improve it, in people with mild cognitive impairment or in the early stages of Alzheimer’s disease. One trial of 52 people ages 55 to 75 who were diagnosed with mild cognitive impairment reported meaningful improvements in memory and overall cognition after getting vagus nerve stimulation for an hour per day, five days a week for about six months.

Research in healthy adults around age 60 – and in healthy adults age 18 to 25 – has even reported improvements in different aspects of memory after just one session of vagus nerve stimulation.

This work is still very preliminary, but it offers hope for a new way of keeping some of the distressing symptoms of Alzheimer’s disease and aging at bay.

The Conversation

Elizabeth Riley receives funding from the National Institute on Aging.

ref. Vagus nerve stimulation shows promise as a way to counter Alzheimer’s disease- and age-related memory loss – https://theconversation.com/vagus-nerve-stimulation-shows-promise-as-a-way-to-counter-alzheimers-disease-and-age-related-memory-loss-269465

The long shadow of Paul Ehrlich’s ‘Population Bomb’ is evident in anti-immigration efforts today

Source: The Conversation – USA (2) – By Brian C. Keegan, Associate Professor of Information Science, University of Colorado Boulder; Harvard University

The idea of overpopulation has been used to argue against immigration. Pandagolik/iStock/Getty Images Plus

Paul Ehrlich opened his 1968 book “The Population Bomb” with a scene recounting returning to his hotel through a crowded Delhi neighborhood on a stifling night in the mid-1960s. He described the physical sensation of overpopulation: people eating, washing, arguing, begging – “people, people, people, people.”

From that visceral opening, he declared that famine, conflict and nuclear war would sweep the globe in the 1970s because of overpopulation. Hundreds of millions of people would starve to death regardless of any crash programs launched to prevent it. Ehrlich argued for population control, chillingly describing population growth as a “cancer” that needed to be cut out.

Ehrlich’s predictions were conspicuously wrong – and experts said so at the time. But his logic resonated through the 1970s and ’80s across the political spectrum. Its shadow is evident in today’s anti-immigration campaigns and White House arguments for mass deportation.

We have followed its long afterlife, as a computational social scientist studying contemporary extremism and as a historian whose book “Building the Population Bomb” analyzed Ehrlich’s impact.

Getting it wrong

Demographers and economists in the decades after World War II rejected the idea that Ehrlich was promoting to millions of readers: that population growth is the primary cause of environmental degradation. Instead, the expert consensus showed how pollution and resource depletion are driven far more by extraction and overconsumption than by head count.

Princeton demographer Ansley Coale told the Population Association of America in 1968, the year “The Population Bomb” was published, that attributing national failures to population growth had become fashionable despite most of the country’s problems having little to do with it.

His colleague and former Population Association of America president Frank Notestein demonstrated at the association’s 1970 meeting that increases in pollution had far outpaced increases in population. Notestein called population control in “developed regions” a distraction from the more immediate need to regulate industry.

People listen at an exhibit displaying a population of just over 4 billion.
Visitors to Chicago’s Museum of Science and Industry listen to a taped explanation of the world population clock in 1976. The world population reached 8 billion in 2022.
Bettmann/Contributor via Getty Images

Ecologist Barry Commoner’s 1971 empirical study confirmed that postwar environmental damage had stemmed almost entirely from new production methods and rising per capita consumption, not from the growing number of people. When the economist Julian Simon challenged Ehrlich in 1980 to a wager on changes in commodity prices over the next decade, Ehrlich accepted – and lost.

In a 2009 retrospective, Ehrlich acknowledged some of “The Population Bomb’s” flaws but did not revisit its central claim. The mass famines he predicted had not materialized in the 1970s because he had not anticipated the Green Revolution, a dramatic expansion of agriculture output. He said the book’s catastrophic scenarios were illustrative exercises, not inevitable forecasts. He dismissed his critics as shills for polluters. Ehrlich’s retrospective concluded, “It was thus a successful tract, and we’re proud of it.”

Origins of the ‘population bomb’ analogy

Ehrlich’s arguments resonated with the popular anxieties of the late 1960s. By tying population growth to the environment, the threat of nuclear war and the sexual revolution, Ehrlich generated left-wing support for population control, which had previously been primarily a concern of the political right.

With the publication of “The Population Bomb,” Ehrlich became a celebrity almost overnight. Though his claims about the consequences of population growth were consistently wrong, Ehrlich had an enormous public impact. A butterfly biologist, he was suddenly booking appearances on Johnny Carson’s “Tonight Show.” He influenced dystopian Hollywood productions, such as “ZPG” (1972), “Soylent Green” (1973) and “Logan’s Run” (1976).

Paul Ehrlich on “The Tonight Show Starring Johnny Carson” in 1980.

The intellectual genealogy behind “The Population Bomb” ran deeper than Ehrlich’s own career. The “bomb” analogy was borrowed from a 1954 pamphlet by Hugh Moore, a businessman whose population anxieties descended from Guy Irving Burch, the anti-immigrant eugenicist who founded the Population Reference Bureau in 1929.

Burch, worried about “alien or negro stock” replacing Europeans, introduced the phrase “population explosion” to American public discourse in the 1930s as part of a campaign for immigration restriction. Moore updated Burch’s framework for the Cold War, warning that population growth in Africa, Asia and Latin America would produce communist expansion and nuclear war.

Ehrlich’s use of ecological carrying capacity – the idea that any environment has a finite number of resources to support a population before collapsing – justified coercive population control initiatives as foreign and domestic environmental policies in the minds of many Americans.

India’s “Emergency” period from 1975-77 subjected an estimated 8 million people to sterilization under conditions ranging from financial inducement to outright coercion. China’s one-child policy was enforced through fines, forced sterilizations and compelled abortions for nearly three decades. Population control programs in some developing countries imposed contraception and sterilization on women without their consent.

California performed sterilizations on some inmates until the 2010s. Hysterectomies on detainees continued in at least one U.S. Immigration and Customs Enforcement detention center until 2019.

Ehrlich tied environment to immigration

Within the United States, Ehrlich co-founded the organization Zero Population Growth, which quickly outlasted its original premise. By 1972, the total fertility rate in the United States was already below the replacement level, and ZPG pivoted to immigration restriction as its primary policy target.

David Brower, the first director of the Sierra Club, authored the famous line “the battle to feed all of humanity is over” in the foreword to “The Population Bomb.” He appointed John Tanton, Ehrlich’s ZPG co-founder, to chair the Sierra Club’s national population committee.

Tanton would go on to build a network of groups that would implement the logic Ehrlich had popularized. This logic linked Ehrlich’s ecological carrying capacity, lifeboat ethics – the idea that wealthy nations risked being swamped by immigration – and reactionary anxieties about demographic change.

Tanton’s anti-immigration network became one of the most influential organizations in late-20th-century American politics. In addition to ZPG, Tanton founded the Federation for American Immigration Reform (FAIR) in 1979, the Center for Immigration Studies in 1985, The Social Contract Press in 1990 and NumbersUSA in 1996.

This network produced policy research and lobbied for drastic reductions in both legal and illegal immigration. It was also instrumental in repackaging nativism into genteel policy briefs for the 1994 Republican revolution, securing the bipartisan passage of the Illegal Immigration Reform and Immigrant Responsibility Act of 1996, and backing anti-immigration efforts that passed in California and Arizona. Ehrlich served on FAIR’s board of advisers until 2002. He died on March 13, 2026.

Ehrlich, Tanton and Brower, as part of Californians for Population Stabilization, tried to push the Sierra Club to adopt immigration restrictions as an official position, but members of the influential environmentalist group resisted. Ballot measures and board elections for the Sierra Club from the late 1990s into the early 2000s exposed the deep ties to anti-immigration activists – and defeated them.

Overpopulation in politics today

Ehrlich’s population anxieties continue to have a long afterlife as political figures build on the idea that immigration constitutes a form of “replacement” of existing populations. Once-fringe grievances suggesting white people were being replaced by people of color have become part of President Donald Trump’s MAGA allies’ “mass deportation now” agenda.

Fifty years separate India’s sterilization camps from today’s ICE detention warehouses, but we believe the logic connecting them is direct: a population defined as excessive, a government apparatus authorized to reduce it, and a scientific vocabulary used by some of the president’s closest allies to justify the means as an ecological necessity. Ehrlich’s contributions to that vocabulary proved far more durable than his predictions.

The Conversation

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

ref. The long shadow of Paul Ehrlich’s ‘Population Bomb’ is evident in anti-immigration efforts today – https://theconversation.com/the-long-shadow-of-paul-ehrlichs-population-bomb-is-evident-in-anti-immigration-efforts-today-279151

College students are writing with AI – but a pilot study finds they’re not simply letting it write for them

Source: The Conversation – USA (2) – By Jeanne Beatrix Law, Professor of English, Kennesaw State University

Debates about generative AI in higher education have been informed by studies of completed student papers, or self-reported survey data. Research shows that artificial intelligence tools can support learning, but also has raised concerns, including students’ overreliance, cheating, and the potential degradation of critical thinking and engagement.

While these types of studies provide interesting snapshots of reported practices, their methodologies may hide something important: how writing actually unfolds while students are composing with the assistance of AI.

A pilot study I led of undergraduate writers at Kennesaw State University takes a different approach. Using think-aloud protocols – a method where participants verbalize their thoughts while performing – our research captures how students interact with generative AI tools during the writing process itself. This method helps us understand decision-making processes as they occur.

Our preliminary findings suggest a more complex reality than the common narrative that students are simply having AI write their assignments. Instead, many students appear to be negotiating when and how AI belongs in their writing.

Looking inside the writing process

In our study, 20 undergraduate students completed a 20-minute writing session responding to the following prompt:

People spend a lot of time trying to achieve perfection in their personal or professional lives. People often demand perfection from others, creating expectations that may be challenging to live up to. In contrast, some people think perfection is not attainable or desirable.

The assignment was to draft a thesis and evidence-based paragraphs that argue their position on the value of striving for perfection. Students were told they were not expected to complete them but to work through their writing process toward finishing. Students were told there were no right or wrong ways to use AI and were asked to use generative AI exactly as they normally would while writing.

Instead of direct observation, the study relied on post-session screen recordings and analysis of students describing their process. Collecting this data – their actions on the computer and transcripts of the voice recordings – allowed researchers to analyze the writing process without interrupting it. To reduce the possibility that students might alter their behavior if they felt observed, researchers set a timer and left the room during the writing session. The goal was to minimize the Hawthorne Effect, a phenomenon in which people change their behavior because they know they are being watched.

What we found

Across the transcripts, a few qualitative patterns consistently emerged in how students collaborated with AI while writing.

First, many participants turned to AI at the beginning of the writing process to help generate ideas or draft a thesis.

What we see in this practice is the student using AI-generated output to spark and shape their own ideas. One student explained the strategy this way: “After [generating a few ideas,] I usually just use that [output] as a prompt.”

In these moments, AI functioned less as a final answer and more as a brainstorming tool that helped students move past the blank page.

However, students frequently continued drafting independently after generating initial ideas. Many transcripts include statements such as “I think my thesis should be …” or “Let me write this part,” suggesting that some students retained control over their argument.

Editing the bot

Another strong pattern across transcripts is that students rarely accept AI text without editing it. Instead, they actively revise the generated language. As one student described the process, the AI “rewrites” their initial prompts and then the student rewrites the AI’s output. This allows the student to claim “authorship and ownership” of the final draft.

Another participant redirected the AI response when it did not align with the assignment: “AI is not following the prompt … try again.”

These moments show students evaluating AI output critically and treating it almost as a sparring partner, rather than simply copying it.

We also found that some students rejected AI’s suggestions altogether.

In several writing sessions, participants explicitly decided not to use the AI responses. One student reflected on this decision while composing: “I don’t really use AI for my research.”

Other transcripts show students switching back to their own writing when AI responses felt too generic or disconnected from their argument. These moments indicate that students are not only collaborating with AI, but they are also drawing boundaries around where it belongs in their writing process.

Finally, several transcripts showed students turning to AI during moments of uncertainty or when they felt stuck.

As one participant explained, “I used a lot of AI because I was struggling.”

Even in those cases, students often used AI as support as they drafted their essays, rather than directly copying and pasting its responses.

What this says about AI and writing

Our analysis suggests that generative AI is entering student writing not as a wholesale replacement for human authorship, but as part of a negotiated collaboration. The results suggest that AI most often enters the composing process during idea generation, revision and moments of writer’s block, while students maintain control over argument choice, voice and final phrasing.

Understanding how decisions to use AI unfold during the writing process, and not just what appears in the final essay, may help educators design assignments and policies that keep the human writer firmly at the helm.

Because our current findings come from a pilot cohort of 20 undergraduate writers, the results should be interpreted cautiously. To test whether these patterns hold at a larger scale, the research team is expanding the study to 100 undergraduate participants. The expanded study will also examine how neurodivergent writers interact with generative AI during composing, an area that remains largely unexplored in current research.

Undergraduate student researchers at Kennesaw State contributed to the preliminary analysis described in this article: Kylee Johnson, Vara Nath, Ruth Sikhamani and Kaylee Ward.

The Conversation

Jeanne Beatrix Law serves on an OpenAI Educator Advisory Group and on an advisory educator group for BoodleBox AI.

ref. College students are writing with AI – but a pilot study finds they’re not simply letting it write for them – https://theconversation.com/college-students-are-writing-with-ai-but-a-pilot-study-finds-theyre-not-simply-letting-it-write-for-them-276856

Supreme Court’s tariff decision still leaves a ‘mess’ for companies trying to grab refunds

Source: The Conversation – USA (2) – By Peter R. Crabb, Professor of Finance and Economics, Northwest Nazarene University; Institute for Humane Studies

Containers are stacked up in a cargo terminal in Frankfurt, Germany. AP Photo/Michael Probst

U.S. companies stung by President Donald Trump’s emergency tariffs had hoped for relief when the U.S. Supreme Court ruled in February 2026 in their favor. But settling on a remedy – namely, rebate checks from the government – may be an even bigger headache.

Fresh wrinkles are prompting businesses to take different routes as they try to recoup money, with many opting to sue to improve their odds. These lawsuits are also underscoring the complex ways that tariffs worked their way through corporate accounting. In some cases, their cost was a clear line item; in others, the impact was muddier – say, through changed supply lines or selective increases in retail pricing. And some have backed off from a legal fight altogether and sold their refund rights to investment firms, often at a deep discount, figuring that getting something is better than risk getting nothing.

These technicalities didn’t seem to concern most members of the high court. In fact, only one Justice, Brett Kavanaugh, raised the question of the decision’s practical complications in his dissent. But his warning of “substantial” repercussions now looks more prescient by the day.

“The United States may be required to refund billions of dollars to importers who have paid the … tariffs, even though some importers may have already passed down costs to consumers or others,” he wrote. “As was acknowledged at oral argument, the refund process is likely to be a ‘mess.’”

We are professors of finance and law who have been following these cases closely. To begin untangling the “mess” this ruling created, it’s helpful to focus on the different ways companies processed these tariffs – and why this means that a quick and clean remedy is unlikely.

To refund or not to refund

In its 6-3 decision, the high court concluded that a broad category of Trump’s tariffs imposed under the International Emergency Economic Powers Act exceeded the president’s legal authority. Many companies that had sued for relief in the form of rebate checks cheered the ruling.

Judge Richard Eaton at the Court of International Trade, tasked with overseeing the refund distribution, then ordered the Trump administration to immediately start the process by asking Customs and Border Protection to recalculate its revenues without the tariffs to determine the rebate total – a tally that the agency estimates at about US$166 billion. But no one is sure how long it will take or whether it will work. And that uncertainty is sparking a fresh round of litigation.

Consider the different approaches taken by two businesses that paid the tariffs: logistics giant FedEx and the retail chain Costco. Costco filed suit against the Trump administration before the Supreme Court decision, while FedEx was among the many businesses that sued after the ruling.

Fedex, which saw some of its cross-border business plummet by 25% to 35%, collected tariffs from both U.S. companies importing goods and from U.S. customers ordering from abroad. In this function as broker, it was able to separate out the tariffs as a line item. That means it can more easily calculate what it would pay back to its customers. If Fedex gets the rebates, it has said it will refund all clients who bore the cost.

The accounting for Costco, by contrast, is less straightforward. It paid the duties but reallocated much of the cost internally. For some goods, it shuffled its extensive global supply chains to mitigate the tariffs’ bite or covered the cost by selectively hiking prices on items where demand would be less affected. It has not made as explicit a commitment of repaying its customers, although it has said it will try to honor it.

In both cases, executive pledges of refunds weren’t enough to prevent class action lawsuits by skeptical consumers since the Supreme Court’s decision, arguing they needed a more ironclad guarantee.

Several women shoppers and a child in a shopping card are looking at outdoor cooking equipment on display in a Costco warehouse.
Shoppers walk by an outdoor cooking display in a Costco warehouse on March 12, 2026, in east Denver.
AP Photo/David Zalubowski

Avoiding the fight

Other companies, meanwhile, are waiving a legal fight altogether and selling their refund rights to investment firms, often at only a fraction of what they had paid in levies, in the expectation that full repayment is unlikely.

These companies typically are too small to finance a legal battle but big enough to have sufficient money at stake for Wall Street to take interest. For example, Atlanta-based Kids2, which sources almost all of its toy and infant products in China, sold its rights before the high court’s ruling for about a quarter of what it paid out in the emergency tariffs.

Legal complications aside, logistical snags are also emerging. In response to Eaton’s order, Customs and Border Protection chief Brandon Lord stated in a filing on March 6, 2026, that the government was “not able to comply” due to the “unprecedented volume of refunds” overwhelming the agency’s technology. It’s working on an online system to “streamline and consolidate refunds and interest payments,” to be operational in 45 days of that filing, he wrote.

In response, Eaton paused his order requiring immediate refunds, but he has demanded regular updates on CBP’s progress. On March 19, Lord reported
that the four components of the new online system were between 45% and 80% functional.

New tariffs may loom

While some companies may get relief for levies they already paid, there’s the risk Trump could still make good on his threat to use other federal statutes to impose tariffs. Those laws aren’t an easy workaround for the administration, but they still provide some options for Trump to apply tariffs on imports, including those that had been affected under the emergency levies.

Further uncertainty, in short, is likely.

As the stock market volatility in 2025 after Trump’s “Liberation Day” announcement showed, this uncertainty can be costly. And the Supreme Court’s decision hasn’t allayed those fears. Companies have delayed investment, stockpiled inventory and diverted resources into compliance and legal review since the tariff wars kicked off.

Such actions can tie up capital that could otherwise fund new employment, higher wages or product innovation. Trump’s trade policy is, in fact, underscoring the basic economic lesson that tariffs don’t eliminate trade but simply make it more expensive, research shows.

Businesses have to decide to either pass these import taxes along to consumers via higher prices or absorb higher input costs themselves. Trump’s experiment is no different. According to fresh research from the New York Federal Reserve, as the average tariff rate jumped from 2.6% to 13% from January through November 2025, almost 90% of the burden hit consumers and businesses.

That’s why tariffs are a rare point of consensus among economists: They harm economic growth and are more costly today than ever before, given how interconnected global supply chains have become. And as the aftermath of the Supreme Court’s ruling shows, undoing their effect is a lot messier than tariff boosters would admit.

The Conversation

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

ref. Supreme Court’s tariff decision still leaves a ‘mess’ for companies trying to grab refunds – https://theconversation.com/supreme-courts-tariff-decision-still-leaves-a-mess-for-companies-trying-to-grab-refunds-276822

Iran has been threatening to close the Strait of Hormuz for years – it’s a key part of Tehran’s defence strategy

Source: The Conversation – UK – By Arshin Adib-Moghaddam, Professor in Global Thought and Comparative Philosophies, Inaugural Co-Director of Centre for AI Futures, SOAS, University of London

In a 1974 interview with the shah of Iran, Mohammad Reza Pahlavi, the US journalist Mike Wallace briefly referred to the dispute over the naming of what has been generally called “Sinus Persicus” (Persian Gulf) since ancient times – and what Wallace called “the Gulf”.

Pahlavi asked his interviewer: “Why do you call it ‘the Gulf’? You have been to school, haven’t you?” to which Wallace replied that he had. “What was the name that you read during your school days?” the shah asked. “The Persian Gulf,” Wallace admitted, adding: “But they call it the Arabian Gulf”. “‘They’ can do many things,” Pahlavi concluded – and considered the dispute settled.

This Iran-centric attitude towards the Persian Gulf explains much of Iran’s strategy in the Strait of Hormuz even today. Match this commonly held and historically formed mindset with the geopolitical reality. Iran has the longest shoreline in the Persian Gulf and it controls the entry to the strait via a string of heavily fortified islands. You would imagine that Tehran’s ability to close the strait should have been clear to the decision-makers in Tel Aviv and Washington.

As if that wasn’t enough, Iran has dropped enough hints over the years that it considers its leverage over the strait as a trump card. Tehran has greeted pretty much every crisis it has faced with the assertion of its ability to control the flow of oil and gas through this chokepoint and the threat to restrict traffic through the strait or close the waterway entirely.

Relatively early in the republic’s existence, in 1987-88 – towards the end of the Iran-Iraq war – the Iranian navy mined international waters in the Persian Gulf. It did so in response to the so-called “tanker war”, a series of military assaults by Iran and Iraq against each other’s merchant vessels in the Persian Gulf and strait of Hormuz.

At about the same time, to protect Kuwaiti oil tankers attempting to transit the strait, the US launched Operation Earnest Will, which lasted from July 1987 to September 1988 and was the largest naval convoy operation since the second world war. As one of the major allies of Saddam Hussein’s Iraq, Kuwait’s vessels were drawing fire from Iran.

This internationalisation of the Iran-Iraq war lowered the threshold for further conflict and brought Iran and the US dangerously close to direct confrontation. In April 1988 the US navy launched Operation Praying Mantis against Iran in retaliation for USS Samuel B. Roberts hitting an Iranian mine.

Operation Mantis was the American navy’s largest surface combat action since the second world war. It destroyed several Iranian naval assets for the loss of one helicopter, before the Pentagon took the decision not to escalate and Iran took the US offer to de-escalate.

Lessons should be learned in terms of civilian casualties: the dangers of escalation became apparent at the end of the Iran-Iraq war when in July 1988, Iran Air Flight 655 – a civilian airliner – was shot down in the strait of Hormuz by the USS Vincennes, killing 290 civilians.

Asymmetric warfare

Throughout the 1990s and increasingly in the past two decades, Iran has continued to project its ability to control the strait of Hormuz in response to real and perceived US aggression. To that end, the Iranian navy has finessed its asymmetric strategy of using small fast-attack boats capable of harassing US navy vessels and international shipping. This is “gunboat diplomacy”, Tehran-style.

Map of Straits of Hormuz
The strait of Hormuz is one of the world’s most important waterways, with 20% of the global trade in oil flowing through a narrow maritime channel.
Wikimedia Commons

Between 2011-12, the then Iranian president Mahmoud Ahmadinejad threatened to close the strait in response to new sanctions from the west over its nuclear energy program. Again, in 2018 when the US president, Donald Trump, withdrew the US from the Iran nuclear deal struck by his predecessor Barack Obama and began to further intensify the sanctions regime against the country, Iran’s president Hassan Rouhani threatened to close the waterway. Neither Ahmadinejad nor Rouhani followed up on the threats, as they largely continued to prioritise diplomacy that would give Iran sanctions relief.

In recent years, whenever the US-Iran stand-off has intensified, Iran has reacted by threatening international shipping through the strait of Hormuz and in the wider Persian Gulf. But in none of those historical instances did Tehran actually follow through in this threat completely. But now it frames the attack from the US and Israel as an “existential” one that threatens Iranian sovereignty and territorial integrity.

This triggers Iran’s civilisational instinct as displayed all those years ago by the last shah. One reading of Persian etymology derives “Hormuz” from the Middle Persian pronunciation of the name of Ahura Mazda, the Zoroastrian deity of the ancient Persian kings. (Another translates the name as a corruption of Hur-Muz – meaning place of dates.)

In Iranian strategic culture, this history gives it the right to act as the hegemon in the Persian Gulf. It is astonishing that US and Israeli strategists were seemingly unaware of this history. They should have known how central the strait of Hormuz has been to Iran’s strategic calculations. Both are now in evidence at this dangerous juncture for the region and the wider world.

The Conversation

Arshin Adib-Moghaddam does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

ref. Iran has been threatening to close the Strait of Hormuz for years – it’s a key part of Tehran’s defence strategy – https://theconversation.com/iran-has-been-threatening-to-close-the-strait-of-hormuz-for-years-its-a-key-part-of-tehrans-defence-strategy-279237

Dennis the Menace turns 75: why rule-breaking kids never go out of style

Source: The Conversation – UK – By Alison Baker, Senior Lecturer in Early Childhood Studies, University of East London

Dennis the Menace has been a popular character for 75 years. mundissima/Shutterstock

For 75 years, Dennis the Menace – wearing his signature red-and-black striped shirt and joined by his scruffy sidekick Gnasher – has been delighting children with his unapologetic mischief.

Dennis the Menace debuted in the Beano comic for children in March 1951 and quickly became a favourite with readers. His name derives from the music hall song Dennis the Menace from Venice, and his distinctive silhouette (very like that of his “Abyssinian wire-haired tripe hound” Gnasher) was first drawn on a cigarette pack in a pub in the Scottish town of St Andrews.

Coincidentally, on the other side of the Atlantic, another “naughty” boy called Dennis made his first appearance a syndicated newspaper comic strip on the same day as British Dennis. In contrast to his British namesake, American Dennis is a blond five year old, with a round face, blue and black striped t-shirt and red dungarees. American Dennis’s mischief comes from his misguided attempts to be helpful, rather than British Dennis’s deliberate misbehaviour.

The appearance of Dennis the Menace has changed somewhat over time, in his height, length of his legs and his possession of a catapult. But his spiked hair, red and black striped jumper, black shorts, knobbly knees and oversized boots have remained.




Read more:
How The Beano survived war and the web to reach its 80th birthday


Dennis & Gnasher through the years.

Like his predecessor William Brown of the Just William books, Dennis has a nemesis – Walter the Softy. Walter has some similarities to William’s enemy Hubert Lane. Both Walter and Hubert are depicted as cowardly, prim and opposed to fun. But, as researchers have explored, there is a somewhat homophobic element to the depiction of Dennis’s menacing of Walter. Walter is portrayed through ballet dancing in a tutu, sewing, playing with dolls and caring for his dog, named Foo-Foo. Dennis’s attitude to Walter was modified in 2012 to limit accusations of homophobia related to his interests in pursuits that are stereotypically considered feminine. He was renamed Walter Brown.

Another thing to have changed with time is the way the strips end. Generally in the 1970s, they’d close with Dennis lying over his father’s knee and getting beaten with a slipper. With the ending of corporal punishment in English state schools in 1986 (independent schools ended it much later, in 1999), teachers beating the Bash Street Kids or Dennis the Menace with a cane was no longer a likely outcome of misbehaviour.

The appeal of ‘naughty’ characters

So what is the appeal of “naughty” characters for children? Researchers have found that different age groups find different things funny. They characterise two types of humour evident in The Beano – disparaging, such as making fun of people, and slapstick. However, despite concerns about the impact of popular reading on the morals of young people that have been evident since the 19th century there is very little evidence of children being led astray by reading about rule-breaking characters.

Instead, comedy can be used to undermine power hierarchies through upending of social status – or, in children’s media, by making fun of adults.

The comeuppance of naughty characters at the end of a story is rarely permanent. For example, in Beatrix Potter’s stories, Peter Rabbit may end up in bed with a cold after disobeying his mother while his well-behaved sisters eat the blackberries they picked, but a few books later, he is back having adventures with his cousin, Benjamin Bunny.

Humorous stories about naughty children provide an imaginative space to be a rule breaker and laugh at powerful adults, to accept the punishment, but to enjoy another day of mischief. Like Peter, Dennis’s irrepressible mischief has made children laugh for generations. Long may he continue to do so.

The Conversation

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

ref. Dennis the Menace turns 75: why rule-breaking kids never go out of style – https://theconversation.com/dennis-the-menace-turns-75-why-rule-breaking-kids-never-go-out-of-style-278688

Les armes à énergie : le futur de la défense ?

Source: The Conversation – in French – By Alexandre Massaux, Chercheur associé à la Chaire Raoul-Dandurand, Université du Québec à Montréal (UQAM)

La guerre à distance que mènent les États-Unis et leurs alliés contre l’Iran repose sur un échange massif de missiles offensifs et de missiles d’interception, dont le coût explose à mesure que les jours passent. En à peine une semaine, Washington aurait déjà dépensé plus de 11 milliards de dollars, dont une part importante en missiles de défense.

Cette économie de la défense est devenue intenable avec l’utilisation massive de drones iraniens peu coûteux, qui obligent à tirer des intercepteurs bien plus coûteux pour les neutraliser. Dans ce contexte, le conflit montre les limites d’une défense exclusivement fondée sur les munitions cinétiques coûteuses, et relance la pertinence des armes à énergie dirigée (comme le laser), dont le coût par tir est beaucoup plus faible.




À lire aussi :
Voici comment les drones modifient les manières de faire la guerre


Je suis un chercheur à la Chaire Raoul-Dandurand. Mes travaux portent sur les conflits armés (en particulier le conflit entre l’Ukraine et la Russie) et sur l’utilisation des nouvelles technologies.

Je propose dans cet article d’analyser la situation au Moyen-Orient (et plus précisément dans les puissances du golfe) et comment les pays se protègent contre les attaques de missiles et de drones, en mettant l’accent sur les différentes technologies utilisées. En particulier, celles qui sont innovantes comme les armes à énergies dirigée.

Des défenses traditionnelles efficaces

Les défenses antimissiles utilisent principalement des intercepteurs de type cinétiques. Cette technologie consiste à envoyer des projectiles sur le vecteur (missile ou drone) ennemi pour le détruire avant qu’il n’atteigne sa destination.

Dans le conflit qui oppose les États-Unis et Israël à l’Iran, le Foreign Policy Research Institute estime que les États-Unis et les pays du Golfe comme l’Arabie Soudite et les Émirats arabes unis utilisent principalement pour se défendre les systèmes Patriot utilisant des missiles PAC-3, et les systèmes THAAD.

De son côté, Israël utilise les systèmes Tamir du Dôme de fer pour les frappes à courte et moyenne distance, et les Arrow 2 et 3 pour les attaques à longue distance. Le système de défense israélien est composé d’un ensemble de couches qui gère différents types de menaces. Ces systèmes fonctionnent avec des radars chargés de détecter les vecteurs ennemis.




À lire aussi :
Les frappes américano-israéliennes contre l’Iran pourraient être un succès militaire, mais à quel prix ?


Le taux d’interception se situe entre 80 % et 90 % en fonction des pays et du type de vecteur qu’ils doivent neutraliser. Par exemple, les Émirats arabes unis interceptent 90 % des missiles et 94 % des drones dirigés vers leur territoire, selon l’Institute for the Study of War. En 2025, Israël avait un taux de 85 % dans son conflit avec l’Iran.

Une guerre de quantité

Ces défenses antimissiles sont efficaces, mais pas sans défauts et faiblesses. Leur consommation de munitions pour intercepter les attaques ennemies pose notamment problème. Elle suppose en effet une logistique et un ravitaillement soutenu pour maintenir la cadence face aux attaques ennemies.

L’arrivée des drones sur le champ de bataille complique grandement le travail des systèmes antiaériens. Envoyés par centaines, voire par milliers, ces vecteurs bon marché peuvent surcharger les défenses. Les drones utilisés par l’Iran pourraient à cet égard révéler les limites des capacités des défenses antimissiles cinétiques.

La production de missiles Patriot PAC-3 était de 620 en 2025. Une production qui semblait peu adaptée à des conflits de haute intensité. En janvier 2026, le département de la guerre américain a augmenté sa production annuelle à 2000.

On constate une situation similaire pour les THAAD, avec un passage de la production de 96 à 400 missiles par an. Mais cette guerre entraine une forme d’asymétrie : les drones coûtent bien moins cher que les missiles chargés de les intercepter.


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Les drones iraniens

L’Iran utilise des drones-suicides Shahed qui coûteraient quelques dizaines de milliers de dollars. Avec le soutien de la Russie, la production serait estimée à 5000 drones par mois. Ces drones, ayant été largement utilisés en Ukraine par la Russie, poussent les pays occidentaux et les pays alliés au Moyen-Orient à s’inspirer des tactiques ukrainiennes en matière de défense.

L’Ukraine a d’ailleurs envoyé du personnel dans les pays du Golfe afin de les conseiller. Dans la mesure où ces drones se déplacent plus lentement qu’un missile, ils peuvent être interceptés par des canons antiaériens. Contre ce genre de drones, l’Ukraine utilise des blindés GEPARD (produits par l’Allemagne) doté d’une paire canons mitrailleurs ayant une cadence de tir de 1000 coups par minute.

Cette puissance de feu est utile pour intercepter les essaims de drones ennemis. Face à des engins bon marché, l’utilisation de munitions mitrailleuses est plus efficace que des missiles coûteux.




À lire aussi :
Lorsque la guerre prend des allures de prophétie : comment les récits apocalyptiques américains façonnent la guerre contre l’Iran


Repenser la défense

Si, à ce jour, la défense est le fait d’armes utilisant des munitions, des projets de plus en plus concrets sur des armes à énergie dirigée (AED) se développent et commencent à être déployées. Ces dernières utilisent l’énergie électromagnétique plutôt que des munitions cinétiques pour détruire l’adversaire. Les lasers à haute énergie font partie de ce type d’armes : un faisceau d’énergie capable de brûler les cibles ennemies.

Le principal avantage des AED est l’absence de munitions : l’arme n’a besoin que d’être alimentée en électricité. Le coût est en outre dérisoire. Pour les armes laser américaines, il serait de quelques dollars par tir : entre 3$ et 10$ en fonction des sources.

L’administration américaine est intéressée par cette technologie. Le système laser HELIOS a commencé à être développé en 2018 et à être déployé en 2026 sur des navires. Le Pentagone cherche aussi à accélérer son développement.

Israël cherche aussi à compléter son système de défense avec l’« Iron beam » (faisceau de fer), un équivalent du dôme de fer avec des armes lasers.

Un besoin de maturité pour les armes à énergie dirigée

Le conflit entre l’Ukraine et la Russie voit une forte utilisation de drones. Cela a amené les pays à intégrer les AED dans leur stratégie avec, par exemple, le Tryzub ukrainien qui est utilisé pour détruire les drones Shahed. Il est fort probable que les défenses laser soient de plus en plus utilisées afin de contrer les drones.

Néanmoins, les AED présentent quelques limites liées aux propriétés des lasers. Plus la cible est éloignée de l’arme, et plus celle-ci perd en efficacité. En outre, les conditions météorologiques comme la pluie et le brouillard perturbent le faisceau. Comme ces armes génèrent par ailleurs d’importantes quantités de chaleur, l’équipement doit être capable de résister aux surchauffes.

Qu’il s’agisse de défenses cinétiques ou à énergie, l’enjeu est désormais la capacité à détruire des vagues d’attaques avec un coût minimal. Les mitrailleuses et les lasers sont tout désignés pour faire face aux mutations qu’impose la multiplication des drones en matière de défense.

La Conversation Canada

Alexandre Massaux ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d’une organisation qui pourrait tirer profit de cet article, et n’a déclaré aucune autre affiliation que son organisme de recherche.

ref. Les armes à énergie : le futur de la défense ? – https://theconversation.com/les-armes-a-energie-le-futur-de-la-defense-278829

2026’s historic snow drought brings worries about water, wildfires and the future in the West

Source: The Conversation – USA (2) – By Alejandro N. Flores, Professor of Geoscience, Boise State University

The snow drought was evident in Park City, Utah, on Feb. 9, 2026. This golf course is normally used for cross-country skiing in winter. Mario Tama/Getty Images

Across much of the Western United States, winter 2026 was the year the snow never came. Many ski resorts got by with snowmaking but shut down their winter operations early. Fire officials and water supply managers are worried about summer.

Where I live in Boise, Idaho, temperatures hit the low 80s Fahrenheit (high-20s Celsius) in mid-March. The same heat dome sent temperatures soaring to 105 F (40 C) in Phoenix.

Ordinarily, water managers and hydrologists like me who study the Western U.S. expect the mountain snowpacks to be at their fullest around April 1. Snowpacks are natural reservoirs of water that farms and communities depend on through the hot, dry summer. Their snow water equivalent, meaning the amount of liquid water in the snowpack, is seen as a bellwether for water supplies.

But the 2026 water year has been anything but ordinary. In fact, its snow drought has few historical analogs.

Data from the U.S. Department of Agriculture’s Natural Resources Conservation Service shows that out of approximately 70 river basins across the Western U.S., only five are at or above the 1991-2020 median snow water equivalent for this time of year. Most of those are clustered around the Yellowstone region of western Wyoming and eastern Idaho.

A map of river basins shows very few with normal snow-water equivalent, primarily near Yellowstone National Park.
The majority of river basins in the Western U.S. were at less than 50% of their 1991-2020 median snow water equivalent on March 23, 2026.
Natural Resources Conservation Service National Water and Climate Center

By contrast, 11 basins have less than 25% of the 1991-2020 median, and more than half are below 50%. The headwaters of critically important rivers, including the Colorado, the Columbia and the Missouri, are peppered with basins that are far below historical averages.

Other important measures of snow water storage and ecosystem health, including which areas have snow cover in the Western U.S and how long it’s been there, also point toward snow reserves that are far below recent years.

How did we get here?

Just because the Western U.S. is in a snow drought doesn’t mean it isn’t getting precipitation. Temperatures have been high enough since the start of the water year in October that a lot of what normally would have fallen as snow fell as rain instead.

The West experienced a very warm December at all but the highest elevations, but strong storms also drenched large parts of the region. Washington state was swamped with rain that triggered flooding and melted the existing snowpack.

A chart shows very low snow cover all winter compared to the arc of most years.
The total area of the Western U.S. with snow cover has been exceptionally low compared to the years 2001 to 2025.
National Snow and Ice Data Center

Temperatures in January were less extreme but still warmer than historical averages. However, precipitation in January was far below the 1991-2020 average throughout much of the region. February brought precipitation conditions closer to historical averages, but temperatures were much warmer than normal.

The Western U.S., therefore, got a triple whammy: Two of the three critical snow-accumulation months were too warm, and the third was too dry.

Water worries ahead

So what does this mean for water supplies and river flows?

A recent assessment of drought conditions from NOAA’s National Integrated Drought Information System suggests 2026 will be a tight year for water supplies.

Water managers in Wyoming and Washington are already signaling that some water rights holders – cities, irrigation districts, individual farms and industries can take limited amounts of water from rivers, canals and aquifers – can expect to receive less than their full allotment of water in 2026. It’s not unreasonable to expect other states to soon follow suit.

Throughout the Western U.S., water rights are administered according to the Doctrine of Prior Appropriation – those who hold the oldest legitimate claims to water from a river, reservoir or aquifer are entitled to receive their allotments first.

Junior water rights holders who may be at risk of receiving less than their full allotment of water likely have difficult decisions ahead related to the planting and management of their crops. The challenges are compounded by the likelihood of increases in fertilizer and transportation costs associated with the ongoing war in Iran.

In the Colorado River Basin, the U.S. Bureau of Reclamation’s most probable forecast indicates water levels in Lake Powell falling below the minimum power pool elevation in December 2026. That’s bad news for power supplies, because below that level, the Glen Canyon Dam can’t produce hydroelectric power. The dam contributes power for millions of customers across seven states.

What the snow drought means for fire season

Another big concern is whether the historic snow drought is setting up the West for a bad fire season. That’s still an open question.

Rain has meant moisture is available now for plants to grow, but the lack of snowpack that normally keeps meltwater flowing through summer raises concerns about whether those plants will dry out, leaving them ready to burn.

Fire is a historically important feature of the forest and rangeland ecosystems of the West, and these ecosystems are to some degree adapted to large swings in conditions from year to year and season to season.

Because precipitation across much of the West is close to historical averages, there is snow in some of the highest-elevation mountains. And at lower elevations, some of the precipitation that fell as rain likely remains in the soils.

A skier next to open ground with a mountain in the background.
Snowmaking kept slopes skiable amid high temperatures in March 2026 in Breckenridge, Colo., but it wasn’t hard to find dry, exposed land nearby.
Michael Ciaglo/Getty Images

Weather conditions in the late spring and summer – how much rain falls and how hot and dry conditions become – will play critical roles in determining the shape forests and rangelands will be in for fire season.

What this winter suggests about the future

The record-low snowpack may be a harbinger of what a warmer future will look like in the region. Many researchers have investigated how climate change will influence snowpacks and water supply throughout the Western U.S., but questions and critical challenges remain.

Among them: In years like this, with near-normal precipitation but low snowpack, are there difficult-to-observe stores of water in the deeper subsurface that can help buffer against loss of snow for periods of time? That’s one of several questions my colleagues and I have been working on.

This year’s snow drought presents a timely, albeit high-stakes, stress test for the West. Everyone will be watching.

The Conversation

Alejandro N. Flores receives funding from the National Science Foundation, the US Bureau of Reclamation, and the USDA Agricultural Research Service.

ref. 2026’s historic snow drought brings worries about water, wildfires and the future in the West – https://theconversation.com/2026s-historic-snow-drought-brings-worries-about-water-wildfires-and-the-future-in-the-west-279163