Category: MIL-OSI

Source: The Conversation – USA – By Sarah Burns, Associate Professor of Political Science, Rochester Institute of Technology; Institute for Humane Studies

Lawmakers in the U.S. House of Representatives set April 21, 2026, as the date to hear from and question top Pentagon officials Adm. Brad Cooper, the head of U.S. Central Command, and Gen. Dagvin R.M. Anderson, head of U.S. Africa Command, about the war in Iran. But Republican legislators put off the hearing for a month, giving up – for now – the opportunity to exercise oversight of the war.

Adam Smith, the top Democratic member of the House Armed Services Committee, told The New York Times, “We are six weeks into this conflict. And we still haven’t gotten a public briefing from anyone in the administration about the war.”

President Donald Trump’s military campaign against the Iranian regime is currently in a ceasefire. Despite the low approval rating of the war, the president has not drawn the conflict to a close, and the result of the operation is so far unclear.

The postponed hearing was only one example of how Congress has been noticeably meek about the war, with most Republicans killing the many Democratic efforts to exercise constitutionally granted power over engaging in such military conflicts. For the fourth time, the Senate on April 16, 2026, rejected a war powers resolution.

As scholars who research war powers and have a book coming out about President Barack Obama’s decision-making about the Afghan war, we know that the reluctance of Congress to assert its power is, in fact, history repeating itself, as is the president’s unilateral action.

Historically meek Congress

Article 1 of the U.S. Constitution gives Congress the power to declare war, not the president. But most modern presidents and their legal counsel have asserted that Article 2 of the Constitution allows the president to use the military in certain situations without prior congressional approval – and have acted on that, sending troops into conflicts from Panama to Libya with no regard for Congress’ will.

Based on the 1973 War Powers Resolution – passed over President Richard Nixon’s veto – the president has an obligation to inform Congress about his actions within 48 hours of initiating military action and requires him to seek legislative authorization if the military operation will last over 60 days.

Since its passage, presidents have dutifully informed Congress within the 48-hour window when they unilaterally initiate military operations. Typically, they use the following language: “Pursuant to” their power as commander in chief and chief executive, they are initiating an operation.

Yet presidents since Nixon have never formally acknowledged the constitutionality of the War Powers Resolution. They have, however, mentioned it in their letters to Congress about their actions, and for the most part they have abided by its restrictions. So language is crucial and presidents tend to use the phrase “consistent with” the War Powers Resolution when they inform Congress about military operations.

The second Trump administration has broken with that standard. In Trump’s message to Congress about the Iran war, sent on March 2 2026, he did not acknowledge the War Powers Resolution or the Constitution, let alone pay lip service to either.

Instead, Trump has sidestepped the traditional use of the War Powers Resolution – and avoided the congressional oversight that comes with it – by relying on executive orders to convey his intent to use military power against the Iranian regime. That move, whether legal or not, has provided the president with a great deal of freedom to decide what the military can do, what tools they can use to do it and how long they can do it. His decision to send another carrier group and the addition of thousands of U.S. troops to the region is just the latest example.

Congress has proved incapable or unwilling to check this presidential unilateralism. Shortly after the start of the military campaign against Iran, Democratic Sen. Chris Murphy introduced war powers legislation to constrain Trump that failed to pass the Senate. In the House on March 5, members narrowly rejected a resolution to impede a broader or longer operation.

To a meaningful extent, we are watching history repeat itself: Over the past seven decades during times of war, members of Congress have not wanted to act, and presidents have not wanted to ask permission.

From alacrity to deference

Presidents Woodrow Wilson and Franklin D. Roosevelt made their case for war and obtained a formal declaration from Congress within three days in 1917 and within the same afternoon in 1941, respectively.

Since the start of the Korean War, however, members of Congress have demonstrated more deference and less assertiveness.

In Korea, President Truman did not get congressional authorization for the war.

Following North Korea’s invasion of the South in June 1950, Truman bypassed Congress, making his case for war to the United Nations Security Council. In July 1950, United Nations Security Council Resolution 84 “authorized the United States to establish and lead a unified command comprised of all military forces from UN member states, and authorized that command to operate under the UN flag.”

Truman’s rhetoric about American combat operations on the Korean peninsula being part of a U.N. “police action” became increasingly tenuous, but he managed to avoid seeking congressional permission. In doing so, Truman created a precedent in which a congressional declaration of war was no longer necessary for the American military to carry out combat operations. Sen. Robert Taft, a Republican, opposed this lack of congressional deliberation, declaring that Truman’s actions represented a “usurpation” of the war powers authority.“ But Congress did nothing to stop the war as the tactical and strategic picture in Korea stalemated.

In Vietnam, in the aftermath of the 1964 Gulf of Tonkin incident – a purported attack by the North Vietnamese on American naval vessels that did not, in fact, occur – President Lyndon Johnson used the alleged crisis to push for congressional authorization for the escalation of force in Southeast Asia.

Johnson presented the Gulf of Tonkin Resolution to Congress, which quickly passed it. The resolution allowed Johnson to freely escalate American military involvement in Southeast Asia with a vague authorization to engage militarily as he saw fit, in contrast to the very clear declarations of war that came before it for previous wars.

Col. Harry G. Summers, who wrote an influential strategic analysis of the Vietnam War, points to the Gulf of Tonkin Resolution as evidence that the relevant actors – the executive, Congress and the military – failed to foresee the scale of the course of action they were embarking on.

The resolution significantly increased the president’s freedom of action – and freedom from oversight – and marked a major step toward the Americanization and escalation of the war in July 1965. Despite the deeply troubled engagement in South Vietnam and the passage of the War Powers Resolution, we still see presidents acting alone, without consulting members of Congress, let alone getting authorization.

Refusing responsibility

In Summers’ Vietnam postmortem, he relates a telling anecdote of a professor at West Point. The professor, an Army officer, remarked, “When people ask me why I went to Vietnam I say, ‘I thought you knew. You sent me,’” a comment indicative of “the civilian sector’s growing refusal to take responsibility for the kind of army it needs.”

In the case of Trump’s decision-making concerning hostilities with Iran, Americans will one day need answers to the questions: Why did the United States engage in this war with unclear political objectives? And why did Congress allow it to continue?

This story contains material from an article published on March 6, 2026.

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

– ref. Trump sidelined Congress’ authority over war on Iran – and lawmakers allowed it, extending a 75-year trend – https://theconversation.com/trump-sidelined-congress-authority-over-war-on-iran-and-lawmakers-allowed-it-extending-a-75-year-trend-280671

Source: The Conversation – USA (2) – By James R. Elliott, Professor of Sociology, Rice University

Ten years ago, the infamous Tax Day storm swamped the Houston area with off-the-charts rainfall. Nearly 2 feet of rain fell in less than 15 hours in parts of the region, starting on April 17, 2016. The rain flooded thousands of homes and exceeded a 10,000-year event at some gauges.

But the storm’s damage could have been much worse.

The brunt of the deluge hit Waller County, west of Houston, where the impact was largely on farms and ranches. Had the same volume of water fallen just a few miles to the east, over Houston’s dense urban core, the tragedy would have been far worse.

What made the Tax Day flood so devastating was its speed. It was a flash event that struck overnight, without warning.

At Rice University’s Center for Coastal Futures and Adaptive Resilience, we used state-of-the-art hydrological modeling conducted by our colleagues at Rice’s Severe Storm Prediction, Education and Evacuation from Disasters Center to see what would happen if a similar storm struck more populated parts of the city today.

The results suggest that current flood planning strategies in Houston – and similar strategies used in communities across the U.S. – are dangerously narrow in how they consider what’s at risk. In today’s world of increasingly extreme downpours, preparing for flood disasters means preparing for more than just what’s probable – it means also preparing for extreme situations that are less likely but could be far more dangerous.

The perils of relying on probability

In the United States, flood risk is publicly defined by maps produced by the Federal Emergency Management Agency. These maps, suggesting which properties face flood risks, guide everything from emergency planning to decisions related to the National Flood Insurance Program.

However, FEMA’s risk maps are based on probabilistic modeling that typically stops at the 500-year flood risk level, meaning a property has 0.2% odds – a 1 in 500 chance – of being flooded in any given year. There is a mathematical reason for doing this: There are simply too few cases to reliably estimate probabilities below that threshold.

Consequently, “off the charts” events like the Tax Day flood are effectively ignored in official planning. Authorities often prefer to view them as unrealistic until more data is collected – a process that can take decades. Yet, parts of Houston suffered another 1,000-year event the following year when remnants of Hurricane Harvey stalled over the city in 2017, and Houston has seen other 500-year floods in recent years.

The Dutch, who are global leaders in flood science by necessity, since more than half their country is at risk of flooding, use a different approach. They take what they consider “worst credible floods” seriously. These are events that extend beyond standard probability models but are still considered by experts to be realistic, or credible, possibilities.

If the Tax Day storm hit today

To get a clearer picture of the Houston area’s credible risks, we simulated the impact of the Tax Day flood from rainfall alone if the storm had centered over two different watersheds in Houston’s Harris County.

The suburban risk: Clear Creek runs through a middle-class suburban area near NASA’s Johnson Space Center. Vast stretches of suburban concrete block its natural drainage, and thousands of homes have been built along its winding, sluggish tributaries.

Even moderate rainfall can quickly transform these waterways into destructive torrents that overflow into nearby townships, including Friendswood and League City.

Our simulations show that if the Tax Day storm had centered over the Clear Creek area, more than 13,500 properties with homes would have quickly flooded with at least 6 inches of water. Above 6 inches is the danger zone where roads become unsafe for most passenger vehicles. In a home, when drywall gets wet it begins to wick water upward, requiring tear-outs. Even in elevated homes, that much water can damage equipment and contaminate water systems. In some areas, our simulations indicate the water depths would have exceeded 3 feet within hours.

The financial “what if” is even more staggering. Our analysis of publicly available data indicates that 92% of homes in Clear Creek’s flood zone likely have no flood insurance, and 52% fall outside the 100-year flood plain in FEMA’s latest proposed maps. Even with FEMA’s latest map updates, most mortgage holders would not be required to carry flood insurance on homes in the area that would have flooded.

The equity gap: When we moved the storm over Hunting Bayou, a working-class area in inner Houston populated largely by residents of color, the results were even more severe. Here, flooding represents the legacy risk of midcentury urbanism, where a naturally shallow, sluggish stream was penned in by industrial warehouses and tightly packed residential streets long before modern drainage standards existed, restricting the waterway’s ability to expand and meander gracefully.

Because much of the area has flat, poorly draining soils, this watershed has become a bottleneck that can rapidly overflow during heavy rains. We found the Tax Day storm would have flooded more than half of all residential lots there with at least 6 inches of water, compared to 16% of residential lots in the Clear Creek area. And flood insurance in the Hunting Bayou area is nearly nonexistent.

Both simulations, viewable through our interactive online tool at the Center for Coastal Resilience and Adaptive Futures, reveal a sobering reality: Devastation that local, state and federal government planning dismisses as improbable is, in fact, entirely possible.

When FEMA or state planners prioritize probabilistic mapping over “worst-case” modeling like we conducted, they treat historic deluges like the Tax Day flood as improbable anomalies rather than predictable consequences of a changing climate and rapid urban expansion. Moreover, unlike hurricanes, which typically arrive with several days’ notice, the sudden destructive force of “normal” storm systems like the Tax Day storm is discounted.

Learning from ‘worst cases’

The levels of destruction we simulated could easily occur in the coming years as global temperatures rise and storm intensity increases.

To prepare, U.S. emergency planners and flood authorities can look to three lessons from the Dutch planners’ possibilistic playbook.

Embrace flexible planning: Overly detailed plans can create a false sense of control and end up paying less attention to neighborhoods considered to be outside the flood plain. Simple and flexible plans that empower local officials to repurpose everyday assets in real time work best. That might include preemptively mobilizing high-water rescue vehicles into geographically vulnerable areas.

Map potential disruption, not just probability: Extending flood planning beyond who is in or out of the 100-year flood zone can also help identify where road networks and critical infrastructure are likely to fail during extreme events. This approach also helps identify infrastructure such as public parks that can double as temporary water retention basins.

Raise public risk perception: Residents can respond more effectively when local flood authorities share plans for “what if” scenarios with the public, along with guidance on how best to prepare.

The 10th anniversary of the Tax Day flood is a reminder of why it’s crucial to stop ignoring improbable events and start scientifically leveraging the possible to make all cities safer in an age of worsening climate change.

This article, originally published April 14, 2026, has been updated to include the Rice University SSPEED Center’s contribution to the research.

Dominic Boyer receives funding from the National Science Foundation and the John S. Guggenheim Foundation.

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

– ref. What if Texas’ destructive Tax Day storm had centered on inner Houston instead? It’s why cities should plan for the improbable – https://theconversation.com/what-if-texas-destructive-tax-day-storm-had-centered-on-inner-houston-instead-its-why-cities-should-plan-for-the-improbable-279964

Source: The Conversation – USA (3) – By Anisah Bagasra, Associate Professor of Psychology, Kennesaw State University

The war with Iran has led to a surge in anti-Muslim rhetoric – spilling into political discourse.

U.S. Rep. Randy Fine of Florida posted on X that “the choice between dogs and Muslims is not a difficult one,” and added in another post, “We need more Islamophobia, not less.” Similarly, U.S. Rep. Brandon Gill of Texas called for stopping the entry of “Muslims immigrating to America.”

A study by the Center for the Study of Organized Hate found that the average number of Islamophobic posts jumped from 2,000 to 6,000 each day on X alone in the first six days of the conflict.

I have studied the impact of Islamophobia on mental health over the past two decades, following soaring hate crimes in the wake of 9/11. Research consistently shows that negative portrayals of Muslims shape public attitudes toward Muslims and can lead to increased discrimination, hate crimes and psychological consequences.

Increase in Islamophobia

Islamophobia in the United States tends to surge during global conflicts, political campaigns and terrorist attacks. Human Rights First, an organization that works to promote human rights in the U.S. and abroad, documented surges in Islamophobia in 2015 following the Syrian refugee crisis, when a large number of people were displaced. That same year the 2015 attacks in Paris and shooting in San Bernardino, California, intensified public anxiety about terrorism, and a surge in crimes against Muslims followed.

Islamophobic rhetoric in the U.S. intensified during Donald Trump’s 2016 presidential campaign and continued into his presidency, often framing Muslims as a security threat. Burton Speakman, a scholar of digital media, and I found an increasing acceptance of such rhetoric among the political right in social media posts from 2016-19.

Social media posts and comments showed an increasing use of dehumanizing language toward Muslims. In a study I conducted in 2020, a majority of 830 Muslim Americans reported encountering the most Islamophobic content on Facebook, followed by Twitter and Instagram. This shift was also reflected in the language and coverage of Islam in right-wing media, which often portrayed Muslims as invaders wanting to impose Sharia law and as a drain on social welfare.

Mainstream media can also amplify negative depictions of Muslims by often discussing Islam within the context of terrorism and portraying Muslims more negatively than other racial, ethnic or religious minority groups.

Hate crimes tend to increase alongside Islamophobic rhetoric. During 2016, a period with high rates of Islamophobic rhetoric, there were 307 reported incidents – the highest recorded number immediately following 9/11. The numbers dropped the following year but were followed by an increase in 2024 with the start of the Israel-Hamas war; the number of reported anti-Muslim hate crimes was 288 that year.

A 2025 poll found that 63% of American Muslims reported experiencing religious discrimination, with many reporting at least one such incident every year since 2016.

Mental health of Muslim Americans

The cumulative effects of Islamophobia have an impact an American Muslims’ mental health and access to care.

Numerous studies since 9/11 link the high rates of discrimination experienced by the Muslim American
community to higher rates of depression. Experiences of discrimination also lead some Muslim Americans to believe they are not viewed as being American.

Thirty-one percent of participants in my 2020 study described the impact of social media on their mental health: Many said they avoided displaying their Muslim identity in social media posts, supporting a Muslim political candidate on social media, or even sharing religious content or videos. Some just withdrew – 27% deactivated or deleted their social media accounts.

In addition, many Muslims report feeling discouraged from seeking both physical and psychological treatment from non-Muslim providers, leading Muslim Americans to significantly underutilize available services compared to other ethnic and religious minority groups.

A 2015 study found that nearly one-third of Muslim Americans report experiencing discrimination in health care settings, which has an impact on their trust in providers. The majority reported being treated rudely by providers, insensitivity regarding modesty requirements, or having their pain disregarded. One participant in that study said: “Going into a surgery, health care providers didn’t recognize the importance of me keeping my hijab on and wanting most of my body covered.”

In my 2023 study, a number of participants described personal experiences with mental health professionals who seemed not to see them as individuals beyond their religious affiliation. One participant described a provider as being “quick to attribute problems” to religion or culture. “I worry about them stereotyping and end up feeling as if I’m on the defense,” this participant said.

My most recent study, conducted in 2024, which is currently under review, asked 325 Muslim Americans who had used any psychological services about their health-seeking behavior: 56% said they were worried ; 57% were worried about being misunderstood.

Following Trump’s travel ban targeting several Muslim countries in 2017, a study conducted by researchers at the Yale School of Public Health found that many Muslim Americans skipped their primary care appointments; at the same time, their visits to the emergency room went up.

Addressing the challenges

In response, a number of initiatives have emerged at the local and national levels.

One approach involves increasing mental health literacy within Muslim communities and creating networks of mental health professionals working with Muslim clients.

For example, mental health professionals and community leaders are working to increase mental health literacy through in-person education and digitally. Muslim community members learn about symptoms of mental health disorders through training, such as Mental Health First Aid. Online directories of Muslim mental health providers have also been created.

Another approach involves training mental health professionals. A team at Stanford University has created a six-part training module that provides therapists with knowledge of religious norms and an opportunity to reflect on their own possible biases.

Finally, Muslim researchers and providers have begun to develop therapies and resources that integrate Muslim beliefs and spiritual approaches with treatment. These include psychotherapy that is inspired by the Quran, the teachings of the prophet and spiritual practices such as self-reflection, prayer and mindfulness.

Muslim Americans can often feel helpless in combating the hate they experience – more awareness and advocacy could reduce Islamophobia and address the mental health needs of an already vulnerable community.

Anisah Bagasra received funding from Meta’s Content Policy Research on Social Media Platforms research award in 2019 to study Islamophobic rhetoric and imagery on social media platforms.

– ref. How Islamophobic rhetoric leaves an impact on the mental health of Muslim Americans – https://theconversation.com/how-islamophobic-rhetoric-leaves-an-impact-on-the-mental-health-of-muslim-americans-279046

Source: The Conversation – USA – By Ahmed Helal, Research Scientist, The University of Texas at Austin

If you walk across the open yard in front of the Physics, Math and Astronomy building at the University of Texas at Austin, you’ll see a 17-story tower and a huge L-shaped building. What you won’t see is what’s underneath you. Two floors below ground, behind heavy double doors stamped with a logo that most students have never noticed, sits one of the most powerful lasers in the United States.

I was the lead laser scientist on the Texas Petawatt, or TPW as we called it, from 2020 to 2024. Texas Petawatt, which is currently closed due to funding cuts, was a government-funded research center where scientists from across the country applied for time to use specialized equipment. It was part of LaserNetUS, a Department of Energy network of high-power laser labs.

This type of laser takes a tiny pulse of light, stretches it out so it doesn’t blast optics to pieces, and amplifies it until, for a brief instant, it carries more power than the entire U.S. electrical grid. Then it compresses the pulse back to a trillionth of a second to create a star in a vacuum chamber.

On a typical shot day, the target might be a piece of metal foil thinner than a human hair, a jet of gas or a tiny plastic pellet – each designed to answer a different scientific question.

Scientists from across the country applied for time on TPW to study everything from the physics of stellar interiors and fusion energy to new approaches for cancer treatment.

Most people hear about petawatt lasers and picture something out of a movie. A “shot day” is actually hours of quiet, repetitive work followed by about 10 seconds where nobody breathes.

I now work as a research scientist at the University of Texas-Austin, studying the interaction of lasers with different materials, but a typical shot day during my time running TPW would look like this:

7 a.m.

I arrive two hours before the first scheduled shot. I put on my gown, boots and hairnet and step into the cold clean room. The laser doesn’t just turn on. You coax it awake.

I start with the oscillator, a small box that generates the first seed of light. I write down the parameters that define how the laser will behave during the shot: energy, center frequency, vacuum pressure in the tubes, cooling water level and flow. At this stage, they are fixed regardless of the experiment. The laser must perform the same way every time before the science can begin. Then I fire up the pump laser that will amplify this tiny pulse from nanojoules to about half a joule.

The system needs at least 30 minutes to stabilize. During that time, I check alignment through every pinhole and every camera along the beam path. A slight misalignment at this stage isn’t just a problem; it can be catastrophic – a mispointed beam at full power can burn through optics that take months to source and replace, setting the entire laser back.

Building the beam

Once the system is warmed up, I send the beam into the first amplifier: a glass rod surrounded by bright flash lamps that pump light into the glass – like charging a battery. With each pass, the beam absorbs energy from the glass and grows stronger. Then the beam travels into a larger rod, where it makes four passes, picking up more energy each time until it reaches about 12 joules, roughly the energy of a ball thrown hard across a room.

This process alone takes the better part of an hour, most of it spent checking and confirming alignment and energy at each stage.

I expand the beam and send it through the final stage: the disk amplifiers. Two amplifiers, each consisting of two massive 30-centimeter glass disks, are pumped by a huge bank of flash lamps powered by capacitor banks – essentially giant batteries that store electrical energy and release it in a sudden burst. They are so large that they have their own room on a separate floor. Fast optical shutters between each stage act as gates, controlling exactly when and where the beam travels.

The shot

When the experimental team confirms that the target is in position, it asks me to prepare for a system shot. I run through the long checklist. We test the shutters and switch to system shot mode. Every monitor in the facility changes to display the same message – “System Shot Mode” – and flashes red.

I lean into the microphone at the control desk, a vintage piece that looks like it belongs in a World War II radio room, and announce that we’re going into a system shot. Then I open the compressor beam dump: a heavy glass plate that normally blocks the beam from reaching the target. It takes about two minutes to move.

“Sweeping, sweeping for a system shot.”

The announcement goes out over speakers across the facility. I grab a small interlock key, put on my laser safety goggles and head downstairs. I walk a specific pattern through every room, checking that nobody is still inside. As I go, I lock each door with the key. If anyone opens one of those doors after I’ve locked them, the entire shot sequence aborts.

Back in the control room, I sit down and start charging the capacitor banks. At this point, there’s no going back except for an emergency shutdown, and that means losing the shot and waiting for everything to cool down.

“Charging.”

The room goes silent. Everyone’s eyes are on the monitors. Nobody talks.

I typically will share a glance with the researcher whose project the shot is for – today it’s Joe, a visiting scientist from Los Alamos National Lab, who designed the target we’re about to vaporize. He’s gripping his coffee cup like it owes him money. I turn back to the console.

“Charge complete. Firing system shot in three, two, one. Fire.”

I press the button. A loud thud rolls through the building as all that stored energy dumps into the beam. The monitors freeze, capturing everything at the moment of the shot: beam profiles, spectra, diagnostics – these metrics provide a full picture of exactly how the laser performed and whether the shot was clean. Downstairs, in the vacuum chamber, a spot smaller than a human hair just reached temperatures measured in millions of degrees.

I lean back in my chair and start recording laser parameters as everyone exhales. A radiation safety officer heads down first to check readings around the target chamber before anyone else can enter. The experimental team follows to collect data.

Sometimes it all works perfectly. Sometimes a shutter fails to open and you lose the shot.

For example, one afternoon in 2023, we’d spent three hours preparing for a high-priority shot. Target aligned. Capacitors charged. I pressed the button and heard nothing. A shutter had failed somewhere in the chain. The monitors stayed frozen, showing black. Nobody said anything. I wrote SHOT FAILED in the logbook and started the hourlong cooldown sequence. That’s the part they don’t show in movies: sitting in silence, waiting to try again. We got the shot four hours later.

This anticipation is all part of the job: hours of patience for 10 seconds you never quite get used to. Everything happens underneath a campus where thousands of people walk above, unaware that for a fraction of a second, a tiny point of matter hotter than the surface of the Sun just existed below their feet.

Ahmed Helal is currently the Founder and CEO of Photonics Dynamics LLC, a consulting company.

– ref. I’ve fired one of America’s most powerful lasers – here’s what a shot day looks like – https://theconversation.com/ive-fired-one-of-americas-most-powerful-lasers-heres-what-a-shot-day-looks-like-279520

Source: The Conversation – USA – By Zelalem Bedaso, Associate Professor of Earth and Environmental Geosciences, University of Dayton

Teeth are like tiny biological time capsules. They tell stories about ancient diets and environments long after their owners have died and landscapes have changed.

After bones break down, tooth enamel stays hard and unchanged, even in fossilized teeth that have been buried under sediment and rock for millions of years and are now being uncovered by erosion or excavation.

Tooth enamel forms when an animal is young, and it remains chemically stable for the rest of that animal’s life. The food an animal eats and the water it drinks during its youth leave chemical signals within the enamel.

Because of that, hidden within the enamel of fossilized teeth, scientists can find traces of extinct forests, expanding savanna grasslands, shifting climates and evolving animal communities.

Over the past 30 years, my colleagues and I have been analyzing chemical traces in fossil teeth from Ethiopia’s Afar region in the East African Rift Valley – often referred to as the cradle of humanity – to uncover what animals ate there millions of years ago, around the time early human ancestors were evolving, and what the world looked like around them.

These clues from ancient meals are enabling scientists to reconstruct pictures of entire ecosystems, including forests, wetlands and grasslands that existed at the time. It’s a reminder that in a very real sense, organisms are what they eat.

Traces of ancient diets in fossil teeth

To determine which plants ancient animals ate, my colleagues and I collect a small amount of enamel powder from fossilized teeth. We then analyze this powder in the laboratory using specialized instruments that detect chemical signals preserved in the enamel.

Trees and grasses have different ways of using photosynthesis to convert sunlight into energy. These methods leave distinct chemical patterns in plant tissues, which then become incorporated into the teeth of animals that eat those plants.

By examining these chemical patterns in tooth enamel, we can determine whether animals primarily fed on trees and shrubs or on grass, providing insight into the vegetation that once covered the ancient landscape.

We can then figure out how an environment changed over time by collecting fossil teeth from different rock layers. Each layer formed at a different time in the past, so teeth found in deeper layers are typically older than those closer to the surface.

By analyzing tooth enamel from fossils across these layers, we can compare the chemical signals preserved in the teeth and see how animal diets and the plants growing in the landscape changed through time.

Adding that knowledge to data from different types of fossils, we can track long-term shifts in vegetation, climate and ecosystems.

A changing landscape in the last 4 million years

Four million years ago, the Afar region looked very different from the dry landscape you will see there today.

Fossils, including tooth enamel, reveal that the area supported a diverse range of environments. Rivers flowed through wooded areas, lakes were scattered across the landscape, and grassy plains stretched across the basin.

Fossilized teeth from animals like antelopes, giraffes, pigs, horses, hippos and elephants show a wide range of diets. Some animals browsed on leaves and shrubs, while others grazed on grass in open habitats.

The chemical signals in the teeth indicate that grasslands were expanding at the time, but forests still played an important role. They show that animals moved through this environment and adapted to the food sources around them.

Around 2 million to 3 million years ago, the environment shifted more drastically toward open grasslands.

The East African Rift Valley gets its shape from three tectonic plates that have been slowly pulling apart. This tectonic activity has changed the landscape over time, altering the regional climate and drainage. Two to three million years ago, it helped shift environments from more wooded habitats to a mix of grasslands and open savannas.

Animals that relied on grass flourished, and the populations of those that didn’t adapt declined. Horses and certain antelopes, for example, developed teeth that could grind tough, gritty plants. This adaptation is recorded on their enamel.

Early humans in a mosaic world

Early human ancestors, like the famous “Lucy,” whose skeleton was discovered in the Afar region, lived in this dynamic landscape.

Fossil teeth from Australopithecus afraensis, an early human that lived in eastern Africa between about 2.9 million and 3.8 million years ago, indicate that early human relatives did not rely heavily on grass. Instead, the chemical signal in their enamel indicates mixed diets and dietary flexibility, which included fruits, leaves and roots, depending on what was available.

In a landscape that combined woodland patches and open savanna, that adaptability may have been key to survival.

This period of environmental change coincided with several important evolutionary developments and morphological changes in pre-humans. Early human ancestors were walking upright. Brain size also gradually increased, allowing for more complex behavior and problem-solving.

During this time, early humans began making and using stone tools, marking a major step in technological innovation and helping them adapt to changing environments.

Diet shapes destiny

The dietary changes in the East African Rift Valley over the past 4 million years, documented through tooth enamel, are providing important clues for reconstructing the environment in which humans’ ancestors lived and how those environments changed.

They also show that species that adjusted their diets as landscapes changed were the ones most likely to survive.

This ongoing research helps explore profound questions of how environmental shifts shaped life on Earth, including human trajectories. And that is helping humanity unlock its collective past.

Zelalem Bedaso 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. Ancient teeth reveal clues to the environment humans’ early ancestors evolved in millions of years ago – https://theconversation.com/ancient-teeth-reveal-clues-to-the-environment-humans-early-ancestors-evolved-in-millions-of-years-ago-279544

Source: The Conversation – USA (2) – By Joshua Vadeboncoeur, Assistant Professor of Sport Management, Gardner-Webb University

Across the United States, the local auto racing tracks that have anchored rural and working-class communities for generations are disappearing.

Some have lost out to real estate developers when suburban sprawl makes the land beneath them too valuable to ignore. Others are strangled, slowly, by noise complaints and nuisance lawsuits filed by residents who moved to the area long after the track had been built.

Now, state legislatures are pushing back. From Georgia to Wisconsin, lawmakers have been introducing so-called “right to race” bills.

Over the past year, at least 13 state legislatures have put forward bills shielding racetracks from nuisance lawsuits filed by property owners who moved into the area after the track was built. These follow the passage of similar legislation in Iowa and North Carolina in 2025.

As a historian and analyst of American stock car racing, I’ve been watching this legislation closely.

The argument being made inside these statehouses is a legal one. But what’s really being contested is something older and harder to legislate: whose idea of a place is preserved, and whose vision is pushed to its margins.

What these laws do

For nearby residents, the impacts of a racetrack can be difficult to ignore. Events are often loud and sometimes unpredictable, and they can run for hours. And the surrounding roads can be clogged with traffic before and after events.

That said, there is a long-standing legal principle known as “coming to the nuisance.” This holds that someone who moves next to existing businesses or infrastructure – whether they’re factories, racetracks, train tracks or airports – cannot then sue over disturbances from their regular operation.

In practice, however, that principle has frequently failed to protect tracks.

Old Dominion Speedway in northern Virginia, opened in the 1950s, was ultimately relocated south to Thornburg, where a new facility opened in 2016, after noise complaints from a nearby townhouse development proved impossible to satisfy.

In Asheville, North Carolina, an environmental nonprofit channeled the opposition of newer residents into a campaign against the New Asheville Speedway. The city ultimately purchased the track’s land in 1998 and converted it into a public park.

Onondaga Dragway in Ingham County, Michigan, which had reopened in 2013 after an earlier closure, spent the next 12 years locked in legal proceedings with neighboring residents before a judge finally ordered it shuttered in 2025. Onondaga’s closure directly prompted Michigan’s right to race legislation.

At their core, right to race bills establish that if a racetrack was lawfully built and operating before a neighboring property owner purchased or developed their land, that owner cannot bring nuisance claims against the facility.

Iowa’s law, signed in May 2025, passed unanimously in both chambers – 45-0 in the Senate and 92-0 in the House. North Carolina’s followed in September 2025, and Kansas enacted similar legislation in April 2026.

The Specialty Equipment Market Association has lobbied for the bills, arguing that they address the same problem that spurred a spate of “right to farm” legislation in the 1970s and ’80s. These laws shielded farmers from nuisance complaints due to odors, noise, dust and slow-moving farm vehicles on local roads.

Right to race legislation hasn’t been politically controversial, in part because it is often framed as a matter of common sense.

As Michigan state Sen. Roger Hauck put it, “I don’t think it’s fair to a business that’s been zoned to be there legally by the township to have someone start complaining about the noise of the racetrack when it’s been there since before the person has been there.”

Still, the bills are not identical, and the differences matter.

Michigan’s bills and Kentucky’s bill extend immunity regardless of any future changes to a facility, meaning a track that dramatically expands its operations would still be shielded.

A more limited approach was proposed in Georgia – though the bill ultimately failed to advance before the April 2026 deadline – which would have preserved the right to sue if an existing track expanded its footprint.

More expansive versions of these bills have drawn concern in some cases. In Wisconsin, for example, Gov. Tony Evers vetoed a similar bill after it passed the Legislature, arguing it would create “unfair and unnecessary hurdles for people pursuing legal avenues to vindicate the use and enjoyment of their land.”

Land value, not noise, is the real threat

While noise complaints and nuisance suits are the immediate trigger of many track closures, they are often symptoms of a deeper economic pressure: land value.

The land that racetracks sit on – large, often flat, typically in areas that were once rural but no longer are – has become extraordinarily attractive to developers. And while housing has been the traditional threat, new ones have emerged.

Warehouses and logistics facilities have taken up land on the outskirts of American cities over the past decade. More recently, the explosion of aritificial intelligence infrastructure investment has compelled developers of data centers to seek out vast tracts of land.

Greenville-Pickens Speedway in South Carolina, the site of NASCAR’s first live televised race in 1971, has been dormant since 2022 as its future became entangled in a potential sale. It’s facing conversion into an industrial park, led by a prospective buyer rather than pressure from nuisance lawsuits. Local supporters have rallied to preserve the site, and county officials have taken steps toward recognizing it as a historic property, but those efforts don’t prevent a private sale or redevelopment. South Carolina’s HB 4706 targets nuisance lawsuits, not private sales or redevelopment, meaning it offers no protection in cases like this.

Nashville’s Fairgrounds Speedway, which has hosted racing since 1904 on city-owned property, isn’t being threatened by a private nuisance suit. Instead, its future is in doubt due to a charter amendment campaign – a ballot-driven effort that would eliminate the site’s designation for auto racing, potentially opening the door to redevelopment.

What communities stand to lose

In my view, most of the bills – even if they don’t say it explicitly – are about whether communities that have grown up around local racetracks have any legitimate claim on the continued existence of those tracks.

As one supporter in the ongoing Greenville-Pickens debate put it, the track is “more than just a racetrack to us. It’s a place where we can actually go and actually talk to others that have the same interests and passion about racing.”

Another supporter plainly said that Greenville-Pickens “is far more than a racetrack. It is the center of our world.”

Research shows that when shared social spaces disappear, the community life built around them does not simply find a new home. And in my ongoing research on grassroots racing, I’ve explored how local tracks function as some of the last spaces in American working-class life where people gather not as passive consumers but as active participants – as drivers, crew members, track workers and fans.

Owosso Speedway Operations Lead Dennis Wheeler, speaking in support of Michigan’s right to race legislation, described his track as not just a racetrack but a “small business … an employer, a tourism driver and a gathering place for families across mid-Michigan.”

These bills address the nuisance lawsuit problem, which is real. But rarely do they address land value, which is often the bigger driver of track closures. Nor do they create any funding mechanism to help tracks modernize or survive economically. And finally, they do not require that developers notify homebuyers of nearby racing facilities.

For now, it’s clear that pressure from real estate developers is threatening something that took generations to build. The bills moving through statehouses this year represent an attempt to fight back.

Some of them are well crafted and appropriately limited. Others are blunt instruments that could create their own problems. But all of them are arriving late, after many tracks have already closed and after many communities have already lost something they cannot get back.

Joshua Vadeboncoeur 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. ‘Right to race’ laws and the battle over America’s local racetracks – https://theconversation.com/right-to-race-laws-and-the-battle-over-americas-local-racetracks-278034