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Conditions in our little pocket of the universe seem to be just right for life – and the much-debated anthropic principle forces us to wonder why

When we look out into the universe, we know it can support life – if it couldn’t, we wouldn’t exist. This has been stated in different ways over the years, but the essential thrust makes up the core of a philosophical argument known as the anthropic principle. It sounds obvious, even tautological, but it isn’t quite as simple as that.

To get your head around it, start with what scientists callthe fine-tuning problem, the fact our universe seems perfectly balanced on the knife’s edge of habitability. Many fundamental constants, from the mass of a neutron to the strength of gravity, must have very specific values for life to be possible. “Some of these constants, if you make them too large, you just destabilise every atom,” saysLuke Barnesat Western Sydney University in Australia.

The anthropic principle began as an attempt to explain why the universe is in this seemingly improbable state, and it boils down to a simple idea: the universe has to be this way, or else we wouldn’t be here to observe it.

Read moreAstronomers have spotted the largest known object in the universe

Astronomers have spotted the largest known object in the universe

There are two main formulations of the principle, both of which were set out in a 1986 book by cosmologist-mathematicians John Barrow and Frank Tipler. The weak principle states that because life exists, the universe’s fundamental constants are – at least here and now – in the range that allows life to develop. The strong principle adds the powerful statement that the fundamental constants must have values in that range because they are consistent with life existing. The “must” is important, as it can be taken as implying that the universe exists in order to support life.

If the weak principle is “I heard a tree fall in the forest, and therefore I must be in a place where trees can grow”, the strong principle says “A tree has fallen nearby, and therefore this planet was destined to have forests all along.”

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For scientists today, the weak anthropic principle serves as a reminder of possible biases in observations of the cosmos, particularly if it isn’t the same everywhere. “If we live in a universe that is different from place to place, then we will naturally find ourselves in a place that has some specific conditions conducive to life,” saysSean Carrollat Johns Hopkins University in Maryland.

As for the strong version of the principle, there are physicists who consider it useful too, Barnes among them. He works on developing different flavours of multiverse models and sees the strong principle as a handy guide.It implies that, within a multiverse, there is a 100 per cent chance of at least one universe forming that is conducive to life. So, for any given multiverse model, the closer that chance is to 100 per cent, the more plausible it is. If the probability is, say, around 50 per cent, Barnes sees that as a good omen for the model’s veracity. “But if it’s one-in-a-squillion, then that’s a problem,” he says.

This mind-blowing map shows Earth’s position within the vast universeSee the circle of galaxy clusters and voids that surround us in this map of the nearby cosmos, extending 200 million light years in each direction

This mind-blowing map shows Earth’s position within the vast universe

See the circle of galaxy clusters and voids that surround us in this map of the nearby cosmos, extending 200 million light years in each direction

In truth, however, most physicists write off the strong principle as simply too strong. It suggests the universe is deterministic; that life was always certain to emerge, according toElliott Soberat the University of Wisconsin–Madison. “But that probability could have been tiny and life could have still arisen, and the observations would be the same.”

Where does that leave us? The strong principle does, on the surface, provide an answer to the fine-tuning problem – but that answer is widely considered unreasonable.On the other hand, while the weak principle doesn’t provide a reason why the constants of our universe are so finely tuned, it is a useful tool for researchers. As principles go, this one is rather slippery.

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With the help of powerful computers, researchers discovered a four-sided shape that naturally rests on one side, and built a real-life version from carbon fibre and tungsten

The self-righting tetrahedronGergő Almádi et al.

A four-sided shape that will always come to rest on the same side no matter what side it starts on has been built by mathematicians, decades after it was first proposed to exist.

Mathematicians have long been fascinated by self-righting “monostable” shapes, which have a preferred resting spot when placed on a flat surface. One famous example is the Gömböc, a curved, tortoise-shell-shaped object that has a precise weight distribution and will rock side to side until it reaches the same stable resting place.

Read moreMathematicians solve 125-year-old problem to unite key laws of physics

Mathematicians solve 125-year-old problem to unite key laws of physics

In 1966, mathematician John Conway was working on how straight-edged shapes balance and proved that a four-sided shape, or tetrahedron, with an even distribution of mass would be impossible. However, he told his colleagues at the time that an unevenly balanced monostable tetrahedron could be possible, but never proved it.

Now,Gábor Domokosat the Budapest University of Technology and Economics, Hungary, and his colleagues have built a monostable tetrahedron, which they call the Bille, using carbon-fibre struts and a plate made of ultra-dense tungsten carbide. The name comes from the Hungarian word for tip,billen.

They first started work on the problem when Domokos asked his student, Gergő Almádi, to search for Conway’s tetrahedron by conducting a brute-force search with powerful computers. “You check every tetrahedron, and with some luck, you find it, or with time, or with [computing power], or a mixture of those,” says Domokos.

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As Conway predicted, they didn’t find any monostable tetrahedra with an even weight distribution, but they did find some candidate uneven ones, and went on to prove their existence mathematically.

Domokos and his team wanted to then build a real-life example, but this proved to be “an order of magnitude more difficult”, he says. This is because, according to their calculations, the difference between the density of the weighted and unweighted parts of the objects needed to be about 5000-fold, meaning the object would need to be essentially made from air but still rigid.

To make the shape, Domokos and his team partnered with an engineering company and spent thousands of euros to precisely engineer the carbon-fibre struts to within a tenth of a millimetre and make the tungsten base plate to within a tenth of a gram.

When Domokos first saw the functioning Bille in real life, he felt like he “was levitating 1 metre above the ground”, he says. “It is a big pleasure to know that you achieved something which would make John Conway happy.”

Read moreMathematicians discover shape that can tile a wall and never repeat

Mathematicians discover shape that can tile a wall and never repeat

“There is no pattern, previous example or nothing in nature which would [have suggested to Conway] that this shape exists,” says Domokos. “It was in such an obscure corner of reality that no human [could] reach it” until now, “when you have powerful computers and you’re willing to pay thousands of dollars”.

The shape they constructed has a specific tipping path between its sides, says Domokos, tipping from B to A, from C to A, and from D to C and C to A. There is another kind of monostable tetrahedron that tips sequentially from D to C to B to A, but Domokos says their calculations indicate they would need a material that is one-and-a-half times as dense as the sun’s core to build it.

Domokos hopes their work will help engineers alter the geometry of lunar landers to make them less likely to fall over, asseveral recentspacecraft have done. “If you can do it with four faces, you can do it with any other number of faces.”

Reference:arXivDOI: arXiv:2506.19244

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A flexible fabric called X-Wear could replace some parts of medical scanners, which would make taking X-rays and CT scans far more comfortable and convenient

Mammograms can be painful, but they may not need to beDaria Artemenko/Alamy

Mammograms can be painful, but they may not need to be

Getting an X-ray can be uncomfortable – you may have to lay still while you’re in pain or have part of your body compressed. But a flexible fabric that makes X-rays easier to detect could eliminate that.

Read moreWe are finally improving prostate cancer diagnoses – here's how

We are finally improving prostate cancer diagnoses – here's how

“Imagine scanning a child’s injury without immobilising them, or enabling pain-free breast exams,” saysLi Xuat the Hong Kong Polytechnic University. She and her colleagues created a textile called X-Wearthat scintillates– meaning it releases light whenexposed to X-rays– which could make this a reality.

Because X-rays are more difficult to detect than visible light, medical and industrial X-rays, as well as CT scans, use scintillating components. These can pick up X-rays after, for example, passing through a limb, converting the rays that emerge into visible light that can then be used to create an image of the body part to show internal detail like broken bones. But the most commonly used scintillators are rigid, which makes the devices they are embedded in bulky and uncomfortable to interact with.

To avoid this, the researchers re-shaped scintillating materials, for instance gadolinium oxide studded with bits of europium, into narrow fibres, which they then wove into fabric.

Xu says that it was a technical challenge to make these fibres flexible while also ensuring they emit enough light to create high-resolution images once they arehit with X-rays. Her team demonstrated that the fabric can be useful for taking dental X-rays – in tests, it made X-Wear conform to the shape of a mouth model made from clay and teeth. It also used it for mammography, where it created an X-Wear bra that eliminated the need for a person’sbreast to be compressedduring imaging, which is standard current practice.

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Imalka Jayawardenaat the University of Surrey in the UK says that X-Wear’s ability to conform to the body is a big advantage compared with other flexible scintillator designs that are typically film-like and bendy, but can’t wrap around objects. However, he says that detectors for light that X-Wear must be paired with are still flat, which currently limits possible uses of the fabric.

The researchers can produce samples of X-Wear up to around a quarter of a square metre, so before it can be widely used, they will have to scale its production to larger sizes and adapt it to industrial-grade equipment, says Xu.

The team is also working on industrial applications for X-Wear, such as small, flexible devices for inspecting electronics or pipelines for flaws. Xu says thatfirst responders in a disaster zonecould also use X-Wear alongside a smartphone and a compact X-ray source to do on-site scans.

Journal referenceScience AdvancesDOI: 10.1126/sciadv.adv5537

Science AdvancesDOI: 10.1126/sciadv.adv5537

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Quantum computers have been hyped as machines that can solve almost any problem. Yet it is becoming clearer that their near-term utility will be narrower

Zhang Bin/China News Service/VCG via Getty Images

Zhang Bin/China News Service/VCG via Getty Images

Over the past decade,quantum computinghas grown into a billion-dollar industry. Everyone seems to be investing in it, from tech giants, such as IBM and Google, to the US military.

ButIgnacio Ciracat the Max Planck Institute of Quantum Optics in Germany, a pioneer of the technology, has a more sober assessment. “A quantum computer is something that at the moment does not exist,” he says. That is because building one that actually works – and is practical to use – is incredibly difficult.

Rather than the “bits” of conventional machines, these computers usequantum bits, or qubits, to encode information. These can be made in several ways, from tiny superconducting circuits to extremely cold atoms, but all of them are complex to build.

The upside is that their quantum properties can be used to do certain kinds of computation more quickly than standard computers.

Such speed-ups are attractive for a range of problems that normal computers struggle with, from simulating exotic physics systems to efficiently scheduling passenger flights or grocery deliveries to supermarkets. Five years ago, it seemed quantum computers would ameliorate these and many other computational challenges.

Read moreThe physicist on a mission to spark a quantum industrial revolution

The physicist on a mission to spark a quantum industrial revolution

Today, the situation is a lot more nuanced. Progress in building ever bigger quantum computers has, admittedly, been stunning, with several companies developing machines with more than 1000 qubits. But this has also revealed impossible-to-ignore difficulties.

One major problem is that, as these computers get larger, they tend to make more errors, and finding ways to prevent or fix these has proven to be harder than expected. Last year, Google’s researchers madethe most notable dent in this problem so far, but even so, fully fledged, useful quantum computers aren’t here yet – as Cirac points out.

Because of this, the list of realistic applications for these machines may be shorter than we once hoped. Weigh the cost of building one against the smaller-than-imagined savings it could deliver, and, for many use cases, it may not make economic sense. “The biggest misconception is that a quantum computer can accelerate any problem,” says Cirac.

A bold new take on quantum theory could reveal how reality emergesAt the smallest scales, everything is made out of a cloud of quantum possibilities. A new idea attempts to explain how our everyday world comes from this, using the laws of thermodynamics

A bold new take on quantum theory could reveal how reality emerges

At the smallest scales, everything is made out of a cloud of quantum possibilities. A new idea attempts to explain how our everyday world comes from this, using the laws of thermodynamics

So, which problems might still benefit from quantum computation? Quantum computers couldbreak the cryptography systemswe currently use for secure communication, and this makes the technology interesting to governments and other institutions whose security could be imperiled by it, saysScott Aaronsonat the University of Texas at Austin.

Another place where quantum computers should still be useful is in modelling materials and chemical reactions. This is because quantum computers, themselves a system of quantum objects, are perfectly suited to simulate other quantum systems, such as electrons, atoms and molecules.

“These will be simplified models; they won’t represent real materials. But if you design the system appropriately, they’ll have enough properties of the real materials that you can learn something about their physics,” saysDaniel Gottesmanat the University of Maryland.

Quantum chemistry simulations may sound more niche than scheduling flights, but some of the possible outcomes –finding a room-temperature superconductor, say – would be transformative.

The extent to which all this can truly be realised is significantly dependent on quantum algorithms, the instructions that tell quantum computers how to run – and help correct those pesky errors. This is a challenging new field thatVedran Dunjkoat Leiden University in the Netherlands says is forcing researchers like him to confront fundamental questions about what information and computing are.

“This provides an amazing motivation to study the hardness of problems and the power of computing devices,” says Dunjko. “For me, this would be reason enough to dedicate a significant fraction of my life to these questions.”

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Packed with puzzles and narrative threads, Matt Wixey's novel Basilisk is an exhilarating read that is hard to put down

Could an idea cause physical harm through exposure, asks this novelSumaid Pal Singh Bakshi/Unsplash

Could an idea cause physical harm through exposure, asks this novel

Sumaid Pal Singh Bakshi/Unsplash

BasiliskMatt Wixey (Titan Books (out 1 July))

I AM hacking your brain. Simply by reading this, you have allowed me to hijack your thoughts, each word leaping from my mind to yours. I can even conjure mental images against your will – quick, don’t think about a pink elephant! Whatever you do, don’t imagine it!

Thankfully, there are limits to what I can do to you with words and ideas alone. But what if there weren’t? What if there were a phrase so powerful that I could use it to turn your own mind against you, to the point of death? That is the subject ofBasiliskby Matt Wixey, an experimental thriller that feels like it was specifically designed for my brain and, I suspect, that of manyNew Scientistreaders.

The book has a multi-layered structure similar toHouse of Leavesby Mark Z. Danielewski. On one level, we follow Alex Webster, an “ethical hacker” who works at a computer security company, attempting to hack clients’ networks and helping them to shore up their defences (a profession shared by first- time author Wixey).

But it isn’t that simple. Webster tells her story in two intermingled strands. In the first, we learn how she and a colleague, Jay Morton, stumbled across a puzzle that ultimately led to his death. In the second, she describes the process of coming to terms with his death, and its consequences.

But we aren’t done yet. Webster’s writing includes footnotes written by both herself and a detective investigating Morton’s death, and is further interspersed by “The Helmsman Texts” – missives released by a mysterious character called the Helmsman, as Webster and Morton solve his puzzles.

This book feels like it was specifically designed for my brain, and those ofNew Scientistreaders

This book feels like it was specifically designed for my brain, and those ofNew Scientistreaders

If that all sounds exhausting,Basiliskprobably isn’t for you. Personally, I found it exhilarating, working to hold all these narrative threads in my head as I pieced together the actual story.

The Helmsman Texts themselves take a number of forms, from bureaucratic emails and scientific reports to Socractic dialogues. They encompass topics that are well-explored here atNew Scientist, from psychology to artificial intelligence (I enjoyed noting the accurate references to scientific papers). The Helmsman describes an attempt to develop a “basilisk” – an idea capable of causing physical harm through exposure alone, named after the mythical creature that could kill you with a single glance.

Matt Wixey’s Basilisk follows “ethical hacker” Alex Webster

Matt Wixey’s Basilisk follows “ethical hacker” Alex Webster

As far as we know, basilisks aren’t real, but the concept is an increasingly fascinating one. Science fiction author David Langford created the idea in his short storyBLIT, in which basilisks take the form of images capable of “crashing” the human mind, in a way that is similar to malformed computer code.

Perhaps the most famous example isRoko’s Basilisk, a fairly stupid suggestion that a future, all-powerful AI would punish anyone in the present who failed to bring about its existence (a more detailed explanation is no more sensible, I’m afraid), which has reportedly caused people mental distress, or at least driven them to post about it online. The most recent series of the sci-fi anthology showBlack Mirroralso featured a basilisk, a reference to Roko’s.

Basilisks are just one form of a wider concept known as cognitohazards, ranging from the knowledge of how to build anuclear weaponto, under some definitions, organised religion.

While readingBasilisk, often staying up late into the night with the urge to read just one more chapter, I wondered whether the book itself qualified as a cognitohazard. I certainly couldn’t stop thinking about it, long after I had actually finished it. And now that you have read this review, perhaps you are also at risk.

Go on. Start the book. Don’t you want to know what happens?

The art and science of writing science fictionTake your science fiction writing into a new dimension during this weekend devoted to building new worlds and new works of artExplore more

Take your science fiction writing into a new dimension during this weekend devoted to building new worlds and new works of art

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Concepts like the “growth mindset” are much misunderstood. But learn to cultivate certain beliefs about your future potential, and evidence suggests it really can foster success and bring health benefits

Hugh Schulte/Millennium Images, UK

Hugh Schulte/Millennium Images, UK

For some of us, the phrase “mindset” might bring to mind the unscientific platitudes that you find in certain kinds of self-help books. A growing body of research, though, is showing that our mindset can powerfully shape our lives, thanks to its impact on our perception, motivation and behaviour.

“We think of mindset as a belief about how the world works – which includes either you or your environment – that, in turn, shapes your interpretations of the world and your responses to events, as well as your goals,” saysDavid Yeagerat the University of Texas at Austin.

It wasCarol Dweckat Stanford University in California who first popularised this concept. She was initially interested in people’s beliefs about intelligence and how these affected their academic achievement.

In psychological questionnaires, some people will strongly endorse statements like “Your intelligence is something very basic about you that you can’t change very much.” These people are said to have a “fixed mindset”. Others are more likely to endorse statements like “No matter how much intelligence you have, you can always change it quite a bit.” They are said to have a “growth mindset”.

Dweck’s research found that people in the latter group tended to be more likely to persevere after failure and were more willing to take on challenges outside their comfort zone – two behaviours that encourage intellectual development.

Crucially, Dweck and her colleagues found that mindsets are malleable; teaching people about their brain’s natural plasticity, for example,seems to promote a growth mindset. Despite some failed replications, the effect appears to be robust, though this depends on the context.

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“The intervention tends to work better in schools that have a supportive culture and when the teachers endorse more of a growth mindset,” says Yeager, wholed some of these studies.

Inspired by Dweck’s research,psychologists have now uncoveredmany other mindsets that might affect our health and prosperity.Alia Crum, also at Stanford University, has pioneered research on “stress mindsets”, showing that people who believe that stress is enhancing and energising tend to cope better with life’s challenges than those who believe that stress is inherently debilitating.

Crum compares our mindsets to “lenses”that filter our view of the world – and recent research suggests those optics can have long-term consequences for our health.A study of first responders, for instance, found that those with the mindset that stress is enhancing had a lower risk of cardiovascular disease, regardless of the total amount of stress they experienced in their lives.

Combining a growth mindset and a stress-is-enhancing mindset may amplify the benefits of both. In aseries of studiespublished in 2022, Yeager found that teaching a “synergistic mindset” that incorporated the two improved students’ mental health and academic progress better than either alone. “These two mindsets go hand in hand,” says Yeager. “You’re daisy-chaining your beliefs.”

Why becoming the right kind of optimist can transform your healthSome kinds of optimism get us into trouble, but others help us prosper. Luckily, a few tricks can help you become the right kind of positive thinker and reap the rewards

Why becoming the right kind of optimist can transform your health

Some kinds of optimism get us into trouble, but others help us prosper. Luckily, a few tricks can help you become the right kind of positive thinker and reap the rewards

That said, mindset research has at times been misinterpreted. The scientists behind it would never propose that a positive mindset can work miracles – as Dweck highlights in her book on the subject. “Do people with [the growth] mindset believe that anyone with proper motivation and education can become Einstein or Beethoven?” she wrote inMindset: The new psychology of success. “No, but they believe that a person’s true potential is unknown (and unknowable).”

Cultivating a growth mindset can also be taken as justifying uncritical encouragement, in which every effort is uniformly praised. Yet having this mindset often means setting high standards. “It sometimes involves being tough, but also supporting someone so that way they can grow to meet those standards,” says Yeager. “It can be uncomfortable.”

So, contrary to the self-help gurus, a positive attitude can’t conjure instant riches. But it can help us to put in the necessary efforts to reach our goals – and to cope with the tears along the way.

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There is mounting evidence that even surprisingly simple animals, like invertebrates, have a level of consciousness – but not in the way you might think

Are dogs conscious, with thoughts and feelings of their own? What about pigeons? Honeybees? Earthworms? Jellyfish? How you answer will probably reflect the human tendency to ascribe consciousness to familiar and so-called “higher” animals, while doubting that it extends to “simpler” ones, such as invertebrates.

In fact, we can never be certain if another being is conscious. “The subjective nature of experience means you can’t be totally sure – you can’t even be 100 per cent sure about other humans,” saysJonathan Birchat the London School of Economics, author ofThe Edge of Sentience.

Nevertheless,we can gather evidence. But first, we must decide what we mean by consciousness. Here, says Birch, it is useful to follow the thinking of philosopher Herbert Feigl and split consciousness into three layers.

The most basic is sentience, the raw sensation of the present moment, including sensations from the outside world and more interior feelings like pain, pleasure, excitement and boredom. On top of that is sapience, the ability to reflect on our experiences – to think, for example: “This pain is the worst pain I’ve ever had.” The final layer, selfhood, is a sense of ourselves as beings with a past, a future and a life of our own.

Studies of animal consciousness tend to focus on sentience. “A lot of that research has been on pain, though people are moving towards looking at positive emotions like joy as well,” saysKristin Andrewsat York University in Toronto. For instance, fish that are in pain may swim to a part of their tank that has a painkiller dissolved in the water.

A second type of evidence of sentience comes from social behaviour. “Animals are socially learning so much of their knowledge and skills,” says Andrews. Even insects do it. Fruit flies, for example,learn whomto have sex with by watching other fruit flies have sex.

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The extent to which some animals are aware of their cultural context is revealed in some extraordinary findings, including the recent discovery thatmice seemingly give “first aid” to unconscious companions. Researchers have also looked for episodic memory, which is the ability to relive past experiences – suggesting selfhood – and found it in various mammals, including rats and chimpanzees, as well as inbirds like scrub jays.

Although evidence of widespread sentience is growing, we still don’t understand the neurobiological requirements of consciousness. There are some studies in mammals pointing to the brain regions that are involved, says Andrews, “but we can’t generalise to other species that have very different neural structures”. For instance, insects don’t have anything like a human brain, and yet there is good evidence they can feel pain – and are therefore sentient.

The radical new experiments that hint at plant consciousnessIt’s a wild idea, but recent experiments suggest plants may have the ability to learn and make decisions. Are the claims true and if so, what does it mean for our understanding of consciousness and the human mind?

The radical new experiments that hint at plant consciousness

It’s a wild idea, but recent experiments suggest plants may have the ability to learn and make decisions. Are the claims true and if so, what does it mean for our understanding of consciousness and the human mind?

Nevertheless, last year, Andrews, Birch and their colleagues released theNew York Declaration on Animal Consciousness, which states there is “a realistic possibility of conscious experience” even in many invertebrates. Andrews goes further, arguing thatwe should start by assuming all animals are conscious.

This upends the current assumptions held by most biologists, but it might not be such a stretch for the rest of us. The idea that animals are unfeeling automata is “an aberration of Western science”, says Birch. “Non-Western cultures, and indeed a lot of people in the West, outside of the academy, have always thought of animals as sentient beings.”

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From acquaintances to besties, our relationships fall on a wide continuum. Research into the ingredients for meaningful and lasting connections can help you strengthen them

Meaningful friendships might feel like something that should come naturally. We enjoy people’s company or we don’t; we find the same things funny or struggle to laugh together. But the unwritten rules of different kinds of friendship can be surprisingly tricky to navigate. Over the past decade, though, careful research has begun to unravel not onlyhow significant such relationships are for our well-beingbut also how to ensure the right ones thrive.

Jeffrey Hall, director of theRelationships and Technology Labat the University of Kansas, is one researcher investigating how to foster friendship. He says it is best tothink of our friendships as lying on a continuum– from mere acquaintances and friends of friends to our besties who are always there for us.

“A minimum standard is that two people like each other, and that there is a frequency of communication that allows for the flourishing in that relationship,” he says. “We expect a sense of trust and reliability, the expectation we can confide our secrets, and that they are people who we genuinely enjoy spending time with and will prioritise over others.”

Read moreThe hidden rules that determine which friendships matter to us

The hidden rules that determine which friendships matter to us

You might have noticed that time investment plays a big role in Hall’s definitions. Ina series of surveys, he asked participants who had recently moved to a different city to chart the development of their new social lives. He found that people needed to spend between 57 and 164 hours with someone before they could be considered a “friend”, and roughly 200 hours together to become a “good” or “best” friend.

The type of time spent together is vital, too. “It’s involving the person in the day-to-day affairs of your life – eating, drinking, playing, hanging out – because you want to have them there, and sharing those things makes them better,” says Hall, who is the co-author of a new book,The Social Biome, exploring these themes. Being forced into each other’s company through work or study, in contrast, did nothing for friendship formation.

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We are considerably more likely to spend time with people who are similar to us, of course. Over the past decade, anthropologistRobin Dunbarat the University of Oxford has identified seven “pillars of friendship” that seem to undergird the most meaningful connections. They are: having the same language or dialect, growing up in the same location, having the same educational and career experiences, having the same hobbies and interests, having the same world view, having the same sense of humour and having the same music taste.

We will share just one or two of these pillars with the 150 or so people that we loosely define as friends rather than acquaintances, but six or seven with our five or so closest allies, he writes in his bookFriends: Understanding the power of our most important relationships.

Surprisingly, similarities between friends even stretch to their neural activity. In 2018,Carolyn Parkinsonat the University of California, Los Angeles, asked university students to watch a series of videos while they lay in an fMRI scanner. She found that she could predict who was friends with whom based on thesimilarity of their brains’ reactionsto the clips they were watching. The closer they were to each other, the more likely it was that the same regions would respond at the same time.

Why frenemies, or love-hate relationships, are so bad for your healthFriends who blow hot and cold put more strain on your physical and mental health than enemies. Here's how to spot them and handle them

Why frenemies, or love-hate relationships, are so bad for your health

Friends who blow hot and cold put more strain on your physical and mental health than enemies. Here's how to spot them and handle them

As I describe in my book,The Laws of Connection, Parkinson’s work chimes with the theory that having a “shared reality” – a common way of viewing the world – is the basis of any strong relationship. “These are people who are paying attention to the same things as us, having similar emotional reactions to what they’re seeing, and so on,” she says. “Such people can be easier to predict and understand when we’re interacting with them – making conversations flow more easily, feel less taxing, and minimising misunderstandings.”

Can we experience that connection remotely? Hall thinks so. “Phone calls and video chats with the people that we love are probably as valuable as face-to-face communication,” he says. “And creating routine opportunities to communicate through the phone or video chat sustains and nourishes relationships.”

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