It is two decades since Facebook introduced the News Feed – letting loose a world in which algorithms would shape ever more of our lives.

In 2006, Facebook was facing something of a crisis. Its internal data suggested that for the first time since its launch two years earlier (as TheFacebook), the company had stopped growing. People weren’t joining, and existing users weren’t spending more time on the site.

The solution co-founder Mark Zuckerberg and colleagues came up with, the News Feed, meant individual users’ homepages would be automatically updated with information tailored to them – in particular, new posts their Facebook friends had added.

Up to then, users had to actively check their friends’ profiles to see what they were up to. Now, this information would automatically be sent to your homepage. With it, a new world of algorithmic interaction was born.

It might seem quaint now, but for many Facebook users at the time, these changes felt like a violation of their privacy and trust. If you were to change your relationship status from “in a relationship” to “it’s complicated”, for example, this could now be broadcast to all of your online friends.

The News Feed caused the first major protest against Facebook. Tens of thousands of users joined a group calling for the return of the original system. A spontaneous protest emerged outside Facebook’s office in the city of Palo Alto, California. For the first time, the company felt it had to hire security guards.

Zuckerberg issued a sort-of-apology, but he didn’t back down. What he and other Facebook engineers could see was that, rather than pushing people away from the site, the News Feed was driving more engagement – leading users to spend more and more time on the platform.

A revolution in media consumption

Twenty years later, we can understand this development as one of the most significant socio-technical changes of the entire digital revolution. It ushered in an age where algorithmic systems structured how people interacted, consumed news and conducted political activity.

Crucially, to enable this new “content pushing” approach, Facebook engineers had to build a new digital architecture that moved the site away from being a static social network, into an algorithmic system built around the extraction and analysis of user data.

Under this new system, in the words of researchers Christina Alaiamo and Jannis Kallinikos, Facebook users could be “computed on the basis of discrete and countable activities”, turning them into “identifiable, knowable and actionable objects”.

Facebook had thus shifted from a site primarily enabling social interaction to one concerned with the production and commercialisation of knowledge. With increasing accuracy, it understood what type of content kept users on the site longer – and what type of information could influence people’s behaviour outside and beyond the site.

Facebook could now continuously optimise the level of social interactions using its algorithmic ranking system, Edge Rank. With a tweak, it could switch from prioritising messages from close friends to content that generated greater interaction, or outrage.

This took power away from users towards the corporation, and raised concerns that users were spending more time on the site than they seemed to want to. (Eventually, this would lead to a “major overhaul” of the News Feed in 2018, with Facebook promising to re-prioritise “meaningful social interactions” over “relevant content”.)

But above all, Facebook’s innovation in 2006 enabled it to capture huge amounts of user data that would, over the next two decades, enable it to expand globally at an astonishing rate – and generate vast amounts of revenue in the process.

A very different algorithmic age

Twenty years on, Facebook’s parent company Meta and other big tech platforms face challenges far more powerful than spontaneous protests on the streets of Palo Alto. Across the world, there is sustained activity from democratic institutions and states to contain the power and perceived harm of the algorithmic systems that emerged from 2006.

In Australia, use of social media platforms by under-16s is banned, and this is potentially spreading to the UK. Meanwhile, courts in the US have forced Meta to restrict the amount of access that children have to their products. While less than 1% of Facebook’s revenue comes from teens, the precedents set by these legal cases appear significant.

However, we also live in a very different algorithmic age than the one heralded by the launch of the News Feed 20 years ago. While Meta continues to derive most of its revenue from its social network platforms, which also include Instagram and WhatsApp, recent investments and prospective AI product launches suggest its leadership believe future revenue streams will largely be tied to developments in machine learning, large language models and “superintelligence”.

The question is: will governments and other institutions react more quickly to the concerns raised by this new era of AI development than they did to the emergence of algorithms two decades ago? On past evidence, this looks unlikely.

Asher Kessler received funding from the Economic and Social Science Research Council.

Heatwaves claimed the lives of tens of thousands of people in Europe’s capital cities this summer, as they experienced record temperatures.

In London, emergency wards filled with elderly patients injured after fainting in the heat. Meanwhile, the dry weather created subsidence and left homes with cracks.

In Paris temperatures exceeded 40°C in late June and people struggled to carry on their lives, and in Madrid, heatwaves burned thousands of hectares on the outskirts of the city.

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Read more: Can the searing European summer put climate action back on the agenda – or will disaster response take over?

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How trees can help

Thami carried out preliminary research on the results of extreme heat on European cities this summer. The study looked into how many buildings have adequate shade from trees. The results were striking.

In London, Paris and Madrid over 90% of buildings did not have enough shade around them to prevent urban heat island effects. These were among the worst results in cities we studied, but even the best performers had a majority of residents without adequate heat protection – cities like Hamburg (56% unprotected) and Barcelona (70% unprotected).

This builds on past research that shows how major cities around the world – including in Europe – tend to struggle to reach useful levels of tree canopies to create shade close to homes and workplaces. It suggests that that homes should have a view of three trees and be within a 300 m walk of a park.

Early results for my research suggests that huge portions of European cities are exposed to avoidable heat island effects.

How urban heat islands work

On many days during summer 2026 it didn’t get much cooler in the evening. This is because of what is known as the urban heat island effect. Cities typically lack shade, due to high rates of tree removal, sparse planting, and poor tree health and there are vast amounts of asphalt, clay and concrete. These are almost the perfect materials to soak up and hold heat from all that direct sunshine. Unshaded asphalt can reach over 70°C on heatwave days.

Even after sunset, cities stay hot because roads, buildings and footpaths begin to radiate their absorbed heat back at us as they cool. The urban heat island effect can add significantly to ambient temperatures, making a day that is already very hot (perhaps 35°C) even more dangerous in high-asphalt, low shade locations (over 40°C).

What could help?

Tree shading is an effective strategy to address this urban heat, with a range of other mental and physical health benefits to local residents. Trees prevent solar radiation reaching heat-absorbing materials such as asphalt, and also keep the sun off our bodies. Tree shade has been shown to reduce the heat absorbed by pedestrians by up to 18°C.

Healthy trees also push water out of their leaves as they photosynthesise, which soaks up heat as it evaporates. This evaporative cooling effect adds an extra few degrees of cooling, in addition to shading people and preventing heat island effects, even during heatwaves as long as trees still have access to water.

Where trees are needed

Planting more trees in cities in the wake of this summer’s heatwaves is going to help cool urban areas down. The thinktank, the Create Streets Foundation, found the temperature on an exposed paved area in London during one heatwave was 55°C but was 25-30°C in a shaded area metres away.

Looking at a city such as London, you might argue that it already has plenty of trees: around 8 million.

But trees are only effective tools against urban heat when they’re close to homes. A lush shady park 800m away isn’t going to prevent dangerous localised heat island effects for you and your neighbours.

The other crucial factor is that there are thresholds of shade cover that have to be reached for trees to actually offer substantial cooling. A few isolated trees creating small islands of shade aren’t enough. Adding more tree canopy has been shown to be effective at preventing urban heat islands when it reaches 30-40% overall shade cover, within 60m of homes and workplaces.

It will also be important to plant trees that are best able to cope with increasingly hot temperatures in Europe.

Adding just a few degrees to an already hot day sharply ramps up the danger that heat poses. In locations where heat islands bump up the ambient air temperature from 33°C to 37°C, or 35°C to 41°C, there’s an increase in patients attending hospital admissions’ rooms due to heat related illness. When air temperature increases above 35°C the human body’s ability to manage the heat is greatly reduced; cardiovascular strain, dehydration, potentially leading to heatstroke and the need for medical intervention.

When it makes nights hotter there are other ramifications. It is during the cooler night hours that the body loses heat to reset for the following day. If the body is still trying to cope with warm temperatures, 24°C and above, this impacts recovery and impairs sleep quality. This means we start the next day in deficit, both physiologically and cognitively, to cope with another hot day. Repeated exposure to days of high heat mean that the deficit builds over time.

Adding more trees works

Medellin in Colombia is an example of what happens when more plants are added to urban streets.

In just a few years, millions of plants and over 12,500 trees were added to form a network of lush greenways across Colombia’s second largest city.

This project has resulted in significant drops in temperature (of 4.5°C in some areas, and 2°C citywide).

There are signs that Paris and London are aware they need to make changes. The recently announced Heat Ready London plan includes a focus on urban greening.

Paris is already starting to add more green space. The city’s school streets programme not only creates safe, car-free areas close to local schools, but also has added more trees. Evidence already suggests that surfaces in school streets are 5°C cooler than their traffic-heavy counterparts, with fewer trees.

As Europe prepares for more hot summers, planting trees close to homes needs to be high on the agenda to help people cope.

Thami Croeser has previously recieved funding from The Australian Research Council, Greenlife Australia, and the European Union's Horizon 2020 program. He is a Director of the Australasian Green Infrastructure Network, a not-for-profit peak body. He occasionally provides urban forest advisory and analytics services in a private consulting capacity.

Simon Hodder has previously received funding from the European Union's Horizon 2020 program and UKRI, Engineering and Physical Sciences Research Council (EPSRC).

Amy, a 27-year-old software developer, has struggled with disordered eating since she was a teenager. “But after learning to code, I got much better,” she said in a research interview. “I often code for ten or more hours without stopping.” Her psychiatrist, however, worried that Amy has replaced one compulsive behaviour with another.

“Digital addiction” is often used to describe our relationship with smartphones, social media and other digital technologies. This way of thinking suggests that people get “hooked” on digital activity because their body becomes “addicted” to dopamine. It borrows from models of substance addiction: the focus is on the physical need to keep using a substance because the body has adapted to it, despite harmful consequences. The implied solution is straightforward: abstinence, which translates into practices like digital detox.

But Amy’s story, which forms part of our ongoing research, points to a more complicated reality of our relationship with digital technology. Coding consumed much of her time and attention, yet it also helped her earn an income and build a professional identity. Like many forms of digital engagement, it was not just a distraction but a way of navigating life.

As research shows, for many people digital technologies are not only a source of entertainment but key components of their education, work and social mobility. Unlike in the case of addictive substances, opting out of digital life is easier said than done when schools, banks and public services increasingly require it.

How people relate to digital technology isn’t just about them as individuals. It’s shaped by their personal vulnerabilities, but also by digital environments intentionally built to hook us, and by the wider social conditions people live in.

So comparing smartphones to substances like alcohol, tobacco or drugs can be misleading. It overlooks the fact that digital devices have become a kind of essential infrastructure for daily life. Given how we have built our lives around them, these technologies are now very difficult to live without.

How, then, do we develop a sustainable relationship with technologies such as smartphones that are both indispensable and potentially harmful?

The sugar model

Amy’s story with disordered eating may be useful here. Recovery from an eating disorder isn’t about eliminating food altogether, but about learning to live with it.

In the same way that we cannot remove food from our lives, it is also difficult to remove digital technologies from our everyday. So the challenge becomes developing ways of living with them.

Take, for example, sugar. In many countries, foods high in sugar are subject to a wide range of public health measures. Think national food safety standards, public health interventions, school nutrition policies, limits on advertising. So it’s not about focusing on one thing only. Rather, it’s the interaction between all of these interventions that shapes patterns of consumption and impacts wellbeing.

A similar approach is needed for digital technologies. At the level of state and industry governance, this includes regulation of platform and design – particularly when it is aimed at capturing and holding users’ attention.

Just as food labels describe ingredients, nutrition and additives, digital products could disclose what data they collect, what algorithms they run on and what psychological techniques keep their users engaged.

The UK’s decision to ban social media for under 16s while continuing to expand digital literacy and coding education reflects an important point: not all digital technologies are the same.

“Digital use” cannot be treated as a single category to be either embraced or banned. Like sugar, the question is not whether children should have it at all, but what kinds, in what quantities, and in what conditions.

Beyond counting calories and screen hours

Just as sharing a meal with family affects people differently from eating alone, playing games with friends is not the same as scrolling endlessly through social media. Both count as screen time, but they create very different social and emotional experiences.

Reflecting on our own digital habits remains important. But tracking screen time is like counting calories: it tells us how much, but not necessarily why. We have to ask ourselves what role digital technologies play in our lives.

Are they helping us work, connect, rest, escape, cope, feel less or more alone? Without this kind of reflection, self-tracking risks turning a complex social issue into a matter of individual self-control.

Understanding digital technologies through the lens of food rather than addiction shifts the emphasis in important ways. Both are domains where necessity, pleasure, risk and social obligation are intertwined, which is why abstinence may not be an adequate, long-term response.

Instead of treating excessive technology use as a matter of personal discipline, approaching them like some foods locates it within broader systems of design, industry governance, state policy and social practices. The challenge then is to integrate these different levels to make life with digital technologies sustainable.

Tanja Ahlin receives funding from the Dutch Research Council (NWO), Grant number VI.Veni.241S.150, https://doi.org/10.61686/EWUXQ23921

Xin Zhan receives funding from the University of Cambridge.

I teach a university course called Hormones and Behaviour. What surprises students is that biological sex is not produced by a single switch. What surprises me is that many students have never been taught this before. It is basic biology, but it helps explain life.

Sex emerges through a sequence of events before birth and continues at puberty. Chromosomes help direct the formation of gonads, the body parts that usually become ovaries or testes. Gonads make hormones. The body then has to respond to those hormones. In most people, these steps flow in the same direction. But in rare cases, they do not.

These cases are known as disorders, more recently differences, of sex development (DSDs). They are not new but they provide a useful way to understand how bodies develop. DSDs can affect hormone production. Some affect the body’s response to hormones. Some affect chromosomes or gonad development. Two people can have a DSD, yet have very different bodies, medical needs and life experiences.

Each condition reveals what can happen when one step in the normal sequence is altered. Here are five ways sex development can take a different path.

Congenital adrenal hyperplasia

This DSD affects around one in 16,000 births.

The adrenal glands, which normally produce small amounts of male hormones, even in females, are hyperactive in this condition.

A baby with two X chromosomes and ovaries can therefore be born with external genitals that look male.

Complete androgen insensitivity syndrome

In contrast, a child with complete androgen insensitivity syndrome (CAIS), can have XY chromosomes and internal testes that make testosterone, but their body cannot respond to that testosterone.

This lack of a response to testosterone keeps the developing fetus in its “default” female state, leading to female external genitals at birth.

Someone with CAIS will develop breasts at puberty. Since their external anatomy is typically female, people with CAIS are usually raised as girls and may only be diagnosed later, often when their periods do not start.

CAIS is estimated to affect one to five in 100,000 live born females.

5-alpha-reductase deficiency

Another condition, called 5-alpha-reductase deficiency, shows how sex development does not finish at birth.

The body needs an enzyme called 5-alpha-reductase to turn testosterone into a stronger version of the hormone before birth. When a genetic mutation inactivates this enzyme, an XY baby may be born with genitals that are read as female and may be raised as a girl. At puberty, however, the normal surge of conventional testosterone masculinises the body.

The condition is rare worldwide and its exact incidence is unknown, partly because conditions affecting sex development have often been surrounded by silence.

In parts of the Dominican Republic, where this condition is known as guevedoces, studies have reported surprisingly high local rates. A rare genetic mutation is more common in these isolated populations, about one in 90 males.

More recently, some of these communities have begun to recognise guevedoces at birth and raise them as boys.

Sex chromosomes disorders

Usually, females receive one X chromosome from their father and one X from their mother, and are therefore XX, while males receive one X chromosome from their mother and the Y chromosome from their father. However, a person with Klinefelter syndrome, affecting one in 500-1,000 male births, has XXY chromosomes, causing smaller testes, scant body hair, lower testosterone and reduced fertility. It is often never diagnosed.

On the other hand, Turner syndrome, or the loss, in females, of one of the two X chromosomes, affects one in 2,500 female births and impairs growth, puberty and fertility. It can affect physical appearance, for instance a wide neck and broad chest and often comes with health conditions such as hearing loss and kidney problems.

Swyer syndrome is rarer: a person has XY chromosomes but with a mutation in the Y chromosome that disrupts the signal that normally drives testes formation. The gonads do not develop into testes, testosterone remains low and the external and internal anatomy is typically female.

These are the clearer examples. Milder sex differences can result from mutations that reduce, rather than completely inactivate, an enzyme or hormone response. For example, non-classic congenital adrenal hyperplasia, where some enzyme activity remains. Their effects may be less obvious, and their incidence is often unknown because many cause subtler changes or are never diagnosed.

What this does and does not tell us

None of this is new. These conditions have been known to scientists for decades. But now genetic testing can identify the mutation behind some cases.

Specialist clinics and patient groups have pushed for clearer information for parents, better psychological support for patients and greater caution around irreversible childhood surgery when it is not medically urgent. Recent patient-centred research shows that clear information, good communication and psychological support are central to good care for people with DSDs. It’s unclear whether increased awareness has improved people’s lives, but the direction is clear: better information, specialist care and long-term support matter.

The lesson is not that sex is meaningless or endlessly fluid. These rare conditions do not provide a simple answer to every argument about sex and gender.

However DSDs do show sex is not a single event. Just like the growth of our body, it is a process. When chromosomes, gonads, hormones and the body’s response to them all follow the usual sequence, the result often looks simple. When one link changes, the body may no longer fit the binary pattern many of us were taught at school.

For the people affected, this is not an abstract puzzle. Some need lifelong hormone treatment. Some face infertility. Some discover their condition only as teenagers or adults. Chromosomes or sex designation at birth may explain part of the biology behinds DSDs. It does not explain what it feels like to grow up, go through puberty, seek fertility treatment or decide who needs to know.

Jean-Michel Fustin is a Medical Research Council-funded Senior Research Fellow in the Division of Integrative Physiology at The University of Manchester. He contributes the level-3 course Hormones & Behaviour.

Jodie Foster tearing up a dirt road, yelling stellar coordinates into a walkie-talkie à la the 1997 sci-fi film Contact. Control rooms alive with a cacophony of “enhance that signal”. Real-time discovery. That’s what I pictured when my PhD supervisor told me I’d be going observing at a telescope.

Cut to 2am on top of a mountain in La Palma last April, at an altitude that makes you forget you’re in the Canary Islands. It was utterly freezing, and I had dressed for the sunny archipelago in thin layers. I almost dropped my mug trying to close the telescope door against the wind.

Coffee and food waited two minutes away in the service building. In the darkness, the wind caught a loose scrap of fabric and scared the life out of me. I fell over within 30 seconds. Winds of 40km/h aren’t uncommon at the observatory; I was just entirely unprepared.

I sat on the road, mourning my dignity. And I looked up. For the first time in my life, I saw the Milky Way. It painted the sky, reminding me violently of my insignificance. Nothing in my life has ever compared to that. I allowed myself to bask in it for ten minutes. Then the work beckoned me: I needed coffee, and hadn’t told my colleague which star was next on the schedule.

How is an observing night prepared?

A night at a telescope begins in the afternoon. At around 4pm, my colleague, who was training me to use the telescope, and I drove up to the Nordic Optical Telescope. It’s a gorgeous piece of kit, with a diameter of 2.56 metres. It collects enough starlight for exquisitely precise measurements.

Every instrument and filter had to be carefully tested. On my side, this was a few lines of code. The telescope operator ensured everything worked properly and set up the telescope. While calibrations ran, I started scheduling the night’s observations.

Telescope time is limited, so having three nights at the helm meant I had to squeeze out every second I could. Hollywood did not prepare me for how many spreadsheets this involves. This sort of scheduling requires careful balancing of many factors. For example, observing stars close together on the night sky consecutively to avoid spending too much time repointing the telescope.

Once calibration and scheduling were complete, I watched the sun set. It was beautiful, but also a warning – working hours will soon begin. If you catch the right moment, you can see a small fleet of astronomers in cars headed to their respective telescopes.

The mountain came to life with domes opening, catching the first starlight of the night. There’s more than 20 telescopes in the observatory on the mountain, whose specialisms range from observing supernovae to exoplanets (any planet beyond our solar system).

The night itself

Around 8pm, the first light from a star – HD153557 in this case , a dwarf star around 59 light-years away – entered the telescope. This is always a bit special. The whir of the dome moving, the shutters opening, seeing the monitors show the first traces of data. I sipped my coffee, turned up the 80s hits, and was content in the knowledge that I’d still be in that chair in 12 hours.

This night started rather predictably. The weather was perfect, not a cloud in sight, and the telescope behaved beautifully. Before long we had a spreadsheet slowly getting filled in with completed observations. I knew the peace wouldn’t last. I’d done ten observing nights at two different telescopes by that point in my career, and not one of them without something disrupting my colour-coded plans. Typically, a cloud will move right in front of a star I’m trying to observe, or it’ll rain and that means we have to close the dome. But every few nights, there’s something a little more exciting.

An email just before midnight brought with it a Target of Opportunity alert. These are observations that need to be done immediately, a blink-and-you’ll-miss-it moment. This one was a gamma-ray burst. It’s one of the most violent events in the universe, over a trillion times brighter than our Sun. This was picked up by a space-based detector and emailed to us to request the observation.

Gamma-ray bursts aren’t in my area of expertise – I research stars like the Sun and their surrounding planets. Far less explosive. Between switching observing instruments, rotating the dome, checking calibrations, I was also digesting as much information as I could about what a gamma-ray burst is. This was probably the closest I’ll ever get to my Jodie Foster moment, and it was a rather anticlimactic, blurry image loading very slowly on a screen.

After the gamma-ray burst was observed, the control room became quiet again. Back to my spreadsheets and falling over trying to get coffee. To feeling slightly lonely but seeing another dome rotating under the moonlight when I stepped outside, and being reminded of the other tired astronomers all working beneath the same stars.

It was 8:30am when I finally got back to my room. Ready for a shower, and bed, and to wake up in five hours and do it all again.

The scientific end product

The reality is that scientific interpretation rarely happens in real time. The telescope measurements are first cleaned and calibrated by a computer programme, which turns them into usable spectra. I then apply my own analysis code to these spectra. For me, this comes much later, at my desk in Birmingham once my sleep schedule has recovered. These particular observations gave us stellar spectra: when a star’s light splits into a rainbow, imposed with patterns that reveal its temperature and chemical composition.

The most common observing nights involve balancing spreadsheets, a whole lot of coffee, and slowly surrendering to the delirium of sleep deprivation. Some of them have dramatic alerts. Some of them end up entirely clouded out and allow for an early bedtime.

There is no pivotal “enhance that signal” moment, but there is the quiet, consistent sense of joy that I’m cataloguing and understanding the stars that could one day be found to host another Earth. Hollywood didn’t prepare me for the scientific process. But it got the wonder spot on.

Alix Violet Freckelton receives funding from UKRI.

In the animal kingdom, any hunt for a meal or encounter with a predator is a matter of life and death. To survive both, animals have evolved a multitude of weapons, of which venoms may be one of the most widespread and effective.

But building a chemical weapon presents an evolutionary dilemma. Should venom be optimised to disarm prey, or to cause rapid pain to deter predators? Our new study suggests that in snakes, a meal comes before self-defence.

Venoms are complex chemical cocktails. Their composition is shaped fundamentally by their intended purpose. Predatory venoms disrupt multiple tissues and organs at once to immobilise prey. On the other hand, defensive venoms have only one job: to cause rapid, intense pain to deter predators. Think of a bee sting, for example.

These differences create a conundrum. What if an animal wants to use its venom for both predation and defence? This is not a trivial question, because the storage capacity of venom glands is limited, and producing venoms is thought to carry an energetic cost. That opens the door to an evolutionary trade-off: investing resources into one function might leave less for the other.

Venomous snakes are probably the best-studied venomous organisms, and for a good reason. Unfortunately, snakebite remains a huge medical issue, especially in tropical countries. More than 100,000 people die yearly and more than 400,000 people suffer lifelong injuries as a consequence of snakebite.

In theory, antivenoms could prevent many of those deaths, but there is another problem. Snake venoms are extremely variable, not just between species but also between different populations of the same species. This means that antivenoms developed for one region can fail to work in another. Understanding what drives this immense venom variation is the first step towards more effective treatments.

Snakes use their venoms both for hunting and self-defence. We have good evidence that diet is the central factor shaping venom composition in many snakes. In contrast, defence against predators has rarely been studied as an important evolutionary driver, and never in comparison with diet.

Based on the results of a previous study, we suspected that species that hunt easy, low-risk prey such as insects might not need a highly lethal predatory venom, freeing up resources to invest in more defensive, pain-inducing compounds instead.

To test this idea, we looked at a group of venomous snakes called meadow vipers (Vipera ursinii and relatives). These curious little snakes live in the lowland steppes and alpine meadows of Eurasia. Their diet is unusual among vipers, as they eat mostly or almost entirely grasshoppers, crickets and locusts.

On the other hand, they also regularly fall prey to predators like birds of prey, badgers and foxes. It’s exactly the kind of pressure that might favour a defensive venom.

For our study, we travelled to where their populations can be found across Europe to obtain venom by “milking” them. It’s a process that causes no harm to the snakes, and they were released back to their habitats afterwards. We also collected venom from other European vipers like the adder (V. berus), asp viper (V. aspis) and nose-horned viper (V. ammodytes), which mostly feed on more dangerous prey, like rodents.

If our trade-off theory held, we would expect these venoms to be more predatory and less pain-inducing than those of meadow vipers.

Putting venom to the test

To measure pain, we tested the venoms on cultures of specialised sensory neuron cells. These are cells responsible for detecting harmful stimuli in the body. If such a cell is activated to produce pain, calcium ions flow into the cell. So, to track whether venom triggered these cells, we treated them with a fluorescent dye that reacts to calcium and measured the emitted fluorescence.

To our surprise, regardless of diet, none of the tested venoms activated these cells, not even that of the insect-feeding meadow vipers. So, it appears that European viper venoms, like in most snakes, probably evolved to overcome prey rather than to fend off predators.

All this does does not mean that viper bites don’t hurt. They do. But it seems that the pain is mostly caused as a side effect of other venom actions, such as inflammation, tissue degradation or muscle spasms.

There are however exceptions elsewhere in the snake world. Some toxins found in lanceheads and coral snakes do directly stimulate pain receptors. However, such toxins have been documented in only a handful of species and their ecological function remains enigmatic.

That means the story of snake venom is far from complete. Rather than revealing a universal rule, our findings suggest that, at least in European vipers, the evolutionary pressure to catch prey has outweighed the need to deter predators. Understanding where that pattern holds – and where it doesn’t – could help explain why snake venoms vary so dramatically, an essential step towards developing better treatments for snakebite around the world.

Bálint Üveges received funding from the Leverhulme Trust, the Bangor Fund / Cronfa Bangor, Bangor University and the Taith research mobility programme of the Welsh Government. He currently receives funding from the National Research, Development and Innovation Office of Hungary.

Wolfgang Wüster receives funding from the Leverhulme Trust, Natural Resources Wales, Natural England and the Amphibian and reptile Conservation Trust

The first moment you look inside a newly discovered ancient tomb is at once exciting and terrifying. I was fortunate to experience this recently as director of an international research team carrying out fieldwork in the Theban necropolis, a Unesco world heritage site near the modern Egyptian city of Luxor.

Our project’s primary aim is to implement a conservation and risk management programme for the necropolis (burial ground) of Lower Sheikh ʿAbd el-Qurna. Due to its location at the foothills of the Theban mountain, monuments in this area are extremely vulnerable to flash flooding from intense bursts of rain.

To direct this floodwater away from the tombs, we are systematically removing debris and excavating the area, using archaeological techniques that ensure all historical information is preserved. This is how we came across this previously unknown, roughly 3,000-year-old tomb.

As we prepared to enter it, we had no idea if the ceiling had collapsed, if the tomb had been looted or destroyed, or if it was still well preserved.

Its layout is typical of Theban elite tombs dating to the New Kingdom period (ca. 1550-1069 BC). At this time, Thebes (now Luxor) was Egypt’s capital and main religious and political centre.

The tomb features an outer courtyard, rock-cut chapel and subterranean burial chambers. The well-preserved courtyard area includes a mudbrick platform with a niche for a stela (upright stone grave marker) and staircase with ramps on either side, giving access to the tomb.

Once inside the rock-cut chapel, we noticed its walls are decorated with vivid paintings of the main tomb owner adoring various deities in shrines, and also sitting with his wife in front of an offering table laden with bread, beer, fruits, meat and flowers. Based on the iconography and painting style, we determined that the tomb dates to the Ramesside period (ca. 1292-1069 BC), named after the many pharaohs called Ramesses in that era.

This was a particularly exciting moment. These wall paintings offer invaluable historical details about ancient Egyptian daily life and society. They also shed light on the tomb owner’s position in the Ramesside hierarchy, and on the other family members buried here – plus, potentially, later reusers of the tomb.

Identifying the tomb’s owner

The vast Theban necropolis, comprising an area of around 10km², was Egypt’s main royal and elite cemetery for half a millennium, from ca. 1550 BC onwards.

Situated opposite the city of Thebes on the west bank of the River Nile, it features many world-famous historical sites including the Valley of the Kings (a burial ground for pharaohs including Tutankhamun and Ramesses II) and Valley of the Queens, plus hundreds of private elite tombs, royal memorial temples and remains of royal palaces.

Our team has been carrying out fieldwork here since 2018, in close collaboration with the Egyptian Ministry of Tourism and Antiquities.

Based on a first analysis of the painted decoration inside the tomb, we identified its main owner as a male official named Paser. However, the paintings are covered in a layer of dirt. Once they are cleaned by a conservation specialist, we expect to find out more about the identities and personal narratives of the people buried here.

One of the main research questions associated with our fieldwork focuses on the question of tomb placement and tomb reuse – for which the newly discovered tomb carries important scholarly significance. It will help us explain why in the Ramesside period, officials such as Paser chose to reuse, modify or build tombs adjacent to the monuments of the preceding 18th-dynasty elites.

Specific questions we will try to answer include: how did features of the ancient mortuary landscape (including proximity to processional routes, tombs of relatives, or monuments of special cultic importance) influence the placement of these tombs? And what influenced the decision to reuse them for burial, rather than building new ones?

A race against time

Unfortunately, our work is something of a race against time. As a result of climate change, the frequency and intensity of flash flooding is expected to increase significantly in the coming years here.

This poses a major threat to the tombs in this area. Flooding can lead to immediate, extensive damage such as moisture-activated growth of salt crystals, loss of painted decoration and, potentially, structural collapse. So, one of the most important aims of our project is to implement a preventive conservation and risk management programme that safeguards these monuments for future generations.

At the same time, these activities also allow us to explore this area archaeologically for the very first time, revealing the historical and cultural development of the Lower Sheikh ʿAbd el-Qurna necropolis. Up to now, this area has barely been studied in comparison with famous nearby sites such as the Valley of the Kings and the large temple complexes of Luxor and Karnak.

But our ongoing research shows that Lower Sheikh ʿAbd el-Qurna is rich in archaeological material. This includes exquisitely decorated tombs that offer a unique glimpse into the daily lives, funerary beliefs, artistry and monuments of Egypt’s ordinary people and officials over many centuries.

The project led by Carina van den Hoven is funded by the Gerda Henkel Foundation, and it also receives funding from the Luxor Archaeological Heritage Foundation. A proof of concept study on the digital documentation and material analysis of the ancient wall paintings in Theban Tomb 45 was funded by the Netherlands Institute for the Near East and the Leiden University Centre for Digital Humanities. In 2017 Carina established the Luxor Archaeological Heritage Foundation, a non-profit organisation aimed at providing financial support for the Dutch archaeological expedition to the Theban Necropolis.

Battles between rival groups are a story as old as time. This sounds like a human story, but it is also one that is playing out across nature.

Conflict between groups of animals competing for territory and resources is widespread, and contests between animals can be dangerous. Getting ambushed, especially by a larger or more powerful group, can have disastrous consequences.

However, conflict is sometimes unavoidable.

Emerging research shows war preparations are not a trait unique to humans.

A new article by my colleagues and I highlights how many of the same principles apply to animals too, and not just in our closest relatives like apes. We reviewed the literature and found examples throughout the animal kingdom of animals preparing for future conflicts. This behaviour probably explains how animals persist in the face of often intense conflict.

Animals may sense the recent presence of their rivals. Many species, such as dwarf mongooses, leave scent marks to advertise their presence, and react to those laid down by rival groups. Others animals may rely on their memories of past conflict to change their behaviour in situations they deem risky, such as at territory edges or contested resources.

There can be sex differences in how animals approach conflict. Vervet monkeys are a good example here. Males often stand to lose more from conflict, while females stand to benefit – as it could lead to securing long-term access to high-quality food. Researchers have observed males attempting to defuse conflict yet females try to promote male participation.

When assessing that the risk of conflict, there are many questions for animals to consider. Are rival groups likely to be close by? How powerful are they? Are they restricting access to key resources? Do you have vulnerable offspring to protect?

Animals use many different approaches to reduce the dangers rivals may pose. Here are three main ones:

1. Inform yourself

Information is power. Across group-living species, from mongooses to invertebrates, there is evidence that animals can prioritise gathering information in risky situations. Chimpanzees have been seen to climb to the top of hills and wait quietly, listening out for rivals before making their next move.

Similarly, when groups of dwarf mongooses encounter the scent of rivals, they move less, investigate their surroundings more and post more sentinels to look out for danger. Gathering information comes at a cost, often in the form of lost opportunities to find food and engage in social interactions. But if the risk is high this can be a small price to pay.

2. Strategise

The way animals use space can be crucial. Some species, such as long-tailed tits and chacma baboons, choose to minimise the time they spend in risky areas, such as where territory overlaps. Others animals, such as meerkats, lay down scent marks near their burrows, which are a valuable resource.

Staying within familiar areas and defending them can give groups of animals a home advantage, as groups are more likely to win when they are on familiar ground. Groups can also stay closer to one another, reducing the chances of animals getting isolated should a contest arise suddenly.

Many species, including ants and apes, raid rival groups. These include targeted forays into rival territory with the goal of injuring and even killing rivals to reduce the threat they pose to their own group. Raids in ant species also allow groups to steal the brood of their rivals, bolstering their future fighting force.

3. Stick together

Make sure your groupmates have your back. Although groups often cooperate with one another, animals can be out for themselves, especially those less related to their groupmates or with less to gain from winning.

Group members therefore need to be confident that the others won’t turn tail when the going gets tough. This can be achieved by both carrot and stick. Chimpanzees play and groom more before conflict occurs. These bond-building activities aim to ensure nobody defects if backs are against the wall. It happens more on days when they later engage in conflict, which suggests they know to some degree that an attack will be more likely.

Vervet monkeys, however, take a different approach. Monkeys that failed to participate in previous contests can face aggression from groupmates, coercing them to step up and help next time.

All of this preemptive behaviour can require animals to keep track of who their rivals are, how strong they are and where they might be. Gathering and processing this information can take a lot of effort. But if it allows animal groups to survive, then intergroup conflict may lead to the evolution of cognitive abilities. Indeed, researchers have suggested the need to outmanoeuvre rivals contributed to the intelligence we have as humans today. That is not to say that all anticipation is mentally costly. When rivals are predictable, simple rules can suffice.

Although our work focused on animals in groups, many of the same principles should generalise to solitary and pair-living animals too. Just imagine how many potential cold wars are playing out between rival animals, each trying to preempt the other while going about their daily lives.

Josh Arbon receives funding from the University of Cambridge Herchel Smith Fund. He works for the University of Cambridge and has previously worked for the University of Bristol.

A solar eclipse is a rare, visually striking phenomenon. The Moon passes between Earth and the Sun, temporarily hiding our star – a geometrical alignment spanning millions of miles.

A partial solar eclipse occurs when the Moon doesn’t fully block the Sun, resulting in a gentle dimming of the sky. A total solar eclipse, however, dramatically plunges a daytime sky into blackness.

Everything has to be perfect for this to happen. An astonishing cosmic coincidence means that solar eclipses as viewed from Earth are spectacular – and unlike those anywhere else in the solar system.

For a given place on Earth, a total solar eclipse will only occur once in a few hundred years. The next total solar eclipse takes place on Wednesday, August 12 2026. The path of totality (the area where a full eclipse can be seen) will pass through parts of Greenland, Iceland, northern Russia, Spain, and a small portion of Portugal.

In Britain and Ireland, between 90% and 97.5% of the Sun will be obscured by the Moon, depending on where a person is.

The eclipse starts at 6.08pm (BST) in Glasgow and Edinburgh, 6.12pm in Galway and Dublin, 6.13pm in Manchester and Liverpool, 6.15pm in Norwich and Birmingham, 6.17pm in London, Bristol and Cardiff and 6.18pm in Truro.

The UK Health Security Agency warned that looking directly at an eclipse can cause permanent eye damage. There are two safe ways to view an eclipse: specialist eclipse glasses (or handheld solar viewers) and indirect methods.

Eclipse glasses or solar viewers must be genuine and sold by a reputable retailer. They should have specially designed filters that meet the international safety standard ISO 12312-2:2015(E). Indirect methods include projecting the Sun’s image onto a sheet of paper using a simple pinhole projector.

A solar eclipse’s appearance is wrapped up in the geometry of the bodies involved; it depends on the apparent sizes. This apparent size depends on the sizes and distances involved. The total solar eclipse we see from Earth is particularly special.

The Sun is around 400 times wider than the Moon, but also about 400 times further away, hence they appear approximately the same size in our sky. During totality, the Moon fits over the Sun like a puzzle piece slotting into place.

People are incredibly fortunate to be able to fly around our planet chasing such events, allowing eclipse watchers to gather under the Moon’s shadow. So how would solar eclipses look if we were able to travel to other planets?

Mars has two moons; the larger is Phobos, at around 14 miles across, and the smaller, Deimos, is only about 7.5 miles in diameter. Both moons are rather lumpy and irregularly shaped.

Neither moon has an apparent size large enough to produce a total solar eclipse on Mars. Phobos, being closer and larger, produces an eclipse that lasts only around 30 seconds. It’s very different from what we’re used to. Phobos appears as an oddly shaped silhouette that can cover just over one-third of the Sun.

Deimos, being smaller, and further away from Mars, appears as a small dot crossing the Sun. The eclipses of Phobos and Deimos are events we’ve seen, thanks to Nasa’s Perseverance and Curiosity rovers allowing us to see eclipses on another planet.

A view from Jupiter

Jupiter has 101 moons, which includes the four large Galilean satellites. These moons can completely obscure the Sun from Jupiter, casting vast shadows across its cloud tops.

Jupiter, unfortunately, doesn’t have a solid surface, hence an observer would need to float on top of its clouds. From there, the moons would appear much larger than the Sun.

Although dramatic, this lacks the satisfying alignment we see from Earth of the Moon and Sun almost matching each other in size. The Galilean moons orbit so fast around Jupiter that such eclipses happen almost every day.

Their shadows are visible from Earth through amateur telescopes as small, distinct black dots moving across the colour bands of Jupiter. The orbits of the moons can even sometimes align such that double, or even triple, solar eclipses are visible.

Saturn has even more moons, with 274 confirmed. Similar vast shadows are seen on Saturn’s clouds during eclipses, with larger moons such as Titan causing the most dramatic displays. Saturn itself has seasons, similar to the Earth. Depending on the season, solar eclipses can happen daily on Saturn.

The limits of solar eclipses

There are parts of the solar system that will never, or very rarely, see a solar eclipse. Mercury and Venus have no moons, so unfortunately miss out on the spectacle entirely. As we go farther from the Sun, it appears smaller in the sky.

Comparatively small moons can therefore completely obscure it. From Pluto, the Sun would look like a very bright point in the sky. Pluto’s largest moon, Charon, would appear far larger and completely cover it up.

These would definitely class as total solar eclipses, but would be very different from the exquisitely balanced spectacle we see from Earth. Far out in the solar system, the moons don’t delicately fit over the Sun. Instead, they would utterly swallow it.

Throughout the solar system, solar eclipses are possible and, from some planets, frequent. From Earth, the occasional alignment of size, distance and time allows for total solar eclipses that make the Moon look as if it was made to fit perfectly over the Sun.

For a few transcendent moments, we are cast into a shadow that allows us to glimpse the solar corona peeking out from behind the Moon. There are many small, chance events that have made our planet habitable. This fleeting geometrical balance that produces our solar eclipses is a chance alignment that isn’t something functional. It’s just beautiful.

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

When you think of advanced futuristic clothing, what comes to mind?

Perhaps shirts that can detect and alert users to low blood glucose levels or socks that can track your running form, step count and speed? What about pyjamas that observe subtle bodily changes while you sleep leading to early detection of cancer or warn carers of imminent seizures? Imagine if all these were items that required no external power source, just the energy generated by your own body.

Although these products are not in the shops yet that day is not far off.

Researchers are already designing advanced textiles that look exactly like regular clothes or fabrics but come with with embedded electronic functions. These are referred to as electronics textiles, e-textiles or smart fabrics.

E-textiles integrate sensing, computation and power into fabrics so that the threads themselves become the sensors and the stitches become the circuits. These textiles can monitor health, temperature, motion and air quality. They can communicate wirelessly and harvest various forms of energy.

University and industry prototypes are currently progressing through clinical trials and are being tested outside labs. The global market for e-textiles is projected to reach over US$15 billion (£11.14 billion) by 2028.

Developments in e-textiles will revolutionise the way humanity views clothing; but at what cost?

A new type of waste

Electronic waste is the fastest growing EU waste stream with a record 62 million tonnes discarded in 2022.

Another 92 million tonnes of waste is generated globally from textiles; a figure expected to reach 134 million by 2030. Textiles alone account for 6.7% of global greenhouse gas emissions with the average European discarding a staggering 11kg of textiles per year.

Electronic textiles will bring a new kind of hybrid waste. E‑textiles commonly use mixed polymers, metal nanoparticle inks, and include components that create fire hazards within conventional textile recycling.

They can release toxic residues if incinerated or landfilled. This results in hazardous and precious materials becoming trapped within garments, leading not only to environmental and health problems, but to a loss of vital resources such as graphene and rare-earth elements. Silver, for instance, is used in conductive yarns, antimicrobial coatings, sensors and electrodes. We need to work out how to recover it because it is valuable as well as toxic to aquatic life in some forms.

So, it’s currently very difficult to recover the valuable materials used in smart clothing, after the shirt or socks are discarded.

At the current rate of e-textile growth, current disposal methods will need to change to cope with these new materials; particularly in the areas of reusability and recyclability.

The EU’s sustainable and circular textiles strategy is part of the EU’s plan to become the first climate-neutral continent. Regulators are now demanding clearer rules on recyclability, chemical safety and product lifespans, and starting to ask how e‑textiles will meet these requirements.

Industry practice is catching up more widely, and placing more responsibility on clothing producers. Digital product passports (these carry information about the materials and their environmental impact) and new recycling technologies are scaling up. These shifts mean manufacturers could face legal and commercial risk if they don’t consider the long-term impact of these products.

Preventing more waste

The good news is that sustainable e‑textiles are an engineering problem with practical solutions. Key measures that industry and funders could adopt now include:

1. design for disassembly. Removable electronic parts help separate electronics from textiles for recycling

2. material passports and transparency. Digital records of various components (such as polymers, inks and batteries) that enable safe sorting and recovery

3. biodegradable and recyclable conductors. Prioritising conductors free from precious metals and using alternatives such as screen printable carbon paste and recyclable conductive inks and yarns

4. energy-first design. Integrating textile energy harvesting (for instance, solar, thermoelectric, piezo/triboelectric nanogenerators) to reduce or eliminate batteries. Some garments embed antennas and wireless power receivers to avoid bulky batteries

5. standards for washability, durability and end-of-life testing. To ensure products survive real-world use and can be repaired rather than discarded.

None of these are optional extras: they determine whether e‑textiles become a public good or a new environmental liability. University research groups and industry consortia are starting to demonstrate printable, stretchable components and trial wireless power that reduce battery dependence, for instance. Printable, stretchable components are flexible electronic parts printed onto fabric that keep working as the textile bends and stretches. They make smart clothing comfortable, lightweight, washable and able to move naturally with the body.

Unless policymakers and industry players adopt sustainable design now, e-textiles could add a dangerous new layer to our global electronic waste mountain.

Governments need to set clear rules on recyclability and chemical safety for e‑textiles. University researchers must find methods to make e-textiles functional, affordable, sustainable and safe. Brands must publish material details and repair guides and ensure sustainable practices are being adhered to throughout their supply chain.

Investors should not fund throwaway novelty. Standards bodies must define test methods for washing, wear and end‑of‑life recovery.

These steps will steer the market toward durable, repairable and recyclable products that could change lives for the better.

Ian Williams receives funding from UK Research Councils, including the Engineering and Physical Sciences Research Council (EPSRC) and its Impact Acceleration Account.

Christina Webb receives funding from UK Research Councils, including the Engineering and Physical Sciences Research Council (EPSRC).

Stephen Beeby receives funding from UK Research Councils, including the Engineering and Physical Sciences Research Council (EPSRC).

The ability to cross oceans has long been a marker of human endeavour, but when did the seas change from being barriers to movement into the maritime highways we know today?

For many years the answer was thought to lie in the Neolithic period – the time when humans made the profound transition from hunting and gathering to practising agriculture and living in settled societies.

Our team’s discovery of the presence of European hunter-gatherers on the tiny Mediterranean island of Malta, reported last year, has overturned this view. It showed that people reached Malta from their starting point in Europe (presumably Sicily) at least 8,500 years ago.

In a new study, we show that these populations were engaging in repeated long-distance sea journeys of at least 100km, well before the advent of farming.

Researchers have known that the occasional very ancient sea crossing must have been made. The most famous example may be the colonisation of Australia, tens of thousands of years before the present.

However, sustained, long distance sea voyaging – particularly to small and remote islands – was long thought to have been beyond the capabilities of hunter-gatherers, who are dependant on the bounty, or deprivation, of natural resources.

This was also the case for Europe’s last hunter-gatherers, in the period of time known as the Mesolithic, the era before the Neolithic. During the Neolithic, a new population introduced agriculture to Europe from Anatolia (which comprises most of the landmass of modern Turkey).

Enter the recent findings from the site of Latnija, on Malta. Did the surprising presence of European hunter-gatherers on Malta reflect a one off, accidental crossing – or perhaps people who somehow became marooned on the island? Conversely, was this Mesolithic presence a reflection of something altogether different, and more complex?

Shifting seas

To explore these possibilities, we investigated whether Malta could support a viable forager population size that could have lived in isolation for the 1,000 year occupation of the island during the Mesolithic.

First, we explored the impacts of changing sea levels since the Last Glacial Maximum (the height of the last ice age), from around 21,000 years ago. This was when waters began to rise from their lowest levels of around 130m below modern sea level. By doing this, we were able to track changes in the size of Malta and its connectivity with surrounding islands and land masses.

During the Last Glacial Maximum, Malta was connected to Sicily by a land bridge, and this connection remained as sea levels continued to rise until around 14,000 years ago, when the land bridge began to be inundated. Continued sea level rise meant that within less than a thousand years, Malta had become far smaller and remote from Sicily, needing a long-distance sea crossing for connectivity.

By the time of the Mesolithic occupation, Malta had almost reached its present configuration, with no significant difference in distances to Sicily. Having understood how sea level rise impacted the size and accessibility of Malta, we next explored how its specific ecological conditions impacted its ability to support forager populations. Since hunter-gatherers are reliant on what nature provides, their population sizes have a direct relationship with ecological productivity.

Accordingly, we modelled the relationship between population density among contemporary forager populations and what’s known as net primary productivity – effectively the baseline of wild resources available to hunter-gatherers. We then extrapolated these findings back into the past using high resolution computer models of past climates (palaeoclimate models).

This enabled us to calculate the total population size that could be supported first on the combined landmass of Malta and Sicily, and then as separate islands as sea levels rose.

Our upper estimates for the total population sizes suggest that after the inundation of the land bridge to Sicily, the total population size that could be theoretically supported on Malta dropped rapidly to 319 people by 13,800 years ago.

There is no evidence yet that people were living on Malta this early, but our models showed that any populations present would have continued to drop in size as sea levels rose until around 9,000 years ago, when it could have accommodated around 170-144 people.

Finally, we compared these findings to thresholds, informed by conservation genetic studies, for the long-term viability and stability of a population. These thresholds suggest the need for an effective (reproducing) population size of 1,000 or more, equivalent to a total population size of 2,500-3,000 (because the total population size includes both younger and older people who are not reproducing).

Long distance voyages

This suggests that Malta was incapable of hosting an isolated, viable population that could have lived continuously through the 1,000-year time frame during which it was settled by Mesolithic hunter-gatherers.

Consequently, we can rule out the persistence of a population stranded on Malta as sea levels inundated the land bridge to Sicily. We can also exclude a single, perhaps unintended, voyage leaving marooned mariners on Malta.

The only alternative is that these Mesolithic hunter-gatherers were making repeated, long distance sea voyages between at least Malta and Sicily, the closest land mass, to maintain the genetic connections that ensured at least a millennium of Mesolithic viability on Malta.

These insights are reshaping our perceptions of late European hunter-gatherers and the sophistication of their societies. To maintain repeated, long-distance overseas connections, they must have had, and conserved, an extensive knowledge of land, sea and sky, as well as the technological know-how for building and preserving sea craft.

We don’t know for certain what type of vessels the hunter-gatherers were using, although we know that dug-out canoes existed at this time. The crossings to Malta occurred several thousand years before the earliest evidence for sails – making the achievement even more impressive.

From wayfinding to getting food at sea overnight, they then had to be able to live sustainably on a small, semi-arid island, which required a finely-tuned knowledge of diverse food sources shaped by the seasons.

With these implicit capabilities, we can then start to ask, where else did they go? There is already evidence of connectivity between Europe and North Africa during this time. Previous work using ancient DNA found the distinctive signature of European hunter-gatherer ancestry in people living in pre-Neolithic Tunisia.

All this suggests we may be looking at a hitherto unknown web of overseas links that marked the beginning of the connected world we know today, centuries before the first farmers reached the central Mediterranean.

Understanding how these groups remained ecologically resilient, while also shaping ecosystems to their needs, may yet prove to have important lessons for humanity’s current and future challenges in a rapidly warming world. As we continue to unravel Malta’s unprecedented hunter-gatherer past, we hope to shed light on this lost ecological knowledge.

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

Humans are not the only animals that communicate. Birds sing to attract mates, dolphins use signature whistles that identify individuals, and many primates produce complex vocalisations that help them coordinate their social lives.

By studying these communication systems, researchers can reconstruct some of the evolutionary steps that eventually led to one of our defining traits: language.

Language doesn’t just mean making sounds – it requires an extraordinary ability to control them. Human speech demands precise coordination between breathing, the vocal folds across the larynx, and our tongue, lips and jaw.

Humans’ closest living relatives – chimpanzees and bonobos – possess vocal tracts that are more similar to ours than scientists once believed. Yet they do not seem to have the same fine voluntary control over the structures – starting with our lips and tongue – that allow us to produce rapid sequences of speech and such diverse sounds.

This raises an intriguing question: when did our ancient ancestors begin to acquire this remarkable vocal control? One possible clue comes from an unexpected source: laughter.

The evolution of laughter

For several years, I have studied the rhythmic structure of vocalisations in non-human primates. Rather than focusing on what calls mean, I have been interested in how they are produced.

The timing of vocalisations can reveal how breathing and vocal movements are coordinated, offering a window into the mechanisms that generate them. Whether analysing the songs of Madagascar’s indris lemur or the calls of orangutans, I kept coming back to the same question: how much control do different primates have over the rhythm of their voices?

Laughter turned out to be an ideal system for exploring this question.

Unlike speech, our ability to laugh is shared with all the great apes. Chimpanzees, bonobos, gorillas and orangutans all produce laughter-like vocalisations during play. Although these sound quite different from our familiar “ha ha ha”, they serve similar social functions, signalling playful intentions and strengthening social bonds.

Human laughter is much more diverse, however. We can produce loud belly laughs, quiet chuckles, giggles, snorts or almost silent laughter. We laugh when we are amused but also when we are embarrassed, nervous or trying to ease social tension. This flexibility makes laughter much more than a simple emotional reflex for us.

Human laughter is highly context-dependent. We laugh differently when we are genuinely amused, when we engage in polite social interactions, when we feel awkward, or when we share an inside joke.

Together with colleagues, I analysed 140 laughter bouts from humans and the four other great ape species. Instead of asking whether laughter sounded similar across species, we examined its rhythm: how quickly each laugh element followed the previous one, and how consistent that timing was. Our results revealed a clear evolutionary pattern.

When laughing, humans show greater temporal variability than our closest relatives. Chimpanzees and bonobos produce laughter at a slower rhythm than humans, while gorillas and orangutans laugh at an even slower pace.

In contrast, human laughter consists of more rapidly repeated elements – successive vocal bursts that together form a laugh. This increased flexibility may be one of the evolutionary changes associated with the emergence of finer voluntary control over vocal production.

In other words, humans’ ability to “laugh fast” may reflect one of the key innovations that eventually made speech possible.

The link between laughter and speech

The evolution of speech may not simply have involved producing new sounds, but changing the very tempo at which vocal actions are organised. Our findings suggest traces of this key evolutionary transition are still preserved in one of our most familiar activities: laughing.

While humans and chimpanzees share a common evolutionary history, we will never hear how our ancient ancestors laughed. Fossils preserve bones not vocalisations, so the only way to reconstruct the evolution of laughter is by comparing living species and inferring the changes that occurred along the hominin lineage.

Because we found that chimpanzee and bonobo laughter differs from human laughter in rhythmic structure and temporal variability, we can use these living species to infer that early hominins may have exhibited laughter patterns which were already distinct from those of other great apes during the evolutionary transition towards modern human laughter.

Three-to-four million years ago, early hominins may already have shown some of the foundations of the flexible laughter patterns seen in humans today. Our findings suggest that increased temporal variability in laughter evolved along the hominin lineage. This may have enabled laughter to become increasingly adapted to different social contexts, from playful interactions to maintaining social bonds and signalling affiliation.

Every time we compare ourselves with our closest great ape relatives, we discover that the gap between humans and other apes is smaller than was once imagined. Yet we also uncover subtle differences that may have had profound evolutionary consequences.

Laughter is one of them. It may seem like a simple expression of joy, but hidden within its rhythm is a record of millions of years of evolution – and, perhaps, one of the clues to how our human ancestors eventually found their voice.

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

Warm sticky nights are becoming more and more common in the UK.

Climate change is raising temperatures, but one factor that adds to that is often ignored. Walk down a city street and you see what would have been front gardens a decade or so ago have now been tarmacked over and turned into driveways.

Individually these changes might seem small, but as more and more gardens disappear this increase in hard driveways can alter the way neighbourhoods heat up during the day and cool down at night. It’s an issue that is suddenly on more people’s minds this summer as they struggle to sleep.

According to a UK’s Royal Horticultural Society (RHS) report in 2025, 42% of domestic garden space is now paved over, including 55% of front garden space.

In 2005, only about 8% of UK front gardens were fully paved. By 2015, that figure had tripled to roughly 24%.

Estimates from the RHS suggest there are 20.6 million domestic gardens (front and back) in the UK, covering around 502,757 hectares. The UK’s domestic gardens together cover an area around three times larger than all national nature reserves combined, giving them enormous potential to support wildlife.

Replacing vegetation with hard surfaces also shrinks habitat for plants and wildlife while increasing surface runoff and the risk of flooding.

The desire for more off-street parking may have contributed to this trend. The shift to electric vehicles could have created another incentive to pave front gardens, as goverment grants helped households finance home-charging points.

How paving stokes heat

Impervious surfaces including asphalt (which many driveways are made of) absorbs heat, raising ground and air temperatures. They both absorb up to 95% of incoming solar radiation during the day, reaching surface temperatures of 50-55°C, compared to 27-32°C for grass or tree-covered areas.

During the day, this heat is stored and slowly released after sunset. This is known as the urban heat island effect. The result is warmer night-time air temperatures, particularly during heatwaves. Unlike vegetation, these hard materials have little capacity to cool themselves through evaporation, and are making cities hotter.

This heat island effect can raise cities’ temperatures by 1-3°C compared to surrounding countryside. That’s why it always feels hotter in the city on summer nights.

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Read more: Heatwaves: how to close the UK’s cooling divide

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And the result can also cause health problems. The 2018 summer heatwave saw an estimated 399 (of 785) heat-related deaths in the Greater London area attributable to this night-time effect.

Paved front gardens eliminate evaporative cooling (the process by which plants release water vapour), which lowers air temperatures. Plants and trees provide cooling through shading and evapotranspiration (defined as the combined loss of water to the atmosphere through two processes: evaporation and transpiration). In urban environments, green spaces release moisture into the air, which humidifies the atmosphere and significantly reduces air temperature, a mechanism entirely absent in paved areas.

What needs to change?

Changing front driveways back to grass can reduce daytime surface temperatures by 1.5-2.0°C and nighttime temperatures by 0.3-0.5°C. Adding trees doubles the benefit: daytime cooling of 2.0-3.0°C and nighttime reductions of 0.5-1.0°C. Therefore, increasing urban greenery by 10% – particularly planting trees – can lower average air temperatures by around 0.5°C.

Front gardens with plants rather than driveways can also reduce flood risk by absorbing rain, filter air pollutants, support biodiversity and improve mental wellbeing. The RHS estimates that restoring plant cover in one million front gardens could save millions of litres of stormwater run-off annually.

But there are ways to have a driveway that doesn’t create so much heat. London’s De-pave Your Garden campaign offers guidance on replacing concrete with permeable paving, gravel or planting strips, an approach that has since been promoted by London boroughs including Lambeth and Ealing.

Leeds City Council’s front garden design guide encourages householders to retain at least 30% green space.

Other things could help change people’s attitudes to front gardens and their value. Financial incentives, such as council tax rebates for depaving or grants for rain gardens, could accelerate change.

In the future, public policy must recognise private gardens as green infrastructure, not merely private amenities. Updating planning permission rules to encourage a mix of plants and gravel, for instance, would help.

The United Nations identifies urban greenery as a key way to reduce heat in cities. The benefits extend beyond gardens: green roofs and balcony gardens can lower indoor temperatures by up to 11°C.

No single garden will transform a city’s climate, but when thousands of gardens are protected and restored across neighbourhoods, the combined cooling effect would become significant.

As climate projections show more frequent, longer and hotter summers, every square metre of restored vegetation matters. Domestic gardens are frontline defences against intensifying heatwaves.

By not opting for a tarmacked driveway or replanting the existing one, households can help cool their streets, protect vulnerable neighbours and reclaim a piece of Britain’s vanishing green heritage.

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

Harnessing renewable resources such as wind and solar energy is vital for the green transition. But these renewables are intermittent and unpredictable. It’s impossible to control when the wind blows and when the sun shines.

Currently, we don’t have to rely on the weather to boil a kettle. That’s largely thanks to our use of fossil fuels. To break our reliance on this finite and polluting source of power, we need to be able to store vast amounts of renewable energy cheaply and safely, but unfortunately, no technologies yet tick all the boxes.

Lithium-ion batteries are used in our phones, laptops, and electric vehicles. But lithium-ion technology depends on costly, geographically concentrated materials such as lithium and cobalt.

Cobalt mining can be a dangerous and polluting process. The organic lithium-ion-containing electrolyte (the liquid chemical between the positive and negative terminals inside a battery) is flammable. Because it poses a fire hazard, it’s risky to deploy these batteries at a large enough scale to power our homes, cities, and industries.

But there is an alternative solution: flow batteries.

In a flow battery, energy is stored in liquid electrolytes which are held in large external tanks. To charge or discharge the liquid, it is pumped through a stack of cells where electrochemical reactions generate or consume electrons. This has several advantages.

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Read more: What will batteries of the future be made of? Four scientists discuss the options – podcast

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In most batteries, two properties (energy and power) are intrinsically linked. Energy refers to how much electricity is actually stored by the battery and therefore how long that supply can run at a given rate. Power is the rate at which the energy is delivered and how much can be supplied within a given time.

Usually, it’s impossible to change one without changing the other. To store more, you add cells, and that adds power you may not need (and cost you don’t want).

However in flow batteries, this is not the case. Need to store more energy? Simply use larger tanks with more liquid. Need more power? Simply use a bigger cell stack. This ability to independently control power and energy makes the technology cheaper to scale up. Additionally, unlike lithium-ion batteries, flow batteries can’t catch fire (as they are mostly water) and are extremely durable. Some flow batteries have been in operation for more than 20 years.

Several large-scale flow battery systems have already been deployed. In China, the largest systems that connect to the grid reach gigawatt-hour scale (equivalent to powering 100,000 homes for a full day). In Switzerland, what will be the world’s largest flow battery, at 2.1 gigawatt-hours (equivalent to powering over 200,000 homes for a full day) is being constructed to power an AI data centre. Nevertheless, flow batteries are still an emerging technology, with several challenges still to solve.

Test cells

Worldwide, researchers like us are developing new electrolyte chemistries and materials to reduce the cost of flow battery systems and drive wider adoption. But getting started in flow battery research can be quite daunting. Test cells can often cost thousands of pounds and testing a new cell requires lots of ancillary equipment.

Through our research, we have developed a low-cost 3D-printed test cell. This makes flow battery research much easier and has enabled our research group to test dozens of these cells. But our team struggled to get repeatable test results. It was also difficult to replicate results from previous flow battery studies by other groups in our own labs at Queen’s University Belfast. This resulted in several months of frustration as we scrutinised every aspect of our testing protocols.

As it turned out, our research group was not alone. At a conference in early 2024, we attended a talk by Fikile Brushett, a chemical engineering professor from the Massachusetts Institute of Technology in the US. He described the lack of protocols in this field. Together, we have led a series of studies to investigate and work out how to tackle the issue of reliably replicating data from reported scientific studies.

In one study, published in April 2026, we sent our low-cost 3D-printed test cell to several leading research groups around the world. We were struck by the extent of performance variability between different groups all nominally testing the same battery. Since then, we have identified several potential causes for this variability and have suggested improvements to testing protocols.

Our latest study has involved more than 30 research groups assessing our test cells. Our testing data is now publicly available online. We are using this to pin down why performance varies across the cohort. Our findings will help the community to develop testing protocols that all researchers can use.

Eventually, this work could make it easier for newcomers to make a start in flow battery research. It could also give established groups a reliable foundation to compare results and accelerate their work. This all helps chemical engineers innovate more quickly towards storing renewable energy cheaply, safely and at scale.

Joshua James Bailey receives funding from UKRI's EPSRC.

Hugh O'Connor received funding from UKRI's EPSRC and PSDI.

William Adams was entranced by energy. As a young man, his interest was nursed by working as a clerk in a London patent office in the 1860s. This gave him an early look at some of the first British designs for exploiting solar energy using mirrors, water or both.

Adams would later recount his excitement at reading about the French mathematician Augustin Mouchot’s invention of the first machine ever to run on energy from the Sun. The device, which connected a solar boiler to a specifically designed steam engine, was warmly received by Napoleon III when it was presented to the emperor in 1866.

Inspired, Adams soon designed and patented his own rudimentary solar boiler. The only problem was, he needed more sun.

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This series is dedicated to lesser-known, highly influential scientists who have had a powerful influence on the careers and research paths of many others, including the authors of these articles.

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When offered the chance to become deputy registrar of Bombay by the Indian city’s governor, Sir Philip Edmond Wodehouse, Adams jumped at the opportunity. There, he became the first Briton to design, build and test a fully-functioning solar steam engine fit for industrial purpose.

But he also came up against the conservatism of India’s colonial rulers, who did not see this Bombay bureaucrat for the energy visionary that he undoubtedly was.

‘The rays beat like missiles’

Adams arrived in Bombay in 1873 to find it in the middle of a cotton boom, with mills popping up like mushrooms across the city. The population was growing so quickly that firewood was depleted for miles around. The landscape grew “bald as a billiard ball”, as Adams put it.

Every morning before setting off for work near Bombay’s central fort, Adams would set up his outdoor laboratory at his home in the southernmost Colaba district, near the open sea. He instructed an Indian fundhi (skilled carpenter) to build a set of three-tiered wooden shelves to hold 18 looking glasses.

“Each glass was moveable on a swivel in the same manner as an ordinary toilet glass”, Adams explained, meaning he could pivot each glass by “the touch of the finger”.

Later, for open-air experiments, Adams used two banks of mirrors (36 in total) which made “the mercury in the thermometer boil, leaping up to over 670 degrees fahrenheit”. He then placed a copper cylinder containing three gallons of water in the focus of all 36 mirrors, making it boil in exactly 20 minutes.

But Adams’s ambition did not end there. To reach sufficient pressure in the boiler to drive a steam engine, this bureaucrat-cum-engineer built a giant concave mirror, 24 feet in diameter. He then sent for his London solar boiler, which was delivered by ship to Bombay in 1876.

One fine morning, Adams – wearing dark glasses for safety – turned his giant concave mirror on the copper cylinder filled with water. “The rays beat like missiles in a continuous and incessant storm of solar fire,” he wrote.

An hour later, the cylinder registered 55 pounds of pressure per square inch. He hired a steam engine of 3 horsepower and connected it to the boiler: the pressure moved the pistons. Adams had built the first working, British-designed solar steam engine.

For a fortnight, he kept the pump going near his bungalow in Colaba – proudly and sweatily displaying his innovation to government officials, newspaper reporters, mill owners and the local Indian communities. Members of the public were invited to witness his experiments too, via a notification in a Bombay newspaper.

‘An inexhaustible source of wealth’

In 1877, Adams wrote a letter to the editor of the Times of India arguing that the application of his solar steam engine would “make India the seat of the principal manufacturing industries of the world”.

Later, in his wildly ahead-of-its-time treatise Solar Heat: A Substitute for Fuel in Tropical Countries (1878), Adams argued that countries near the equator “possess, in their clear skies, a gratuitous and inexhaustible source of wealth, equal to that which western nations have to dig, with infinite labour and toil, from the bowels of the Earth”.

Adams sketched out plans to use solar heat for everything from cotton gins (engines to separate cotton fibres from seeds) to Hindu crematoria. He called upon the colonial British government to invest in this promising substitute for coal, which was then being imported to India at great expense.

Adams envisioned solar energy transforming the Raj. Just like the coal-combusting steam engine had replaced the waterwheel in England, he argued that thermal heat could now replace fossil fuels in India. But his colonial bosses were not persuaded.

‘Too subversive’

Adams was part of a 19th-century wave of global research into solar steam engines, as I explore in my postdoctoral project and upcoming book. But in contrast to fellow pioneers including Frenchman Mouchot, Adams built his solar steam engine to stimulate local Indian industry, not to benefit the colonial government.

The locals shared Adams’s belief in this technology. One even wrote to Scientific American magazine to express their desire for the rapid adoption of solar power:

My residence is in a tropical part of India … where fuel is scarce and dear … In this part of the country (about 300 miles north of Bombay), there is a great opening for cheap power in small units.

Bombay’s new governor Sir Richard Temple concluded, however, that solar heat “could not be used for commercial purposes on a large scale”. He argued that local factory owners would not like giving “the workmen a holiday on days when the sky is not clear”.

In truth, Adams’s invention was too subversive for Britain’s colonial officials and capitalists. In less sunny climes, solar energy – tethered to the seasonal rhythms of nature – might negate their commercial ambition for timeless industrial production. But they also saw India as an important market for British coal exports.

While a few mill owners adopted Adams’s auxiliary solar heater for their steam engines, most regarded it as a primitive contraption unfit to satisfy the demands of modern civilisation.

Increasingly frustrated that neither the industrial capitalists nor the colonial government supported his vision, Adams abandoned further experiments. His dream of India switching away from coal to solar power, from combustion to concentration, would not happen for at least another century.

Now, however, India is a world leader in the global energy transition. It heads the International Solar Alliance, and is the third largest solar power generator in the world.

Which begs the question: how much further advanced would this technology be had Adams’s 19th-century solar experiments been embraced by India’s colonial rulers at the time?

Sebastian Egholm Lund receives funding from the Carlsberg Foundation. His upcoming book, Changing the Climate at the Fin de Siècle, is published by Cambridge University Press (September 2026).