Rocky Balboa would be proud. Halfway across the Milky Way, a gas cloud has punched a hole in the galaxy, leaving a blast wave and a gaping void 3000 light years across.

Compared with our galaxy, this cloud, named CHVC040, is a lightweight: only 16,000 times the mass of the sun. It is moving at high velocity and should have disintegrated on impact with the galactic disc, according to simulations, so it鈥檚 a mystery how it created this hole.

The galaxy is dotted with these spherical abysses, called supershells. Most are thought to be caused by a series of supernova explosions, when the hottest young stars in a cluster blow themselves to bits. The expanding blast waves burst through the galaxy with an energy equivalent to dozens of such exploding stars

But many supershells have no trace of star clusters at their centre, so there might be other causes.

One suggestion was that the compact clouds of gas that swarm around the Milky Way might be jabbing into the disc from above and below, causing explosive impacts. Much larger clouds have been spotted ploughing through the galaxy, but whether the smaller ones could make a mark remained an open question. Supershells dissipate quickly, and evidence of such a collision has been hard to come by.

Blast waves

Until this one. A pair of South Korean astronomers with no apparent cause back in 2007. But when Seoul National University graduate student Geumsook Park took a close look at new data from the highly sensitive in Puerto Rico, she saw a compact high-velocity cloud smack dab in the middle of the shell.

When she showed the data to , her adviser and one of the supershell鈥檚 discoverers, he got excited. 鈥淚 knew that this was important,鈥� he says. 鈥淚 think this is the first convincing example.鈥� Park and Koo think the odds that the cloud and the shell could appear together by chance are exceedingly low.

Understanding just how these shells form should tell us more about the lifecycle of stars in the universe, as the blast waves from supershells are thought to sweep up debris into clumps that turns atomic gas into molecular clouds, which then become the next generation of stellar nurseries.

Interpreting three-dimensional structure from radio data can be tricky, says astronomer of Macquarie University in Sydney, but she finds the results convincing. The supershell is in relatively empty space, well below the densest part of the Milky Way disc, so exploding stars are unlikely to have made it. 鈥淚 pretty much bought it,鈥� she said. 鈥淚t鈥檚 really nice to see an article where they have some reasonable evidence that a cloud is smashing through the disc and forming a shell.鈥�

Journal reference: Astrophysical Journal Letters,

AFTER defeat comes resolve. AlphaGo, the artificial intelligence that has mastered one of our oldest and most complex games听鈥� Go听鈥� is the toast of Silicon Valley. But in South Korea, where Go is considered a form of expression akin to martial arts, the mood is different. Here, the game pulls in television contracts and corporate sponsors. Scholars study it full time in academies. Now, after 2500 years of tradition in the region, South Korea鈥檚 top player has been bested by a cyborg, its culture shaken by technology.

Watching Google鈥檚 AlphaGo AI eviscerate Korean grandmaster Lee Sedol put the nation into shock, especially after the national hero confidently predicted that he would sweep AlphaGo aside. The actual result laid bare the power of AI.

鈥淟ast night was very gloomy,鈥� said Jeong Ahram, lead Go correspondent for the Joongang Ilbo, one of South Korea鈥檚 biggest daily newspapers, speaking the morning after Lee鈥檚 first loss. 鈥淢any people drank alcohol.鈥�

Wariness of AI already has deep roots all over the world. Films like The Terminator influenced it, and people like Stephen Hawking and Elon Musk have made public warnings of AI鈥檚 future power. But AlphaGo鈥檚 schooling of Lee carries extra bite where Go holds a central place in the cultural legacy.

鈥淜oreans are afraid that AI will听destroy human history and human culture,鈥� said Jeong. 鈥淚t鈥檚听an emotional thing.鈥�

It is perhaps the perceived beauty of AlphaGo鈥檚 moves, that听it听beat Lee not mechanically, but听wonderfully, that has ruffled the most feathers. 鈥淎lphaGo actually does have an intuition,鈥� Google co-founder Sergey Brin told New 女生小视频 hours after his firm鈥檚 series-clinching third victory, which he鈥檇 flown in to witness. 鈥淚t makes beautiful moves. It even creates more beautiful moves than most of us could think of.鈥�

This ability to make beauty has听left many shaken. 鈥淭his is a听tremendous incident in the history of human evolution 鈥� that听a machine can surpass the intuition, creativity and communication, which has previously been considered to be听the territory of human beings,鈥澨齁ang Dae-Ik, a science philosopher at Seoul National University, told The Korea Herald.

鈥淏efore, we didn鈥檛 think that听artificial intelligence had creativity,鈥� said Jeong. 鈥淣ow, we听know it has creativity听鈥� and more brains, and it鈥檚 smarter.鈥�

As Lee鈥檚 losses stacked up, I kept getting worried messages from my Korean friends. 鈥淚 thought it might be fun to watch, but now it鈥檚 getting really scary,鈥� one of them said. Another told me: 鈥淭hinking that these AIs are only accessible to a few groups and people听鈥� it is scary.鈥�

Headlines stacked up in the South Korean press too: 鈥淭he 鈥楬orrifying Evolution鈥� of Artificial Intelligence,鈥� and 鈥淎lphaGo鈥檚 Victory鈥� Spreading Artificial Intelligence 鈥楶hobia鈥�.鈥�

Some are upbeat that the impact of Lee鈥檚 loss will spark a revolution in education and learning in South Korea. 鈥淲e鈥檙e very weak at听AI,鈥� says Lee Seok-bong, a journalist for South Korean science website HelloDD.com. 鈥淯p to this point, Korean people didn鈥檛 know much about AI. But because of this match, every Korean knows about it now.鈥�

Maybe AlphaGo is fallible after all. Korean Go master Lee Sedol claimed victory over Google DeepMind鈥檚 Go-bot on Sunday, his first in the five-game series.

It came too late to affect the outcome of the series 鈥� AlphaGo clinched it on Saturday with its third straight win. But Lee鈥檚 victory reversed the event鈥檚 sombre tone, inspiring the Go community, and the entire region.

After his win, Lee strolled into a press conference to unrestrained cheers from reporters, chants of 鈥淟EE-SE-DOL鈥�. He acknowledged them almost shyly, with a slight bow, his eyes on the floor. But the grin on his face was a picture of relief.

鈥淚f I had lost one game, it would have hurt tremendously,鈥� he said. 鈥淏ut because I lost three matches and got this single win, I wouldn鈥檛 exchange it for anything in the world.鈥�

The day before, he had lost to AlphaGo鈥檚 most complete performance yet, falling behind early and never recovering.

鈥淚t was so hard to watch,鈥� said Andrew Jackson of the . 鈥淗e just got steamrolled.鈥�

Astonishing play

In Sunday鈥檚 game, Lee started conservatively, ceding the centre of the board. But on move 78, he turned the game around with an astonishing wedge play in the middle. Gu Li, one of Lee鈥檚 rivals, commenting on the game in China, called it the 鈥渉and of god鈥�, the kind of language that was being applied to AlphaGo in previous games.

AlphaGo responded to the unexpected move with a weak counter, which set off a brilliant sequence from Lee to capitalise. According to Demis Hassabis, one of DeepMind鈥檚 founders, AlphaGo didn鈥檛 realise its mistake until eight moves later. 鈥淟ee Sedol beat AlphaGo at its own game,鈥� said Jackson.

Watch the best human player take on the mighty AlphaGo AI at Go

Lee sat up straighter as he closed in on victory. The press room began to buzz as AlphaGo played increasingly bizarre moves, the death throes of an algorithm. Across the table from Lee, Aja Huang, the AlphaGo programmer who acts as its human avatar and places its stones on the board, appeared resigned. And then, a message appeared on his monitor: 鈥淭he result 鈥榳hiteresign鈥� was added to the game information. AlphaGo resigns.鈥�

Lonely fight

After the third match, with camera shutters clicking, Lee had apologised 鈥渇or not being able to satisfy a lot of people鈥檚 expectations鈥�. More than one reporter later admitted to holding back tears. Lee stressed it was not humanity鈥檚 defeat, but his alone. He said that the pressure had got to him, and that he felt 鈥渒ind of powerless鈥�.

One of Lee鈥檚 fellow pros, Lee Hyun-wook, paid tribute to his heart and spirit. 鈥淗e is fighting such a lonely fight, and a hard fight against this invisible opponent.鈥�

The next day was an emotional 180. Yet, in his moment of victory, if Lee cracked a smile, I didn鈥檛 see it. His focus was back on the board, replaying the game.

In Go, it鈥檚 customary to go over the match with your opponent to share your thought process. But across from Lee, there was only Aja Huang, looking around, unable to explain any of AlphaGo鈥檚 blunders. As he left his chair, Lee gave him barely a nod. In victory, just as in defeat, Lee Sedol was utterly alone.

Read more:听Does a machine beating a Go master mean human-like AI is close?

Read more:听鈥業鈥檓 in shock!鈥� How an AI beat the world鈥檚 best human at Go

Read more:听Google AI program crushes Korean Go legend again in round two

Is AlphaGo unstoppable? It felt like it today, as Google鈥檚 artificial intelligence crushed the best that humanity has to offer in Go. It wasn鈥檛 even close.

After yesterday鈥檚 historic round one loss, it may have been a restless night for legendary player Lee Sedol. Lee arrived in the arena noticeably worn, his eyes blinking.

He seemed to eke out an early advantage in game two, but AlphaGo seized control of the board as the game wore on, making a series of incisive yet unorthodox moves.

The software flashed its cold, calculating nature towards the end of the game when it seemed to make a mistake, allowing Lee to capture several stones. Lee blinked in disbelief as he recounted the board. But it was false hope: AlphaGo didn鈥檛 care about the gap 鈥� it makes whichever move will maximise its chances of winning, regardless of the margin.

Hard, cold intelligence

Commentators were stunned as the reality set in. 鈥淕oodness gracious,鈥� said Andrew Jackson of the American Go Association, in a . 鈥淗ow could this happen?鈥� sighed his broadcast partner, Go professional Myungwan Kim. 鈥淚 can鈥檛 believe this.鈥�

Lee鈥檚 second loss is made more crushing because, aside from one slightly questionable move midgame, nobody could point to a crucial mistake from the human. 鈥淗e might have a tough time even winning one game now,鈥� said Kim.

Watch the best human player take on the mighty AlphaGo AI at Go

In the minutes after today鈥檚 match ended, Jackson said AlphaGo鈥檚 flawless play left him in shock. 鈥淭hings that looked questionable in hindsight turned out to be correct. That鈥檚 its hallmark.鈥�

At yesterday鈥檚 post-game press conference, Lee looked shell-shocked. Today he seemed resigned. One reporter asked what AlphaGo鈥檚 weaknesses are? Lee laughed: 鈥淲ell, I guess I lost the game because I wasn鈥檛 able to find out.鈥�

As Lee filed out of the press conference, his thin frame lit up by flashing cameras, a lone Korean reporter cried out, 鈥淟ee Sedol, fighting!鈥�

No one responded.

Read more:听Does a machine beating a Go master mean human-like AI is close?

Humanity鈥檚 machines just outstripped us, again. A few hours ago in Seoul, South Korea, an artificial intelligence built by Google defeated top player Lee Sedol in one of our most complex games, Go.

鈥淭his is history, you saw it folks,鈥� said Chris Garlock of the American Go E-Journal, one of the match鈥檚 commentators. The match was the first of a five-game series in Seoul.

As the game reached its conclusion, the reality of Lee鈥檚 defeat set in slowly across the venue, prompting quiet gasps of shock. This was stark contrast to Tuesday, when some Korean journalists had openly cheered Lee at a press conference. It was hard not to feel sympathy with Lee as I watched this opening defeat. He carries the hopes of a nation 鈥� not to mention a species 鈥� on his shoulders.

The news, that artificial intelligence has defeated humanity鈥檚 best Go player, has sent shock waves through the international Go community. 鈥淚 felt emotional and dizzy, and stepped outside for a minute,鈥� said Ben Lockhart, one of the top US amateur players, watching on in the press room.

AlphaGo made headlines in January when DeepMind 鈥� an artificial intelligence company that Google bought in 2014 鈥� announced that its AI had defeated reigning European champion Fan Hui 5鈥�0. Most observers had thought such an AI was a decade away. That prompted DeepMind to challenge Lee, considered the game鈥檚 dominant force of the last decade.

Putting on a show

The match against Fan was played in secret. Not this one. Google鈥檚 AlphaGo is facing off against Lee Sedol in the swanky Four Seasons hotel in the heart of downtown Seoul. The match has captured public imagination in Korea, with dozens of cameras and hundreds of reporters descending on the match site. The press filled two separate conference rooms 鈥� one with English commentary and one with Korean.

The match itself took place in a room that organisers wouldn鈥檛 disclose. There, isolated from outside noise, Lee sat across the board from Aja Huang, one of AlphaGo鈥檚 lead programmers, who referred to a monitor plugged into AlphaGo. A sign gave their names and flags 鈥� a Union Jack for Google DeepMind鈥檚 London headquarters.

Watch the best human player take on the mighty AlphaGo AI at Go

Go is riding a recent wave of pop culture relevance here in Korea, thanks to a couple of recent TV dramas featuring Go players. The game was televised live across Korea, China and Japan, where the game is most popular, and . On Naver, the top Korean search engine, combinations of 鈥淟ee Sedol鈥� or 鈥淎lphaGo鈥� were the top three search terms on the day of the match.

Human nature

Lee Sedol is a national hero in his native South Korea, known for his unconventional and creative play, as well as his brashness. He flashed his swagger at , predicting he would win in a 鈥渓andslide鈥�. 鈥淥f course, there would have been many updates in the last four or five months, but that isn鈥檛 enough time to challenge me,鈥� he said.

But after watching DeepMind explain the algorithm at a press conference on Tuesday, Lee admitted to being 鈥渜uite nervous鈥� and backed off from his 5鈥�0 prediction.

Lee had been in fine form, with a runner-up finish in the world championship and victory in the Korean national championship in January, where it is known as baduk. Most professional players thought that based on AlphaGo鈥檚 play in October, Lee would win handily. But no one knew how much progress it had made, or how it would respond to tougher competition.

Play-by-play

Lee showed his opening gambit in the game鈥檚 seventh move, with an unusual play in the middle right of the board, allowing him to stake out territory along the right side of the board. But AlphaGo continued to push, playing unconventionally for a human. 鈥淚t鈥檚 unheard of! It鈥檚 crazy,鈥� said Jackson.

AlphaGo fell further behind in the midgame with a bizarre stretch of moves that had observers shaking their heads. But as it fought back over the rest of the match, Lee grew agitated, dabbing at his chin with his fist and tapping his finger on the side of the board. 鈥淚鈥檝e never seen him so nervous before,鈥� said Lockhart.

The match ended in what Garlock called a 鈥渟lugfest鈥�, with AlphaGo鈥檚 performance impressing. 鈥淚t鈥檚 all that I hoped for or expected,鈥� said Michael Redmond, one of other commentators and the only Western Go pro to have reached 9-dan, the game鈥檚 highest level.

As the endgame played out, Lee appeared downbeat, his hands shaking at every move. He flashed a wan smile as he resigned.

The question is whether Lee can recover. In AlphaGo鈥檚 previous match, experts say Hui Fan鈥檚 moves grew erratic after dropping the first game.

鈥淚t鈥檚 so shocking. I expected AlphaGo to win one game, but I didn鈥檛 expect it to be the first one,鈥� said Myung-wan Kim, a Korean 9-dan professional living in Los Angeles and commenting with Jackson.

鈥淚 am in shock, I admit that,鈥� said Lee. But he said he had no regrets about accepting the challenge and planned to come back strong in the rest of the matches. 鈥淚 didn鈥檛 think AlphaGo would play the game in such a perfect manner.鈥�

For more on machine learning, watch our Explanimator video:

[youtube]https://www.youtube.com/watch?v=bctMvKrB_y0[/youtube]

Read more:听Does a machine beating a Go master mean human-like AI is close?

A dog lies unconscious on the operating table, as Woosuk Hwang gently lifts the puppy from its womb. While I watch, one of his researchers, David Kim, tells me about the original 鈥� the source of this puppy鈥檚 DNA.

He calls it the original, because the nearly born puppy is a clone.

Hwang snips open the amniotic sac and the little fur ball slips out into the world. It鈥檚 black, wet 鈥� and motionless. An assistant wraps it in a towel, massages it gently 鈥� and it starts to yelp. Success!

This puppy is a sign of things to come for Hwang and his lab. For the past few years, the lab has worked on cloning domestic dogs. Now the researchers plan move on to saving their wild relatives. They want to rescue some of the world鈥檚 most endangered canids, including the Ethiopian wolf and the dhole, or Asiatic wild dog.

This has raised concerns among conservationists, not least because they fear cloning will be little more than a shiny distraction from wider efforts to preserve habitats and biodiversity.

From hero to disgrace to hero again

In 2005, Hwang became a national hero. In the space of three months, he made international headlines twice: first, with the creation of 11 stem cell lines cloned from human embryos that could be used to study the diseased cells of individual patients, and then with the unveiling the world鈥檚 first cloned dog.

But a year later, he had been unmasked as a fraud. Seoul National University found he had faked the human stem cell lines and expelled him, and a national bioethics commission found he had forced some junior members of his lab to donate their eggs for research. He was sentenced to two years in prison, but this was suspended.

Although an international pariah, he still had supporters in South Korea, who funded the creation of a private lab, , in Seoul. There he turned to cloning canines 鈥� a verified accomplishment 鈥� charging bereaved dog owners to to the tune of $100,000 a pup.

Hwang鈥檚 team extracts the nucleus of skin cells from the animal you wish to clone, and then inserts them into an egg with its nucleus removed. The technique is called somatic cell nuclear transfer (SCNT), and they have now refined and extended it to coyotes and grey wolves, using dogs as egg donors and surrogates. Soon they hope to be producing clones of endangered species. 鈥淚t is the most meaningful way that we can use the SCNT technology to contribute to society,鈥� says Sooam鈥檚 research director Yeonwoo Jeong.

Cloning the Ethiopian wolf

First up is the Ethiopian wolf, of which fewer than 500 remain, living in Ethiopia鈥檚 high-altitude alpine meadows. The degradation of the highlands because of human expansion has shrunk their range to six enclaves on different mountains, all isolated from each other. Such low numbers of individuals creates that can reduce their ability to reproduce and survive.

Sooam hopes to preserve these gene pools by cryogenically banking the cells of as many individual wolves as possible. If an animal dies in the wild, Sooam could thaw its stored cells, create clones using domestic dog surrogates, and introduce them into the wild.

Since no Ethiopian wolves are held in captivity they will first need to be captured. In January, Sooam inked an agreement to collaborate with Arsi University in central Ethiopia through which it hopes to receive permission from the Ethiopian government to collect tissue samples. If they succeed, they hope to be providing cloned pups for repopulation efforts within a year.

Because Ethiopian wolves are very closely related to dogs, the team expects the actual cloning to go smoothly. 鈥淚 don鈥檛 think there will be too much of a complication,鈥� says Kim.

Sooam also hopes to start work later this year on the dhole. This canid鈥檚 range once included nearly all of east Asia, but now has fragmented into groups scattered across the mountain forests of India and south-east Asia. They also suffer from direct conflict with humans. If they kill livestock, herders sometimes retaliate by poisoning the carcasses, which can wipe out an entire pack. fewer than 2500 dholes remain in the wild.

Asiatic wild dogs, and more

The dhole will test Sooam鈥檚 cloning expertise: it鈥檚 more distantly related to the domestic dog and classified in a separate genus. In principle, domestic dogs can become surrogates to any canid, but in reality the success rate will vary. 鈥淚t depends, species by species, on how closely related they are to the dog,鈥� says Kim. Hwang鈥檚 team has attempted to clone the African wild dog, which is also in its own genus. These tests resulted in successful impregnations, but no successful births, so how easy it will be to clone the dhole remains to be seen.

Sooam鈥檚 researchers are also starting work on cloning the Siberian musk deer, a fanged deer that has been nearly wiped off the Korean peninsula. They already have technical expertise beyond dogs. They routinely clone pigs with genes susceptible to disease to be used for drug tests. They also clone breeds of cows prized for their high-quality meat, and have worked on genetically modifying cows to produce therapeutic proteins in their milk. In total, they produce about 500 cloned embryos every day across all species.

Is cloning just a high-tech distraction?

So can work like Hwang鈥檚 actually help conserve endangered species? Many researchers are far from convinced. Some feel the lab is operating in a vacuum and its work could even hurt existing conservation efforts.

One such sceptic is conservation biologist , who founded the at the University of Oxford. 鈥淭hey are the last man standing in terms of representing the wilderness of those African meadows,鈥� he says of the Ethiopian wolves.

Three years ago, Sooam proposed a collaboration to help conserve the wolves, he says. But he turned them down, saying cloning wouldn鈥檛 be worth their time.

The most pressing problem for Ethiopian wolves is not genetic diversity or any difficulty in reproducing, he says. It鈥檚 that they鈥檙e losing their habitat and prey, and are susceptible to diseases spread by local domestic dogs. Genetic diversity could be preserved simply by moving animals between packs, he says. And he worries that politicians presented with what looks like a simple solution will choose cloning over the kinds of wide-reaching and long-term conservation programmes that are really needed.

, a conservation biologist at the University of Rome, also thinks cloning is a 鈥渨aste of resources鈥� that should be reserved for extreme, near-extinction situations. 鈥淚 do not see any canid species in this desperate situation yet,鈥� he says.

听

Read more: Struggling to find an appetite for cloned meat

Dollymania: the creation of a celebrity sheep

Brazil aims to clone endangered animals

听

Looks like something left the lights on. The supermassive black holes at the cores of some galaxies give off a tremendous amount of light. It comes from superheated discs of gas that slowly spiral into the maws of the black holes, but where all that gas came from has been debated for decades. Now, observations reveal tell-tale signs of debris that suggest ancient galactic crashes flipped the light switch in the brightest of these 鈥渁ctive galaxies鈥�.

One of the main hypotheses is that the gas could be funnelled towards black holes when colliding galaxies send vast amounts of it toward their shared centre as they merge. But an alternate theory has gained traction recently, especially to explain fainter galaxies. This theory holds that the structure of galaxies becomes unstable over time and causes a self-implosion.

To test which process is more frequent, Jueun Hong and of Seoul National University in South Korea imaged 39 of these bright active galaxies, with telescopes in , and . They spent up to four hours on each galaxy to capture fine, faint details. They inspected the images for signs of a past or ongoing merger 鈥� wispy trails of stars flung violently into space during an intergalactic pile-up.

Gassy galaxies

The team found that 17 of the galaxies had such features, which was between four and eight times more than they saw in a sample of images of non-active galaxies.

Im says the results show that although both mechanisms could trigger active galaxies, mergers are the main cause for the brightest ones. 鈥淵ou have to have a great amount of gas supply to fuel them,鈥� he says.

The study is 鈥渁 new piece of the puzzle鈥�, says of the National Institute of Astrophysics in Bologna, Italy. In 2011, Cappelluti and his colleagues published a study of fainter, more distant active galaxies, and found no signs of collisions. 鈥淚n this paper they study much brighter sources than ours and in this case, the merger scenario works,鈥� he says.

Journal reference: Astrophysical Journal, DOI:

Dreams and careers rest on the decision. Do you go all out in the semi-final or rest your stars so they are fresh for the final?

of Pukyong National University in Busan, South Korea, and his colleagues have applied game theory to this 鈥渟emi-finalists鈥� dilemma鈥�, and the results could apply in the boardroom as much as in basketball or football.

They constructed a simple mathematical model in which winning depends on stamina, which is a finite quantity that each team must choose how to distribute over its final two matches of a tournament.

In a winner-takes-all format, the best strategy is to copy what everyone else does, Baek鈥檚 team says. If your opponents rest their stars, you ought to as well. Otherwise, you risk being more tired than the opponent in the final. This sort of scenario in which no player has an incentive to go off-strategy is what game theorists call a Nash equilibrium.

Chasing bronze

But it鈥檚 different when there鈥檚 the chance of redemption in a third-place play off. You need to introduce an element of chance to catch your opponents off guard, says Baek鈥檚 team. Either go all out in the semis, or save everything for the next match. A team may be crushed in the semi-final, but saving energy increases the odds of taking home a prize: the bronze.

The work could help explain why animals sometimes seem to cooperate in nature, even when competing for a mate, says co-author of Sejong University in Seoul, South Korea. A seemingly cooperative pair of males may not be altruistic 鈥� they may have simply converged on saving their stamina for future rounds with other opponents.

The results could also guide companies in setting incentive schemes. 鈥淭he pay-off system is effectively sending a signal to people on how to behave,鈥� says Baek. For instance, a company wanting to cultivate specialists on its management team may wish to avoid paying the CEO far more than others, because that might push people to develop the same skill set to compete for the top job.

Group theory

鈥淵ou could see that career structure as a bunch of subsequent stages where some proceed to the next stage and other people don鈥檛,鈥� says , an evolutionary game theorist at the University of Amsterdam, the Netherlands. He says the work could also be extended into exploring the game theory of an entire World Cup tournament, group stage and all: 鈥淭his shows the principle.鈥�

He says the Dutch side has reached the World Cup semis five times without solving the dilemma.

Jeong says his nation鈥檚 Olympic squad is one example of how a different pay-off structure might alter a team鈥檚 strategy. South Korean male athletes are exempted from their two years of mandatory military service if they bring back an Olympic medal, giving them an incentive to ensure they get a bronze.

It might be coincidence, but in the football at the 2012 London Olympics, South Korea suffered a 3鈥�0 thrashing from Brazil in the semi-final, but went on to overcome arch-rivals Japan 2鈥�0 and snatch bronze.

Journal reference: Physical Review E; journals.aps.org/pre/accepted/7807dR6fFd419718908d1c99d99366454f9e6b9a5