Etikett: Theconversation.com

On this day three years ago, we witnessed the nail-biting launch of the James Webb Space Telescope (JWST), the largest and most powerful telescope humans have ever sent into space.

It took 30 years to build, but in three short years of operation, JWST has already revolutionised our view of the cosmos.

It’s explored our own Solar System, studied the atmospheres of distant planets in search of signs of life and probed the farthest depths to find the very first stars and galaxies formed in the universe.

Here’s what JWST has taught us about the early universe since its launch – and the new mysteries it has uncovered.

Eerie blue monsters

JWST has pushed the boundary of how far we can look into the universe to find the first stars and galaxies. With Earth’s atmosphere out of the way, its location in space makes for perfect conditions to peer into the depths of the cosmos with infrared light.

The current record for the most distant galaxy confirmed by JWST dates back to a time when the universe was only about 300 million years old. Surprisingly, within this short time window, this galaxy managed to form about 400 million times the mass of our Sun.

This indicates star formation in the early universe was extremely efficient. And this galaxy is not the only one.

When galaxies grow, their stars explode, creating dust. The bigger the galaxy, the more dust it has. This dust makes galaxies appear red because it absorbs the blue light. But here’s the catch: JWST has shown these first galaxies to be shockingly bright, massive and very blue, with no sign of any dust. That’s a real puzzle.

There are many theories to explain the weird nature of these first galaxies. Do they have huge stars that just collapse due to gravity without undergoing massive supernova explosions?

Or do they have such large explosions that all dust is pushed away far from the galaxy, exposing a blue, dust-free core? Perhaps the dust is destroyed due to the intense radiation from these early exotic stars – we just don’t know yet.

Artist’s impression of what a blue galaxy in the early universe would look like. ESO/M. Kornmesser.

Unusual chemistry in early galaxies

The early stars were the key building blocks of what eventually became life. The universe began with only hydrogen, helium and a small amount of lithium. All other elements, from the calcium in our bones to the oxygen in the air we breathe, were forged in the cores of these stars.

JWST has discovered that early galaxies also have unusual chemical features.

They contain a significant amount of nitrogen, far more than what we observe in our Sun, while most other metals are present in lower quantities. This suggests there were processes at play in the early universe we don’t yet fully understand.

JWST has shown our models of how stars drive the chemical evolution of galaxies are still incomplete, meaning we still don’t fully understand the conditions that led to our existence.

Different chemical elements observed in one of the first galaxies in the universe uncovered by JWST.
Adapted from Castellano et al., 2024 The Astrophysical Journal; JWST-GLASS and UNCOVER Teams

Small things that ended the cosmic dark arges

Using massive clusters of galaxies as gigantic magnifying glasses, JWST’s sensitive cameras can also peer deep into the cosmos to find the faintest galaxies.

We pushed further to find the point at which galaxies become so faint, they stop forming stars altogether. This helps us understand the conditions under which galaxy formation comes to an end.

JWST is yet to find this limit. However, it has uncovered many faint galaxies, far more than anticipated, emitting over four times the energetic photons (light particles) we expected.

The discovery suggests these small galaxies may have played a crucial role in ending the cosmic “dark ages” not long after the Big Bang.

Rectangles highlight the apertures of JWST’s near infrared spectrograph array, through which light was captured and analysed to unravel the mysteries of the galaxies’ chemical compositions.
Atek et al., 2024, Nature

Read more:
What ended the ’dark ages’ in the early universe? New Webb data just brought us closer to solving the mystery

The mysterious case of the little red dots

The very first images of JWST resulted in another dramatic, unexpected discovery. The early universe is inhabited by an abundance of “little red dots”: extremely compact red colour sources of unknown origin.

Initially, they were thought to be massive super-dense galaxies that shouldn’t be possible, but detailed observations in the past year have revealed a combination of deeply puzzling and contradictory properties.

Bright hydrogen gas is emitting light at enormous speeds, thousands of kilometres per second, characteristic of gas swirling around a supermassive black hole.

This phenomenon, called an active galactic nucleus, usually indicates a feeding frenzy where a supermassive black hole is gobbling up all the gas around it, growing rapidly.

But these are not your garden variety active galactic nuclei. For starters: they don’t emit any detectable X-rays, as is normally expected. Even more intriguingly, they seem to have the features of star populations.

Could these galaxies be both stars and active galactic nuclei at the same time? Or some evolutionary stage in between? Whatever they are, the little red dots are probably going to teach us something about the birth of both supermassive black holes and stars in galaxies.

In the background, the JWST image of the Pandora Cluster (Abell 2744) is displayed, with a little red dot highlighted in a blue inset. The foreground inset on the left showcases a montage of several little red dots discovered by JWST.
Adapted from Furtak et al., and Matthee et al., The Astrophysical Journal, 2023-2024; JWST-GLASS and UNCOVER Teams

The impossibly early galaxies

As well as extremely lively early galaxies, JWST has also found extremely dead corpses: galaxies in the early universe that are relics of intense star formation at cosmic dawn.

These corpses had been found by Hubble and ground-based telescopes, but only JWST had the power to dissect their light to reveal how long they’ve been dead.

It has uncovered some extremely massive galaxies (as massive as our Milky Way today and more) that formed in the first 700 million years of cosmic history. Our current galaxy formation models can’t explain these objects – they are too big and formed too early.

Cosmologists are still debating whether the models can be bent to fit (for example, maybe early star formation was extremely efficient) or whether we have to reconsider the nature of dark matter and how it gives rise to early collapsing objects.

JWST will turn up many more of these objects in the next year and study the existing ones in greater detail. Either way, we will know soon.

A dead galaxy, observed 2 billion years after the Big Bang. A small red source in the Hubble Space Telescope image proves to be a monstrous galaxy as seen by JWST.
Glazebrook et al., Nature, 2024

What’s next for JWST?

Just within its first steps, the telescope has revealed many shortcomings of our current models of the universe. While we are refining our models to account for the updates JWST has brought us, we are most excited about the unknown unknowns.

The mysterious red dots were hiding from our view. What else is lingering in the depths of cosmos? JWST will soon tell us.

Read more:
10 times this year the Webb telescope blew us away with new images of our stunning universe Läs mer…

COVID emerged suddenly, spread rapidly and killed millions of people around the world. Since then, I think it’s fair to say that most people have been nervous about the emergence of the next big infectious disease – be that a virus, bacterium, fungus or parasite.

With COVID in retreat (thanks to highly effective vaccines), the three infectious diseases causing public health officials the greatest concern are malaria (a parasite), HIV (a virus) and tuberculosis (a bacterium). Between them, they kill around 2 million people each year.

And then there are the watchlists of priority pathogens – especially those that have become resistant to the drugs usually used to treat them, such as antibiotics and antivirals.

Scientists must also constantly scan the horizon for the next potential problem. While this could come in any form of pathogen, certain groups are more likely than others to cause swift outbreaks, and that includes influenza viruses.

One influenza virus is causing great concern right now and is teetering on the edge of being a serious problem in 2025. This is influenza A subtype H5N1, sometimes referred to as “bird flu”. This virus is widely spread in both wild and domestic birds, such as poultry. Recently, it has also been infecting dairy cattle in several US states and found in horses in Mongolia.

When influenza cases start increasing in animals such as birds, there is always a worry that it could jump to humans. Indeed, bird flu can infect humans with 61 cases in the US this year already, mostly resulting from farm workers coming into contact with infected cattle and people drinking raw milk.

Compared with only two cases in the Americas in the previous two years, this is quite a large increase. Coupling this with a 30% mortality rate from human infections, bird flu is quickly jumping up the list of public health officials’ priorities.

Luckily, H5N1 bird flu doesn’t seem to transmit from person to person, which greatly reduces its likelihood of causing a pandemic in humans. Influenza viruses have to attach to molecular structures called sialic receptors on the outside of cells in order to get inside and start replicating.

Flu viruses that are highly adapted to humans recognise these sialic receptors very well, making it easy for them to get inside our cells, which contributes to their spread between humans. Bird flu, on the other hand, is highly adapted to bird sialic receptors and has some mismatches when “binding” (attaching) to human ones. So, in its current form, H5N1 can’t easily spread in humans.

However, a recent study showed that a single mutation in the flu genome could make H5N1 adept at spreading from human to human, which could jump-start a pandemic.

If this strain of bird flu makes that switch and can start transmitting between humans, governments must act quickly to control the spread. Centres for disease control around the world have drawn up pandemic preparedness plans for bird flu and other diseases that are on the horizon.

For example, the UK has bought 5 million doses of H5 vaccine that can protect against bird flu, in preparation for that risk in 2025.

Even without the potential ability to spread between humans, bird flu is likely to affect animal health even more in 2025. This not only has large animal welfare implications but also the potential to disrupt food supply and have economic effects as well.

Bird flu has been spreading in dairy herds in the US.
BearFotos/Shutterstock

Everything is connected

This work all falls under the umbrella of “one health”: looking at human, animal and environmental health as interconnected entities, all with equal importance and effect on each other.

By understanding and preventing disease in our environment and the animals around us, we can better prepare and combat those diseases entering humans. Similarly, by surveying and disrupting infectious diseases in humans, we can protect our animals and the environment’s health too.

However, we must not forget about the continuing “slow pandemics” in humans, such as malaria, HIV, tuberculosis and other pathogens. Tackling them is paramount alongside scanning the horizon for any new diseases that might yet come. Läs mer…

Anyone out winter walking in the Yorkshire dales will probably be familiar with the dramatic scenery of limestone pavements. Distinctive and beautiful, they can also be found elsewhere in Britain, as well as in mainland Europe and Canada – not to mention in Harry Potter and the Deathly Hallows, where Harry and Hermione set up camp in a rocky clifftop.

Limestone pavements were formed more than 300 million years ago in the Dinantian period, when the ice sheets scraped away soil, leaving limestone rock exposed. Over time, rainfall wore away the rock into the uneven patterns that we see today.

Mountain avens.
Sophia Granchinho

Limestone pavements are made up of large slabs of rock called clints, interspersed with cracks called grikes that can be a few metres deep. Living in these grikes is a secret world of plant life, including rare species such as the pretty white mountain-avens, the poisonous baneberry and the rigid buckler fern, which only ever grows on limestone.

Why these areas matter

The habitats in these grikes are important for conservation, since limestone pavements only cover an area of around 28km² across Great Britain, equivalent to the size of a small town. In the 1970s a landmark national survey of British limestone pavements led by two scientists, Stephen Ward and David Evans, led to an increase in their protection.

This was necessary because many pavements had been damaged by people removing the stone for building or for decorative rockeries. Individual sites were now designated as reserves or sites of special scientific interest. Then in 1981 the Wildlife and Countryside Act introduced Limestone Pavement Orders, which made it illegal to remove any of the stones.

Removing stones from limestone pavements has been illegal since the early 1980s.
Phil MacDPhoto

To see what has happened to the plants that live in and around the pavement and grikes over the last half a century, I have spent five years undertaking a new national survey. In research just published in Functional Ecology, I revisited and surveyed the same sites as the 1970s study, including in northern England, Scotland and Wales. I found a very mixed picture.

In some areas, grazing by sheep and cows has stopped or reduced. Whereas in the 1970s, farmers received payments from the then European Economic Community (EEC) for each animal they grazed, now they receive money for looking after land for conservation.

This reduction in grazing intensity is mostly positive, but in some areas it has led to scrub and trees encroaching on the pavement. This can reduce the amount of light for other plants, and in many cases, I found large reductions in biodiversity. For example, some areas of pavement where there had been large increases in tree cover had lost more than 20 plant species in the years between the two surveys.

Many people think of plants as nice-looking greens. Essential for clean air, yes, but simple organisms. A step change in research is shaking up the way scientists think about plants: they are far more complex and more like us than you might imagine. This blossoming field of science is too delightful to do it justice in one or two stories.
This article is part of a series, Plant Curious, exploring scientific studies that challenge the way you view plantlife.

On the plus side, the reductions in grazing intensity have also meant that some pavement species that are particularly sensitive to grazing, such as baneberry, seem to be on the increase. Equally, however, not all the species that have increased are desirable. There has been a large increase in thistles, especially creeping thistles, which are not typical of limestone pavements and have the potential to disrupt their ecosystems.

Just as the area of pavements covered by trees and shrubs has increased, so has the area with no trees at all. In these areas, the pavements are actually over-grazed. Sheep, for instance, will put their heads as far down a grike as they can to get to the plants that they want to eat.

This too can affect the ecosystem: some species have been over-eaten, though I didn’t collect on which ones, while high nutrient levels in the pavements from sheep dung has increased the abundance of excessively competitive species such as stinging nettles.

Too much grazing here, too little grazing there.
Elliot Photography

More generally, it’s striking that there has been little research into limestone pavements and the plants that grow in them. This is despite their importance for conservation, and the fact that many areas are now nature reserves.

Having evidence to support decisions about how we best manage these natural habitats is important, so building a solid research base is a priority for the future. My survey will play a part, but there’s still a lot to learn, including how these habitats might respond to climate change, so that we can ensure our spectacular limestone pavements stay special for future generations. Läs mer…

Operation Chastise, as the Dambusters’ May 1943 bouncing bomb attack on the Möhne, Eder and Sorpe dams was officially called, was a heroic example of precision bombing by the Royal Air Force (RAF). It was also a very temporary victory.

The Nazi regime deployed slave labour and the dams were soon repaired. The raid killed so many aircrew and destroyed so many aircraft that the RAF did not even return to attack those completing the repairs.

The truth is that Chastise was a propaganda coup by the air ministry and ministry of information. Deploying public relations skills they had pioneered during the Battle of Britain, they fed newspapers a meticulously managed account that highlighted heroism and scientific innovation and glossed over the cost.

The Dambusters were a big hit on both sides of the Atlantic. The New York Times reported: “RAF Blasts 2 Big Dams in Reich” and “Ruhr Power Cut, Traffic Halted as Floods Cause Death and Ruin”.

In the UK, the Air Ministry press team achieved a clean sweep in popular and broadsheet newspapers. The Daily Mirror declared “Torrent Rages Along Ruhr – Huns Get a Flood Blitz”. The accompanying story described “hundreds of square miles of devastation” in Germany’s “most vital industrial areas”.

Also included in the immensely popular left-wing Mirror’s account was a colourful depiction of Wing Commander Guy Gibson’s selfless courage. The Daily Mirror explained how Gibson drew enemy fire to allow fellow Lancaster Bomber crews to press their own attacks.

None of the reports mentioned bouncing bombs. Their existence was strictly secret. The Mirror explained that Gibson dropped mines before flying alongside the Möhne dam to “attract the fire” of the anti-aircraft guns on it.

The equally popular Daily Express ran a headline across all eight columns of its front page: “Floods Roar Down Ruhr Valley”. It described waterspouts leaping 1,000 feet into the sky as the RAF pressed the attack. Wing Commander Gibson was pictured on the front page in uniform and smoking his pipe.

Elite titles joined the chorus. The Times celebrated “vast damage” that had dealt the enemy “a severe blow”. Sir Arthur Harris, head of RAF Bomber Command, had initially opposed the raid as ill-conceived. Now he explained that: “We had high hopes, but the immediate results of breaching the dams were beyond our expectations”. The Times praised Gibson’s leadership. It would praise him again ten days later when he was awarded the Victoria Cross.

The Manchester Guardian echoed the consensus. The raid demonstrated the audacity and courage of Gibson and the squadron he led. Gibson was “a pilot with contempt for danger”. He attacked with perfect accuracy and then, when “guns appeared out of slots in the wall of the dam”, he flew alongside it to draw flak away from his comrades. The raid was “a new blow at Ruhr industries”, the Guardian concluded.

In Britain, extensive newspaper coverage of the raid continued for two weeks after it took place. Air Ministry and Bomber Command reconnaissance pictures were offered and published. These were selected to provide “proof of the accuracy and intensity of the RAF attack”.

Terrible cost

Newspapers responded to the Dambusters by acting as cheerleaders for Bomber Command. They conveyed the message that precision was a particular attribute of the service that had excelled in the Battle of Britain and continued to display its efficiency in taking the war to Germany. In fact, accuracy in low-altitude attacks such as those on the dams was achieved at extremely high cost.

National hero: Guy Gibson.
CBW / Alamy Stock Photo

The Dambusters raid involved 19 Lancaster bombers of 617 Squadron. Each had a crew of seven. Eight failed to return. Of the 133 highly skilled airmen who flew from RAF Scampton in Lincolnshire on the night of 16 May 1943, 53 were killed. These were skilled and experienced crews.

Their loss was not prominent in contemporary reporting of the raid. Indeed, newspaper editors fell willingly in line with Sir Arthur Harris’ message to the surviving crews: “Your skill and determination in pressing home the attack will forever be an inspiration to the RAF”.

The Dambusters were inspiring. But while the Air Ministry engaged enthusiastically in public relations about the precision attacks on the Ruhr dams, it was not keen to repeat such complex precision bombing. Area bombing of enemy cities was a more efficient way to disrupt industry and kill German workers.

Five months after the Dambusters raid, 504 aircraft from RAF Bomber Command attacked the centre of the city of Hanover. This raid on the night of October 8-9 1943 killed 1,200 on the ground and inflicted serious damage on the city. Meanwhile, 27 bombers and their crews were lost. So, just over 5% of the aircraft and skilled crew sent to bomb Hanover failed to return. In the Dambusters Raid, 42% of the aircraft were lost and almost 40% of the aircrew died.

The statistics explain why Gibson and his colleagues deserve immense respect and gratitude for their skill and courage. The Dambusters raid was a triumph of secret planning, precision accuracy and outstanding technology carried out by heroes.

In addition to Gibson’s Victora Cross, survivors received awards including Distinguished Service Orders, Distinguished Flying Crosses, Conspicuous Gallantry Medals and Distinguished Flying Medals. The raid enhanced morale on the home front.

It was a huge propaganda victory, but it was not a model for future success. The bouncing bomb was never used again, but saturation bombing continued apace with Berlin, Dresden, Hamburg and Pforzheim among the cities reduced to rubble by area attacks. Läs mer…

The festive season can have a strange effect on our perception of time. Days blur together, hours stretch or vanish, and a sense of timelessness sets in. So, what better period to enjoy films that help us to reflect on time itself?

From mind-bending narratives to meditative explorations on time’s passage, these films are perfect for losing yourself – and finding new perspectives on time.

1. Citizen Kane (1941)

Orson Welles’ cinematic masterpiece doesn’t just tell the story of publishing tycoon Charles Foster Kane, it fragments it. It begins with Kane’s death and enigmatic final word, “Rosebud”. The film then unfolds in flashbacks narrated by those who knew him as they seek to discover the word’s meaning.

Each perspective adds a layer to his life while challenging the idea of a singular truth. Welles uses time as a puzzle, showing how memory and perception overlap to shape our understanding of the past.

Citizen Kane trailer.

2. Memento (2000)

Christopher Nolan’s breakthrough film has a reverse chronological structure, intercut with black-and-white sequences moving forward in time. The story is told through a series of scenes that move backwards while the protagonist, Leonard Shelby (Guy Pearce), moves forward with no short-term memory.

The film opens with the end so we know what happens but we don’t know why or how we got there. Each scene ends where the previous scene began, creating a sense of disorientation that mirrors Leonard’s condition.

3. The Clock (2010)

Christian Marclay’s 24-hour video installation turns time itself into art. It includes a stunning montage of scenes from film and television that feature clocks, timepieces or people waiting. More than 12,000 clips are meticulously assembled to create an artwork that itself functions as a clock.

The film’s presentation is synchronised with the local time, resulting in the time shown in any scene being the actual time. This makes viewers acutely aware of time’s passage while simultaneously losing themselves in a hypnotic stream of cinematic moments.

Cinematic and actual time run parallel in a 24-hour montage in The Clock.

4. High Noon (1952)

This landmark Western film collapses real time with screen time. Marshal Will Kane (Gary Cooper) is preparing to retire and leave town with his new wife, Amy (Grace Kelly). But he receives news that Frank Miller, a criminal he sent to prison, has been pardoned and is arriving on the noon train seeking revenge.

Despite pleas from his wife and townspeople to flee, Kane decides to stay and face Miller and his gang. He then finds himself increasingly isolated as the town abandons him. The film unfolds in approximate real time (85 minutes) between 10.40am and noon.

5. The Killing (1956)

Stanley Kubrick’s non-linear “one-last job” heist movie fragments time to brilliant effect. The narrative unfolds in a series of progressive flashbacks and even “flash sideways”, in which the actions and events are repeated from different characters’ points of view.

The studio hated it and asked him to cut it in a conventional fashion. But Kubrick abandoned the re-edit and returned the film to its original structure. As he told film critic Alexander Walker in 1971: “It was the handling of time that may have made this more than just a good crime film.”

The Killing’s official trailer from 1956.

6. Donnie Darko (2001)

This cult favourite merges teenage alienation and mental health with metaphysical time travel. Jake Gyllenhaal’s Donnie is haunted by visions and drawn into a “tangent universe” where time corrupts and loops back on itself. The film’s complex temporal structure involves parallel universes, predestination and sacrifice.

Its ambiguous ending leaves viewers debating whether Donnie’s actions were heroic sacrifice or delusion, making time itself an unreliable narrator.

7. Groundhog Day (1993)

Bill Murray’s cynical weatherman wakes up to the same day – again and again. As he relives February 1’s Groundhog Day in an endless loop, he is able to improve himself. He eventually evolves from selfishness and cynicism to empathy and kindness.

Interestingly, the film doesn’t reflect on why its protagonist relives the same day over and over again, and just accepts it.

Bill Murray’s character wakes up at 6am on the same day, every day.
Landmark Media/Alamy

8. Run Lola Run (1998)

This German-language thriller tells the same story three times, each with a different outcome. It presents alternative scenarios of Lola’s (Franka Potente) attempt to save her boyfriend’s life.

The film explores chaos theory and the butterfly effect through kinetic storytelling, with tiny variations in Lola’s choices rippling into dramatically different futures. The film’s use of different media, including animation and still photography, for different temporal states adds visual sophistication to its exploration of chance and choice.

9. Arrival (2016)

Time is not linear, at least not for the alien visitors in Denis Villeneuve’s sci-fi drama. As linguist Louise Banks (Amy Adams) learns to decode their language, she begins to experience time as they do – all at once.

The “Heptapod” language requires understanding the entire sentence before beginning it. This serves as a metaphor for how we might experience time if we could see it all at the same time.

10. Back to the Future (1985)

Marty McFly races through time.
Ralf Liebhold/Shutterstock

Few films play with the concept of time as joyfully as Robert Zemeckis’s 1980s classic, and no list of this type would be complete without it. Marty McFly (Michael J. Fox) adventures between the 1980s and 1950s using a DeLorean car retrofitted as a time machine.

It explores time, space and consequence, as Marty races to ensure his teenage parents fall in love to restore the future. It also spawned two popular sequels.

All of these films remind us that time isn’t just a backdrop. It’s a force that shapes our lives, memories and stories. As you sink into the cosy limbo of the season, let these cinematic journeys through time inspire reflection on your own. Läs mer…

On Boxing Day 2004, an earthquake in the Indian Ocean near Indonesia set off a tsunami which killed almost 250,000 people. It was the deadliest natural disaster this century, and was probably the deadliest tsunami in human history.

As coastal engineers who specialise in tsunamis and how to prepare for them, we have seen how the events of 2004 reshaped our global disaster management systems. Among the lessons learned since that day, three themes stand out.

First, the importance of early warning systems, providing time to escape impact zones. Second, the importance of local preparations and educating people about the risks. Finally, the ongoing need for – but not overreliance on – coastal defences.

The evolution of early warning systems

The absence of a comprehensive early warning system contributed to the devastating loss of life in 2004. About 35,000 people died in Sri Lanka, for instance, which wasn’t hit until two hours after the earthquake.

Significant investment has been made in the years since, including the Indian Ocean tsunami warning system which operates across 27 member states. This system was able to issue warnings within eight minutes when another earthquake struck the same part of Indonesia in 2012. Similarly, when an earthquake hit Noto, Japan, in January 2024, swiftly issued tsunami warnings and evacuation orders undoubtedly saved lives.

However, these systems are not in use globally and weren’t able to detect the tsunamis that swept the Tongan islands in 2022 following the eruption of an undersea volcano in the South Pacific. In this instance, better monitoring of the volcano would have helped detect the early signs of a tsunami.

Championing community resilience

But early warning systems alone are not enough. We still need education and awareness campaigns, evacuation drills, and disaster response plans.

This sort of planning proved effective in the village of Jike, Japan, which was hit by the Noto tsunami in January 2024. Having learned from a major tsunami in 2011 (the one that hit Fukushima nuclear power plant), engineers constructed new evacuation routes to tsunami shelters. Though the village was destroyed, residents evacuated up a steep stairway and no casualties were reported in Jike.

Left: The coastline near Jike, Japan. Right: The lifesaving evacuation route to the top of the hill behind Jike.
Tomoya Shibayama

The role of engineering defences

In the years since the Boxing Day tsunami, countries at risk have invested in “hard” engineering defences including seawalls, offshore breakwaters and flood levees. While these structures offer a measure of protection, their effectiveness is limited.

In Japan, the idea that hard measures can protect against the loss of life has been discarded, with the view that large-scale tsunamis can overwhelm even the most robust defences. For instance, in 2011, even a rubble breakwater followed by a five-metre-high wall could not protect the city of Watari. The tsunami covered half the city and hundreds of people died.

Tsunamis in the past decade or two have exposed vulnerabilities in existing protection strategies, with our field surveys showing breakwaters and other structures having suffered severe damage. While complete failure is expected in the face of extreme events, it’s crucial that certain critical infrastructure, such as power plants, are designed to withstand the biggest tsunamis. This requires further research into resilient engineering designs that may be able to partially fail but remain functional.

Measuring inundation depth at a house damaged by the 2004 tsunami, during the authors’ field survey in Polhena, Sri Lanka.
Ravindra Jayaratne

After the 2011 tsunami, Japanese engineers created two tsunami measurement levels. Level one tsunamis are more frequent, occurring perhaps once every century, but less dangerous.

Level two tsunamis are the big ones that any given bit of coastline might expect only once every thousand or so years: Indian Ocean 2004, Japan 2011. It is these tsunamis that critical infrastructure like power plants must prepare for. Nothing will entirely hold back a 2004-sized tsunami, but the goal is for structures to overflow without being destroyed. They should still be able to assist the evacuation process by reducing tsunami height and delaying the time it takes.

In the labs, the authors work on modelling how seawalls will respond to a tsunami.
Ravindra Jayaratne

Despite evolving views on hard defences, there remains value in building and planning coastal urban areas in more sustainable and responsible ways. In particular, critical infrastructure and densely populated areas in tsunami-threatened regions should be built on higher ground where possible.

Engineering advancements must also account for environmental consequences, including damage to ecosystems and disruption of natural coastal processes, with consideration given to nature-based solutions. Strengthening coral reefs with rock armour or heavy sandbags, and planting coastal forests as buffer zones may be a cheaper and more ecologically sensitive option than building high walls.

Climate change and the road ahead

The progress is undeniable. However, tsunami and earthquake data still isn’t shared widely around the world, and local authorities and experts often don’t communicate the risk to residents of flood-prone communities. The passage of time can erode the memory of best practice when it comes to people’s disaster preparedness.

Added to that, rapid climate change is making sea levels rise and extreme weather, such as storms, more frequent. This doesn’t cause more tsunamis, but it can make them worse, and it does make “hard” defences less sustainable in the long term.

While significant and urgent challenges remain, they are not insurmountable. By continuing to learn more about tsunamis and to prepare for the worst, we can minimise their impact and protect millions of lives.

Don’t have time to read about climate change as much as you’d like?
Get a weekly roundup in your inbox instead. Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. Join the 40,000+ readers who’ve subscribed so far. Läs mer…

A new artificial intelligence (AI) model has just achieved human-level results on a test designed to measure “general intelligence”.

On December 20, OpenAI’s o3 system scored 85% on the ARC-AGI benchmark, well above the previous AI best score of 55% and on par with the average human score. It also scored well on a very difficult mathematics test.

Creating artificial general intelligence, or AGI, is the stated goal of all the major AI research labs. At first glance, OpenAI appears to have at least made a significant step towards this goal.

While scepticism remains, many AI researchers and developers feel something just changed. For many, the prospect of AGI now seems more real, urgent and closer than anticipated. Are they right?

Generalisation and intelligence

To understand what the o3 result means, you need to understand what the ARC-AGI test is all about. In technical terms, it’s a test of an AI system’s “sample efficiency” in adapting to something new – how many examples of a novel situation the system needs to see to figure out how it works.

An AI system like ChatGPT (GPT-4) is not very sample efficient. It was “trained” on millions of examples of human text, constructing probabilistic “rules” about which combinations of words are most likely.

The result is pretty good at common tasks. It is bad at uncommon tasks, because it has less data (fewer samples) about those tasks.

AI systems like ChatGPT do well at common tasks, but struggle to adapt to new situations.
Bianca De Marchi / AAP

Until AI systems can learn from small numbers of examples and adapt with more sample efficiency, they will only be used for very repetitive jobs and ones where the occasional failure is tolerable.

The ability to accurately solve previously unknown or novel problems from limited samples of data is known as the capacity to generalise. It is widely considered a necessary, even fundamental, element of intelligence.

Grids and patterns

The ARC-AGI benchmark tests for sample efficient adaptation using little grid square problems like the one below. The AI needs to figure out the pattern that turns the grid on the left into the grid on the right.

An example task from the ARC-AGI benchmark test.
ARC Prize

Each question gives three examples to learn from. The AI system then needs to figure out the rules that “generalise” from the three examples to the fourth.

These are a lot like the IQ tests sometimes you might remember from school.

Weak rules and adaptation

We don’t know exactly how OpenAI has done it, but the results suggest the o3 model is highly adaptable. From just a few examples, it finds rules that can be generalised.

To figure out a pattern, we shouldn’t make any unnecessary assumptions, or be more specific than we really have to be. In theory, if you can identify the “weakest” rules that do what you want, then you have maximised your ability to adapt to new situations.

What do we mean by the weakest rules? The technical definition is complicated, but weaker rules are usually ones that can be described in simpler statements.

In the example above, a plain English expression of the rule might be something like: “Any shape with a protruding line will move to the end of that line and ‘cover up’ any other shapes it overlaps with.”

Searching chains of thought?

While we don’t know how OpenAI achieved this result just yet, it seems unlikely they deliberately optimised the o3 system to find weak rules. However, to succeed at the ARC-AGI tasks it must be finding them.

We do know that OpenAI started with a general-purpose version of the o3 model (which differs from most other models, because it can spend more time “thinking” about difficult questions) and then trained it specifically for the ARC-AGI test.

French AI researcher Francois Chollet, who designed the benchmark, believes o3 searches through different “chains of thought” describing steps to solve the task. It would then choose the “best” according to some loosely defined rule, or “heuristic”.

This would be “not dissimilar” to how Google’s AlphaGo system searched through different possible sequences of moves to beat the world Go champion.

In 2016, the AlphaGo AI system defeated world Go champion Lee Sedol.
Lee Jin-man / AP

You can think of these chains of thought like programs that fit the examples. Of course, if it is like the Go-playing AI, then it needs a heuristic, or loose rule, to decide which program is best.

There could be thousands of different seemingly equally valid programs generated. That heuristic could be “choose the weakest” or “choose the simplest”.

However, if it is like AlphaGo then they simply had an AI create a heuristic. This was the process for AlphaGo. Google trained a model to rate different sequences of moves as better or worse than others.

What we still don’t know

The question then is, is this really closer to AGI? If that is how o3 works, then the underlying model might not be much better than previous models.

The concepts the model learns from language might not be any more suitable for generalisation than before. Instead, we may just be seeing a more generalisable “chain of thought” found through the extra steps of training a heuristic specialised to this test. The proof, as always, will be in the pudding.

Almost everything about o3 remains unknown. OpenAI has limited disclosure to a few media presentations and early testing to a handful of researchers, laboratories and AI safety institutions.

Truly understanding the potential of o3 will require extensive work, including evaluations, an understanding of the distribution of its capacities, how often it fails and how often it succeeds.

When o3 is finally released, we’ll have a much better idea of whether it is approximately as adaptable as an average human.

If so, it could have a huge, revolutionary, economic impact, ushering in a new era of self-improving accelerated intelligence. We will require new benchmarks for AGI itself and serious consideration of how it ought to be governed.

If not, then this will still be an impressive result. However, everyday life will remain much the same. Läs mer…

I am standing on a dune looking out to sea. It’s 2024, but I’m thinking about a very different time. Hundreds of thousands of years ago this 350km stretch of southern African coast looked very different. It was home to giant zebra, bird species that are now extinct, giant tortoises and crocodiles. Our hominin ancestors roamed the area.

We know some of these facts because of body fossils. But South Africa’s Cape south coast is also home to another rich source of information, which our research team from the African Centre for Coastal Palaeoscience at Nelson Mandela University has documented over the past 15 years: fossilised tracksites. These trace fossils date to the Pleistocene epoch, with ages ranging from 400,000 years to 35,000 years. Most of them are preserved in a rock type known as aeolianite (cemented dune surfaces).

The tracksites are an example of what’s known as geoheritage, which the Geological Society of South Africa calls a “descriptive term applied to sites (geosites) or areas of geologic features with significant scientific, educational, cultural, or aesthetic value”. The importance of geoheritage is becoming increasingly recognised at a global level; for example, it is relevant to the United Nations’ 2030 Agenda Sustainable Development goals, and Unesco’s Global Geoparks “celebrate the links between geological heritage and all other types of heritage”.

Given our discoveries on the Cape south coast, as well as what other researchers have found in the West Coast National Park, about 120km outside Cape Town, it’s clear that South Africa is home to some remarkable geoheritage.

Read more:
Gigantic wolverines, otters the size of wolves: fossils offer fresh insights into the past

In a recently published scientific paper we outlined this geoheritage, examined the threats it faces from both nature and human interference, and suggested how it could be preserved.

These sites have almost certainly come and gone over previous centuries and millennia without our knowledge. However, now that we know about them and can appreciate them, scientists and heritage authorities have an obligation to celebrate, protect and preserve them as vitally important geoheritage items, and to raise awareness about this precious, newly discovered resource.

Threats

A stretch of South Africa’s Cape south coast.
Raphael Rivest/Shutterstock

The Cape coastal sites are threatened on many fronts. Cliff collapse events expose new sites, while known sites slump into the sea or are eroded rapidly by wind, high tides and storm surges. In addition, humans find these surfaces attractive and engrave graffiti into them, potentially damaging the precious fossil tracksites.

Read more:
Graffiti threatens precious evidence of ancient life on South Africa’s coast

Many of the sites are of hominin origin. Some are ancestral human trackways; others preserve patterns made by our ancestors on dune surfaces that may be some of the oldest examples of art. These patterns, which we’ve dubbed ammoglyphs, have been reported only on the Cape coast and nowhere else in the world. They are therefore of global heritage value. One site even contains the oldest known fossil footprint attributed to our own species.

Read more:
World’s oldest _Homo sapiens_ footprint identified on South Africa’s Cape south coast

I regard each of these sites as a miracle of preservation, of something that we are now able to recognise and interpret, against all the odds. We know what to look for and we know these surfaces have the capacity to record this priceless heritage. We just need to be vigilant and keep visiting this coastline, especially after storm surges or cliff-collapse events.

Managing the sites

Mixed with this good fortune, however, come problems, questions, and management challenges.

This fragile site in the Garden Route National Park, featuring large fossilised flamingo tracks, was destroyed by a storm surge, but it is preserved through a digital 3D photogrammetry model.
Charles Helm, Author provided (no reuse)

Which sites require active management, and how should they be ranked in importance? What is the scientific and heritage value of the sites? Is physical recovery possible by helicopter or four-wheel drive, or is replication through digital technology the most appropriate route to follow? And if physical recovery is possible, are there suitable repositories for specimens? What if nothing is done – how significant are the threats to a site’s integrity, and how accessible or remote is it?

In addressing these challenges, we came up with a ranking checklist. At a global level, such checklists are surprisingly rare; we are aware of only two examples.

We used these as a basis for our checklist, modifying their criteria to be applicable to the Cape coast. Criterion categories included a site’s uniqueness and scientific value, threats in the current location, accessibility and feasibility of recovery, research and education value, and the potential for post-removal care.

The resulting checklist forms the basis for constructive collaboration with management authorities like national parks, provincial nature reserves, municipalities or private landowners, as well as national and provincial heritage authorities. Good working relationships between these roleplayers and scientific researchers are key if geoheritage sites are to properly handled and preserved. The published article and the ranking checklist are not an end in themselves. We hope they will provide a starting point for meaningful collaboration and discussion. Läs mer…

20 years have passed since the Aceh tsunami, leaving deep scars on Indonesia, especially for those directly affected. Aceh was also recovering from a three-decade armed conflict between the Free Aceh Movement and the national government

Throughout December 2024, The Conversation Indonesia, in collaboration with academics, is publishing a special edition honouring the 20 years of efforts to rebuild Aceh. We hope this series of articles preserves our collective memory while inspiring reflection on the journey of recovery and peace in the land of ‘Serambi Makkah.’

In the aftermath of the 2004 Indian Ocean Tsunami, the Acehnese interpreted the disaster in various ways.

Initially, the tsunami was interpreted as a punishment or warning from God. Over time, a collective interpretation of the disaster emerged: “The tsunami as a test from God”.

This later narrative was compelling enough to accelerate the post-tsunami recovery process. People in Aceh moved past the tsunami trauma by believing their deceased family members were martyrs who deserved a place in heaven, while those who survived were given the opportunity by Allah to live better lives.

The process of forming this narrative is called memory canonisation. It occurs when the government and ruling elites impose a specific interpretation or narrative of a disaster, including what to remember and how to remember it.

Memory canonisation is evident in the creation of disaster monuments and commemoration events, including in Aceh. Unfortunately, many survivors feel detached from the monuments because they do not evoke personal memories of the tsunami.

Memory canonisation through monuments

Constructing permanent memorials after a disaster is a common trend in a modern society. Many tsunami monuments exist in Aceh, and some have even become tourist destinations.

Tsunami monuments can be divided into two categories based on the construction.

First, monuments built from tsunami debris that are deliberately maintained, modified, or enhanced with certain elements. Examples include the stranded electric-generator ship (the PLTD Apung), the ship on the top of a house in Lampulo, and the tsunami debris at the Rahmatullah Mosque in Lampuuk.

Second, monuments intentionally designed and constructed as new buildings after the tsunami, such as the Aceh Tsunami Museum and the Tsunami Poles erected in over 50 locations across Banda Aceh and Aceh Besar.

Historical images of the 2004 Aceh tsunami displayed at the Aceh Tsunami Museum. Rizki Mulana/shutterstock.

The establishment of disaster memorials is always political. Disaster monuments represent how governments and elites promote specific interpretations as dominant. This is achieved through specific architectural designs or curated narratives in the monument.

However, the memory canonisation process is never final. Once established, each disaster monument becomes a place to form, strengthen, modify, alter, and revise the interpretation of the disaster.

How monuments affect Acehnese memory – or not

In a post-disaster situation, the affected community faces ‘push and pull’ between remembering and forgetting the disaster. They must let go of trauma to move forward while preserving disaster memories to honour victims and enhance future preparedness.

The memory of the disaster resides in the back of their mind, but not constantly remembered in everyday life. It will move to the surface as an active memory only when triggered by certain factors, such as a place, object, or event. This memory closely relates to how the survivors give meaning to the disaster.

In everyday life, survivors interact with disaster monuments in various contexts –for instance, as a source of income or a place for leisure. Thus, the meaning of a disaster monument can vary, even becoming completely unrelated to its creators’ narratives and original goals.

Preliminary findings from my ongoing research in Aceh show that among survivors, tsunami memories are often triggered by specific places associated with their experiences. These include the house where they found safety, the coastal area that swept them away, or the ruins of their homes. I refer to these as “the forgotten memories of the tsunami.”

Since many tsunami monuments were erected without involving local residents, they feel barely connected, let alone have a sense of ownership, towards the monuments. For survivors, the established monuments do not trigger their memories of the tsunami.

Disaster monument for disaster education

Today, 20 years after the tsunami, we can still meet survivors who offer valuable and insightful stories about starting over, rebuilding their homes and villages, and cultivating cultural awareness about tsunamis while embracing vulnerability.

However, once these survivors pass away, future generations will lose access to primary sources of learning about the tsunami. This includes new inhabitants who moved to Aceh after the tsunami and rent houses in coastal areas.

The names of the 2004 Aceh tsunami victims are written on one of the memorials. Sofyaaaa/shutterstock.

They will, therefore, depend on the tsunami memorials around them, though many have been neglected.

To address these risks, I recommend two measures.

First, we can document the “forgotten tsunami memories” creatively through formats like documentary videos, comics, photos, social media content, or other mediums that highlight stories offering insights into disaster risk reduction and education for younger generations.

Second, we must encourage sustainable and meaningful interactions between locals and tsunami monuments. Disaster memorials serve their purpose best — preserving the memory of the disaster and educating younger generations — when they remain relevant to residents’ daily activities.

Locals’ active participation is essential in Aceh, including school visits and involvement in preservation and curation efforts.

These measures aim to foster a sense of ownership among residents of the tsunami monuments in their neighbourhoods. They encourage voluntary maintenance of the monuments and make them integral to disaster risk reduction efforts. Läs mer…

20 years have passed since the Aceh tsunami, leaving deep scars on Indonesia, especially for those directly affected. Aceh was also recovering from a three-decade armed conflict between the Free Aceh Movement and the national government

Throughout December 2024, The Conversation Indonesia, in collaboration with academics, is publishing a special edition honouring the 20 years of efforts to rebuild Aceh. We hope this series of articles preserves our collective memory while inspiring reflection on the journey of recovery and peace in the land of ‘Serambi Makkah.’

Acehnese women have long been integral to the history of their region, particularly after the 2004 tsunami, one of Indonesia’s deadliest natural disasters, and the Helsinki Peace Agreement, which ended years of conflict between the government and the Free Aceh Movement (GAM). Despite their crucial contributions to rebuilding and fostering peace, women in Aceh still face major challenges in ensuring that the peace achieved includes their needs and rights.

Their efforts often go unrecognised, and the policies that shape their lives fail to address their realities. In some cases, these policies actively discriminate against women.

Policies that marginalise women

As the conflict in Aceh escalated into firefights, lasting over a decade of 1989-2005, many women became primary breadwinners, ensuring their children’s education and providing emotional support to their families. Around 2,000 women actively participated in the fight, picking up arms as combatants.

In the years following the 2004 tsunami and the 2005 Helsinki Peace Agreement, some progress was made to include women in policy-making processes. However, the outcomes have been unremarkable. Policies implemented after the peace agreement rarely put women’s needs first or acknowledged their efforts.

For instance, Aceh’s 2009 Qanun–a regulation unique to Aceh–aims to promote women’s empowerment and protection, but its implementation remains weak. Women have little say in decision-making, and their representation in province, district, and city-level leadership posts remains minimal.

Here are some examples of how women in Aceh have been sidelined in decision-making, discriminated against in their daily lives and frequently harassed:

Absent in politics: In 2017, only one woman was elected deputy mayor among 23 district leaders. Similarly, just two out of 65 top provincial officials were women. These figures reflect a stark imbalance, especially when compared to the substantial roles women played during the conflict and its aftermath.
Clothing guideline: Regulations ostensibly implemented under Islamic law often restrict women’s freedoms. For example, West Aceh’s 2010 regulation requires women to wear skirts, prohibiting the use of trousers despite their roots in traditional Aceh’s attire. Women become subjects of public inspection, and violations ends with them not receiving public services that should be open for any citizens.
Discriminatory norms and limiting women’s freedom: In Lhokseumawe, a 2013 circular mandated women ride sidesaddle on motorcycles, even though such a position increases the risk of accidents. Similarly, a 2018 directive in Bireuen forbids women from being served in cafes after 9 PM without a male guardian and bans women from sitting with unrelated men.
Gender-based violence: Aceh also faces high rates of violence against women. Between 2019 and 2023, more than 5,000 cases of violence against women and children were reported. Shockingly, Aceh has the highest number of rape cases in Indonesia.
Insufficient support for victims: Despite the severity of the issue, support for survivors remains inadequate. From 2020 to 2024, only 0.12% of Aceh’s provincial budget was allocated to the Women’s Empowerment and Child Protection Agency. While this allocation has increased slightly over time, it is still lacking to address the needs of women, particularly those who suffered from violence and the conflict.

Young women as the agents of change

The younger generation, particularly Gen Z, offers hope for a brighter future. Acehnese young women are increasingly leveraging digital platforms to advocate for their rights and challenge societal norms. Their ability to connect with global networks gives them tools to amplify their voices and demand equality.

This new generation has the potential to drive meaningful change, but they face entrenched patriarchal norms that require dismantling. To achieve substantial peace and gender equality in Aceh, empowering young women as agents of change and supporting their initiatives to create a more inclusive society is essential.

To ensure that Aceh achieves lasting peace that benefits everyone, several steps are necessary:

Inclusive policy-making: Women must be included in all decision-making processes, especially those related to peacebuilding and post-conflict recovery.
Reforming discriminatory policies: Laws restricting women’s rights must be repealed to create a more equitable environment.
Comprehensive support for survivors: Addressing the needs of survivors of violence through legal, medical, and psychological support is crucial.
Strengthening Legal Protections: Laws like Aceh’s Qanun Jinayah (Islamic Criminal Law) should be revised better to protect women, particularly victims of sexual violence.

Acehnese women have demonstrated remarkable resilience and strength throughout the region’s history. By ensuring their voices are heard and their rights respected, Aceh can move closer to achieving true peace and equality for all its citizens. Läs mer…