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What actually was the biggest dinosaur?

– Zavier, 14, Tauranga, New Zealand.

Great question Zavier, and one that palaeontologists (scientists who study fossil animals and plants) are interested in all around the world.

And let’s face it, kids of all ages (and I include adults here) are fascinated by dinosaurs that break records for the biggest, the longest, the scariest or the fastest. It’s why, to this day, one of most famous dinosaurs is still Tyranosaurus rex, the tyrant king.

These record-breaking dinosaurs are part of the reason why the Jurassic Park movie franchise has been so successful. Just think of the scene where Dr Alan Grant (played by New Zealand actor Sam Neill) is stunned by the giant sauropod dinosaur rearing up to reach the highest leaves in the tree with its long neck.

But how do scientists work out how big and heavy a dinosaur was? And what were the biggest dinosaurs that ever lived?

Calculating dinosaur size

In an ideal world, calculating how big a dinosaur was would be easy – with a nearly complete skeleton. Standing next to the remarkable Triceratops skeleton on permanent display at Melbourne Museum makes you realise how gigantic and formidable these creatures were.

By measuring bone proportions (such as length, width or circumference) and plugging them into mathematical formulas and computer models, scientists can compare the measurements to those of living animals. They can then work out the likely size and weight of dinosaurs.

Calculating the size of dinosaurs is easy when you have near complete skeletons like this Triceratops at Melbourne Museum.
Ginkgoales via Wikimedia Commons, CC BY-NC-SA

Every palaeontologist has their own favourite formula or computer model. Some are more accurate than others, which can lead to heated arguments!

In palaeontology, however, we are not always blessed with nearly complete skeletons. In a process called “taphonomy” – basically, what happens to the bones after an animal dies – dinosaur skeletons can be broken up and bones lost.

The more fragmented the remains of a dinosaur are, the more error is introduced into size and weight estimates.

The reconstructed skeleton of a Patagotitan on display in London’s Natural History Museum.
Getty Images

Enter the titanosaurs

If we could travel back in time to South America during the Cretaceous period (about 143 million to 66 million years ago), we’d find a land ruled by a group of four-legged, long-necked and long-tailed, plant-eating sauropods. They would have towered over us, and the ground would shake with every step they took.

These were the titanosaurs. They reached their largest sizes during this period, before an asteroid crashed into what is now modern day Mexico 66 million years ago, making them extinct.

There are several contenders among the titanosaurs for the biggest dinosaur ever. Even the list below is controversial, with my palaeontology students pointing out several other possible contenders.

But based on six partial skeletons, the best estimate is for Patagotitan, which is thought to have been 31 meters long and to have weighed 50–57 tonnes.

A couple of others might have been as big or even bigger. Argentinosaurus has been calculated to be longer and heavier at 30–35 metres and 65–80 tonnes. And Puertasaurus was thought to be around 30 metres long and 50 tonnes.

But while the available bones of Argentinosaurus and Puertasaursus suggest reptiles of colossal size (the complete thigh bone of Argentinosaurus is 2.5 metres long!), there is currently not enough fossil material to be confident of those estimates.

An artist’s reconstruction of Spinosaurus, thought to have been the largest carnivorous dinosaur.
Getty Images

Spinosaurus rules North Africa

An ocean away from South America’s titanosaurs, Spinosaurus lived in what is now North Africa during the Cretaceous period.

By a very small margin, Spinosaurus is currently thought to have been the largest carnivorous (meat-eating) dinosaur, weighing in at 7.4 tonnes and 14 meters long. Other Cretaceous giants are right up there, too, including Tyranosaurus rex from North America, Gigantosaurus from South America, and Carcharodontosaurus from North Africa.

Spinosaurus is unique among predatory dinosaurs in that it was semi-aquatic and had adapted to eating fish. You can see in the picture above how similar its skull shape was to a modern crocodile.

Palaeontology is now more popular than ever – maybe because of the ongoing Jurassic Park series – with a fossil “gold rush” occurring in the Southern Hemisphere.

The latest Jurassic Park movie – in cinemas from July 2025 – is about finding the biggest prehistoric species from land, sea, and air.

Members of the public (known as “fossil forecasters”) are making new discoveries all the time.

So, who knows? The next discovery might turn out to be a new record holder as the biggest or longest dinosaur to have ever lived. There can be only one!

Hello curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au Läs mer…

Secretary of State Marco Rubio has said that the government will deport lawful permanent residents who support Hamas and came to the U.S. as students “with an intent rile up all kinds of anti-Jewish student, antisemitic activities,” referencing the Palestinian rights protests at universities in 2024.

“And if you end up having a green card – not citizenship, but a green card – as a result of that visa while you’re here and those activities, we’re going to kick you out. It’s as simple as that. This is not about free speech. This is about people that don’t have a right to be in the United States to begin with,” Rubio said on March 12, 2025.

That policy has now ensnared Mahmoud Khalil, a recent graduate of Columbia University and a leader in the Palestinian rights protest movement at the school. Khalil, a Palestinian who was born in Syria, faces deportation after he was arrested on March 8, 2025, in New York City. The Department of Homeland Security said that the secretary of state had determined Khalil’s presence or activities in the country posed “serious adverse foreign policy consequences for the United States.”

Khalil, a Palestinian who was born in Syria, entered the U.S. on a student visa in 2022. In 2024, he received a green card and became a lawful permanent resident – meaning he has the legal right to work and stay in the U.S. There are an estimated 12.8 million lawful permanent residents in the country.

Khalil’s lawyers say that his arrest and pending deportation are unconstitutional.

In many respects, the rights of lawful permanent residents and citizens are similar. Yet citizens and lawful permanent residents do not enjoy equal status under the law.

The Supreme Court and other courts recognize that lawful permanent residents have First Amendment rights to free speech.

Yet the Supreme Court upheld deporting lawful permanent residents in the 1950s based on their political activity, in particular membership in the Communist Party.

So, while lawful permanent residents may not be criminally prosecuted for their political speech or activity, what they say or write may well affect their ability to remain in the U.S., if the government determines that they are a security risk.

I’m a scholar of immigration law. Here are three major differences between the rights of citizens and lawful permanent residents.

Court officers watch protestors demonstrating for the release of Mahmoud Khalil at Foley Square in New York City on March 10, 2025.
David Dee Delgado/Getty Images

1. Limited political rights

Lawful permanent residents are people born in other countries who can legally work and live in the U.S. for as long as they like. They may enlist in the U.S. armed forces, apply to become U.S. citizens, and are legally protected against discrimination by private employers.

States also generally cannot discriminate against lawful permanent residents – though states may require certain groups of people, such as teachers or police, to have U.S. citizenship.

Between 1820 and 1920, noncitizens routinely participated in different aspects of government, including voting, holding office and jury service in many states and territories.

These days, states and the federal government generally allow only citizens to serve on juries, hold political positions and vote. With a few exceptions, such as voting in some local elections, permanent residents are not able to do any of these things.

2. Limited public benefits

The distinction between noncitizens and citizens extends to other areas of life, such as public benefits.

The Supreme Court has frequently stated, “In the exercise of its broad power over naturalization and immigration, Congress regularly makes rules that would be unacceptable if applied to citizens.”

In practice, this means that the federal government – and to a much lesser extent, states – do not offer public benefits, such as Medicaid and other kinds of government support, to lawful permanent residents and other noncitizens on the same basis as citizens.

For example, lawful permanent residents must generally wait five years before becoming eligible for certain programs intended to support low-income people, such as Supplemental Security Income and the Supplemental Nutrition Assistance Program.

3. Reversal of immigration status

Finally, unlike citizens, lawful permanent residents can lose their legal immigration status.

Congress has enacted many grounds for deporting a noncitizen, or stopping them from entering the country.

Some courts have found that the U.S. government can deport a lawful permanent resident because of national security or terrorism concerns, even if the person has not committed a crime.

The Trump administration argues that they can deport lawful permanent residents like Khalil under
the 1952 Immigration and Nationality Act, which states that a lawful permanent resident can be deported if the secretary of state has reasonable ground to believe that this person “would have potentially serious adverse foreign policy consequences for the United States.”

The Trump administration had initiated deportation proceedings against Khalil on this ground.

U.S. law also provides that any non-citizen can be deported if the secretary of state and the attorney general jointly determine that the person is associated with terrorism, or poses a threat to the U.S. In addition, the law says an immigrant can be deported if they “endorse or espouse terrorist activity or persuades others” to endorse or espouse terrorist activity or support a terrorist organization.

Still, lawful permanent residents are entitled to certain basic rights, such as retaining a lawyer to represent them in administrative hearings and court before they are deported.

By contrast, the U.S. government cannot deport a U.S. citizen for any reason. However, sometimes U.S. citizens are deported by mistake.

Indeed, the Supreme Court has found that while it is constitutional to execute a military member for desertion in wartime, it would be cruel and unusual punishment to deprive them of citizenship.

Secretary of State Marco Rubio, seen on March 12, 2025, in Shannon, Ireland, has said that the U.S. will deport any noncitizen who supports Hamas.
Saul Loeb/POOL/AFP via Getty Images

Legal grounds for deporting noncitizens

There have been few recent court cases testing the scope of deporting lawful permanent residents on national security grounds based on pure speech.

In 1999, the Supreme Court ruled that if a person is deportable, they are deportable – even if there is some other reason that motivated the government’s deportation proceedings, such as a suspicion that the non-citizen is involved with crime or terrorism.

The Supreme Court also then held that the government could deport non-citizens for technical visa violations, even if the case was based on the government’s belief that the non-citizens were associated with a terrorist group.

There is also some precedent arguing that deportation based on “adverse foreign policy consequences” is too broad and nonspecific to be constitutional.

Indeed, Marianne Trump Barry, the sister of the president, held this opinion when she was a federal judge in the mid-1990s. But Samuel Alito, then an appeals court judge, overturned Barry’s ruling on procedural grounds in 1996.

For its part, the Supreme Court has occasionally held that very broad and indeterminate deportation grounds are “void for vagueness,” meaning so sweeping and imprecise that they are unconstitutional.

Khalil’s lawyers appeared with U.S. government lawyers before a federal judge in New York on March 12. Their goal: to get Khalil moved from internment in Louisiana back to internment in New York. But that may well be just the beginning of a long haul for the Palestinian student. Courts have proved reluctant to second-guess security grounds rationales in immigration cases. For these reasons, cases like Khalil’s may go on for years. Läs mer…

The Trump administration announced on March 12, 2025, that it is “reconsidering” more than 30 air pollution regulations in a series of moves that could impact air quality across the United States.

“Reconsideration” is a term used to review or modify a government regulation. While Environmental Protection Agency Administrator Lee Zeldin provided few details, the breadth of the regulations being reconsidered affects all Americans. They include rules that set limits for pollutants that can harm human health, such as ozone, particulate matter and volatile organic carbon.

Zeldin wrote that his deregulation moves would “roll back trillions in regulatory costs and hidden ‘taxes’ on U.S. families.” But that’s only part of the story.

What Zeldin didn’t say is that the economic and health benefits from decades of federal clean air regulations have far outweighed their costs. Some estimates suggest every $1 spent meeting clean air rules has returned $10 in health and economic benefits.

How far America has come, because of regulations

In the early 1970s, thick smog blanketed American cities and acid rain stripped forests bare from the Northeast to the Midwest.

Air pollution wasn’t just a nuisance – it was a public health emergency. But in the decades since, the United States has engineered one of the most successful environmental turnarounds in history.

Thanks to stronger air quality regulations, pollution levels have plummeted, preventing hundreds of thousands of deaths annually. And despite early predictions that these regulations would cripple the economy, the opposite has proven true: The U.S. economy more than doubled in size while pollution fell, showing that clean air and economic growth can – and do – go hand in hand.

The numbers are eye-popping.

An Environmental Protection Agency analysis of the first 20 years of the Clean Air Act, from 1970 to 1990, found the economic benefits of the regulations were about 42 times greater than the costs.

The EPA later estimated that the cost of air quality regulations in the U.S. would be about US$65 billion in 2020, and the benefits, primarily in improved health and increased worker productivity, would be around $2 trillion. Other studies have found similar benefits.

That’s a return of more than 30 to 1, making clean air one of the best investments the country has ever made.

Science-based regulations even the playing field

The turning point came with the passage of the Clean Air Act of 1970, which put in place strict rules on pollutants from industry, vehicles and power plants.

These rules targeted key culprits: lead, ozone, sulfur dioxide, nitrogen oxides and particulate matter – substances that contribute to asthma, heart disease and premature deaths. An example was the removal of lead, which can harm the brain and other organs, from gasoline. That single change resulted in far lower levels of lead in people’s blood, including a 70% drop in U.S. children’s blood-lead levels.

Air Quality regulations lowered the amount of lead being used in gasoline, which also resulted in rapidly declining lead concentrations in the average American between 1976-1980. This shows us how effective regulations can be at reducing public health risks to people.
USEPA/Environmental Criteria and Assessment Office (1986)

The results have been extraordinary. Since 1980, emissions of six major air pollutants have dropped by 78%, even as the U.S. economy has more than doubled in size. Cities that were once notorious for their thick, choking smog – such as Los Angeles, Houston and Pittsburgh – now see far cleaner air, while lakes and forests devastated by acid rain in the Northeast have rebounded.

Comparison of growth areas and declining emissions, 1970-2023.
EPA

And most importantly, lives have been saved. The Clean Air Act requires the EPA to periodically estimate the costs and benefits of air quality regulations. In the most recent estimate, released in 2011, the EPA projected that air quality improvements would prevent over 230,000 premature deaths in 2020. That means fewer heart attacks, fewer emergency room visits for asthma, and more years of healthy life for millions of Americans.

The economic payoff

Critics of air quality regulations have long argued that the regulations are too expensive for businesses and consumers. But the data tells a very different story.

EPA studies have confirmed that clean air regulations improve air quality over time. Other studies have shown that the health benefits greatly outweigh the costs. That pays off for the economy. Fewer illnesses mean lower health care costs, and healthier workers mean higher productivity and fewer missed workdays.

The EPA estimated that for every $1 spent on meeting air quality regulations, the United States received $9 in benefits. A separate study by the non-partisan National Bureau of Economic Research in 2024 estimated that each $1 spent on air pollution regulation brought the U.S. economy at least $10 in benefits. And when considering the long-term impact on human health and climate stability, the return is even greater.

Hollywood and downtown Los Angeles in 1984: Smog was a common problem in the 1970s and 1980s.
Ian Dryden/Los Angeles Times/UCLA Archive/Wikimedia Commons, CC BY

The next chapter in clean air

The air Americans breathe today is cleaner, much healthier and safer than it was just a few decades ago.

Yet, despite this remarkable progress, air pollution remains a challenge in some parts of the country. Some urban neighborhoods remain stubbornly polluted because of vehicle emissions and industrial pollution. While urban pollution has declined, wildfire smoke has become a larger influence on poor air quality across the nation.

That means the EPA still has work to do.

If the agency works with environmental scientists, public health experts and industry, and fosters honest scientific consensus, it can continue to protect public health while supporting economic growth. At the same time, it can ensure that future generations enjoy the same clean air and prosperity that regulations have made possible.

By instead considering retracting clean air rules, the EPA is calling into question the expertise of countless scientists who have provided their objective advice over decades to set standards designed to protect human lives. In many cases, industries won’t want to go back to past polluting ways, but lifting clean air rules means future investment might not be as protective. And it increases future regulatory uncertainty for industries.

The past offers a clear lesson: Investing in clean air is not just good for public health – it’s good for the economy. With a track record of saving lives and delivering trillion-dollar benefits, air quality regulations remain one of the greatest policy success stories in American history. Läs mer…

The Trump administration announced on March 12, 2025, that it is “reconsidering” more than 30 air pollution regulations in a series of moves that could impact air quality across the United States.

“Reconsideration” is a term used to review or modify a government regulation. While Environmental Protection Agency Administrator Lee Zeldin provided few details, the breadth of the regulations being reconsidered affects all Americans. They include rules that set limits for pollutants that can harm human health, such as ozone, particulate matter and volatile organic carbon.

Zeldin wrote that his deregulation moves would “roll back trillions in regulatory costs and hidden ‘taxes’ on U.S. families.” But that’s only part of the story.

What Zeldin didn’t say is that the economic and health benefits from decades of federal clean air regulations have far outweighed their costs. Some estimates suggest every $1 spent meeting clean air rules has returned $10 in health and economic benefits.

How far America has come, because of regulations

In the early 1970s, thick smog blanketed American cities and acid rain stripped forests bare from the Northeast to the Midwest.

Air pollution wasn’t just a nuisance – it was a public health emergency. But in the decades since, the United States has engineered one of the most successful environmental turnarounds in history.

Thanks to stronger air quality regulations, pollution levels have plummeted, preventing hundreds of thousands of deaths annually. And despite early predictions that these regulations would cripple the economy, the opposite has proven true: The U.S. economy more than doubled in size while pollution fell, showing that clean air and economic growth can – and do – go hand in hand.

The numbers are eye-popping.

An Environmental Protection Agency analysis of the first 20 years of the Clean Air Act, from 1970 to 1990, found the economic benefits of the regulations were about 42 times greater than the costs.

The EPA later estimated that the cost of air quality regulations in the U.S. would be about US$65 billion in 2020, and the benefits, primarily in improved health and increased worker productivity, would be around $2 trillion. Other studies have found similar benefits.

That’s a return of more than 30 to 1, making clean air one of the best investments the country has ever made.

Science-based regulations even the playing field

The turning point came with the passage of the Clean Air Act of 1970, which put in place strict rules on pollutants from industry, vehicles and power plants.

These rules targeted key culprits: lead, ozone, sulfur dioxide, nitrogen oxides and particulate matter – substances that contribute to asthma, heart disease and premature deaths. An example was the removal of lead, which can harm the brain and other organs, from gasoline. That single change resulted in far lower levels of lead in people’s blood, including a 70% drop in U.S. children’s blood-lead levels.

Air Quality regulations lowered the amount of lead being used in gasoline, which also resulted in rapidly declining lead concentrations in the average American between 1976-1980. This shows us how effective regulations can be at reducing public health risks to people.
USEPA/Environmental Criteria and Assessment Office (1986)

The results have been extraordinary. Since 1980, emissions of six major air pollutants have dropped by 78%, even as the U.S. economy has more than doubled in size. Cities that were once notorious for their thick, choking smog – such as Los Angeles, Houston and Pittsburgh – now see far cleaner air, while lakes and forests devastated by acid rain in the Northeast have rebounded.

Comparison of growth areas and declining emissions, 1970-2023.
EPA

And most importantly, lives have been saved. The Clean Air Act requires the EPA to periodically estimate the costs and benefits of air quality regulations. In the most recent estimate, released in 2011, the EPA projected that air quality improvements would prevent over 230,000 premature deaths in 2020. That means fewer heart attacks, fewer emergency room visits for asthma, and more years of healthy life for millions of Americans.

The economic payoff

Critics of air quality regulations have long argued that the regulations are too expensive for businesses and consumers. But the data tells a very different story.

EPA studies have confirmed that clean air regulations improve air quality over time. Other studies have shown that the health benefits greatly outweigh the costs. That pays off for the economy. Fewer illnesses mean lower health care costs, and healthier workers mean higher productivity and fewer missed workdays.

The EPA estimated that for every $1 spent on meeting air quality regulations, the United States received $9 in benefits. A separate study by the non-partisan National Bureau of Economic Research in 2024 estimated that each $1 spent on air pollution regulation brought the U.S. economy at least $10 in benefits. And when considering the long-term impact on human health and climate stability, the return is even greater.

Hollywood and downtown Los Angeles in 1984: Smog was a common problem in the 1970s and 1980s.
Ian Dryden/Los Angeles Times/UCLA Archive/Wikimedia Commons, CC BY

The next chapter in clean air

The air Americans breathe today is cleaner, much healthier and safer than it was just a few decades ago.

Yet, despite this remarkable progress, air pollution remains a challenge in some parts of the country. Some urban neighborhoods remain stubbornly polluted because of vehicle emissions and industrial pollution. While urban pollution has declined, wildfire smoke has become a larger influence on poor air quality across the nation.

That means the EPA still has work to do.

If the agency works with environmental scientists, public health experts and industry, and fosters honest scientific consensus, it can continue to protect public health while supporting economic growth. At the same time, it can ensure that future generations enjoy the same clean air and prosperity that regulations have made possible.

By instead considering retracting clean air rules, the EPA is calling into question the expertise of countless scientists who have provided their objective advice over decades to set standards designed to protect human lives. In many cases, industries won’t want to go back to past polluting ways, but lifting clean air rules means future investment might not be as protective. And it increases future regulatory uncertainty for industries.

The past offers a clear lesson: Investing in clean air is not just good for public health – it’s good for the economy. With a track record of saving lives and delivering trillion-dollar benefits, air quality regulations remain one of the greatest policy success stories in American history. Läs mer…

The Trump administration announced on March 12, 2025, that it is “reconsidering” more than 30 air pollution regulations in a series of moves that could impact air quality across the United States.

“Reconsideration” is a term used to review or modify a government regulation. While Environmental Protection Agency Administrator Lee Zeldin provided few details, the breadth of the regulations being reconsidered affects all Americans. They include rules that set limits for pollutants that can harm human health such as ozone, particulate matter and volatile organic carbon.

Zeldin wrote that his deregulation moves would “roll back trillions in regulatory costs and hidden ‘taxes’ on U.S. families.” But that’s only part of the story.

What Zeldin didn’t say is that the economic and health benefits from decades of federal clean air regulations have far outweighed their costs. Some estimates suggest every $1 spent meeting clean air rules has returned $10 in health and economic benefits.

How far America has come, because of regulations

In the early 1970s, thick smog blanketed American cities and acid rain stripped forests bare from the Northeast to the Midwest.

Air pollution wasn’t just a nuisance – it was a public health emergency. But in the decades since, the United States has engineered one of the most successful environmental turnarounds in history.

Thanks to stronger air quality regulations, pollution levels have plummeted, preventing hundreds of thousands of deaths annually. And despite early predictions that these regulations would cripple the economy, the opposite has proven true: The U.S. economy more than doubled in size while pollution fell, showing that clean air and economic growth can – and do – go hand in hand.

The numbers are eye-popping.

An Environmental Protection Agency analysis of the first 20 years of the Clean Air Act, from 1970 to 1990, found the economic benefits of the regulations were about 42 times greater than the costs.

The EPA later estimated that the cost of air quality regulations in the U.S. would be about US$65 billion in 2020, and the benefits, primarily in improved health and increased worker productivity, would be around $2 trillion. Other studies have found similar benefits.

That’s a return of more than 30 to 1, making clean air one of the best investments the country has ever made.

Science-based regulations even the playing field

The turning point came with the passage of the Clean Air Act of 1970, which put in place strict rules on pollutants from industry, vehicles and power plants.

These rules targeted key culprits: lead, ozone, sulfur dioxide, nitrogen oxides and particulate matter – substances that contribute to asthma, heart disease and premature deaths. An example was the removal of lead, which can harm the brain and other organs, from gasoline. That single change resulted in far lower levels of lead in people’s blood, including a 70% drop in U.S. children’s blood-lead levels.

Air Quality regulations lowered the amount of lead being used in gasoline, which also resulted in rapidly declining lead concentrations in the average American between 1976-1980. This shows us how effective regulations can be at reducing public health risks to people.
USEPA/Environmental Criteria and Assessment Office (1986)

The results have been extraordinary. Since 1980, emissions of six major air pollutants have dropped by 78%, even as the U.S. economy has more than doubled in size. Cities that were once notorious for their thick, choking smog – such as Los Angeles, Houston and Pittsburgh – now see far cleaner air, while lakes and forests devastated by acid rain in the Northeast have rebounded.

Comparison of growth areas and declining emissions, 1970-2023.
EPA

And most importantly, lives have been saved. The Clean Air Act requires the EPA to periodically estimate the costs and benefits of air quality regulations. In the most recent estimate, released in 2011, the EPA projected that air quality improvements would prevent over 230,000 premature deaths in 2020. That means fewer heart attacks, fewer emergency room visits for asthma, and more years of healthy life for millions of Americans.

The economic payoff

Critics of air quality regulations have long argued that the regulations are too expensive for businesses and consumers. But the data tells a very different story.

EPA studies have confirmed that clean air regulations improve air quality over time. Other studies have shown that the health benefits greatly outweigh the costs. That pays off for the economy. Fewer illnesses mean lower health care costs, and healthier workers mean higher productivity and fewer missed workdays.

The EPA estimated that for every $1 spent on meeting air quality regulations, the United States received $9 in benefits. A separate study by the non-partisan National Bureau of Economic Research in 2024 estimated that each $1 spent on air pollution regulation brought the U.S. economy at least $10 in benefits. And when considering the long-term impact on human health and climate stability, the return is even greater.

Hollywood and downtown Los Angeles in 1984: Smog was a common problem in the 1970s and 1980s.
Ian Dryden/Los Angeles Times/UCLA Archive/Wikimedia Commons, CC BY

The next chapter in clean air

The air Americans breathe today is cleaner, much healthier and safer than it was just a few decades ago.

Yet, despite this remarkable progress, air pollution remains a challenge in some parts of the country. Some urban neighborhoods remain stubbornly polluted because of vehicle emissions and industrial pollution. While urban pollution has declined, wildfire smoke has become a larger influence on poor air quality across the nation.

That means the EPA still has work to do.

If the agency works with environmental scientists, public health experts and industry, and fosters honest scientific consensus, it can continue to protect public health while supporting economic growth. At the same time, it can ensure that future generations enjoy the same clean air and prosperity that regulations have made possible.

By instead considering retracting clean air rules, the EPA is calling into question the expertise of countless scientists who have provided their objective advice over decades to set standards designed to protect human lives. In many cases, industries won’t want to go back to past polluting ways, but lifting clean air protections means future investment might not be as protective. And it increases future regulatory uncertainty for industries.

The past offers a clear lesson: Investing in clean air is not just good for public health – it’s good for the economy. With a track record of saving lives and delivering trillion-dollar benefits, air quality regulations remain one of the greatest policy success stories in American history. Läs mer…

Some Canadian musicians and content creators are reflecting a sudden surge in patriotism as they listen anxiously to the crescendo and decrescendo of United States President Donald Trump’s rhetoric against their country.

The pro-Canada songs currently spreading across social media, including some by Canadian celebrities, reveal a range of reactions to Trump’s tariffs and annexation threats, while also contributing to the national mood.

These songs are striking, because Canadians have in recent decades been relatively uninterested in loud assertions of nationalist sentiment, outside of sporting events.

Sidney Crosby’s jersey from the 2010 Winter Olympics is on display at a hockey exhibit at the Museum of History in Gatineau, Québec, in March 2017.
THE CANADIAN PRESS/Patrick Doyle

Shared identity

When shared identity has been emphasized, it has often been to promote provincial separatism or the rights of Indigenous Peoples. Uncritical Canadian nationalism has, to some, felt inappropriate since the 2015 findings and recommendations of the Truth and Reconciliation Commission.

Read more:
Home game: Rethinking Canada through Indigenous hockey

Patriotic feelings were further complicated during the pandemic, when the flag was co-opted by people opposing public health restrictions.

In these contexts, many commentators have for some time struggled to locate a shared Canadian attitude toward the nation.

Terms such as “multicultural nationalism,” “plural nationalism” or even “a postnational country” are perhaps the best descriptors of nationalist sentiment when it’s expressed in Canada.

In music, Canadian nationalism is only rarely articulated, beyond performances of the anthem. The pop songs that tell particularly Canadian stories tend to be more sentimental than nationalistic — songs like Gordon Lightfoot’s “Canadian Railroad Trilogy” or Anne Murray’s “Snowbird.”

Yet something has shifted amid Trump’s verbal and economic attacks on Canada began, as the reactions of sports fans to performances of the U.S. anthem have also demonstrated.

Songs on the trade war

As a scholar of music and nationalism, I’m interested in what the several dozen songs about the trade war that I have located might suggest about that shift.

The patriotic songs by apparently Canadian creators that I discuss here are all drawn from Facebook and Instagram feeds and searching YouTube using English-language terms such as “Canada tariffs song,” “51st state song,” and “Canadian patriotic song.” A deeper dive into Québec-specific, francophone and multilingual responses would be additional significant ways of looking at this.

They represent an array of musical styles, including rock, metal, reggae, country, folk and pop.

Most of the songs I found have original music: those setting new lyrics to existing copyrighted tunes are not included here. I also excluded the few songs with potentially slanderous material. A number make use of AI. Indigenous and self-identified immigrant perspectives so far seem under-represented.

Read more:
Music helps us remember who we are and how we belong during difficult and traumatic times

Patriotism, Canadian-style

An explicit patriotism is the most striking — and new — feature of this repertoire. What is clear in this sampling, however, is that Canadians still remain allergic to jingoistic nationalism — blindly professing or adhering to belief in the virtue of one’s nation.

TV host and comedian Tom Green’s “I’m a Canadian”, for example, is a humorous, self-deprecating song that celebrates Canada’s uniqueness without being exclusionary or making claims of exceptionalism.

Tom Green’s ‘I’m a Canadian.’

This gentle Canadianism is also reflected in stereotypically polite refusals of Trump’s offer to join the United States: “Thanks, but we’re already great! We don’t need to borrow your stars or your fate!”

These songs celebrate politically benign features of Canada — its natural world, its cold winters, its food and its love of sports.

Canadian values, meanwhile, are presented as compassionate, noble and good: “We stand for truth and kindness, and we help those in need.”

Where Canadians are the primary audience, resilience is often foregrounded.
The soothing singer-songwriter style of “Canada’s Home,” for example, gently encourages strength and fortitude. Again, strong moral values are emphasized: “Canada’s integrity is what bullies can’t stand.”

Songs for the U.S.

Many songs seem aimed at an American audience, in addition to a Canadian one.

In “We Used to Be the Best of Friends” by Jim Cuddy, a Canadian Music Hall of Famer and Blue Rodeo frontman, the listener is politely reminded of the long friendship between the U.S. and Canada. Cuddy uses a charming folk style to remind Americans of cultural and political experiences shared with Canada, and of challenging times when Canadians had their back.

Jim Cuddy’s ‘We Used to Be the Best of Friends.’

Cuddy’s wistfulness for a threatened friendship contrasts with songs that take a more assertive stance, especially in response to Trump’s 51st state threats. With titles like “Canada is Not For Sale,” such songs emphasize the flag and the rights of Canadians.

A few songs go further still, abandoning traditional courtesies for sarcasm and even rudeness.

Assertions of Canadian strength recur repeatedly. The “elbows up” movement, inspired by the moment Canadian comedian Mike Myers mouthed this hockey phrase associated with Gordie Howe on Saturday Night Live, has produced several songs about Canada’s readiness to resist American actions.

Although songs of this type are more defiant, they nevertheless hold true to traditional Canadian values. “Elbows Up Canada!” celebrates unity and “holding the line” together. Using AI-created video imagery, this song juxtaposes images of early settlers with a brief image of Indigenous people in traditional dress or regalia standing with a Canadian flag, reflecting the lyrics, “side by side”.

‘Elbow’s Up Canada!’ video.

I’ll note that this song’s brief depiction of Indigenous presence is unusual among songs I found. In meditations about national unity, most of these creators make no allusions to Indigenous Peoples, or Canada’s ethnolinguistic or racial diversity.

In so doing, these songs minimize identities that are important to many Canadians in order to bolster national identity. They implicitly encourage all citizens to put aside what separates them to address an external threat.

Read more:
Canada Day: Why renaming roads and how we tell stories matter for reconciliation

In a cross-border context, these songs do not articulate hatred of Americans as a people. The frustration they express is consistently directed at Trump, not the U.S. as a whole.

But with a looming election in Canada and the actions and rhetoric of both countries shifting every day, it’s possible this may change. Will the music and the cultural conversation become more hostile? Will Canadians themselves grow concerned if their country’s patriotic turn becomes belligerent?

As Cornell University political scientist Benedict Anderson argued in 1983, a nation is ultimately an “imagined community,” because we can never know everyone within it. The feeling of national belonging happens solely in our minds and is reinforced by the stories we tell ourselves.

Music has a unique capacity to participate in this reinforcement, building shared identity across vast and varied spaces. It can also allow us to differentiate ourselves from others. Both capacities are being fully exploited in this challenging moment. Läs mer…

After a long, stressful day at work, or when pressed for time, the temptation to have a quick, satisfying snack – like crisps or a chocolate bar – can be strong. Research shows that these ultra-processed, high-calorie foods play a significant role in the development of obesity, but the lasting effects these foods have on the brain was not clear – until now.

Surprisingly, even short-term consumption of highly processed, unhealthy foods can significantly reduce insulin sensitivity in the brains of healthy people. This effect persists even after returning to a normal diet, as shown in a recent study my colleagues and I conducted, highlighting the brain’s important role in the development of obesity.

Unhealthy fat distribution and ongoing weight gain are linked to the brain’s response to insulin. In a healthy person, insulin helps control appetite in the brain. However, in people with obesity, insulin loses its ability to regulate eating habits, leading to insulin resistance.

Insulin plays many roles in the body, including helping sugar, or glucose, reach muscle cells to be used for energy after a meal. In the brain, insulin also signals the body to eat less by reducing food intake.

Not every brain responds the same

But not every brain responds equally to insulin. Many people have a weak or absent insulin response in the brain, known as “brain insulin resistance”. People with brain insulin resistance experience more food cravings and have more belly fat.

Fat can promote obesity and so contribute significantly to insulin resistance. The more fat cells there are, especially in the belly, the less effective insulin is. Fat releases messenger substances that promote insulin resistance.

However, the signs of reduced insulin sensitivity in the brain can already be seen way before we speak of obesity, which is defined as a body mass index (BMI) above 30. This is calculated as weight (in kilograms) divided by the square of height (in metres), but has its limitations. So it is recommended that excess obesity needs to be confirmed by measuring body fat.

After just five days of consuming an extra 1,500 calories consisting of chocolate bars and crisps, the insulin sensitivity in the brains of the study participants drastically dropped. Symptoms that, until now, have mostly been seen in obese people.

Even one week after resuming a normal diet, MRI scans showed a persistently low insulin sensitivity in the brain. Although no significant weight gain was seen, the short period was long enough to let liver fat rise significantly.

MRI brain scans showed persistent reduced insulin sensitivity.
VesnaArt/Shutterstock

It seems that obesity is not only a matter of poor diet and insufficient exercise. It also has a lot to do with the adaption of the brain’s insulin response to short-term changes in diet before any weight gain occurs.

But is insulin resistance in the brain a permanent issue? In the past, exercising regularly for a specific amount of time has been shown to restore brain insulin sensitivity in overweight and obese people. The assumption can be made that this also could apply to people of normal weight.

The number of obese people worldwide has more than doubled in the past two decades. And there is little evidence that this trend will shortly come to an end. Still, the role of the brain has to be taken into account since the mechanisms in the body that lead to obesity are more complex than just a poor diet and lack of exercise. Läs mer…

Mandy Beaumont’s debut novel, The Furies, was unrelentingly intense in its depictions of self-hatred, violence, rape and induced abortion. Her latest novel, The Thrill of It, is a more controlled and conventional excursion into male violence against women. It is just as serious in its exposure of misogyny. But it has a stronger narrative, with episodes of relief from its scenes of debasement.

Review: The Thrill of It – Mandy Beaumont (Hachette)

The Thrill of It reimagines the events surrounding John Wayne Glover, better known as the Granny Killer, who was convicted of murdering six elderly women on Sydney’s North Shore between 1989 and 1990. It occupies a sometimes uncertain territory, somewhere between case study and crime thriller.

The novel’s starting point is the murder in 1977 of a celebrity designer and businesswoman named Marlowe Kerr – a murder that mirrors the brutal, still-unsolved killing of real-life designer Florence Broadhurst, famous for her iconic wallpaper designs.

Chapters alternate between third-person accounts of the horrific crimes and domestic life of the killer – a modestly successful salesman with a model North Shore family – and first-person chapters in the voice of Kerr’s granddaughter Emmerson Kerr, known as “Em”.

Em found her grandmother’s murdered body back in 1977. She is the first person in Sydney to see the connection between a spate of sexualised murders of aged women and Kerr’s death 12 years earlier.

Mandy Beaumont.
Hachette Australia

Read more:
Trauma and loss define Mandy Beaumont’s unapologetically feminist debut novel

So ordinary, he is barely visible

Em is a smart, inquisitive, critical, attractive and observant character, who could well feature in future novels. She plans to join the police force, but becoming involved in this case could cruel her chances. She might be interfering too amateurishly, and her reckless mother managed to persuade someone (possibly a boyfriend) to steal evidence from the crime scene back in 1977.

This thread of the narrative, the most fictionalised aspect of the plot, allows for an outsider’s fresh view into how the police do and don’t “get it” when it comes to the murder of women. The police have come to early conclusions and are looking for a young man, so they are missing clues and ignoring leads that could save lives and hasten the discovery of the killer, though their incompetence does not entirely undo what they bring to the investigation.

The chapters that describe the murderer’s home life and his increasingly manic killings follow real events from 1989 more closely. He has a job as a travelling salesman for Big Boys Pies and Sweets, which gives him access to aged-care homes. There, he can select victims, harass the residents and cause havoc without being noticed. He is one of those men who appear so ordinary they are almost invisible.

The novel makes a point of showing the older women who become his victims are not merely “grannies”. They are full of personality. They have impressive achievements and live rich and vital lives. Their deaths will long be grieved by those who loved them. This point is made again and again.

Yet it is the killer who occupies centre stage for a good part of the novel and his atrocities are shockingly detailed. Beaumont is determined, across both her novels, to avoid euphemisms when she depicts male violence against women. This is becoming one of her trademarks.

Florence Broadhurst’s life and death inspires one thread of Mandy Beaumont’s new novel.

Blaming the mother

The Thrill of It takes us inside the killer’s mind, tracing the psychological motive for the murders back to bizarre sexual teasing by his mother (at least, as he perceived it), in between visits from her lovers and clients.

It is a common trope in crime fiction that the mother carries much of the responsibility (if not the blame) for the son’s twisted sexual appetites – and his resulting need for revenge upon women. At times, The Thrill of It takes on the characteristics of a psychological case study. But its adherence to the thriller genre also seems to determine some of its attributed motivations – especially in the case of the monstrous mother. Here, the novel as serious inquiry and the novel as entertainment become an uneasy match.

From Crime and Punishment to In Cold Blood, writers have often been drawn to the gratuitous act of murder for its drama, its contradictions, and its arresting effect on the many of us who can barely imagine the mind behind such violence.

Many writers would wilt under the challenge of entering the mind of a man who kills for the thrill and power of it – particularly a man who focuses this insane pleasure on the act of killing older women.

Beaumont keeps to her task and makes something real of her portrait, though at times her own sense of horror draws her back from fiction into summary statements, even when they are delivered via the killer’s psyche:

Yes, of course he wishes he could stop what he’s been doing, but he can’t, he hasn’t been able to since he was young – the thrill of it all has become an unstoppable surge.

In the end, however, the novel – dedicated to the victims of the real-life killer – is not about attempting to understand this all too ordinary and banally evil man who likes to eat fish and chips in his car. Rather, The Thrill of It is about the real lives lost, the long work of grief, and the dangers that are always present for women in a society where male violence is too common. Läs mer…

It feels like everything is slowly but surely being affected by the rise of artificial intelligence (AI). And like every other disruptive technology before it, AI is having both positive and negative outcomes for society.

One of these negative outcomes is the very specific, yet very real cultural harm posed to Australia’s Indigenous populations.

The National Indigenous Times reports Adobe has come under fire for hosting AI-generated stock images that claim to depict “Indigenous Australians”, but don’t resemble Aboriginal and Torres Strait Islander peoples.

Some of the figures in these generated images also have random body markings that are culturally meaningless. Critics who spoke to the outlet, including Indigenous artists and human rights advocates, point out these inaccuracies disregard the significance of traditional body markings to various First Nations cultures.

Adobe’s stock platform was also found to host AI-generated “Aboriginal artwork”, raising concerns over whether genuine Indigenous artworks were used to train the software without artists’ consent.

The findings paint an alarming picture of how representations of Indigenous cultures can suffer as a result of AI.

How AI image generators work

While training AI image generators is a complex affair, in a nutshell it involves feeding a neural network millions of images with associated text descriptions.

This is much like how you would have been taught to recognise various objects as a small child: you see a car and you’re told it’s a “car”. Then you see a different car, and are told it is also a “car”. Over time you begin to discern patterns that help you differentiate between cars and other objects.

You gain an idea of what a car “is”. Then, when asked to draw a picture of a car, you can synthesise all your knowledge to do so.

Many AI image generators produce images through what is called “reverse diffusion”. In essence, they take the images they’ve been trained on and add “noise” to them until they are just a mix of pixels of random colour and brightness. They then continually decrease the amount of noise, until the correct image is displayed.

Diffusion models work by decreasing ‘noise’ until an image is displayed.
Author provided (no reuse)

The process of creating an AI image begins with a text prompt by the user. The image generator then compares how the words in the prompt associate with its learning, and produces an image that satisfies the prompt. This image will be original, in that it won’t exist anywhere else.

If you’ve gone through this process, you’ll appreciate how difficult it can be to control the image that is produced.

Say you want your subject to be wearing a very specific style of jacket; you can prompt it as precisely as you like – but you may never get it perfect. The result will come down to how the model was trained and the dataset it was trained on.

We’ve seen early versions of the AI image generator Midjourney respond to prompts for “Indigenous Australians” with what appeared to be images of African tribespeople: essentially an amalgam of the “noble savage”.

Cultural flattening through AI

Now, consider that in the future, millions of people will be generating AI images from various generators. These may be used for teaching, promotional materials, advertisements, travel brochures, news articles and so on. Often, there will be little consequence if the images generated are “generic” in appearance.

But what if it was important for the image to accurately reflect what the creator was trying to represent?

In Australia, there are more than 250 Indigenous languages, each one specific to a particular place and people. For each of these groups, language is central to their identity, sense of belonging and empowerment.

It is a core element of their culture – just as much as their connection to a specific area of land, their kinship systems, spiritual beliefs, traditional stories, art, music, dance, laws, food practices and more.

But when an AI model is trained on images of Australian Indigenous peoples’ art, clothing, or artefacts, it isn’t also necessarily fed detailed information of which language group each image is associated with.

The result is “cultural flattening” through technology, wherein culture is made to appear more uniform and less diverse. In one example, we observed an AI image generator produce an image of what was mean to be an elderly First Nations man in a traditional Papuan headdress.

This is an example of technological colonialism, wherein tech corporations contribute to the homogenisation and/or misrepresentation of diverse Indigenous cultures.

We’ve also seen pictures of “Indigenous art” on stock footage websites that are clearly labelled as being produced by AI. How can these be sold as images of First Nations art if no First Nations person was involved in making them? Any connection to deep cultural knowledge and lived experience is completely absent.

Artist Angelina Boona from Erub Island poses next to her artworks during the 2024 Darwin Aboriginal Art Fair.
Liz Hobday/AP

Besides the obvious economic consequences for artists, long-term technological misrepresentation could also have adverse impacts on the self-perception of Indigenous individuals.

Read more:
Labelling ’fake art’ isn’t enough. Australia needs to recognise and protect First Nations cultural and intellectual property

What can be done?

While there’s currently no simple solution, progress begins with discussion and engagement between AI companies, researchers, governments and Indigenous communities.

These collaborations should result in strategies for reclaiming visual narrative sovereignty. They may, for instance, implement ethical guidelines for AI image generation, or reconfigure AI training datasets to add nuance and specificity to Indigenous imagery.

At the same time, we’ll need to educate AI users about the risk of cultural flattening, and how to avoid it when representing Indigenous people, places, or art. This would require a coordinated approach involving educational institutions from kindergarten upwards, as well as the platforms that support AI image creation.

The future goal is, of course, the respectful representation of Indigenous cultures that are already fighting for survival in many other ways. Läs mer…

We all know microplastics are bad for the environment and our health, but do we really know how bad?

Our new study, published this week in the journal Science Advances, compared changes in 745 proteins found in seabirds with and without plastics in their stomachs.

We focused on young sable shearwaters (seabirds, Ardenna carneipes). They were less than 90 days old and appeared healthy. Despite their young age, the birds with plastic in their stomachs had signs or symptoms of neurodegenerative disease, as well as kidney and liver disease.

We also found evidence of significant damage to the lining of the stomach, likely from microplastics that became embedded in the tissue. It meant proteins that should only be found in the stomach were detected circulating in the blood.

While our findings don’t directly relate to human health, this work paints a distinct picture of the insidious and slow impacts plastic can have on a bird’s health – even if it doesn’t kill them.

The sable shearwater lives around the Pacific Ocean.
jimchurches/iNaturalist, CC BY-NC-SA

Harmful but not deadly?

Some studies have found health impacts of plastics (such as increased exposure to heavy metals), while others have not. Why is that?

An initial study looking at plastic exposure might start out by just looking at what’s known as a single response. This could be the condition of the animal’s body, for example.

While important, such studies don’t account for the diversity of conditions an animal could realistically experience. If you’ve recently been unwell, you might respond to a health test differently than if you were fully healthy. Birds will, too.

Recently, a handful of more in-depth studies have documented a range of plastic impacts on birds; these were harmful, but not severe enough to cause death. For example, birds that consumed plastic had higher cholesterol, were smaller and had shorter wings, and had plasticosis, an inflammatory condition that leads to scar tissue formation.

But consider a loved one with an invisible, chronic health condition. To a stranger they might appear healthy, but their quality of life is actually impacted by their condition. The same is true for birds and other wildlife.

Thankfully, we have more fine-grained tools at our disposal.

The diversity of shapes, types, and colours of plastic items ingested by a single sable shearwater chick in 2022.
Jennifer Lavers

Studying proteins

Proteomics is the study of protein composition and regulation, and the role these play in the body. While commonly used in the medical field and other disciplines, omic technologies (including proteomics) are rarely used in wildlife studies.

Certain key proteins are well-known markers of disease. For example, we found low levels of a protein called albumin in the blood of birds with plastic. Having less albumin is a sign of poor liver function.

Birds with plastic also had less of a protein called brain-derived neurotrophic factor. This protein plays a crucial role in the growth and survival of neurons (nerve cells), including those involved in the development of the birds’ ability to recognise each others’ song.

Our results suggest while not all birds die from plastics exposure, they may have health issues and suffer from reduced cognitive functions, including those needed for courtship (such as song). This may make it more difficult for them to successfully find mates and produce chicks.

Many of the health impacts from plastic exposure have been documented beyond the point of exposure – that is, the stomach. While our findings revealed notable damage to the stomach lining, changes have now been reported in liver, kidneys, spleen and brain of these chicks.

This suggests ingested plastic can have wide-ranging, potentially whole body consequences, and we’ve barely scratched the surface.

We must listen closely

It’s important to remember that all the worrying health impacts we found via protein analysis were documented in very young birds that were seemingly healthy.

So what does this mean for other wild species that haven’t yet benefited from proteomics analysis or other in-depth studies? Could these findings change our understanding of how microplastic exposure affects human health? This is a task for future research, but it’s not an easy one.

The reality is, we may never have comparable data for most of the world’s wild species. For our lab alone, it’s taken a decade of laying the groundwork to understand the complexity of this problem in a single bird species, one that’s relatively accessible and easy to work with.

For humans, we may never be able to put a number on the impact of plastics because of the huge array of personal, environmental and social determinants of health.

So, there’s a lot we can learn from these birds. As a society, it’s in our best interest to listen to the story they’re trying to tell us.

Acknowledgements: The authors would like to acknowledge research collaborator Alexander Bond from the Natural History Museum, UK. Läs mer…