Due process: What it means in US law and its implications for migrant rights

Source: The Conversation – USA – By Ray Brescia, Associate Dean for Research and Intellectual Life, Albany Law School

A core principle of the U.S. justice system is that the government must act in accordance with the rule of law. arsenisspyros, iStock Getty Images

As the United States edges up to the 250th anniversary of the Declaration of Independence in 2026, one of the core principles the founders sought to advance – that the government must act with accountability and in accordance with the rule of law – is being strongly tested.

In their deliberations leading up to the declaration, the founders would not just raise deep concerns that the government of King George III was violating the Colonists’ rights, which they described in the declaration. They would also enshrine these principles in the U.S. Constitution over a decade later through the concept of “due process.”

What did the framers likely mean when they did so? That’s no longer simply an academic question for legal scholars like me. The meaning and application of due process has become a crucial issue in the U.S., most often with respect to the Trump administration’s migrant deportation efforts.

Over the past several months, the U.S. Supreme Court has made several rulings in deportation-related cases with respect to what’s called the due process clause of the Constitution.

In April 2025, in the case Trump v. J.G.G., the court seemed to state quite clearly that deportations could not take place without due process. More recently, however, in D.H.S. v. D.V.D., the Supreme Court prevented a lower court from providing due process protections to a group of men the administration wanted to deport to South Sudan, where they are at risk of facing torture and even death.

These seemingly contradictory rulings not only make it unclear when due process applies but probably leave many asking what the term “due process of law” even means and how it works.

A large white, pillared building at the back of a plaza, with clouds in a blue sky behind it.
Over the past several months, the U.S. Supreme Court has made several rulings about due process in deportation-related cases.
Mike Kline, Moment/Getty Images

The origins of due process

The American concept of due process can be traced from medieval England to its modern formulation by the U.S. Supreme Court. Doing so allows the meaning of due process to come into focus. It also calls into question the court’s most recent ruling on this issue.

The concepts of due process and the rule of law largely emerged in the 13th century in the Magna Carta, a formal, written agreement between King John of England and the rebel aristocracy that effectively established legal constraints on government.

One key passage from the Magna Carta provided that “No Freeman shall be taken, or any otherwise imprisoned, or be disseised of his Freehold, or Liberties, or free Customs, or be outlawed, or exiled, or destroyed; nor we will not pass upon him, nor condemn him, but by lawful Judgment of his Peers, or by the Law of the Land.”

This accord established formal constraints on a previously unrestrained regent, setting English law on the course that would prioritize rule of law over the whims of the monarch.

Over a century later, Parliament would pass the English statute of 1354 that said “That no Man of what Estate or Condition that he be, shall he put out of Land or Tenement, nor taken nor imprisoned, nor disinherited, nor put to death, without being brought in Answer by due Process of the Law.”

These principlesd evolve over time in British law and then informed the emerging revolutionary spirit in the American Colonies.

Released in January 1776, Thomas Paine’s pamphlet Common Sense would help galvanize and steel many Colonists for the revolutionary conflict to come. The work shifted the focus of Colonists’ anger from trying to force the king to treat them better to more radical change: independence and a country governed by the rule of law.

An antique publication from 1776 with the title 'COMMON SENSE.'
Thomas Paine wrote in this influential 1776 political pamphlet, ‘For as in absolute governments the King is law, so in free countries the law ought to be King; and there ought to be no other.’
Library of Congress Rare Book and Special Collections Division

What the Colonists wanted, Paine wrote, was not a monarch: “So far as we approve of monarchy, that in America THE LAW IS KING. For as in absolute governments the King is law, so in free countries the law ought to be King; and there ought to be no other.”

Defining due process

After independence, many of the original 13 states adopted their own constitutions that would enshrine principles akin to due process to protect their constituents from government overreach, such as that government was to be bound, as it was in Virginia’s Declaration of Rights in 1776, by “the law of the land.”

But it was not until the nation adopted the Bill of Rights – the first 10 amendments to the Constitution – in 1791 that the federal government could not act in a way that deprived the populace of life, liberty or property without due process of law. After the Civil War, the 14th Amendment would apply these same protections to all government action, state and federal.

The contemporary and most comprehensive formulation of what due process requires can be found in the Supreme Court’s ruling in the 1970 case Goldberg v. Kelly, brought by welfare recipients challenging their loss of such benefits without a hearing.

In that case, the court determined that when governments attempt to deprive someone of their life, liberty or property, the target of those attempts must receive fair notice of the charges or claims against them that would justify that loss; be given an opportunity to defend against those claims; and possess the right to have such defenses considered by an impartial adjudicator.

The Supreme Court in 1976 would accept that due process protections in different settings will vary based on a number of variables. Those include what is at stake in the case, the likelihood that government might make a mistake in a particular setting, and the benefits and burdens of providing certain forms of process in a given situation.

When someone’s life is literally on the line, for example, more exacting procedures are required. At the same time, regardless of how important the interest that is subject to due process – whether it is one’s life, one’s home, one’s liberty, or something else – the components of fair notice, an opportunity to be heard, and to have one’s case decided by an impartial adjudicator must be meaningful.

As the court said in Mullane vs. Central Hanover Bank & Trust Co. in 1950: “Process which is a mere gesture is not due process.”

The Conversation

Ray Brescia 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. Due process: What it means in US law and its implications for migrant rights – https://theconversation.com/due-process-what-it-means-in-us-law-and-its-implications-for-migrant-rights-259756

Urban trees vs. cool roofs: What’s the best way for cities to beat the heat?

Source: The Conversation – USA (2) – By Ian Smith, Research Scientist in Earth & Environment, Boston University

Trees like these in Boston can help keep neighborhoods cooler on hot days. Yassine Khalfalli/Unsplash, CC BY

When summer turns up the heat, cities can start to feel like an oven, as buildings and pavement trap the sun’s warmth and vehicles and air conditioners release more heat into the air.

The temperature in an urban neighborhood with few trees can be more than 10 degrees Fahrenheit (5.5 Celsius) higher than in nearby suburbs. That means air conditioning works harder, straining the electrical grid and leaving communities vulnerable to power outages.

There are some proven steps that cities can take to help cool the air – planting trees that provide shade and moisture, for example, or creating cool roofs that reflect solar energy away from the neighborhood rather than absorbing it.

But do these steps pay off everywhere?

We study heat risk in cities as urban ecologists and have been exploring the impact of tree-planting and reflective roofs in different cities and different neighborhoods across cities. What we’re learning can help cities and homeowners be more targeted in their efforts to beat the heat.

The wonder of trees

Urban trees offer a natural defense against rising temperatures. They cast shade and release water vapor through their leaves, a process akin to human sweating. That cools the surrounding air and reduces afternoon heat.

Adding trees to city streets, parks and residential yards can make a meaningful difference in how hot a neighborhood feels, with blocks that have tree canopies nearly 3 F (1.7 C) cooler than blocks without trees.

Two maps of New York City show how vegetation matches cooler areas by temperature.
Comparing maps of New York’s vegetation and temperature shows the cooling effect of parks and neighborhoods with more trees. In the map on the left, lighter colors are areas with fewer trees. Light areas in the map on the right are hotter.
NASA/USGS Landsat

But planting trees isn’t always simple.

In hot, dry cities, trees often require irrigation to survive, which can strain already limited water resources. Trees must survive for decades to grow large enough to provide shade and release enough water vapor to reduce air temperatures.

Annual maintenance costs – about US$900 per tree per year in Boston – can surpass the initial planting investment.

Most challenging of all, dense urban neighborhoods where heat is most intense are often too packed with buildings and roads to grow more trees.

How cool roofs can help on hot days

Another option is “cool roofs.” Coating rooftops with reflective paint or using light-colored materials allows buildings to reflect more sunlight back into the atmosphere rather than absorbing it as heat.

These roofs can lower the temperature inside an apartment building without air conditioning by about 2 to 6 F (1 to 3.3 C), and can cut peak cooling demand by as much as 27% in air-conditioned buildings, one study found. They can also provide immediate relief by reducing outdoor temperatures in densely populated areas. The maintenance costs are also lower than expanding urban forests.

Two workers apply paint to a flat roof.
Two workers apply a white coating to the roof of a row home in Philadelphia.
AP Photo/Matt Rourke

However, like trees, cool roofs come with limits. Cool roofs work better on flat roofs than sloped roofs with shingles, as flat roofs are often covered by heat-trapping rubber and are exposed to more direct sunlight over the course of an afternoon.

Cities also have a finite number of rooftops that can be retrofitted. And in cities that already have many light-colored roofs, a few more might help lower cooling costs in those buildings, but they won’t do much more for the neighborhood.

By weighing the trade-offs of both strategies, cities can design location-specific plans to beat the heat.

Choosing the right mix of cooling solutions

Many cities around the world have taken steps to adapt to extreme heat, with tree planting and cool roof programs that implement reflectivity requirements or incentivize cool roof adoption.

In Detroit, nonprofit organizations have planted more than 166,000 trees since 1989. In Los Angeles, building codes now require new residential roofs to meet specific reflectivity standards.

In a recent study, we analyzed Boston’s potential to lower heat in vulnerable neighborhoods across the city. The results demonstrate how a balanced, budget-conscious strategy could deliver significant cooling benefits.

For example, we found that planting trees can cool the air 35% more than installing cool roofs in places where trees can actually be planted.

However, many of the best places for new trees in Boston aren’t in the neighborhoods that need help. In these neighborhoods, we found that reflective roofs were the better choice.

By investing less than 1% of the city’s annual operating budget, about US$34 million, in 2,500 new trees and 3,000 cool roofs targeting the most at-risk areas, we found that Boston could reduce heat exposure for nearly 80,000 residents. The results would reduce summertime afternoon air temperatures by over 1 F (0.6 C) in those neighborhoods.

While that reduction might seem modest, reductions of this magnitude have been found to dramatically reduce heat-related illness and death, increase labor productivity and reduce energy costs associated with building cooling.

Not every city will benefit from the same mix. Boston’s urban landscape includes many flat, black rooftops that reflect only about 12% of sunlight, making cool roofs that reflect over 65% of sunlight an especially effective intervention. Boston also has a relatively moist growing season that supports a thriving urban tree canopy, making both solutions viable.

Two aerial images show very different building coloring in two cities.
Phoenix, left, already has a lot of light-colored roots, compared with Boston, right, where roofs are mostly dark.
Imagery © Google 2025.

In places with fewer flat, dark rooftops suitable for cool roof conversion, tree planting may offer more value. Conversely, in cities with little room left for new trees or where extreme heat and drought limit tree survival, cool roofs may be the better bet.

Phoenix, for example, already has many light-colored roofs. Trees might be an option there, but they will require irrigation.

Getting the solutions where people need them

Adding shade along sidewalks can do double-duty by giving pedestrians a place to get out of the sun and cooling buildings. In New York City, for example, street trees account for an estimated 25% of the entire urban forest.

Cool roofs can be more difficult for a government to implement because they require working with building owners. That often means cities need to provide incentives. Louisville, Kentucky, for example, offers rebates of up to $2,000 for homeowners who install reflective roofing materials, and up to $5,000 for commercial businesses with flat roofs that use reflective coatings.

Two charts show improvements
In Boston, planting trees, left, and increasing roof reflectivity, right, were both found to be effective ways to cool urban areas.
Ian Smith et al. 2025

Efforts like these can help spread cool roof benefits across densely populated neighborhoods that need cooling help most.

As climate change drives more frequent and intense urban heat, cities have powerful tools for lowering the temperature. With some attention to what already exists and what’s feasible, they can find the right budget-conscious strategy that will deliver cooling benefits for everyone.

The Conversation

Lucy Hutyra has received funding from the U.S. federal government and foundations including the World Resources Institute and Burroughs Wellcome Fund for her scholarship on urban climate and mitigation strategies. She was a recipient of a 2023 MacArthur Fellowship for her work in this area.

Ian Smith 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. Urban trees vs. cool roofs: What’s the best way for cities to beat the heat? – https://theconversation.com/urban-trees-vs-cool-roofs-whats-the-best-way-for-cities-to-beat-the-heat-260188

How wind and solar power helps keep America’s farms alive

Source: The Conversation – USA (2) – By Paul Mwebaze, Research Economist at the Institute for Sustainability, Energy and Environment, University of Illinois at Urbana-Champaign

About 60% of Iowa’s power comes from wind. Farmers can earn extra cash by leasing small sections of farms for power production. Bill Clark/Getty Images

Drive through the plains of Iowa or Kansas and you’ll see more than rows of corn, wheat and soybeans. You’ll also see towering wind turbines spinning above fields and solar panels shining in the sun on barns and machine sheds.

For many farmers, these are lifelines. Renewable energy provides steady income and affordable power, helping farms stay viable when crop prices fall or drought strikes.

But some of that opportunity is now at risk as the Trump administration cuts federal support for renewable energy.

Wind power brings steady income for farms

Wind energy is a significant economic driver in rural America. In Iowa, for example, over 60% of the state’s electricity came from wind energy in 2024, and the state is a hub for wind turbine manufacturing and maintenance jobs.

For landowners, wind turbines often mean stable lease payments. Those historically were around US$3,000 to $5,000 per turbine per year, with some modern agreements $5,000 to $10,000 annually, secured through 20- to 30-year contracts.

Nationwide, wind and solar projects contribute about $3.5 billion annually in combined lease payments and state and local taxes, more than a third of it going directly to rural landowners.

A U.S. map shows the strongest wind power potential in the central U.S., particularly the Great Plains and Midwestern states.
States throughout the Great Plains and Midwest, from Texas to Montana to Ohio, have the strongest onshore winds and onshore wind power potential. These are also in the heart of U.S. farm country. The map shows wind speeds at 100 meters (nearly 330 feet), about the height of a typical land-based wind turbine.
NREL

These figures are backed by long-term contracts and multibillion‑dollar annual contributions, reinforcing the economic value that turbines bring to rural landowners and communities.

Wind farms also contribute to local tax revenues that help fund rural schools, roads and emergency services. In counties across Texas, wind energy has become one of the most significant contributors to local property tax bases, stabilizing community budgets and helping pay for public services as agricultural commodity revenues fluctuate.

In Oldham County in northwest Texas, for example, clean energy projects provided 22% of total county revenues in 2021. In several other rural counties, wind farms rank among the top 10 property taxpayers, contributing between 38% and 69% of tax revenue.

The construction and operation of these projects also bring local jobs in trucking, concrete work and electrical services, boosting small-town businesses.

A worker wearing a hardhat stands on top of a wind turbine, with a wide view of the landscape around him.
A wind turbine technician stands on the nacelle, which houses the gear box and generator of a wind turbine, on the campus of Mesalands Community College in Tucumcari, N.M., in 2024. Colleges in other states, including Texas, also developed training programs for technicians in recent years as jobs in the industry boomed.
Andrew Marszal/AFP via Getty Images

The U.S. wind industry supports over 300,000 U.S. jobs across construction, manufacturing, operations and other roles connected to the industry, according to the American Clean Power Association.

Renewable energy has been widely expected to continue to grow along with rising energy demand. In 2024, 93% of all new electricity generating capacity was wind, solar or energy storage, and the U.S. Energy Information Administration expected a similar percentage in 2025 as of June.

Solar can cut power costs on the farm

Solar energy is also boosting farm finances. Farmers use rooftop panels on barns and ground-mounted systems to power irrigation pumps, grain dryers and cold storage facilities, cutting their power costs.

Some farmers have adopted agrivoltaics – dual-use systems that grow crops beneath solar panels. The panels provide shade, helping conserve water, while creating a second income path. These projects often cultivate pollinator-friendly plants, vegetables such as lettuce and spinach, or even grasses for grazing sheep, making the land productive for both food and energy.

Federal grants and tax credits that were significantly expanded under the 2022 Inflation Reduction Act helped make the upfront costs of solar installations affordable.

A farmer looks at the camera with cows around him and a large red bar with solar panels on the roof behind him. The photos was taken at the Milkhouse Dairy in Monmouth, Maine, on Oct. 3, 2019.
Solar panels can help cut energy costs for farm operations like dairies.
Shawn Patrick Ouellette/Portland Press Herald via Getty Images

However, the federal spending bill signed by President Donald Trump on July 4, 2025, rolled back many clean energy incentives. It phases down tax credits for distributed solar projects, particularly those under 1 megawatt, which include many farm‑scale installations, and sunsets them entirely by 2028. It also eliminates bonus credits that previously supported rural and low‑income areas.

Without these credits, the upfront cost of solar power could be out of reach for some farmers, leaving them paying higher energy costs. At a 2024 conference organized by the Institute of Sustainability, Energy and Environment at the University of Illinois Urbana-Champaign, where I work as a research economist, farmers emphasized the importance of tax credits and other economic incentives to offset the upfront cost of solar power systems.

What’s being lost

The cuts to federal incentives include terminating the Production Tax Credit for new projects placed in service after Dec. 31, 2027, unless construction begins by July 4, 2026, and is completed within a tight time frame. The tax credit pays eligible wind and solar facilities approximately 2.75 cents per kilowatt-hour over 10 years, effectively lowering the cost of renewable energy generation. Ending that tax credit will likely increase the cost of production, potentially leading to higher electricity prices for consumers and fewer new projects coming online.

The changes also accelerate the phase‑out of wind power tax credits. Projects must now begin construction by July 4, 2026, or be in service before the end of 2027 to qualify for any credit.

Meanwhile, the Investment Tax Credit, which covers 30% of installed cost for solar and other renewables, faces similar limits: Projects must begin by July 4, 2026, and be completed by the end of 2027 to claim the credits. The bill also cuts bonuses for domestic components and installations in rural or low‑income locations. These adjustments could slow new renewable energy development, particularly smaller projects that directly benefit rural communities.

While many existing clean energy agreements will remain in place for now, the rollback of federal incentives threatens future projects and could limit new income streams. It also affects manufacturing and jobs in those industries, which some rural communities rely on.

Renewable energy also powers rural economies

Renewable energy benefits entire communities, not just individual farmers.

Wind and solar projects contribute millions of dollars in tax revenue. For example, in Howard County, Iowa, wind turbines generated $2.7 million in property tax revenue in 2024, accounting for 14.5% of the county’s total budget and helping fund rural schools, public safety and road improvements.

In some rural counties, clean energy is the largest new source of economic activity, helping stabilize local economies otherwise reliant on agriculture’s unpredictable income streams. These projects also support rural manufacturing – such as Iowa turbine blade factories like TPI Composites, which just reopened its plant in Newton, and Siemens Gamesa in Fort Madison, which supply blades for GE and Siemens turbines. The tax benefits in the 2022 Inflation Reduction Act helped boost those industries – and the jobs and local tax revenue they bring in.

On the solar side, rural companies like APA Solar Racking, based in Ohio, manufacture steel racking systems for utility-scale solar farms across the Midwest.

An example of how renewable energy has helped boost farm incomes and keep farmers on their land.

As rural America faces economic uncertainty and climate pressures, I believe homegrown renewable energy offers a practical path forward. Wind and solar aren’t just fueling the grid; they’re helping keep farms and rural towns alive.

The Conversation

The Sustainably Co-locating Agricultural and Photovoltaic Electricity Systems (SCAPES) project, led by the University of Illinois Urbana-Champaign, is funded by the U.S. Department of Agriculture’s National Institute of Food and Agriculture.

ref. How wind and solar power helps keep America’s farms alive – https://theconversation.com/how-wind-and-solar-power-helps-keep-americas-farms-alive-260657

The beach wasn’t always a vacation destination – for the ancient Greeks, it was a scary place

Source: The Conversation – USA (3) – By Marie-Claire Beaulieu, Associate Professor of Classical Studies, Tufts University

Ixia Beach, located on the northwestern coast of the Greek island of Rhodes, is a popular destination. Norbert Nagel via Wikimedia Commons, CC BY-SA

Many of us are heading to the beach to bask in the sun and unwind as part of our summer vacations. Research has shown that spending time at the beach can provide immense relaxation for many people. Staring at the ocean puts us in a mild meditative state, the smell of the breeze soothes us, the warmth of the sand envelops us, and above all, the continuous, regular sound of the waves allows us to fully relax.

But beach vacations only became popular in the 19th and early 20th centuries as part of the lifestyle of the wealthy in Western countries. Early Europeans, and especially the ancient Greeks, thought the beach was a place of hardship and death. As a seafaring people, they mostly lived on the coastline, yet they feared the sea and thought that an agricultural lifestyle was safer and more respectable.

As a historian of culture and an expert in Greek mythology, I am interested in this change of attitude toward the beach.

Couple dressed in 19th-century clothing walking on a beach with horse and cart.
‘On the Beach at Trouville,’ an 1863 painting by French artist Eugène Boudin.
Metropolitan Museum of Art, New York

The sensory experience of the beach

As I write in my 2016 book, “The Sea in the Greek Imagination,” Greek literature discounts all the positive sensations of the beach and the sea and focuses on the negative ones in order to stress the discomfort the ancient Greeks felt about the beach and the sea in general.

For instance, Greek literature emphasizes the intense smell of seaweed and sea brine. In the “Odyssey,” an eighth century B.C.E. poem that takes place largely at sea, the hero Menelaus and his companions are lost near the coast of Egypt. They must hide under the skins of seals to catch the sea god Proteus and learn their way home from him. The odor of the seals and sea brine is so extremely repulsive to them that their ambush almost fails, and only magical ambrosia placed under their noses can neutralize the smell.

Similarly, while the sound of the waves on a calm day is relaxing for many people, the violence of storms at sea can be distressing. Ancient Greek literature focuses only on the frightening power of stormy seas, comparing it to the sounds of battle. In the “Iliad,” a poem contemporary with the “Odyssey,” the onslaught of the Trojan army on the Greek battle lines is compared to a storm at sea: “They advanced like a deadly storm that scours the earth, to the thunder of Father Zeus, and stirs the sea with stupendous roaring, leaving surging waves in its path over the echoing waters, serried ranks of great arched breakers white with foam.”

Finally, even the handsome Odysseus is made ugly and scary-looking by exposure to the sun and salt of the sea. In the “Odyssey,” this hero wanders at sea for 10 years on his way home from the Trojan War. At the end of his tribulations, he is barely hanging on to a raft during a storm sent by the angry sea god Poseidon. He finally lets go and swims to shore; when he lands on the island of the Phaeacians, he scares the attendants of the Princess Nausicaa with his sunburned skin, “all befouled with brine.”

A Greek vase showing a naked Odysseus begging from Athena and a young woman, Nausicaa.
A vase depicting Odysseus coming out of the sea and scaring the attendants of Princess Nausicaa. 440 B.C., Staatliche Antikensammlungen, Munich.
Carole Raddato/flickr, CC BY-SA

The sand of the beach and the sea itself were thought to be sterile, in contrast to the fertility of the fields. For this reason, the “Iliad” and “Odyssey” regularly call the sea “atrygetos” – meaning “unharvested.”

This conception of the sea as sterile is, of course, paradoxical, since the oceans supply about 2% of overall human calorie intake and 15% of protein intake – and could likely supply much more. The Greeks themselves ate plenty of fish, and many species were thought to be delicacies reserved for the wealthy.

Death at the beach

In ancient Greek literature, the beach was frightening and evoked death, and in fact, it was common to mourn deceased loved ones on the beach.

Tombs were frequently located by the sea, especially cenotaphs – empty graves meant to memorialize those who died at sea and whose bodies could not be recovered.

Ancient monument on top of a cliff by the sea.
An example of a Greek tomb by the sea. The tomb of the tyrant Kleoboulos on the island of Rhodes, Greece.
Manfred Werner (Tsui) via Wikimedia, CC BY-SA

This was a particularly cruel fate in the ancient world because those who could not be buried were condemned to wander around the Earth eternally as ghosts, while those who received proper funerals would go to the underworld. The Greek underworld was not a particularly desirable place to be – it was dank and dark, yet it was considered the respectable way to end one’s life.

In this way, as classical scholar Gabriela Cursaru has shown, the beach was a “liminal space” in Greek culture: a threshold between the worlds of the living and the dead.

Revelation and transformation

Yet the beach was not all bad for the Greeks. Because the beach acted as a bridge between sea and land, the Greeks thought that it also bridged between the worlds of the living, the dead and the gods. Therefore, the beach had the potential to offer omens, revelations and visions of the gods.

For this reason, many oracles of the dead, where the living could obtain information from the dead, were located on beaches and cliffs by the sea.

The gods, too, frequented the beach. They heard prayers and sometimes even appeared to their worshippers on the beach. In the “Iliad,” the god Apollo hears his priest Chryses complain on the beach about how his daughter is being mistreated by the Greeks. The angry god retaliates by immediately unleashing the plague on the Greek army, a disaster that can only be stopped by returning the girl to her father.

Besides these religious beliefs, the beach was also a physical point of connection between Greece and distant lands.

Enemy fleets, merchants and pirates were all apt to land on beaches or to frequent the coasts because ancient ships lacked the capability to stay at sea for long periods. In this way, the beach could be a fairly dangerous place, as military historian Jorit Wintjes has argued.

On the bright side, flotsam from shipwrecks could bring pleasant surprises, such as unexpected treasure – a turning point in many ancient Greek stories. For example, in the ancient novel “Daphnis and Chloe,” the poor goatherd Daphnis finds a purse on the beach, which allows him to marry Chloe and bring their love story to a happy conclusion.

Perhaps something remains today of this conception of the beach. Beachcombing is still a popular hobby, and some people even use metal detectors. Besides its demonstrated positive psychological effects, beachcombing speaks to the eternal human fascination for the sea and all the hidden treasures it can provide, from shells and sea glass to Spanish gold coins.

Just as it did for the Greeks, the beach can make us feel that we are on the threshold of a different world.

The Conversation

Marie-Claire Beaulieu 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. The beach wasn’t always a vacation destination – for the ancient Greeks, it was a scary place – https://theconversation.com/the-beach-wasnt-always-a-vacation-destination-for-the-ancient-greeks-it-was-a-scary-place-259356

Why government support for religion doesn’t necessarily make people more religious

Source: The Conversation – USA (3) – By Brendan Szendro, Faculty Lecturer in Political Science, McGill University

History offers plenty of lessons about what happens when governments support faith groups – and it doesn’t always help them. cosmonaut/iStock via Getty Images Plus

The IRS will offer religious congregations more freedom to endorse political candidates without jeopardizing their tax-exempt status, the agency said in a July 2025 court filing. President Donald Trump has previously vowed to abolish the Johnson Amendment, which bars charitable nonprofits from taking part in political campaigns – although the latest move simply reinterprets the rule.

Celebrating the change, House Speaker Mike Johnson highlighted an argument that’s popular among some conservatives: that the Constitution does not actually require the separation of church and state.

Thomas Jefferson, who coined the phrase, did not intend “to keep religion from influencing issues of civil government,” Johnson wrote in a July 12 op-ed published on the social platform X. “The Founders wanted to protect the church from an encroaching state, not the other way around.”

Officials in several red states have challenged long-standing norms surrounding religion and state, ranging from introducing prayer and Bibles in public classrooms to attempts to secure government funding for religious schools.

Conservative thinkers have long pushed for closer ties between religion and the government, arguing that religious institutions can create strong communities. In my own research, I’ve found that mass shootings are less likely in a more religious environment.

For critics, of course, attempts to lower the wall of separation between church and state raise constitutional concerns. The First Amendment states that “Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof.” What’s more, critics fear that recent attempts to lower barriers between church and state favor conservative Christian groups over other faiths.

But as a scholar of religion and politics, I believe another reason for caution is being overlooked. Research indicates that strong relationships between religion and state can be a factor that actually decreases religious participation, rather than encouraging it.

All or nothing

Some scholars suggest that religious institutions operate like businesses in a marketplace, competing for believers. Government policies toward religion can change the balance of power between competing firms the same way that economic policies can affect markets for consumer goods.

At a glance, it might seem like government support would strengthen religious institutions. In reality, it can backfire, whether or not the government promotes one particular faith above others. In some cases, adherents who cannot practice religion on their own terms opt out of practicing it entirely.

In Israel, for example, Orthodox Jewish institutions receive government recognition that more liberal Jewish denominations do not. Orthodox authorities are allowed to manage religious sites, run public religious schools and perform marriages. Many couples who do not want to get married under Orthodox law, or cannot, hold a ceremony abroad or register as a common-law marriage.

A couple embraces side by side as they observe a small wedding in a wooded area.
Guests attend a wedding in Israel’s Ein Hemed National Park in December 2017.
AP Photo/Ariel Schalit

In fact, many scholars refer to Israel as an example of a religious “monopoly.” Because the government sponsors a particular branch, Orthodox Judaism, Jewish citizens sometimes face an “all or nothing” choice. The country’s Jewish population is sharply divided between people who are religiously observant and people who identify as secular.

Government involvement can also hurt religious institutions by making them seem less independent, decreasing people’s trust. In a 2023 study of 54 Christian-majority countries, political scientists Jonathan Fox and Jori Breslawski found that some adherents felt that religious institutions become less legitimate when backed by the government. In addition, support from the state decreased people’s confidence in government.

Their findings built on previous research showing that the public is less likely to contribute to faith-based charities and attend religious services when the government offers funding for religious institutions.

In fact, many of the world’s lowest rates of religiosity are found in wealthy countries that have official churches, or had one until relatively recently, such as Sweden. Others have a history of separating people of different faiths into their own schools and other institutions, such as Belgium and the Netherlands.

History lessons

Perhaps the strongest example of how government support for religion can decrease religious participation is found in the former Soviet Union and its allies.

During the Cold War, Soviet officials sought to stamp out religious activity among their citizens. However, policies to repress independent religious institutions worked hand in hand with policies to co-opt religious institutions that would work with the government. Access to religious spaces made it easier for officials to spy on members and punish clergy who protested their rule.

In Hungary, the Communist Party sponsored government-run Catholic churches that were cut off from the Vatican. In Romania, the regime integrated formerly Catholic Churches into a state Orthodox Church. In the former Czechoslovakia, meanwhile, the Communist Party paid clergy’s salaries to keep them subservient.

To this day, many countries in the former Eastern Bloc have low rates of religious participation. In Russia, for example, a majority of citizens call themselves Orthodox Christians, and the church wields influence in politics. Yet only 16% of adults say religion is “very important” in their lives.

While scholars can point to the legacy of overt repression as a source of low religiosity, government support of religious institutions is also a lingering factor. Most post-Soviet states inherited systems that require religious groups to register, and they only provide funding to faiths that the government considers legitimate. Similar policies remain common in southeastern and central Eastern Europe.

In recent years, some countries in the region, including Russia and Hungary, have experienced democratic backsliding at the hands of populist leaders who also politicize religion for their own gain. Because of low rates of religious practice in such countries, religious leaders may welcome government support.

Two men, one in black clerical robes, stand stiffly in an ornate room with gold-framed paintings.
In this photograph distributed by the Russian government news agency Sputnik, President Vladimir Putin and Russia’s Orthodox Patriarch, Kirill, visit the Annunciation Church of the Alexander Nevsky Lavra in Saint Petersburg on July 28, 2024.
Alexey Danichev/Pool/AFP via Getty Images

Free market for faith

Most wealthy countries have witnessed steep declines in religiosity in the modern era. The United States is an outlier.

Overall, the percentage of Americans belonging to a religious congregation is declining, as is the share of Americans who regularly attend worship services. However, the percentage of Americans who are intensely religious has remained unchanged over the past several decades. Around 29% of Americans report praying several times a day, for example, and just under 7% say they attend religious services more than once a week.

Some religion scholars argue that the “free-market approach” – where all faiths are free to compete for worshippers, without government interference or preference – is what makes America relatively religious. In other words, they believe that this so-called “American exception” is because of the separation between church and state, not in spite of it.

Time will tell if conservatives’ push for collaboration between religion and the government will continue, or have its intended effects. History suggests, however, that governments’ attempts to strengthen particular religious communities may backfire.

The Conversation

Brendan Szendro 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 government support for religion doesn’t necessarily make people more religious – https://theconversation.com/why-government-support-for-religion-doesnt-necessarily-make-people-more-religious-258541

Dynasties familiales : comment la famille Rothschild a bâti un empire… et pourquoi elle a échoué aux États-Unis

Source: The Conversation – France (in French) – By Liena Kano, Professor, Haskayne School of Business, University of Calgary

Mayer Amschel Rothschild (1745–1812), fondateur de la maison Rothschild est avec d’autres membres de sa famille : Mayer Karl Rothschild, Nath. Mayer v. Rothschild, Baron Lion. Nath. Rothschild, James v. Rothschild, Baron Alb. v. Rothschild, Sal. Mayer v. Rothschild, Anselm Sal. Frh. von Rothschild et Anselm [sic] Mayer von Rothschild. Wikimediacommons

Quelles leçons tirer de l’entreprise Rothschild, la société multicentenaire née au XVIIIe siècle, pour affronter les crises ? Une résilience fondée sur un langage organisationnel commun, des objectifs de long terme, une réputation de marque et des routines. Mais l’entreprise familiale s’est heurtée à ses limites en ratant son développement aux États-Unis : une prise de décision basée sur les émotions, sans déléguer à des associés hors de la famille.


Les entreprises familiales constituent une composante vitale du paysage économique en France. Dans le contexte économique turbulent actuel, marqué par les tensions géopolitiques, les perturbations technologiques et l’évolution des structures commerciales, être une entreprise compétitive est plus important que jamais.

Partout dans le monde, les entreprises familiales ont fait preuve d’une résilience remarquable face aux chocs externes. Certaines des plus anciennes entreprises au monde sont des entreprises familiales qui ont survécu à des guerres mondiales, des révolutions, des catastrophes naturelles et des pandémies.

Parmi ces multinationales de longue date figure la société Rothschild, une banque d’investissement familiale européenne vieille de plusieurs siècles. Notre étude de cas sur la famille Rothschild, fondée sur une analyse historique, met en lumière la façon dont des relations durables, des routines organisationnelles fiables et des objectifs de long terme lui ont conféré des avantages significatifs dans le commerce international.

En même temps, les structures familiales peuvent contribuer à créer des « biais de bifurcation », qui consistent à privilégier les ressources familiales par rapport à des ressources non familiales de valeur égale ou supérieure. Notre étude révèle que ce biais de bifurcation peut compromettre le développement international d’une entreprise, en particulier sur des marchés éloignés et complexes.

Une brève histoire des Rothschild

Mayer Amschel Rothschild (1744-1812), fondateur de la dynastie.
Wikimedia Commons

À l’origine une entreprise commerciale, de prêt sur gages, la société est fondée à la fin du XVIIIe siècle par Mayer Amschel Rothschild, né dans le ghetto juif de Francfort (Hesse, Allemagne).

Rothschild et sa femme, Guttle, ont dix enfants, dont cinq fils : Amschel, Salomon, Nathan, Carl et James.

En 1798, Rothschild envoie Nathan à Manchester en Angleterre. Par effet de ricochet, l’entreprise se développe dans ce pays et opère sa mutation d’opérations purement marchandes à des transactions financières. Dans les années 1820, Rothschild devient une banque multinationale, avec Amschel, Salomon, Nathan, Carl et James à la tête de maisons bancaires à Francfort, à Vienne, à Londres, à Naples et à Paris, respectivement.

Avantages et inconvénients des liens familiaux

Nathan Mayer Rothschild (1777-1836). Fondateur de la branche dite « de Londres », il finança l’effort de guerre britannique contre les ambitions napoléoniennes.
Wikimedia Commons

Au XIXe siècle, la stratégie des Rothschild consistant à s’appuyer sur les membres de la famille fonctionne bien pour l’entreprise.

Ingénieux, les cinq frères Rothschild correspondent dans un langage codé. Ils partagent également un pool commun de ressources à une époque où l’échange de données financières est rare dans le secteur bancaire international.

Leurs liens familiaux étroits permettent aux frères de transférer des informations, de l’argent et des marchandises à travers les frontières à une vitesse et une portée inaccessibles à leurs concurrents.

Cette cohésion interne protège les affaires des Rothschild, en facilitant les transactions et en leur permettant de rester résilients à travers les périodes de bouleversements politiques importants : une vision audacieuse pendant les guerres napoléoniennes, le ralliement républicain en 1848 et un patriotisme économique durant la Première Guerre mondiale.

Cette même dépendance excessive à la famille devient un inconvénient lorsque l’entreprise Rothschild se développe aux États-Unis.

Biais de bifurcation

Les Rothschild montrent un intérêt pour le marché états-unien dès les années 1820. Leurs tentatives répétées d’envoyer des membres de leur famille aux États-Unis pour étendre leurs opérations échouent, car aucun n’est prêt à y rester, préférant le confort de la vie européenne.

August Belmont fut agent de la banque Rothschild aux États-Unis.
Wikimediacommons

Comme ils ne sont pas en mesure d’établir un ancrage familial dans le pays, les Rothschild nomment un agent, August Belmont, pour diriger les opérations états-uniennes en leur nom en 1837.

Belmont n’a pas le pouvoir de prendre des décisions entrepreneuriales, de faire des investissements ou de conclure des accords. Il n’a pas non plus un accès illimité au capital et n’a jamais été chargé d’un mandat officiel Rothschild ou reconnu comme un associé à part entière. Les Rothschild ne sont pas disposés à déléguer de telles décisions à quelqu’un qui n’est pas un descendant masculin direct du fondateur, Mayer Amschel Rothschild.

Cette incapacité à utiliser Belmont comme lien entre la famille – avec ses expériences réussies, ses capacités, ses routines et ses connexions en Europe – et le marché états-unien – avec ses opportunités croissantes et les précieux réseaux que Belmont commence à développer – empêche finalement l’entreprise Rothschild de reproduire son succès aux États-Unis.

Les Rothschild sont finalement éclipsés par les banques Barings et J P Morgan en Amérique. Les deux concurrents suivent un chemin différent sur le marché en ouvrant des filiales états-uniennes à part entière sous leurs marques d’entreprise, avec des fonds importants et une autonomie décisionnelle.

Garde-fous

Ce « biais de bifurcation » n’a pas toujours un impact négatif immédiat. Les pratiques de gouvernance biaisées sont restées sans conséquence pour les Rothschild – tant qu’il y avait suffisamment d’héritiers compétents pour diriger les opérations de la banque dispersées aux quatre coins du monde.

À court et à moyen terme, les liens de la famille, ses routines éprouvées et sa confiance mutuelle ont construit un réservoir de résilience qui a soutenu la banque tout au long du XIXe siècle, l’une des périodes politiques les plus instables de l’histoire européenne.

Mais lorsque les ambitions internationales d’une entreprise dépassent la taille de la famille, le biais de bifurcation peut nuire à la compétitivité, tant sur les marchés internationaux qu’au pays.

À un moment donné, les entreprises familiales doivent passer d’une prise de décision émotionnelle et biaisée à des systèmes de gouvernance efficaces. Ceux-ci impliquent l’intégration de gestionnaires non familiaux et la sélection de ressources, d’emplacements et de projets qui n’ont pas de signification émotionnelle.

La famille Tata, à la tête d’un groupe industriel indien créé en 1868, a mis en place des garde-fous pour empêcher les biais de bifurcation.
Shutterstock

De nombreuses entreprises familiales prospères mettent en œuvre des outils dans leurs systèmes de gouvernance pour détecter et éliminer les comportements biaisés. Par exemple, les multinationales familiales telles que Merck en Allemagne, Cargill aux États-Unis et Tata Group en Inde ont créé des freins et garde-fous qui empêchent les décideurs de penser uniquement en termes familiaux.

Les stratégies les plus efficaces pour se prémunir contre le biais de bifurcation invitent à un examen extérieur dans la prise de décision des entreprises : nomination de PDG extérieurs à la famille, mise en place de conseils d’administration indépendants, embauche de consultants et octroi de pouvoirs de décision aux associés.

Leçons pour les entreprises familiales

Aujourd’hui, alors que l’environnement commercial mondial est sans doute confronté à une instabilité sans précédent, les entreprises cherchent à renforcer leur résilience.

Les entreprises familiales multigénérationnelles doivent apprendre à se prémunir contre le biais de bifurcation pour prospérer sur les marchés internationaux. Leur capacité démontrée à résister aux chocs externes offre de précieuses leçons pour d’autres entreprises.

Comment les entreprises non familiales peuvent-elles imiter le succès et la longévité des Rothschild ? Le cas Rothschild nous enseigne l’importance d’avoir un langage organisationnel commun, de fixer des objectifs à long terme, de maintenir des routines stables et de mettre l’accent sur la réputation de la marque.

Ces stratégies peuvent aider toute entreprise, familiale ou non, à renforcer sa résilience en période de volatilité.

The Conversation

Liena Kano a reçu des financements de SSHRC.

.

Alain Verbeke a reçu des financements de SSHRC.

Luciano Ciravegna a reçu des financements d’INCAE Business School, où il dirige la chaire Steve Aronson.

Andrew Kent Johnston 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. Dynasties familiales : comment la famille Rothschild a bâti un empire… et pourquoi elle a échoué aux États-Unis – https://theconversation.com/dynasties-familiales-comment-la-famille-rothschild-a-bati-un-empire-et-pourquoi-elle-a-echoue-aux-etats-unis-260735

Is that wildfire smoke plume hazardous? New satellite tech can map smoke plumes in 3D for better air quality alerts at neighborhood scale

Source: The Conversation – USA – By Jun Wang, Professor of Chemical and Biochemical Engineering, University of Iowa

Smoke from Canadian wildfires prompted air quality alerts in Chicago as it blanketed the city on June 5, 2025. Scott Olson/Getty Images

Canada is facing another dangerous wildfire season, with burning forests sending smoke plumes across the provinces and into the U.S. again. The pace of the 2025 fires is reminiscent of the record-breaking 2023 wildfire season, which exposed millions of people in North America to hazardous smoke levels.

For most of the past decade, forecasters have been able to use satellites to track these smoke plumes, but the view was only two-dimensional: The satellites couldn’t determine how close the smoke was to Earth’s surface.

The altitude of the smoke matters.

If a plume is high in the atmosphere, it won’t affect the air people breathe – it simply floats by, far overhead.

But when smoke plumes are close to the surface, people are breathing in wildfire chemicals and tiny particles. Those particles, known as PM2.5, can get deep into the lungs and exacerbate asthma and other respiratory and cardiac problems.

An animation shows mostly green (safe) air quality from ground-level monitors. However, in Canada, closer to the fire, the same plume shows high levels of PM2.5.
An animation on May 30, 2025, shows a thick smoke plume from Canada moving over Minnesota, but the air quality monitors on the ground detected minimal risk, suggesting it was a high-level smoke plume.
NOAA NESDIS Center for Satellite Applications and Research

The Environmental Protection Agency uses a network of ground-based air quality monitors to issue air quality alerts, but the monitors are few and far between, meaning forecasts have been broad estimates in much of the country.

Now, a new satellite-based method that I and colleagues at universities and federal agencies have been working on for the past two years is able to give scientists and air quality managers a 3D picture of the smoke plumes, providing detailed data of the risks down to the neighborhood level for urban and rural areas alike.

Building a nationwide smoke monitoring system

The new method uses data from a satellite that NASA launched in 2023 called the Tropospheric Emissions: Monitoring of Pollution, or TEMPO, satellite.

A map shows blue over the Dakotas, Nebraska and western parts of Minnesota and Iowa. Pink is over Pennsylvania up through Maine.
Data from the TEMPO satellite shows the height of the smoke plume, measured in kilometers. Light blue areas are closest to the ground, suggesting the worst air quality. Pink areas suggest the smoke is more than 2 miles (3.2 kilometers) above the ground, where it poses little risk to human health. The data aligns with air monitor readings taken on the ground at the same time.
NOAA NESDIS Center for Satellite Applications and Research

TEMPO makes it possible to determine a smoke plume’s height by providing data on how much the oxygen molecules absorb sunlight at the 688 nanometer wavelength. Smoke plumes that are high in the atmosphere reflect more solar radiation at this wavelength back to space, while those lower in the atmosphere, where there is more oxygen to absorb the light, reflect less.

Understanding the physics allowed scientists to develop algorithms that use TEMPO’s data to infer the smoke plume’s altitude and map its 3D movement in nearly real time.

An illustration shows a satellite, Sun and smoke plume at different heights. Higher plumes reflect more light.
Aerosol particles in high smoke plumes reflect more light back into space. Closer to Earth’s surface, there is more oxygen to absorb light at the 688 nanometer wavelength, so less light is reflected. Satellites can detect the difference, and that can be used to determine the height of the smoke plume.
Adapted from Xu et al, 2019, CC BY

By combining TEMPO’s data with measurements of particles in the atmosphere, taken by the Advanced Baseline Imager on the NOAA’s GOES-R satellites, forecasters can better assess the health risk from smoke plumes in almost real time, provided clouds aren’t in the way.

That’s a big jump from relying on ground-based air quality monitors, which may be hundreds of miles apart. Iowa, for example, had about 50 air quality monitors reporting data on a recent day for a state that covers 56,273 square miles. Most of those monitors were clustered around its largest cities.

NOAA’s AerosolWatch tool currently provides a near-real-time stream of wildfire smoke images from its GOES-R satellites, and the agency plans to incorporate TEMPO’s height data. A prototype of this system from my team’s NASA-supported research project on fire and air quality, called FireAQ, shows how users can zoom in to the neighborhood level to see how high the smoke plume is, however the prototype is currently only updated once a day, so the data is delayed, and it isn’t able to provide smoke height data where clouds are also overhead.

Wildfire health risks are rising

Fire risk is increasing across North America as global temperatures rise and more people move into wildland areas.

While air quality in most of the U.S. improved between 2000 and 2020, thanks to stricter emissions regulations on vehicles and power plants, wildfires have reversed that trend in parts of the western U.S. Research has found that wildfire smoke has effectively erased nearly two decades of air quality progress there.

Our advances in smoke monitoring mark a new era in air quality forecasting, offering more accurate and timely information to better protect public health in the face of these escalating wildfire threats.

The Conversation

Prof. Wang’s group have been supported from NOAA, NASA, and Naval ONR to develop research algorithm to retrieve aerosol layer height. The compute codes of the research algorithm were shared with colleagues in NOAA.

ref. Is that wildfire smoke plume hazardous? New satellite tech can map smoke plumes in 3D for better air quality alerts at neighborhood scale – https://theconversation.com/is-that-wildfire-smoke-plume-hazardous-new-satellite-tech-can-map-smoke-plumes-in-3d-for-better-air-quality-alerts-at-neighborhood-scale-259654

Is that wildfire smoke plume hazardous? New satellite tech can map smoke height for better air quality alerts at neighborhood scale

Source: The Conversation – USA (2) – By Jun Wang, Professor of Chemical and Biochemical Engineering, University of Iowa

Smoke from Canadian wildfires prompted air quality alerts in Chicago as it blanketed the city on June 5, 2025. Scott Olson/Getty Images

Canada is facing another dangerous wildfire season, with burning forests sending smoke plumes across the provinces and into the U.S. again. The pace of the 2025 fires is reminiscent of the record-breaking 2023 wildfire season, which exposed millions of people in North America to hazardous smoke levels.

For most of the past decade, forecasters have been able to use satellites to track these smoke plumes, but the view was only two-dimensional: The satellites couldn’t determine how close the smoke was to Earth’s surface.

The altitude of the smoke matters.

If a plume is high in the atmosphere, it won’t affect the air people breathe – it simply floats by, far overhead.

But when smoke plumes are close to the surface, people are breathing in wildfire chemicals and tiny particles. Those particles, known as PM2.5, can get deep into the lungs and exacerbate asthma and other respiratory and cardiac problems.

An animation shows mostly green (safe) air quality from ground-level monitors. However, in Canada, closer to the fire, the same plume shows high levels of PM2.5.
An animation on May 30, 2025, shows a thick smoke plume from Canada moving over Minnesota, but the air quality monitors on the ground detected minimal risk, suggesting it was a high-level smoke plume.
NOAA NESDIS Center for Satellite Applications and Research

The Environmental Protection Agency uses a network of ground-based air quality monitors to issue air quality alerts, but the monitors are few and far between, meaning forecasts have been broad estimates in much of the country.

Now, a new satellite-based method that I and colleagues at universities and federal agencies have been working on for the past two years is able to give scientists and air quality managers a 3D picture of the smoke plumes, providing detailed data of the risks down to the neighborhood level for urban and rural areas alike.

Building a nationwide smoke monitoring system

The new method uses data from a satellite that NASA launched in 2023 called the Tropospheric Emissions: Monitoring of Pollution, or TEMPO, satellite.

A map shows blue over the Dakotas, Nebraska and western parts of Minnesota and Iowa. Pink is over Pennsylvania up through Maine.
Data from the TEMPO satellite shows the height of the smoke plume, measured in kilometers. Light blue areas are closest to the ground, suggesting the worst air quality. Pink areas suggest the smoke is more than 2 miles (3.2 kilometers) above the ground, where it poses little risk to human health. The data aligns with air monitor readings taken on the ground at the same time.
NOAA NESDIS Center for Satellite Applications and Research

TEMPO makes it possible to determine a smoke plume’s height by providing data on how much the oxygen molecules absorb sunlight at the 688 nanometer wavelength. Smoke plumes that are high in the atmosphere reflect more solar radiation at this wavelength back to space, while those lower in the atmosphere, where there is more oxygen to absorb the light, reflect less.

Understanding the physics allowed scientists to develop algorithms that use TEMPO’s data to infer the smoke plume’s altitude and map its 3D movement in nearly real time.

An illustration shows a satellite, Sun and smoke plume at different heights. Higher plumes reflect more light.
Aerosol particles in high smoke plumes reflect more light back into space. Closer to Earth’s surface, there is more oxygen to absorb light at the 688 nanometer wavelength, so less light is reflected. Satellites can detect the difference, and that can be used to determine the height of the smoke plume.
Adapted from Xu et al, 2019, CC BY

By combining TEMPO’s data with measurements of particles in the atmosphere, taken by the Advanced Baseline Imager on the NOAA’s GOES-R satellites, forecasters can better assess the health risk from smoke plumes in almost real time, provided clouds aren’t in the way.

That’s a big jump from relying on ground-based air quality monitors, which may be hundreds of miles apart. Iowa, for example, had about 50 air quality monitors reporting data on a recent day for a state that covers 56,273 square miles. Most of those monitors were clustered around its largest cities.

NOAA’s AerosolWatch tool currently provides a near-real-time stream of wildfire smoke images from its GOES-R satellites, and the agency plans to incorporate TEMPO’s height data. A prototype of this system from my team’s NASA-supported research project on fire and air quality, called FireAQ, shows how users can zoom in to the neighborhood level to see how high the smoke plume is, however the prototype is currently only updated once a day, so the data is delayed, and it isn’t able to provide smoke height data where clouds are also overhead.

Wildfire health risks are rising

Fire risk is increasing across North America as global temperatures rise and more people move into wildland areas.

While air quality in most of the U.S. improved between 2000 and 2020, thanks to stricter emissions regulations on vehicles and power plants, wildfires have reversed that trend in parts of the western U.S. Research has found that wildfire smoke has effectively erased nearly two decades of air quality progress there.

Our advances in smoke monitoring mark a new era in air quality forecasting, offering more accurate and timely information to better protect public health in the face of these escalating wildfire threats.

The Conversation

Prof. Wang’s group have been supported from NOAA, NASA, and Naval ONR to develop research algorithm to retrieve aerosol layer height. The compute codes of the research algorithm were shared with colleagues in NOAA.

ref. Is that wildfire smoke plume hazardous? New satellite tech can map smoke height for better air quality alerts at neighborhood scale – https://theconversation.com/is-that-wildfire-smoke-plume-hazardous-new-satellite-tech-can-map-smoke-height-for-better-air-quality-alerts-at-neighborhood-scale-259654

Arsenalisation de l’espace : quelles armes, quelles menaces, quel droit ?

Source: The Conversation – in French – By Katia Coutant, Chercheuse associée à la chaire Espace de l’ENS-PSL, Université Paris Nanterre – Université Paris Lumières

L’humanité a longtemps connu deux terrains de conflictualité : la terre et la mer. L’air est venu s’y ajouter au début du XXe siècle ; cent ans plus tard est venu le temps du cyber… mais quid de l’espace ? Si les affrontements armés entre vaisseaux spatiaux relèvent encore de la science-fiction, l’arsenalisation de l’espace est déjà en cours. Mais de quoi parle-t-on exactement quand on emploie cette expression de plus en plus en vogue ?


À première vue, on pourrait définir l’arsenalisation de l’espace comme l’ensemble des technologies, des activités et des capacités qui visent à permettre le combat et les actions offensives dans l’espace extra-atmosphérique, par exemple à travers le placement d’armes en orbite.

Pourtant, le terme et son champ exact restent sujets à débat, et l’expression de « course à l’armement dans l’espace » pourrait lui être préférée.

« Arsenalisation » ou « militarisation » ?

L’usage croissant de l’expression « arsenalisation » reflète la conception grandissante de l’espace extra-atmosphérique comme étant un terrain de conflictualité. La définition même de l’arsenalisation est débattue, et soulève l’enjeu de la distinction entre l’arsenalisation et la militarisation de l’espace.

La militarisation couvrirait l’utilisation des moyens spatiaux en soutien à des opérations militaires et aurait ainsi un objet différent de l’arsenalisation. Prenons des exemples : un satellite d’observation utilisé pour surveiller des mouvements de troupes au sol relève a minima de la militarisation. Un dispositif en orbite capable de détruire un satellite adverse, au moyen d’un laser ou d’un missile, relève à coup sûr de l’arsenalisation.

Le groupe d’experts gouvernementaux chargé d’étudier de nouvelles mesures concrètes de prévention d’une course aux armements dans l’espace, rattaché à l’Organisation des Nations unies (ONU), prend en compte toutes les menaces liées aux infrastructures spatiales, y compris les vecteurs « Terre-espace, espace-Terre, espace-espace, et Terre-Terre ». Cette conception large permet de mieux identifier les risques liés à la prolifération d’armes en lien avec le secteur spatial, sans se limiter au piège de la cible géographique parfois associé à l’arsenalisation.

Quelles sont les menaces existantes ?

Il existe différents types de systèmes ou armes ciblant les infrastructures spatiales. Les tests antisatellitaires à ascension directe, dont la légalité est questionnée à l’ONU actuellement, consistent en la capacité pour un État de tirer sur ses propres satellites depuis la Terre.

Si, jusqu’ici, les tirs réalisés par les États ont consisté en des tests sur leurs propres satellites, ces tirs soulèvent toutefois le problème de la création de débris et des risques de collision de ceux-ci avec des satellites, et prouvent que ces États sont capables de viser (et d’atteindre) un satellite ennemi.

La question « Existe-t-il des armes positionnées dans l’espace qui pourraient viser la Terre ? » est souvent posée. Bien que ce soit en théorie envisageable, en pratique, les États n’ont pas recours à ce type de projets.

Les coûts de développement et de maintenance ainsi qu’une efficacité questionnable expliquent la préférence pour les techniques terrestres.

Surtout, de nombreuses technologies duales – c’est-à-dire d’utilisation civile et militaire – existent. Un satellite d’observation peut aussi bien servir à surveiller la déforestation qu’à repérer des infrastructures militaires. Ce flou complique considérablement la mise en place de règles claires.

Si l’on se limite aux technologies visant des cibles dans l’espace depuis l’espace, quelques exemples d’armes existent.

Déjà, en 1962, les États-Unis ont mené un essai d’explosion nucléaire dans l’espace, appelé Starfish Prime. Il a rendu inopérables de nombreux satellites, et les États ont par la suite décidé d’interdire les essais d’armes nucléaires dans l’espace. À ce jour, il n’y a donc pas d’armes nucléaires dans l’espace.

Au-delà des armes nucléaires, différentes technologies ont été essayées. Du côté soviétique, dès les années 1970, la station Almaz avait expérimenté l’installation d’un canon en orbite sur un satellite. Puis, en 2018, un satellite russe a été repéré très près d’un satellite franco-italien. Cette technologie, dite satellite « butineur », peut interférer avec le fonctionnement de la cible.

En réponse à cette situation, la France développe le système Laser Toutatis qui vise à équiper des satellites de défense d’un laser capable de neutraliser tout objet suspect qui s’en approcherait.

Guerre et paix dans l’espace

Cette présence d’armes confirme que l’espace est un lieu de conflictualité. Pourtant, dès 1967, grâce au Traité de l’espace, le principe de l’utilisation pacifique de l’espace a été acté.

Cette expression ne signifie pas que les armes sont illégales dans l’espace : leur présence n’est pas interdite tant qu’elles ne sont pas utilisées. Une nuance : en vertu de ce traité, si l’espace extra-atmosphérique peut accueillir certaines armes, les corps célestes, eux, demeurent entièrement exempts de toute arme, quelle qu’en soit la nature.

Ainsi, si l’on se limite à l’orbite autour de la Terre, l’arsenalisation est (pour l’instant) permise sauf pour les armes nucléaires et de destruction massive. Cela ne veut pas pour autant dire que le recours à la force armée est autorisé dans l’espace.

La Charte des Nations unies, également applicable dans l’espace, interdit le recours à la force ; en revanche est permise la légitime défense. C’est la raison pour laquelle les acteurs présentent leurs nouvelles technologies sous le nom de « technologie de défense active ».

Des initiatives visant à encadrer davantage ces pratiques existent, et des négociations sont en cours dans le cadre de la Conférence du désarmement à Genève.


La série « L’envers des mots » est réalisée avec le soutien de la Délégation générale à la langue française et aux langues de France du ministère de la culture.

The Conversation

Katia Coutant a reçu des financements du ministère de l’enseignement supérieur et de la recherche.

ref. Arsenalisation de l’espace : quelles armes, quelles menaces, quel droit ? – https://theconversation.com/arsenalisation-de-lespace-quelles-armes-quelles-menaces-quel-droit-260465

Netflix is now using generative AI – but it risks leaving viewers and creatives behind

Source: The Conversation – UK – By Edward White, PhD Candidate in Psychology, Kingston University

Netflix’s recent use of generative AI to create a building collapse scene in the sci-fi show El Eternauta (The Eternaut) marks more than a technological milestone. It reveals a fundamental psychological tension about what makes entertainment authentic.

The sequence represents the streaming giant’s first official deployment of text-to-video AI in final footage. According to Netflix, it was completed ten times faster than traditional methods would have allowed.

Yet this efficiency gain illuminates a deeper question rooted in human psychology. When viewers discover their entertainment contains AI, does this revelation of algorithmic authorship trigger the same cognitive dissonance we experience when discovering we’ve been seduced by misinformation?

The shift from traditional CGI (computer-generated imagery) to generative AI is the most significant change in visual effects (VFX) since computer graphics displaced physical effects.

Traditional physical VFX requires legions of artists meticulously crafting mesh-based models, spending weeks perfecting each element’s geometry, lighting and animation. Even the use of CGI with green screens demands human artists to construct every digital element from 3D models and programme the simulations. They have to manually key-frame each moment, setting points to show how things move or change.

Netflix’s generative AI approach marks a fundamental shift. Instead of building digital scenes piece by piece, artists simply describe what they want and algorithms generate full sequences instantly. This turns a slow, laborious craft into something more like a creative conversation. But it also raises tough questions. Are we seeing a new stage of technology – or the replacement of human creativity with algorithmic guesswork?


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El Eternauta’s building collapse scene demonstrates this transformation starkly. What would once have demanded months of modelling, rigging and simulation work has been accomplished through text-to-video generation in a fraction of the time.

The economics driving this transformation extend far beyond Netflix’s creative ambitions.

The text-to-video AI market is projected to be worth £1.33 billion by 2029. This reflects an industry looking to cut corners after the streaming budget cuts of 2022. In that year, Netflix’s content spending declined 4.6%, while Disney and other major studios implemented widespread cost-cutting measures.

AI’s cost disruption is bewildering. Traditional VFX sequences can cost thousands per minute. As a result, the average CGI and VFX budget for US films reached US$33.7 million (£25 million) per movie in 2018. Generative AI could lead to cost reductions of 10% across the media industry, and as much as 30% in TV and film. This will enable previously impossible creative visions to be realised by independent filmmakers – but this increased accessibility comes with losses too.

The trailer for El Eternauta.

The OECD reports that 27% of jobs worldwide are at “high risk of automation” due to AI. Meanwhile, surveys by the International Alliance of Theatrical Stage Employees have revealed that 70% of VFX workers do unpaid overtime, and only 12% have health insurance. Clearly, the industry is already under pressure.

Power versus precision

While AI grants filmmakers unprecedented access to complex imagery, it simultaneously strips away the granular control that defines directorial vision.

As an experiment, film director Ascanio Malgarini spent a year creating an AI-generated short film called Kraken (2025). He used AI tools like MidJourney, Kling, Runway and Sora, but found that “full control over every detail” was “simply out of the question”.

Malgarini described working more like a documentary editor. He assembled “vast amounts of footage from different sources” rather than directing precise shots.

Kraken, the experimental AI short film by Ascanio Malgarini.

And it’s not just filmmakers who prefer the human touch. In the art world, studies have shown that viewers strongly prefer original artworks to pixel-perfect AI copies. Participants cited sensitivity to the creative process as fundamental to appreciation.

When applied to AI-generated content, this bias creates fascinating contradictions. Recent research in Frontiers in Psychology found that when participants didn’t know the origin, they significantly preferred AI-generated artwork to human-made ones. However, once AI authorship was revealed, the same content suffered reduced perceptions of authenticity and creativity.

Hollywood’s AI reckoning

Developments in AI are happening amid a regulatory vacuum. While the US Congress held multiple AI hearings in 2023, no comprehensive federal AI legislation exists to govern Hollywood’s use. The stalled US Generative AI Copyright Disclosure Act leaves creators without legal protections, as companies deploy AI systems trained on potentially copyrighted materials.

The UK faces similar challenges, with the government launching a consultation in December 2024 on copyright and AI reform. This included a proposal for an “opt-out” system, meaning creators could actively prevent their work from being used in AI training.

The 2023 Hollywood strikes crystallised industry fears about AI displacement. Screenwriters secured protections ensuring AI cannot write or rewrite material, while actors negotiated consent requirements for digital replicas. Yet these agreements primarily cover the directors, producers and lead actors who have the most negotiating power, while VFX workers remain vulnerable.

Copyright litigation is now beginning to dominate the AI landscape – over 30 infringement lawsuits have been filed against AI companies since 2020. Disney and Universal’s landmark June 2025 lawsuit against Midjourney represents the first major studio copyright challenge, alleging the AI firm created a “bottomless pit of plagiarism” by training on copyrighted characters without permission.

Meanwhile, federal courts in the US have delivered mixed rulings. A Delaware judge found against AI company Ross Intelligence for training on copyrighted legal content, while others have partially sided with fair use defences.

The industry faces an acceleration problem – AI advancement outpaces contract negotiations and psychological adaptation. AI is reshaping industry demands, yet 96% of VFX artists report receiving no AI training, with 31% citing this as a barrier to incorporating AI in their work.

Netflix’s AI integration shows that Hollywood is grappling with fundamental questions about creativity, authenticity and human value in entertainment. Without comprehensive AI regulation and retraining programs, the industry risks a future where technological capability advances faster than legal frameworks, worker adaptation and public acceptance can accommodate.

As audiences begin recognising AI’s invisible hand in their entertainment, the industry must navigate not just economic disruption, but the cognitive biases that shape how we perceive and value creative work.

The Conversation

Edward White is affiliated with Kingston University.

ref. Netflix is now using generative AI – but it risks leaving viewers and creatives behind – https://theconversation.com/netflix-is-now-using-generative-ai-but-it-risks-leaving-viewers-and-creatives-behind-261699