26 January 2019, No3214 New Scientist (Australia)

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S PE CI A L R E PORT

HOW TO KEEP YOUR BRAIN YOUNG Eight things to start doing today

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Why empty space holds the secret to everything

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The enduring mystery at the heart of who we are

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PLUS DNA SOLVES NAZI CONSPIRACY THEORY / TIP OF THE FATBERG / LAST DAYS OF THE NEANDERTHALS / A FORMULA FOR PRIMES

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WHAT IS A SPECIES?

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News DNA settles Rudolf Hess conspiracy theory 9

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30 How to keep your brain young Eight things to start doing today

5

The complex moral impacts of our choices. Should we ditch the idea of “species”?

40 The something inside nothing Why empty space holds the secret to everything

6

36 What is a species? The enduring mystery at the heart of who we are

THIS WEEK Earliest animal ever found. CRISPR baby investigation. Meteorite hits moon during eclipse

8

NEWS & TECHNOLOGY Ordinary camera made to see around corners. World leaders worry about climate chaos. DNA solves Nazi conspiracy theory. Neanderthal’s last stand. Formula for prime numbers. Robot dog learns to run. Fish could help us live in space. AI copies drugs cheaply. Moon impacts reveal Earth’s history. Prosecco may be eroding Italian hills. Beatles-style songs made by machines

Plus DNA solves Nazi conspiracy theory (9). Tip of the fatberg (22). Last days of the Neanderthals (10). A formula for primes (10)

News

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19 IN BRIEF Saturn’s young rings. Feeling injuries without pain. Why hermit crabs have long penises. New type of blood vessel found

Analysis 22 INSIGHT Everything you want to know about fatbergs but are too disgusted to ask 24 COMMENT Why it’s not worth spending billions to upgrade the LHC. Share seeds, feed the world 25 ANALYSIS Can a diet save the planet?

Features 30 How to nurture your mind Eight things to start doing today 36 Is this the end of species? The enduring mystery at the heart of who we are 40 Something from nothing We are about to find out what empty space is made of

Culture 44 A virtual voyage begins What discoveries await an epic player mission to the Milky Way’s edge? 45 Unveiling the obvious Images of the digital world reveal little. PLUS: The week’s cultural picks 46 World of pain The unsung story of slave women makes a play that merits a wide audience

Regulars 28 APERTURE Icy discworld 52 LETTERS Genetic testing lessons 55 CROSSWORD 56 FEEDBACK Mona Lisa ’s gaze 57 THE LAST WORD A key question

26 January 2019 | NewScientist | 3

LEADERS

Editorial Editor Emily Wilson Art editor Craig Mackie Executive editor Richard Webb

News THE GOOD PLACE/NBC, PHOTO COLLEEN HAYES

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Getting better at good

Culture and Community Editors Liz Else, Mike Holderness, Simon Ings, Frank Swain

In a world of baffling complexity, a scientific mindset offers help

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THE moral impact of buying a tomato probably isn’t something most of us spend time dwelling on, but perhaps we should. In a recent episode of The Good Place, a sitcom in which humans are scored on the morality of their actions to determine their place in the afterlife, one character complains that life has simply become too complex for anyone to be truly good. In his example, the act of purchasing a tomato scores morality points for being a healthy choice, but loses them because producing a tomato involves the use of pesticides, carbon-emitting vehicles and

underpaid labour, resulting in a net negative. Putting aside the fact that scoring pesticides as morally negative is scientifically questionable – without them, farmers would have to destroy larger areas of wildlife habitat to feed us – The Good Place succinctly demonstrates how our choices can unknowingly or unthinkingly cause harm. Take the booming demand for Prosecco. You might think you are just having a fun bottle of fizz, but you are actually massively eroding Italy’s hillsides (see page 16). Wash the dishes incorrectly and you contribute to the rise of

Time to kill ‘species’? Environment ISO 14001 Certification applies to Offset Alpine Printing

© 2019 New Scientist Ltd, England. ISSN 1032-1233 New Scientist (Online) ISSN 2059 5387 New Scientist is published weekly by New Scientist Ltd, 25 Bedford Street, London, WC2E 9ES, UK Registered as a newspaper. Printed in Australia by Offset Alpine Printing, 42 Boorea St, Lidcombe, NSW 2141, Australia

DIVIDE and conquer! This isn’t just a political or military strategy, it is a human imperative. Categorising is in our nature. It is how we make sense of the world, from personal identity to scientific investigation. But sometimes, something happens that illuminates the arbitrariness of our classifications – something like the discovery that our species,

Homo sapiens, contains DNA from Neanderthals. Most of us think of a species as a group of individuals that can interbreed to produce fertile offspring. In which case, either humans are hybrids or we have been mistaken in seeing Neanderthals as “other”. In fact, it isn’t that simple. This definition is just one of 34, all of which are

fatbergs (see page 22). And while you relax on a Mediterranean cruise, coastal cities in the region are choking on the resulting air pollution (see page 6). It is exhausting trying to keep up, but we must make an effort. Researchers have laid out a plan to transform our diets to improve both our health and the environment, tackling two modern problems in one (see page 25). And thankfully, global leaders are also starting to correctly prioritise the major challenges facing us today (see page 8). The world isn’t yet a good place, but a scientific mindset can at least help us reach a “getting better” place. ■

valid ways of categorising the living world, depending on your viewpoint (see page 36). This taxonomic confusion goes far beyond human identity to the heart of how we value nature: using an alternative definition can instantaneously transform one species into several – or reclassify an endangered species as a hybrid. One solution is to ditch the idea of “species” altogether. Whatever would Darwin think? ■ 26 January 2019 | NewScientist | 5

THIS WEEK

JOSE M. MADIEDO/MIDAS AT THE UNIVERSITY OF HUELVA

Meteorite hits moon MILLIONS of people around the world watched a total lunar eclipse on Monday. Some of those viewing streaming broadcasts online noticed a tiny, yellow-white flash on the lunar surface – a suspected meteorite impact (see arrow, left). José María Madiedo at the University of Huelva in Spain has confirmed that the impact is genuine, and the first to be seen during a lunar eclipse. He and his colleagues have been hoping to observe such an event for years, but they are difficult to capture due to the moon’s brightness. On this occasion, Madiedo doubled the number of telescopes trained on different parts of the moon – from four to eight – in the hope of seeing an impact. “I had a feeling, this time will be the time it will happen,” says Madiedo.

After the eclipse, software automatically pinpointed a flash in imagery recorded by several of his telescopes. This helped to confirm that those watching the live stream hadn’t just seen an optical anomaly on the camera sensors. “I was really, really happy when this happened,” says Madiedo. He notes that the flash was quite bright and it occurred when the eclipse was not overly luminous itself, perhaps making the strike easier to detect. Although he hasn’t yet formally calculated the likely size of the space rock that collided with the moon, Madiedo thinks it probably weighed about 2 kilograms and was roughly the size of a football.

CRISPR babies researcher fired

For more on lunar impacts, see page 15

Plan to clear the air in the Med

AUSTRALIAN children who were vaccinated against a common virus

CLEANING up air pollution from shipping in the Mediterranean

tankers, cargo ships and cruise ships. The report, commissioned by the French environment ministry, concludes that particulate pollution from shipping causes a serious burden of disease around the Mediterranean

had lower rates of type 1 diabetes nearly a decade later.

Sea would have financial benefits as well as saving lives, according

and results in 6000 premature deaths each year. A ban would save

has been fired after an investigation found he “illegally conducted the

In Australia, the vaccine for rotavirus – the most prevalent cause

to a feasibility report looking at implementing a low emission zone

€8 to €14 billion per year in health bills, but would cost less than €3 billion.

research in the pursuit of personal fame and gain”.

of severe diarrhoea in young children – was added to routine, early-childhood

for ships in the region. Many ships burn fuels, such as

Switching to fuels with less than 0.1 per cent sulphur would cut

In November 2018, the world was shocked when He Jiankui claimed that

immunisations in 2007. Kirsten Perrett at the University

heavy fuel oil, that contain high levels of polluting sulphur. Up to 40 per cent

particulate emissions by 95 per cent, says the report. Such fuels are

two gene-edited babies had already been born and that a woman was

of Melbourne and her colleagues compared the rates of diabetes in the eight years before and after the rotavirus vaccine was introduced and found a 14 per cent drop in type 1 diabetes in children under the age of 5 (JAMA Pediatrics, DOI: 10.1001/ jamapediatrics.2018.4578). Rotavirus infects pancreas cells by hijacking a natural receptor on their surface, which leads to cell death. The vaccine stops this process in insulin-producing cells, which may be why it is effective against diabetes as well. Perrett and her team are now looking into links between type 1 diabetes and reduction in pancreas size associated with the disease.

of the air pollution in coastal towns around the Med can come from

available, but aren’t widely used because they are more expensive.

pregnant with another. On Monday, the Xinhua state news agency reported the findings of a provincial authority investigation. It found that He avoided supervision and organised researchers on his own to carry out the work. The university that employed He, the Southern University of Science and Technology in Shenzhen, put out a statement: “SUSTech will rescind the work contract with Dr. Jiankui He and terminate any of his teaching and research activities at SUSTech.” However, it seems He made little use of the university’s facilities and instead used his own wealth to fund the work.

6 | NewScientist | 26 January 2019

SUPANAT SAKORNTRAKUN/GETTY

Vaccine may guard against diabetes

THE Chinese scientist who created the world’s first gene-edited babies

For new stories every day, visit newscientist.com/news

Earliest animal ever discovered 600-million-year old fossils uncovered in China, reports Graham Lawton If the new fossils are comb jellies, more discoveries may yet be to come. The vast majority of living comb jellies today are predators, feeding on small marine organisms. If the 600-million-year-old fossil was a carnivore too, then it must have been part of a food web and hence a surprisingly complex ecosystem. “There are many other creatures in the deposit, but we are not sure what they are,” She told New Scientist.

Ancient carnivores

RON OFFERMANS, BUITEN-BEELD/FLPA

MOVE over, Dickinsonia. This 558-million-year-old creature was named the earliest known animal last year, but New Scientist can now exclusively reveal one that existed even earlier – by more than 40 million years. This previously unknown animal comes from 600-millionyear-old rocks in China and doesn’t have a name yet. While Dickinsonia was an Ediacaran – a primitive group of organisms that went extinct about 541 million years ago – the unnamed animal seems to have belonged to a group of animals that still exists today: comb jellies. It was discovered by Zhenbing She at the China University of Geosciences, Wuhan. “The origin and earliest evolution of animals is a fascinating question that has puzzled scientists for many decades,” said She as he unveiled his findings at a meeting of the Geological Society of London in London last week. The fossils were found in a drill core taken from the Doushantuo Formation in southern China. These beds have already yielded She said these features are exquisitely preserved fossils from reminiscent of the comb jelly as far back as 631 million years phylum Ctenophora. The cilia ago. These mysterious fossils are clusters in particular look like only visible through microscopes, structures called ctenes that and may be algal cells, developing comb jellies use to swim. animal embryos or something The fossils most closely resemble else entirely. the living genus of comb jellies Among these rocks, She’s team called Pleurobrachia, or sea has found fossils visible to the gooseberries, She told the meeting. naked eye, measuring about “It was a very interesting talk – 0.7 millimetres across. The first it seems like they have some very clue to their identity was their interesting biological creatures jellyfish-like shape. Microscopic preserved,” says Emily Mitchell analysis revealed what appear at the University of Cambridge, to be tentacles, muscle tissue, who attended the conference. nerve cells, gonads, mucous “If these fossils are comb layers and clusters of hairlikejellies, they may have structures called cilia. been part of a surprisingly True jellyfish belong to the complex ecosystem” Cnidaria phylum of animals, but

The oldest known animal looked like modern sea gooseberries

As a rule, comb jellies are more primitive than jellyfish, says Dominic Papineau of the London Centre for Nanotechnology, whose laboratory helped to analyse the fossils. They have a simpler life cycle and are anatomically less advanced. Nonetheless, comb jellies would be remarkably advanced for 600 million years ago, says Tim Lenton at the University of Exeter, one of the meeting organisers. Living comb jellies have a gut connecting their mouth and anus, a feature not present in many other primitive groups including the Cnidarians.

Papineau confirmed that the deposits contain other, unidentified fossils that the comb jellies could have eaten. They resemble algae, he says. The discovery has yet to be peer-reviewed or published in a journal but has been seen by other scientists, said She. Some have doubts about the discovery. Maoyan Zhu of Nanjing Institute of Geology and Palaeontology, who was also at the meeting, says he doesn’t accept She’s interpretation. The comb-jelly-like structures could be artefacts or bacterial contamination, he says. If it does check out, the discovery won’t radically alter our knowledge of life before the Cambrian explosion – the sudden appearance of many kinds of animal fossils about 541 million years ago. We know that the ancestors of modern species must have appeared long before this time, says Zhu – it is just that nobody has found them yet. Zhu presented his own evidence of early, non-Ediacaran animal life from Doushantuo at the same conference, but revealed that his work has been rejected by some leading journals. ■ 26 January 2019 | NewScientist | 7

NEWS & TECHNOLOGY

WE MAY soon be able to see what is lurking out of sight, thanks to an algorithm that allows a camera to make out objects hidden from view. This might one day enable autonomous vehicles to spot hazards before they are visible. The algorithm was created by Vivek Goyal at Boston University in Massachusetts and colleagues. It works by analysing the faint reflections of obscured objects on a surface such as a wall. Specialist equipment isn’t needed to gather the images of reflections – a normal digital camera suffices. To test the system, an LCD monitor was placed 1 metre away from a white wall. The team then placed a digital camera so that it

on the screen, including colours and shapes (see pictures below). “We are able to use natural illumination and a simple camera to reconstruct images that aren’t within direct sight,” says Goyal. Other groups have managed to reconstruct objects from their

CHARLES SAUNDERS

Left to right: The original image, its reflection, and its reconstruction

also faced the white wall, but with an opaque dividing screen between the camera and monitor. Different images were displayed by the monitor and the algorithm attempted to recreate them using only the reflection. The results, however, were a little disappointing, so Goyal and his colleagues tweaked the set-up so that a small square object, the size of two credit cards, stood between the monitor and wall. This blocked some of the reflection in a predictable way, giving the algorithm extra information about the hidden object (Nature, DOI: 10.1038/ s41586-018-0868-6). This greatly improved the reconstructions, which although pixelated, accurately showed features of the original images

MICHAEL KELLEY/GETTY

Ordinary camera made to see around corners

reflections, but only by using lasers and costly sensors. “There are situations where you can’t shine laser light everywhere and still be stealthy,” says Goyal. The team thinks that phone cameras may be good enough for the technique and that eventually they will be able to create an app for seeing objects around corners. “The results are stunning,” says Gordon Wetzstein at Stanford University, California. He says this is the first time that a technique like this has produced full-colour reconstructions. The approach could prove to be helpful for autonomous vehicles, allowing them to see other traffic before it goes around a bend. Yvaine Ye ■

World leaders worry about climate chaos THE top five dangers facing the world are environmental or technological, according to a major annual survey. The 2019 Global Risks Report from the World Economic Forum (WEF) ranks extreme weather, climate policy failure and natural disasters as most likely to trouble us. Fourth and fifth are data fraud/theft and cyberattacks. Human-made environmental 8 | NewScientist | 26 January 2019

disaster was sixth, with biodiversity loss or ecosystem collapse eighth. The list is based on an annual snapshot of views from around 1000 business and political leaders worldwide. “There has been a real shift towards environmental risks,” said report author Aengus Collins at an event to launch it. In contrast, 10 years ago, the top five risks were asset price collapse, economic slowdown in China, chronic disease, gaps in global governance and retrenchment from globalisation. The findings emphasise the growing realisation among the global

elite that environmental issues such as climate change and biodiversity loss are an “existential threat”, said Børge Brende, president of the WEF. The top five are the same as last year, albeit in a different order – with climate change climbing from five to two after another year of stark warnings from the Intergovernmental Panel on Climate Change but little meaningful action by nations. These

“There has been a real shift towards environmental risks, like extreme weather and natural disasters”

risks eclipsed many others that often get more attention, such as a new financial crisis, terrorism, interstate conflict and mass migration. Technological risks must be taken more seriously, said Brende. “It is hard to overstate how reliant we are on technology and how rapidly technologies are evolving. Networked societies are very vulnerable.” The issues raised in the report will be aired at the WEF’s annual meeting in Davos, Switzerland, this week, traditionally seen as a problemsolving forum for the global elite. Graham Lawton ■

For daily news stories, visit newscientist.com/news

DNA solves Nazi conspiracy theory Rowan Hooper

IT IS one of the greatest remaining conspiracy theories of the second world war. In May 1941, Adolf Hitler’s deputy führer, Rudolf Hess, flew from Germany to Scotland in an apparent attempt to broker a peace deal. Hess’s plan failed and he was arrested in the UK. He was eventually tried at the military tribunals in Nuremberg and incarcerated in Spandau prison in Berlin, where he died in 1987. Or did he? From the start, there were doubts over whether the prisoner designated as “Spandau #7” really was Hess. The wartime US president, Franklin D. Roosevelt, believed the man in Spandau was an imposter, an idea perpetuated by a British doctor who worked at the prison, W. Hugh Thomas. Despite official investigations into the claims, the “doppelgänger conspiracy” has

KEYSTONE PICTURES USA/ZUMAPRESS

Rudolf Hess (right) was Adolf Hitler’s deputy führer

during my pathology residency at Walter Reed,” says McCall. “I only became aware of the historical controversy a few years later.” McCall immediately realised the slide’s potential for solving the Hess controversy. “Making it happen was another matter entirely,” he says. McCall contacted Jan Cemper-Kiesslich, a molecular biologist at the University of Salzburg, Austria, and told him about the slide.

persisted for 70 years. When the German government cremated Hess’s remains in 2011, it was thought the last chance to pursue DNA analysis had been lost. Now the mystery has finally been solved by a retired US Army doctor and forensic scientists “When Rudolf Hess’s wife from Austria. They conclude visited Spandau prison, that the prisoner known as she joked: ‘How is the Spandau #7 was indeed Hess. In 1982, US Army doctor Phillip doppelgänger today?’ “ Pittman took a blood sample from Working under standard the prisoner as part of a health forensic DNA protocols, Cempercheck. A pathologist, Rick Wahl, Kiesslich’s team extracted DNA mounted some of the blood on from the dried blood. Now they a microscope slide to perform a had to find a living male relative cell count. The slide was labelled of Rudolf Hess to make a “Spandau #7” and hermetically comparison. “The family is sealed, and kept by Wahl for very private,” says McCall. “The teaching purposes at the Walter name is also rather common in Reed Army Medical Center in Germany, so finding them was Washington DC. difficult.” But in the end, they In the mid-1990s, another US military doctor, Sherman McCall, managed it, and obtained the DNA they needed. was resident at the army hospital The forensic DNA analysis when he heard about the blood centred on the Y chromosome, sample. “I first became aware of which is inherited only down the existence of the Hess blood the male line, and on a range of smear from a chance remark

genetic markers across other parts of the genome. The male relative and another member of the Hess family have seen and approved the publication of the DNA results, but don’t want to take part in any further discussion of the findings. It is already a matter of public record that Hess’s wife, Ilse, didn’t believe that Spandau #7 was an imposter, says McCall. When she met the British governor of Spandau on a visit, she joked: “How is the doppelgänger today?” Statistical analysis of the results suggests a 99.99 per cent likelihood that the blood sample on the slide comes from a close family member of the living relative of Hess, “strongly supporting the hypothesis, that prisoner ‘Spandau #7’ indeed was Rudolf Hess, the Deputy Führer of the Third Reich”, writes Cemper-Kiesslich’s team (Forensic Science International Genetics, doi.org/czwk). An assessment of the Hess DNA results is made more difficult by the ethical issues concerning his relatives, says Turi King, a geneticist at the University of Leicester, UK, who led the forensic examination of the last Plantagenet king of England, Richard III. The paper omits DNA details of Hess’s relative to prevent him being identified, but from what you can see, she says, it appears that the scientists have disproved the conspiracy theory. “They’ve got a perfect match with the Y chromosome and a living male Hess relative,” says King. “If this person was a doppelgänger, you wouldn’t get that match, so from that point of view it’s a good sign.” “The manuscript underwent review by two anonymous reviewers,” says Walther Parson, a forensic molecular biologist at Innsbruck Medical University in Austria. “I have no reason to assume that the data and science are not sound. I know the scientists are great.” ■ 26 January 2019 | NewScientist | 9

NEWS & TECHNOLOGY

Colin Barras

WE USED to think the Iberian Peninsula was the Neanderthals’ final stronghold. It seemed our species had somehow failed to find a way into the region until about 35,000 years ago, leaving the last remaining Neanderthal population untouched until then. But stone tools from a cave in southern Spain may have now sunk that idea once and for all. They seem to be the type of tools our species, Homo sapiens, made, and suggest that we actually reached southern Spain 43,000 years ago, meaning Neanderthals may have vanished from Iberia soon after – at the same time that they disappeared from the rest of Europe. Neanderthals lived in Europe for hundreds of thousands of years. Then just before 43,000 years ago, H. sapiens arrived in the continent and quickly occupied the entire landmass, probably contributing to the disappearance of the Neanderthals. But there is one corner of Europe where we have struggled to apply this simple model. It has proved difficult to find evidence

Formula generates 50 prime numbers MATHEMATICIANS have spent millennia trying to understand prime numbers – those only divisible by themselves and 1 – but so far no one has discovered a formula for all of them. Now mathematician Simon Plouffe has found a way to produce long sequences of prime numbers, improving on previous efforts. For example, we have known since 10 | NewScientist | 26 January 2019

that H. sapiens arrived in the Iberian Peninsula before about 35,000 years ago. What’s more, some people say they have found stone tools indicating that Neanderthals were still living in Iberia thousands of years after they had vanished from the rest of Europe. At some sites, such as Gorham’s cave in Gibraltar, tools are claimed to show that Neanderthals survived until 32,000 years ago – because there were no H. sapiens to compete with. But Francisco Jiménez-Espejo at the Japan Agency for MarineEarth Science and Technology and his colleagues think that idea no longer stands, after they reanalysed stone tools found at Bajondillo cave near Malaga. The group says it can see the moment when Neanderthal-style tools give way to distinctly human-style tools (Nature Ecology & Evolution, doi.org/czt6). New radiocarbon dates from the cave suggest this transition happened 43,000 years ago, implying that our species did arrive in southern Iberia at about the same time it reached other regions of Europe.

the 18th century that n2 + n + 41 is prime for values of n up to 39. It breaks down at n = 40, because that gives 1681, which is equal to 412 and thus not prime. Other types of prime-generating formulae start with a carefully chosen number and use this to generate a string of primes. If you start with n = 1.92878, calculate 2n and replace n with this new value, you get a sequence of numbers. Ignore everything after the decimal points and the first three numbers in the sequence are prime. By tweaking the value of n more

NATURAL HISTORY MUSEUM, LONDON/SCIENCE PHOTO LIBRARY

The final stand of the Neanderthals

Neanderthals are thought to have died out shortly after we turned up

“It is new, and very exciting,” says Rachel Wood at the Australian National University. A few years ago, Wood and her colleagues argued that there were problems with the dates for many of the Neanderthal sites in Iberia. Their assessment suggested there was little evidence Neanderthals clung on in the region after they had vanished from the rest of Europe. But not everyone is convinced.

precisely, you can generate as many primes as you want – but not all of them. That is because the sequence grows too rapidly, skipping many primes and becoming more difficult to calculate. The function described above generates 3 and then 13, skipping 5, 7 and 11. After that, it jumps to 16,381, followed by a prime 4932 digits long – that’s nearly 105000 times bigger.

“We have known since the 18th century that n2 + n + 41 is prime for values of n up to 39”

João Zilhão at the University of Barcelona says it is impossible to put a precise date on the first appearance of H. sapiens in the area because crucial soil layers used in the analysis may have been disturbed and mixed. In response, Jiménez-Espejo and his colleagues say that other recent studies by different research groups also support the idea that Neanderthals were abandoning sites about 42,000 years ago. ■ For more on human origins, see page 36

Plouffe has tried to find something that doesn’t grow too quickly, but will work indefinitely, unlike the n2 + n + 41 example. He starts with a carefully chosen prime number, 10500 + 961, and uses a formula that generates a string of digits that produce a prime about 100,000 times bigger. Applying the formula again produces another prime, again 100,000 times bigger, so the sequence grows reasonably slowly (arxiv.org/abs/1901.01849). Using this method, Plouffe was able to generate 50 primes – more than any other prime-generating algorithm to date. Katie Steckles ■

Humanity will need the equivalent of 2 Earths to support itself by 2030.

People lying down solve anagrams in 10% less time than people standing up.

About 6 in 100 babies (mostly boys) are born with an extra nipple.

60% of us experience ‘inner speech’ where everyday thoughts take a back-and-forth conversational style. We spend 50% of our lives daydreaming.

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NEWS & TECHNOLOGY Robodog trains itself to stand after a fall

account when doing basic locomotion tasks, like moving in a straight line or running in a circle. Like a toddler learning to walk, the AI tested out one motion at a time to see how well it worked, learning as it went to create instructions that could control the real robot (Science Robotics, doi.org/czsz). “For the locomotion tasks, it took just 4 hours on a normal desk computer,” says Hwangbo. The team ran simulations for a running gait, and the AI discovered how to make ANYmal beat its own speed record, topping out at 1.5 metres per second. A trotting gait similar to that of a four-legged animal proved the most efficient way to achieve speed without falling over. The AI also learned to roll over and pick itself back up after being pushed over, which could come in handy when crossing rocky landscapes. Or, it could help it fight back when researchers insist on shoving it in the name of science. Chelsea Whyte ■ 12 | NewScientist | 26 January 2019

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IT GETS knocked down, but it gets up again. A dog-like robot has learned to explore all the ways to stand up after falling over – or being shoved, as often happens during testing. It is one of the toughest tests for four-legged robots to pass. ANYmal is about the size of a large dog, standing 70 centimetres high and weighing 35 kilograms. It has 12 moving parts that must be coordinated so it can walk, run or right itself after falling over. Modelling all the positions they could take in various landscapes and at different speeds would take weeks for a human to input, says Jemin Hwangbo at ETH Zurich in Switzerland, who led the study. Instead, he and his team used artificial intelligence to do the hard work. The AI modelled the motion of ANYmal, trying to strike a balance between moving efficiently, using the least amount of power, avoiding slips and maintaining stable motion. All these need to be taken into

Species like goldfish can provide food for both plants and people

Fish could help us live in space Abigail Beall

Natalia Tikhomirova and her colleagues at the Krasnoyarsk Scientific Center in Russia have now discovered that travelling with crucian carp could complete the loop. They found that the leftover parts of a carp dinner, such as the bones, scales and internal organs, could be converted into a nutritionally complete plant feed.

HOW can we sustain people on long space missions? The answer may be fish. A well-stocked aquarium could provide nutrients for fertilising astronauts’ crops, while also offering a healthy source of protein. The ideal spaceship is a closed system, where those on board can grow everything they need to survive and all waste is treated “On the International Space Station, urine is collected for reuse. On the International and processed so that it is Space Station, for example, urine safe to drink” is collected and processed so that it is safe to drink. To cultivate crops, one To make the mix, space approach would be to use human travellers would first have to waste as a plant feed. However, create hydrogen peroxide from this alone isn’t enough, as plants water and oxygen. This would be need more calcium, magnesium, placed in an alternating current phosphorus and sulphur than it alongside human waste and the contains. Carrying extra nutrients fish remains to break them down on board would take up space and and extract nutrients, which takes they could run out if a journey about 3 hours. takes longer than expected. The resulting concoction would

then be mixed with nitric acid – which helps convert minerals in the mix into a form available for plants and can also be synthesised from urine – to create the plant food. To test the recipe, the team fed it to wheat plants on Earth. After 180 days, the crop was similar in size to what would have been expected with regular plant feed (Life Sciences in Space Research, doi.org/czsw). “Living and working in space will require sophisticated recycling of limited resources such as biowaste,” says Dorit Donoviel at the Baylor College of Medicine in Texas. In practical terms, the idea of taking fish into space isn’t out of the question. Blasting them off Earth and then tasking astronauts with caring for them is feasible – in fact, it has already been done, says Anicca Harriot, a biologist at the University of Maryland. In the past, zebrafish have flown on the International Space Station, in experiments looking at muscle biology. However, they are much smaller than the crucian carp used in the new study. In addition, ensuring that the aquarium water is regularly cleaned and recirculated will be tricky on a long space flight. “There will be major challenges with setting up the flow in the tanks due to the near-zero gravity environment,” says Ivaylo Nedyalkov at the University of New Hampshire. The team has not yet calculated how many fish would need to be taken on a space trip, nor how often they would need to be eaten. It is also unclear if taking them on board would ultimately be worth the hassle. Looking after fish, processing their waste and feeding it to plants might take more effort than carrying additional plant food, says Harriot. ■

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AI knows how to bust drug patents art and devise better chemical recipes than humans can. Now, he has started using the AI to find ways to make drugs that aren’t just as effective as existing ones, but different. This matters because when a pharmaceutical firm’s patent on a drug expires, it may still hold patents on many of

PHARMACEUTICAL companies spend billions researching blockbuster drugs – and billions more on lawyers’ fees to patent and protect recipes for making them. But an artificial intelligence has shown it can quickly find new, legal ways to cook up such drugs. Chemists often create their recipes through a process called retrosynthesis. This involves working backwards from the desired end product, for example a cancer medicine. Using knowledge of possible chemical reactions, you work out which bonds in the compound could be cut until you are left with a list of simple ingredients. By reversing the process, you can stage a series of reactions and make the drug. A bit like chefs trying to create a complex dish, retrosynthesis is often considered an art because there are many ways of making the end product, some more optimal than others. However, Bartosz Grzybowski at the Ulsan National Institute of Science and Technology in South Korea has been developing an AI called Chematica to master this

Moon craters reveal rise in Earth impacts EARTH and the moon are two peas in a pod, at least when it comes to being pummelled by space rocks. An analysis has found that the rate of impacts that result in relatively large craters is about equal on both worlds, and that there was a massive increase in this about 290 million years ago. On a cosmic scale, Earth and the moon are at essentially the same spot

A dose of AI makes life easier for those who want to copy drugs

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Joshua Howgego

the chemical steps to create it. In other words, rivals that are able to copy a drug after its patent ends often have to pay the original firm to use the still-patented recipes. That is, unless they can come up with alternatives – just what Chematica did for an antibiotic, a bone cancer drug and a diabetes medicine. It learned hundreds of patented reactions then devised recipes that avoid them (Chem, doi.org/czs4). “Pharmaceutical

in space. That means they should see similar meteorite strike rates. But there has been an assumption that some big craters and many small ones on Earth have been erased by geological activity. That wouldn’t be the case on the moon, which isn’t tectonically active. This implied the crater record on Earth, especially for older impact sites, would appear to be artificially low. To investigate, Sara Mazrouei at the University of Toronto in Canada and her colleagues used data from NASA’s Lunar Reconnaissance Orbiter to examine craters on the moon and

determine if the frequency of those more than 10 kilometres across is the same on Earth and the moon. They found a strong match, so erosion might not be as destructive to large craters on Earth as thought. They also found another surprise: from about 290 million years ago, the rate of impacts that caused these large craters went up by a factor of about 2.6 compared with

“About 290 million years ago, the rate of impacts causing these large craters on the moon increased”

companies spend billions making sure there are no loopholes and people think these patents are bulletproof,” says Grzybowski. “But actually it seems quite possible to get around them.” Chematica caused an earlier stir in 2012, when Grzybowski and his colleagues used it to find ways of making the nerve agent VX from readily available chemicals including water, table salt and sulphuric acid. This earned him an invitation to the Pentagon, he says, where he called for better regulation of chemicals that can be used to make weapons. This latest work is a similar wake-up call for pharmaceutical firms, he says: “I think they should be a little more diligent.” Derek Lowe, a chemist for a drug firm in Massachusetts, says the paper is interesting but not surprising. “This is exactly the sort of thing I’d expect AI to be used for,” he says. After a patent on a drug expires, other companies already work hard to find ways around legally protected recipes, he says, and the AI is just a better way of finding them. Lowe expects drug-makers will increasingly adopt AIs like Chematica. In fact, Grzybowski’s software was bought by German pharma giant Merck last year. “AIs will not replace chemists,” says Lowe. “But the chemists that use AIs will replace the chemists that don’t.” ■

the previous 700 million years (Science, doi.org/czs2). “This work has some very interesting implications,” says Meenakshi Wadhwa at Arizona State University. The rise in impact rate indicates that one or more large asteroids in the asteroid belt may have broken up at that time, sending a rain of shrapnel towards the inner solar system, she says. This shrapnel may have threatened Earth for a long time. It may be linked to the impact thought to have killed off the dinosaurs 65 million years ago, says Mazrouei. Leah Crane ■ 26 January 2019 | NewScientist | 15

NEWS & TECHNOLOGY

GITOTREVISAN/GETTY

Songwriting machine churns out Beatles hits

Prosecco hills may be washing away Chris Baraniuk

data on rainfall, soil type and what kind of soil cover, if any, is found in the vineyards. The vineyards don’t have much vegetation growing through the soil, so rain can wash it away more easily there than from other areas of hillside. This is a concern because large areas of hill soil can be removed over time. In the region the team studied, Prosecco must abide by strict quality controls and is marked “DOCG” on the label. Although soil erosion occurs across the DOCG area, the research suggests

SOME of the world’s best Prosecco comes from the exquisite sloping hillsides of Italy’s north-eastern wine region. But a big problem is fermenting at the heart of this stunning place. Soil in the vineyards seems to be washing away at an alarming rate. In the traditional centre of Prosecco production, between the towns of Valdobbiadene and Conegliano, an analysis estimates that 400,000 tonnes of soil is lost every year from the vineyards. The region produces 90 million “In the traditional centre bottles of the sparkling wine of Prosecco production, annually, meaning that about vineyards lose 400,000 4.4 kilograms of soil is lost for tonnes of soil every year” every bottle of fizz. “I find myself in disbelief,” says Caroline Mazzey, a plant that vineyards are behind nearly scientist at Hadlow College, UK, three-quarters of the total – even who wasn’t involved with the though they only cover a third of study. “It’s more soil than the the land (bioRxiv, doi.org/czsx). physical volume of the bottle.” Based on a 2009 analysis by To come up with the estimate, the European Commission, Salvatore Eugenio Pappalardo the erosion rate in the DOCG area at the University of Padua, Italy, is about 40 times greater than and his colleagues factored in the continent’s “tolerable limit”, 16 | NewScientist | 26 January 2019

Will the fizz disappear from vineyards in north-east Italy?

the point at which soil health begins to be affected. Prosecco has boomed in popularity in recent years and production across Italy has consequently increased apace. Wine-makers in the other, larger Prosecco-making region, known as the “DOC” area, are said to be aiming for annual production of 1 billion bottles in the next few years, nearly double the amount produced last year. The researchers suggest Prosecco-related erosion could be halved by allowing grass to grow between rows of vines, which would protect the soil from rainfall. However, a consortium representing DOCG Prosecco producers says this is “already a common management practice”. The consortium also disputes the findings, which have yet to be peer-reviewed. “Managing erosion is a primary interest of the winegrower,” a consortium representative said in an email. “There is already far too much soil loss on a global scale due to poor agricultural practices,” says Chris Foss, head of wine at Plumpton College, UK. “The wine industry should definitely not be adding to it.” ■

THOUSANDS of songwriters have honed their skills listening to the Beatles – now there is one more. An AI developed by a team at Snap, the company that owns the social network Snapchat, can write pop songs in the style of the Fab Four. Computers have been composing music for years. Many video games use computer-generated soundtracks and AI-composed symphonies have been performed by live orchestras. But pop songs like those written by the Beatles typically require a human ear for harmony, with catchy vocal melodies and chord progressions. Yichao Zhou and his colleagues at Snap took up the challenge with BandNet, an AI that tries to mimic the genius of John Lennon and Paul McCartney. The results are more muzak than music, but with a little tweaking, the software has come up with a handful of tunes that get your foot tapping. The AI was trained on 123 Beatles songs. Some of its early tunes contained bum notes because it had learned the Beatles’ trick of playing notes outside the key of the song. But unlike the Beatles, BandNet couldn’t tell when such notes sounded good and when they didn’t. To fix this, the team restricted the software to only using notes within a given key. Zhou and his colleagues asked a professional composer to score the content and structure of the system’s compositions out of 5. The composer gave the AI-generated tunes an average rating of 3.65 compared with 4.59 for the original Beatles songs. The team also asked 17 volunteers to score BandNet’s tunes based on how similar they were to Beatles songs, how professional they sounded and how interesting they were. On average, people scored them 3 out of 5 across the categories (arxiv.org/abs/1812.07126). Software like BandNet could soon let anyone create their own Beatles-style song. Douglas Heaven ■

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WHAT IF TIME STARTED FLOWING BACKWARDS?

WHAT IF THE RUSSIANS GOT TO THE MOON

FIRST?

WHAT IF DINOSAURS STILL RULED THE EARTH? AVAILABLE NOW newscientist.com/books

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IN BRIEF Pain, but without the ouch feeling

Deep secrets and youthful halo of Saturn are revealed MORE of Saturn’s mysteries have been solved thanks to a

structure and movement beneath the gas giant’s outer atmosphere influence that field. The measurements indicated the winds that blow around Saturn’s equator extend much deeper into the lower atmosphere than we thought, to 9000 kilometres below the cloud tops.

closer look at its gravity. We now know the planet’s winds extend far below its upper layer and that its rings are

The team also nailed down the mass of Saturn’s rings at about 15 billion billion kilograms. Combined with

relatively new. NASA’s Cassini spacecraft measured the gravity around

measurements of dust falling into the rings, this mass means the rings are probably fairly young compared to

Saturn by turning off its thrusters during orbits that took it between the planet and its rings. That meant the craft’s

Saturn, which is 4.5 billion years old. The study suggests the rings may have formed from

motion was governed only by momentum and gravity. This allowed Burkhard Militzer at the University of

a violent event, such as smashed moons or a shredded comet, in the past 10 to 100 million years (Science, doi.

California, Berkeley, and colleagues to reconstruct the gravitational field of Saturn and its icy rings. The

org/czsm). If so, this questions the view that the recent history of the solar system was peaceful, says Militzer.

New type of blood vessel found in bones IT IS time to rewrite the anatomy books: a new kind of blood vessel has been discovered in our bones. The vessels run from a bone’s surface to its internal cavity and may shed light on diseases such as osteoporosis and conditions involving the immune system. Matthias Gunzer at the University of Duisburg-Essen in Germany and his colleagues made the find by using chemicals to

make a mouse bone transparent. This revealed tiny red blood vessels crossing the bone shaft. In the animal’s lower leg bone they saw about a thousand of these capillaries, which they dubbed trans-cortical vessels. Beforehand, we knew of just a few blood vessels entering the bone either at its ends or half-way along. The newly found capillaries cover the whole bone, making up

most of its blood supply. It seems people have similar vessels, as the team spotted them in pieces of thigh bone. However, their extent in a whole human bone isn’t yet known. Marrow inside bones is where immune cells are made, and the team in mice the trans-cortical vessels turned out to be a key route for immune cells to exit (Nature Metabolism, doi.org/ czvp). The same might go for people, says Gunzer.

PAIN doesn’t have to hurt. Brain cells have been found in mice that add the unpleasant feeling to pain signals – and they can be blocked. Pain receptors in the body detect painful stimuli and send signals to the brain. But according to Grégory Scherrer at Stanford University, California, these signals don’t have any emotional value, or unpleasant feeling, until they reach the amygdala, a brain region that deals with emotions. To see what happens to pain signals there, Scherrer and his colleagues identified amygdala cells that respond to pain stimuli such as a pin prick. Next, they silenced these cells in mice. The animals could still detect painful stimuli and withdraw from them, but didn’t react as though they were hurt (Science, doi.org/czsj). It is likely that a similar set of cells can be found in humans, says Scherrer. The hope is this could lead to new pain treatments.

Bot gives clues on shift to life on land A ROBOT version of an ancient creature is shedding more light on the move to life on dry land. Amphibians tend to move with legs mostly horizontal and low bellies, while reptiles tend to have more vertical legs and raised bellies for a more efficient walk. But when did the change happen? John Nyakatura at Humboldt University of Berlin and his team studied Orobates, an animal from 290 million years ago that lies between amphibians and reptiles. Using a skeleton and footprints as a guide, they built a robot version. The bot, and possibly Orobates, reproduced the footprints best if it moved like a reptile. So efficient walking seems to have evolved while animals still partly lived in water (Nature, doi.org/gftgsb). 26 January 2019 | NewScientist | 19

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IN BRIEF

SOME hermit crabs have unusually long penises, and now we might know why. It allows a male to mate without leaving its prized shell, reducing the risk it will be stolen. Many species of hermit crabs protect themselves by moving into empty mollusc shells, which they carry with them. A few species, especially those in a group called the Coenobita, modify these shells. They tear away some of the hard material inside to make it roomier. But such shells are seen as more desirable, making them a target for theft by another crab. Mark Laidre at Dartmouth College, New Hampshire, wondered whether this risk might explain a curious feature of Coenobita hermit crab anatomy, namely, that some males have penises 60 per cent as long as their body. Laidre wondered if a male with a larger penis can remain inside his home while mating. To test the idea, he measured penis length in closely related hermit crab species – some that don’t move into shells, some that do but don’t modify them and some that do remodel shells. He found males of species that remodel shells have penises that are significantly longer than the other species. And the more remodelling a species does, the longer the penis (Royal Society

PETE OXFORD/MINDEN PICTURES

Open Science, doi.org/czsr).

20 | NewScientist | 26 January 2019

We’ve seen methane rain gleaming on the icy plains of Titan WE HAVE spotted the rainy season near the north pole of Saturn’s moon Titan for the first time. Images from the Cassini probe revealed a huge shining plain of damp ground that probably came from a summer storm on Titan. Titan is in some ways a bizarre version of Earth, with seas, lakes and rivers. However, they aren’t full of water on Titan, but liquid methane and other hydrocarbons. When Cassini arrived in 2004, it was summer at Titan’s south pole, and there were signs of clouds and rainfall there. Models predicted

the stormy weather should shift to the north pole over the next decade or so. But by 2014, just a few clouds had gathered there. It wasn’t until Rajani Dhingra at the University of Idaho and her colleagues examined images taken by Cassini in 2016 that the first evidence of rain near Titan’s north pole emerged. On 6 May that year, the pole was blanketed in clouds. On 7 June, two Titan days later, the clouds were gone and the area was shining bright. On 25 July, the gleam was gone. When the researchers analysed

the light reflecting from the area they found that it was likely to be from a wet, slightly rough surface, similar to a damp pavement after a rain shower. The wetness was probably due to methane rain that later flowed into lakes or evaporated away (Geophysical Research Letters, doi.org/gftg67). Aside from the -179°C average temperature, standing in such a storm would be odd. “Raindrops on Titan should fall extra slowly because of the low gravity… if you stood there in the rain, you would feel each drop,” Dhingra says. NATUREPL

Size matters for some crustaceans

Modified probiotics could treat disease SUPPLEMENTS of genetically tweaked bacteria could be used to treat liver and bowel diseases by mopping up toxins in the gut. Many people take daily doses of probiotics to top up good bacteria in the gut, although it is unclear how much good they really do. But genetically altering bacteria to give them new abilities could take things to the next level, says Caroline Kurtz of Synlogic, a biotech firm in Massachusetts. Ammonia is made in the gut as a by-product of food digestion. It normally goes to the liver to be dealt with, but cirrhosis or certain metabolic disorders can lead to a build-up of ammonia in the blood, causing seizures or death. Synlogic has modified the genes of a strain of bacterium called E. coli Nissle – already sold as a probiotic in unmodified form – to boost its uptake of ammonia. The bacteria turn the toxin into an amino acid present in our diet. Daily doses with the bacteria improved survival in mice with raised ammonia levels. When healthy people took it for two weeks, the bacteria worked as intended (Science Translational Medicine, doi.org/czs3). A trial has started in people with cirrhosis.

How slime allows time for a getaway WHEN a hagfish (pictured) is chased by a shark, it spews out slime that clogs the predator’s jaws, allowing it to escape. The slime expands very fast, and now we know how. To investigate, Gaurav Chaudhary at the University of Illinois at Urbana-Champaign and colleagues analysed the workings of the goo. They found it is a mix of mucus cells and 1-micrometre-thick thread-like fibres that are 10 to 16 centimetres long and twisted into a tiny ball. These balls have a single thread sticking out. They unravel in under 0.4 seconds to help form a fibrous

network for mucus to stick to. To figure out how this happens so fast, Chaudhary and his team first established that a force must pull on the thread. This force comes from the drag of moving seawater acting on a mucus-covered thread. The unravelling is even quicker if one end of the thread is stuck to a surface, like the shark’s mouth. Best though was attachment to its gills, where water is moving more quickly. This helps explain why a shark gets a shot of slime to the gills when it goes for a hagfish (Journal of the Royal Society Interface, doi.org/czsq).

Where did we come from? How did it all begin?

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INSIGHT BLOCKED SEWERS

Rise of the fatbergs Disgusting behemoths of fat keep surfacing in UK sewers. Is there a reason they are on the rise, asks Kelly Oakes THE fatbergs are coming. These Tom Curran of University huge lumps of cooking oil and College Dublin, Ireland, says there wet wipes lurk beneath UK streets, has been a rise in the number of threatening to block sewers and fatbergs and various factors have put everyone off their lunch. contributed to it: growing urban And they really are huge. In populations, ageing sewers, a rise 2017, a 250-metre-long, 130-tonne in eating out and our increased monstrosity was found under flushing of wet wipes. Whitechapel in east London – Fatbergs are made up of fat, a piece of it still resides at the oil and grease congealed around Museum of London. Last year, wet wipes and other things that another rivalling it in size was people shouldn’t flush down found south of the river Thames “A 250-metre-long fatberg and later analysed on a TV was found under east programme called Fatberg London – a piece of it still Autopsy, while in December, a resides in a museum” whopping 800 tonnes of fat were removed from sewers in Cardiff. Even a relatively modest 64-metre the toilet, like cotton buds and blockage in Sidmouth, Devon, tampons. A 2017 report by made national headlines last industry body Water UK found month. So is this a new problem, that, out of the solid items that or do Brits just have a new-found could be identified, 93 per cent love of talking about it? of the material recovered from The word “fatberg” was sewer blockages were noncoined in 2008, but only rose to flushable wipes. Clearing the UK’s prominence in 2013 when utility 300,000 annual sewer blockages firm Thames Water discovered costs £100 million, it says. a 15-tonne blockage in London’s Plenty of other items have sewers. By 2017, the portmanteau been found inside fatbergs too: had been added to the Oxford condoms and chocolate bar English Dictionary, so clearly it wrappers were spotted in parts has caught people’s imaginations. of the Whitechapel monster.

This mass of solid material is a problem, but as the name “fatberg” suggests, fat plays an important role in creating blockages. Cooking oil from a pan, excess gravy tipped down the sink and salad dressing rinsed off a plate all contain fats that end up in wastewater pipes. Both commercial and domestic kitchens are culpable, but restaurants take the lion’s share of the blame because they prepare more meals and use more cooking oil than individual homes. It isn’t just places that prepare hot food: baristas who swill away coffee grounds and milk are also feeding fatbergs, says Raffaella Villa of Cranfield University, UK, who was part of the team that analysed the Whitechapel one. We used to think that fat congealing as it cools was the main contributor to fatbergs, but a 2008 study on fat deposits in US sewers found that a key step is the saponification – turning into soap – of fats. Fats washed down the drain break into fatty acids, and those combine with calcium in the water to create hard, water-insoluble, soap-like

Putting things we shouldn’t down the drain is contributing to the rise of fatbergs Home

Restaurant

Cafe

Bathroom Wet wipes, sanitary products Kitchen Cooking fat Cooking fat, salad dressing Fat breaks down into fatty acids, which combine with calcium to form soap-like deposits that trap wet wipes and other solids

22 | NewScientist | 26 January 2019

Coffee grounds, milk

deposits. These deposits build up around the sides of a sewer, like plaque builds up in arteries, and trap wet wipes as they grow, until you get a fatberg.

Clean-up operation So we have an idea of how fatbergs form – but is there a reason they have drawn most attention in the UK? Blockages occur in sewers around the world, with recent notable fatbergs in Baltimore in the US, and in Newcastle, Australia, yet the UK does seem to have cultivated a reputation for creating giant ones. “London has larger Victorian sewers, which lend themselves to larger fatbergs more likely to get high profile media attention,” says Michael Benke from Thames Water. Curran says there is another factor that might be contributing to the monster fatbergs forming in UK sewers: letting food outlets off the hook. The UK Water Industry Act 1991, which governs the nation’s sewers, doesn’t explicitly mention fats, but it does say that you shouldn’t pour away “any matter likely to injure the sewer or drain, to interfere with the free flow of its contents”. UK building regulations also state that commercial hot food kitchens should be fitted with equipment to filter out fat, oil and grease. “The wording of legislation is not as clear-cut as it is in other places around the world,” says Curran. For example, Dublin requires that waste water from restaurants doesn’t exceed a fat, oil and grease content of 100 milligrams per litre. Specific targets make it easier to enforce

ADRIAN DENNIS/AFP/GETTY IMAGES)

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It can take weeks of manual labour to break up and remove fatbergs

the rules, he says. “There tends to be a softly-softly approach with following up with restaurants.” The Dublin example shows how to fight the fatbergs. Before 2008, the city had about 1000 sewer blockages every year. That year, it began requiring food outlets to hold waste-water licences and started a programme of inspections, sampling waste water and promoting the importance of not letting fat out into the sewers. Since then, the number of blockages has gone down to fewer than 100 per year. Doing the same in the UK might not be so straightforward. UK water companies are privately owned and don’t have the power to inspect restaurants themselves, only local councils do, says Villa. It is clear the problem needs

fixing, though. Villa ran a survey that could indicate a blockage of 103 restaurants in the UK downstream. And a company towns of Reading and Bedford called Nuron is putting fibre-optic and found that 70 per cent had cables through sewers to both no grease management in place. deliver broadband and act as “The restaurants understand pressure and temperature sensors that fats are the cause of fatbergs, to monitor the sewer conditions but they don’t understand that in real time. they are causing the problem,” For its part, Thames Water she says. is focusing on educational Addressing this misconception campaigns, both for households is essential, because once fatbergs and for businesses, to stop people are in the sewers, removing them is tricky. It tends to involve high- “Restaurants understand pressure jets and weeks of manual that fats cause fatbergs, labour to break them into smaller but don’t get that they are causing the problem” parts that can be taken away. A better solution would be contributing to fatbergs. Its to monitor the sewers before “Bin it – don’t block it” campaign, fatbergs arise. Curran is working launched in 2013, encourages on using low-cost sensors to people to flush only “the three provide an early-warning system Ps” – pee, poo and toilet paper – for fatberg formation. Ultrasonic and to collect cooking oil in a sensors, for example, could container that can be put in the monitor the sewage level in the bin, rather than down the sink. pipes. If the level starts rising,

There are signs that it is working: the number of blockages the water company has to deal with is on the decline, from 85,000 per year when the campaign started, to 75,000 now. “The number is gradually falling, but it is still a massive problem,” says Benke. Meanwhile, for those who can’t bring themselves to bin wet wipes, Water UK is launching a “fine-to-flush” label identifying products that will break down quickly after flushing. Curran has first-hand experience of how problematic wet wipes can be. Before he began researching fatbergs, when his children were small, he fell prey to a brand of “flushable” wipes – and just weeks later, the sewer outside his house was blocked. “You can flush a lot of things down the toilet,” he says, “but it has consequences.” ■ 26 January 2019 | NewScientist | 23

COMMENT

Collision course The research potential of a proposed €21 billion particle smasher doesn’t justify its price tag, says Sabine Hossenfelder

JOSIE FORD

CERN, the physics laboratory near Geneva, Switzerland, is well known as the home of the world’s biggest particle smasher, the Large Hadron Collider (LHC). Now it has revealed plans for an even mightier machine, the Future Circular Collider (FCC). Costs start at €9 billion for the least-expensive version, going up to an eye-watering €21 billion for the grandest vision. Inside a 100-kilometre-long ring tunnel, particles would be smashed together at energies that dwarf those achievable in the LHC. The problem is, the FCC isn’t worth it. It is possible that in such a collider we will find novel sub-atomic particles, in the same way that the LHC found the Higgs particle. But it is unlikely. We have no good reason to think this will happen because the most reliable scientific predictions say any discoveries will require energies

Sowing innovation The future of food depends on seed sharing, say Johannes Kotschi and Bernd Horneburg FOR millennia, crop seeds have been regarded as a common good, bred by farmers into a rich diversity of cultivars. Over the past 70 years, however, genetic resources in agriculture have been increasingly privatised, made possible by intellectual property rights such as patents and plant variety protection. 24 | NewScientist | 26 January 2019

to what is required to cope with global agricultural challenges: adaptation to climate change, increased production to feed an expected 11 billion people and transformation of agriculture based on agrochemicals into an organic form. For this, we need a great diversity of crops with manifold cultivars. The private seed sector cannot supply this. Instead, we need a commons-based seed sector. With the Open Source Seed

Today, three corporations control more than 60 per cent of the global commercial seed market. This creates uniformity in agricultural production, stifles innovation and makes society increasingly dependent on just a “Diversity is essential for few companies, with diminishing maintaining food security, ecosystem services and choice and rising costs. All this is diametrically opposed cultural landscapes”

14 orders of magnitude higher than those the FCC could achieve. So with no reason to believe new particles will be accessible with this collider, what might it do? The only thing it will reliably achieve is measure the properties of known particles in more detail. The CERN plan also notes some hypothetical particles that could be ruled out with the FCC, such as dark matter candidates called WIMPs. But physicists have conjectured no end of such particles. Ruling out a few among millions offers little progress. Supporters of the FCC make the usual arguments that investing in a science project this size would benefit some industries as well as education and scientific networks. But any large-scale experiment would have such benefits. We might get more bang for the buck if we waited for better particle-smashing technologies.

(OSS) Licence and the newly established service provider OpenSourceSeeds, the German NGO Agrecol offers plant breeders a chance to maintain seeds as a commons. The first OSS licensed cultivar, the tomato Sunviva, was presented in 2017. The OSS Licence sets three rules. Anyone may use the seed, multiply it, enhance it, breed with it and pass it on within existing laws. No one may privatise the seed and any further developments. And each recipient assigns the same obligations to further developments. Plant breeding must be seen as a societal task rather than an

For more opinion articles, visit newscientist.com/opinion

Sabine Hossenfelder is a physicist at the Frankfurt Institute for Advanced Studies in Germany

economic activity. If cultivars are developed for small, site-specific purposes, revenues from patent royalties would be insufficient to finance plant breeding. Seed diversity is essential for maintaining food security, ecosystem services and cultural landscapes, but most of all for enhancing our capacity to adapt to climate change. ■ Johannes Kotschi is the founder of OpenSourceSeeds at Agrecol (Association for AgriCulture and Ecology) and Bernd Horneburg is head of genetic resources and organic plant breeding at the University of Göttingen in Germany

ANALYSIS Healthy diet

KATARZYNA BIALASIEWICZ/ALAMY STOCK PHOTO

One example is the plasma wakefield acceleration method, which would allow more powerful but smaller colliders. High temperature superconductors may reach a point where they become usable for the magnets in a more potent collider. Both may arrive in a decade or two. It would make more sense to put the hunt for novel particles on hold for 20 years to see whether new technologies are available, or more concrete predictions for new physics have been made to justify costly new accelerators. Other large-scale experiments, such as radio telescopes, would more reliably offer fresh insights into the foundations of physics. And smaller experiments that tend to fall off the table when big collaborations eat up money and attention would be less likely to suffer too. Not to mention that we might be better off investing in other areas of science entirely. A large particle collider is one of the most expensive experiments you can think of, and we don’t currently have a reason to believe it would discover anything new. That alone makes this super accelerator a non-starter. ■

We have to pay the real cost of food Michael Le Page

are sound and should surprise no one, as they reflect a huge body of evidence. When New Scientist looked last year at how to eat well for yourself and the planet, our answers were much the same. The big question is really, how do we persuade people to change their diets? Or, in the case of most of the world’s population, how do we stop them adopting the terrible diets of people in the US and Europe as they grow richer? The report essentially says we must throw the kitchen sink at the problem. We need to persuade

OUR food is killing us, and the planet. That’s the message from a group of 37 experts called the EAT-Lancet Commission, which spent three years poring over the evidence to work out the best diet in terms of health and the environment. Their conclusion: we need to radically change what we eat. That means far more fruits, vegetables, whole grains, nuts and tubers, and far less meat, dairy and sugar. On an average day, for instance, we should eat just 14 grams of red meat and 250 grams of whole milk or derivatives such as cheese. “It certainly is an enormous change, “Consumers, farmers and shops must switch especially for the Western world,” says Fabrice DeClerck of the Stockholm to healthier, more sustainable foods” Resilience Centre in Sweden, one of the report’s authors. Telling people to change their consumers to change what they buy diets is always likely to spark a strong and cook, while farmers and shops reaction. “They say ‘you are what you must produce and promote healthier, eat’ and that must be true because more sustainable foods. this is nuts,” said Christopher Snowdon Such radical change is unlikely at the Institute of Economic Affairs, to happen if left to the whim of the a right-wing think tank. consumer. “Environmental and societal But the reality is that the broad health costs of food supply and conclusions of the EAT-Lancet report consumption should be fully reflected

in pricing by introducing taxes,” states the report. “As a result, food prices might increase.” That statement is buried deep in the report, and DeClerck plays it down. “That’s one of the options. There are others,” he says. But it is hard to see how diets could be radically changed without effectively imposing a carbon tax on the most polluting foods. It isn’t just about changing diets. The report also stresses the need for “sustainable intensification”: producing more food per hectare so land can be left aside for wildlife. It is agnostic about how this is achieved. It could mean using precision agriculture, genetically modified organisms or organic farming, if organic methods can produce high enough yields. And then there is food waste. This is not just about millennials letting avocados rot in the fridge. In poorer countries, much food is wasted before it even reaches markets because of inadequate storage and transport systems, the report says. Changing all this will require joined-up action. All too often, health, environmental and farming policies push in different directions. What isn’t an option is continuing as we are. If billions more people start to eat as much meat as those in the US and Europe, for instance, we would have to cut down most remaining forests to create more farmland, says DeClerck. “We simply don’t have enough resources.” ■ 26 January 2019 | NewScientist | 25

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Discworld FREEZING weather brought a surprising new feature to Westbrook in Maine. An enormous circle of ice has formed in the Presumpscot river in the city centre. The disc, estimated to be 90 metres across, slowly rotates anticlockwise, like a never-ending frozen carousel. Ducks sitting on the formation seemed to enjoy the ride. Tina Radel, marketing and communications director at the mayor’s office, used the city’s drone to take this aerial shot. She first learned of the disc on 14 January, but a local birdwatcher told her it has been growing for about three weeks. “It’s been bringing a lot of people to our downtown area,” says Radel. According to a neighbouring city’s paper, the Portland Press Herald, the scene “had Westbrook buzzing almost as much as when city police spotted a giant snake eating a beaver in roughly the same location in June 2016”. The disc is thought to result from ice forming in an eddy in shallow water on one side of the river. As the disc rotates, it grinds against the shore, smoothing the edge and maintaining its regular circular shape. One or two ice discs are reported in the US each year, but most are around a tenth the diameter of Westbrook’s. An illustration of a 7-metre “revolving ice cake” in the Mianus river, New York, was published in Scientific American in 1895. Sam Wong

Photographer Tina Radel City of Westbrook

26 January 2019 | NewScientist | 29

MARTINLEONBARRETO

30 | NewScientist | 26 January 2019

How to nurture your mind Kayt Sukel has the low-down on the best ways to keep your brain in shape

1. Flex your mental muscle

Think fast The longer you have studied a musical instrument before age 25, the quicker your brain is able to recognise words in later life 31

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SOURCE: doi.org/f5hns3

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The brain is often likened to a muscle, and for good reason: give it a good workout and it will stay strong. But what does that really mean? A few years ago, headlines were full of claims about brain-training apps and computer games that offered a shortcut to improved cognitive fitness. But these have largely been debunked. “There’s no magic activity that will do it,” says Yaakov Stern, a neuropsychologist at Columbia University in New York. Instead, the trick seems to be to find activities that boost what’s known as cognitive

Time taken for brainstem to respond to spoken words (milliseconds)

HE studies are cruelly consistent: by the age of 45, your basic cognitive abilities begin to slip. As we get older, the crucial brain regions involved in memory, attention and perception begin to shrink and no longer communicate with one another as efficiently as they once did. You may find that you aren’t quite as quick as you once were. It takes longer to recall where you left your keys, more effort to help your kids with their maths homework. Except that isn’t the final word. There are plenty of science-backed strategies for keeping your brain fitter for longer. And it is never too late to begin.

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reserve. You can think of this as spare mental capacity, a kind of extra padding that allows your brain to sustain more damage before you feel the effects. The concept has been used to explain why two people with Alzheimer’s disease, and the same amount of damaging protein plaques in their brain, may not be equally affected. Studies have linked this cognitive reserve to higher IQ and greater educational and occupational attainment. This helps explain why, with better education, rates of dementia have fallen in developed countries (even if absolute numbers have risen because people live longer). But regardless of your education, there is still time to adopt activities that bring the same benefits. One option is to be socially active (see “Mix and mingle”, page 33). “Anything that people enjoy and has a social component should be fine,” says Stern. If you want to pick a winner though, there seems to be something special about music and language. For instance, people who played an instrument as a child, even for a few years, tend to be protected later in life from decline in the brain areas associated with hearing (see chart, left). And people who speak more than one language develop dementia later, on average, than monolinguals. A 2018 study found that musical training and speaking a second language both help the brain work more efficiently, requiring less energy to accomplish the same cognitive tasks. Music to our ears. > 26 January 2019 | NewScientist | 31

Outlandish ways of dialling back brain age are already under investigation

Psychobiotics Evidence is mounting that gut bacteria influence how the brain works. Some microbes synthesise key brain signalling molecules, and others affect the expression of receptors in the brain. So could we boost our cognitive powers by manipulating the microbiome inside us, perhaps gulping down certain types of bacteria or changing our diet to encourage their growth? It is a promising idea. Although the field of “psychobiotics” — a term coined in 2012 — is in its infancy, perhaps we will one day take a probiotic pill for the mind.

Neural transplants If your cognitive abilities are sliding, maybe a transplant of fresh neurons is in order. Human trials are under way to treat Parkinson’s disease using fetal brain cells, with the aim of growing them into replacement neurons. Stem cell therapy might do the same. In animal studies, this approach shows great promise, and a few human trials are in progress, on stroke patients for example. If neurons can be regenerated this way  — a big if — it raises the possibility of using neural transplants to pimp healthy brains too.

Brain zapping Many studies have shown that magnetic or electrical stimulation via devices placed on the scalp can improve cognitive functions such as memory, creativity or mathematical ability. The results can last for weeks, but, unfortunately, the studies so far use such different methods that we can’t say for sure what they amount to. Others are exploring a more drastic approach: implanting electrodes in the brain. Deep brain stimulation has shown success in treating Parkinson’s disease, but its invasive nature means it is unlikely to find general use as a brain hack.

2. Get moving It is one of the lesser known benefits of pounding the pavements, but regular physical exercise can do wonders for your mental fitness. The evidence is conclusive, says neuroscientist Arthur Kramer at the University of Illinois: “Exercise helps promote a healthy brain and mind.” Exercise increases the production of a chemical called brain-derived neurotrophic factor. Sometimes referred to as brain fertiliser, it spurs the creation of neurons in the hippocampus, a part of the brain that helps consolidate memories, and new connections between them. It also boosts the number of mitochondria, the energy factories of cells, inside the brain. Together, these changes seem to bolster the brain against dementia and Alzheimer’s disease. It isn’t clear exactly how exercise translates into a brain boost, although one idea is that it is down to increased blood flow to the area. You don’t have to start running marathons to reap the benefits. Doing moderate exercise such as walking, cycling or swimming between three and five days a week for 45 to 60 minutes seems to be enough, says Kramer.

3. Look after your ears Your parents probably told you to wash behind your ears, but it is far more important to take care of their insides. People with mild hearing loss are more likely to develop cognitive issues. Neuroscientist Arthur Wingfield at Brandeis University in Massachusetts has

found that impaired hearing hinders people’s ability to remember information they have just heard. Why so? The hypothesis is that when you struggle to hear, the extra concentration involved comes at the cost of other mental processes. “I’m so busy trying to focus and recognise the words that there’s nothing left to help me remember those words,” says Wingfield. Mild-to-moderate hearing loss affects between 40 and 50 per cent of people aged over 65, but it is usually easy to correct. Get your ears checked regularly and bear in mind that the most common sort of hearing loss can be rectified with a hearing aid that amplifies the frequencies the ears are insensitive to. You can also protect your ears by keeping the volume down when watching the TV or listening to music – even short bursts of loud noise such as at gigs can damage nerves in the ears. So next time you go to a concert, take some earplugs. Your brain will thank you for it.

4. Chill out A couple of years ago, Bei Wu at New York University published details of a strange study. She had followed the lives of 8000 people in China for 13 years, recording their cognitive function and tooth count. She found a strong correlation between tooth loss and a drop in cognitive function, even after accounting for the natural changes that occur in both with age.

What is the MIND diet? The diet shows promise for reducing the risk of Alzheimer’s disease. Here is what you would need to eat over seven days. A serving means roughly half a cup Eat at least this many servings Whole grains like wheat, oats, quinoa Other vegetables Green leafy vegetables

Young blood At least two companies have conducted controversial experiments to test whether infusions of blood from young people can rejuvenate older people, both physically and cognitively. No one knows if it will work, because the studies are so irregular, sometimes involving paying customers. But studies in mice show that young blood can boost cognitive function in older rodents. Young blood treatments are also being investigated as a treatment for Alzheimer’s disease. Alison George 32 | NewScientist | 26 January 2019

Eat no more than this many servings

Olive oil should be your primary source of fat

Nuts Beans Chicken and other poultry

The diet also recommends one small glass of wine a day

Berries like blueberries or strawberries Fish Pastries and sweets

No more than a tablespoon of butter

Red meat Fried food Cheese Number of servings per week

SOURCE: doi.org/f3jbxp

BRAIN HACKS OF THE FUTURE

The finding still needs to be backed up, but it could be part of a wider link between inflammation, the body’s response to injury or attack, and brain health. Inflammation can be a natural and helpful process. Cut your foot, say, and the area will quickly get hot and red as blood vessels dilate and release fluids and immune cells to fend off foreign microbes. But some aspects of modern life, particularly stress, can trigger a chronic inflammatory response, which spreads throughout the body. This isn’t helpful and the longer it lasts, the worse its effects. Inflammation in the brain increases the activity of a neurotransmitter called glutamate. That leads to the shrinkage of individual brain cells and a reduction in their formation. “It’s part of the cascade that can lead to the destruction of brain cells and on to dementia,” says Bruce McEwen, a neuroscientist at the Rockefeller University in New York. Tooth loss, then, is just another hint at the deeper problem of inflammation. It typically results from poor oral health, which comes with inflamed gums. It doesn’t mean that taking better care of your teeth is a guaranteed route to better cognitive function. Equally important is to properly manage your stress. There is some evidence that meditation and mindfulness practices can help by dialling down inflammation. A 2018 analysis by researchers at the University of Nevada looked at seven studies of how mindfulness meditation helped reduce older people’s stress levels. One study on 34 adults who had taken mindfulness classes over eight weeks found they had significant improvements in memory and verbal fluency. Maybe that’s something to practise next time you are in the dentist’s chair.

5. Find your purpose From zookeepers to doctors, researchers have been asking people for decades what makes their jobs meaningful. The results boil down to six factors. Authenticity, the feeling that you can be your true self at work, was on the list, as was a sense of belonging. If these tally with your working life, it also bodes well for your mind: finding a purpose in life is a sure way to stave off mental decline. One of the largest studies demonstrating this was published in 2017. Nathan Lewis at Carleton University in Canada and his colleagues phoned 3500 people and asked them about their sense of purpose. Those whose answers suggested they felt that their life had direction

“As brain workouts go, there is something special about learning an instrument” 6. Mix and mingle and their actions were guided by overarching goals tended to perform better when given memory and cognitive tasks. McEwen says this fits with what we already know. A sense of purpose can provide motivation and end up pushing people into activities that help build, you guessed it, cognitive reserve. It tends to make you more active and more social. “And we know that these improve overall health, including brain health,” says McEwen. Finding purpose doesn’t necessarily require you to quit your job and join the Red Cross. As the career surveys showed, meaning comes in many flavours. Maybe your job aligns with your core values. Or maybe your colleagues give you a sense of belonging. If those elements are lacking, volunteering with local organisations, helping to raise your grandchildren or cultivating a hobby you are passionate about can do the trick.

Like it or not, humans are social animals. And it turns out that hanging out with other people can help preserve cognitive health in a similar way to activities like learning an instrument – yes, it is about building that all important cognitive reserve (see “Flex your mental muscle”, page 31). Some of the evidence comes from studies of married couples. In a 2018 analysis, Andrew Sommerlad, a psychiatrist at University College London, and his colleagues demonstrated that being married is strongly associated with a reduced risk of cognitive decline and dementia. He says the differences are probably due to regular conversation and the effort involved in maintaining a good relationship between spouses. So you don’t need to tie the knot to reap the benefits. “There’s no one type of social contact that is better than another,” says Sommerlad. “I’d recommend social contact that you enjoy.” > 26 January 2019 | NewScientist | 33

7. Get your Zs Good sleep helps clear out gunk from the brain, staving off cognitive decline

HEXX/PLAINPICTURE

You already know from bitter experience that a bad night’s rest makes you grumpy. But the effects are more insidious. Study after study suggests that not getting enough of the right kind of sleep can have long-term impacts on the brain. One of the most important findings came in 2013, when neuroscientist Maiken Nedergaard, now at the University of Copenhagen in Denmark, demonstrated that during sleep is when the brain gets rid of the biochemical gunk that accumulates throughout the day. That includes the proteins that can build up into the telltale plaques and tangles seen in neurodegenerative diseases like Alzheimer’s. “We now see the function of sleep is to help clean the brain,” says Nedergaard. “It is very important to take sleep seriously and develop strategies to sleep well.” What does that look like? The recommendation is to get 7 to 8 hours every night. We also know that the different phases of sleep have varying functions. For instance, our deep, non-rapid eye movement sleep is known to be involved in laying down new memories. This sleep comes in sections separated by about 2 hours, so if you sleep less than the optimal amount, you are robbing yourself of them. If you struggle to doze off, there are plenty of things to try aside from the standard advice of drinking and smoking less. For example, warnings about the shortwavelength blue light from phones and tablets disrupting the production of the body’s sleep-regulating hormone, melatonin, are

spot on. So switch off a good few hours before bed. Another neglected factor is having the right temperature in your bedroom. You want to aim for between 18 and 21°C.

8. Mind what you eat The Paleo, the keto, the 5:2, the Atkins — our obsession with fad diets isn’t going away. Most of them claim to keep us physically healthy and shift a little weight. But what should you eat to keep your mind sharp? You might have heard of the benefits of the Mediterranean diet, which recommends eating plenty of fruit, vegetables, whole grains and olive oil. It does seem to keep us healthy, cutting the risk of heart disease and early death. But recently a few studies have begun to suggest it can stave off cognitive decline too. Yet the Mediterranean diet isn’t designed to specifically include foods that we think benefit

FIVE THINGS YOU REALLY SHOULDN’T DO Don’t smoke

The Hisayama Study, an ongoing investigation of a suburban Japanese community, has found that smoking in mid to late life not only raises the risk of lung cancer, but also ups the chance of developing dementia. Smokers who quit, even in their 40s or 50s, didn’t see the same rise in risk. Don’t binge on booze (or go teetotal)

Too much is bad, but so is too little. The latest large studies on alcohol consumption suggest that those who drink

excessively or give up completely are more likely to suffer cognitive decline. Those who drink moderately fare better.

brain volume. That was the finding of a 2017 study looking at nearly 4000 people. That drink also worsened memories of personal experiences.

Don’t retire early

The Whitehall Study, which followed some 3500 UK civil servants as they aged, found that retirement seemed to accelerate cognitive decline, especially related to verbal memory. Don’t gulp down sugar

Even one extra sugary drink a day is associated with having significantly reduced total

34 | NewScientist | 26 January 2019

Don’t lose those last few pounds

Being a healthy weight is an all-round good idea. But don’t go too far. A study that looked back on the diets of some 2 million people over 20 years found that, compared with people of a healthy weight, underweight people had a 34 per cent higher risk of getting dementia.

the brain. So Martha Morris, a nutritionist at Rush University in Chicago, tweaked the Mediterranean diet, trying to optimise it for brain health. The result, which she called the MIND diet, emphasises eating leafy green vegetables and berries, drinking wine, and limiting cheese, sweets and fried food (see diagram, page 32). Berries are on the list because people who eat them generally have better cognitive abilities. This might be because they contain lots of antioxidants, chemicals that protect cells from damaging free radicals. The same is true of leafy vegetables. Foods that are high in saturated fat or sugar are no-nos because of their association with inflammation in the brain and body. To assess the diet, Morris studied 923 people living in retirement homes near Chicago. She randomly assigned them to eat either the Mediterranean diet, another plan called the DASH diet, designed to lower blood pressure, or her MIND diet. She found the MIND diet outperformed the others, lowering the risk of developing Alzheimer’s disease by 53 per cent for those who stuck to it most strictly. In 2017, a larger study backed this up. Ken Langa at the University of Michigan looked at the Health and Retirement Study, a huge study of how people in the US have aged, which has run since 1990. He assessed participants’ diet records and collated data on those who had eaten the Mediterranean or MIND diets. People who stuck to them had better cognitive performance than those who didn’t. As for the drip-drip of headlines touting the cognitive benefits of individual superfoods, Langa counsels restraint. Protecting your brain with your diet means paying attention to your whole diet, there’s no one food that will do it. ■ Kayt Sukel is a science writer based in Texas

The end of species

IOLOGY is a messy business. Witness these sage words: “It is really laughable to see what different ideas are prominent in various naturalists minds, when they speak of ‘species’… It all comes, I believe, from trying to define the undefinable.” Strong stuff. And from a surprising source. Charles Darwin wrote those lines in a letter to fellow naturalist Joseph Hooker, just three years before the publication of On the Origin of Species. Darwin clearly had a problem with the word to which his name is now so intimately linked. It turns out he is not alone. Today, almost 160 years after he revolutionised biology, how to define a species is more problematic than ever. You probably learned that a species is a group of individuals that can breed to produce fertile offspring, but this is just one of dozens of competing definitions. The lack of consensus on what a species is has big implications for how we think about the natural world and for our efforts to conserve it. But the problems go even deeper. Recent revelations about interbreeding between what some regard as separate species of ancient humans have left many of us wondering: who are “we”, who are “they” and are we actually all one and the same? In other words, how we define a species has become a question at the very heart of human identity. Perhaps it is time to rethink the whole concept. The idea that the living world is divided into distinct species has deep roots. Frank Zachos at the Natural History Museum Vienna, Austria, suspects it predates the

B

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written word. He thinks that even livestock farmers living 10,000 years ago understood it. “Cows produce cows,” he says. “Dogs produce dogs.” Early farmers would have noticed this and seen it as reflecting some underlying order to the natural world. For much of human history, people credited the gods for that order; species were created at the dawn of time and remained fixed and unchanging. It was this belief that Darwin undermined in the 1850s. But even before him, biologists were having problems with the idea that species never change. In the 18th century, for example, Carl Linnaeus, the “father of taxonomy”, was disturbed by a specimen of common toadflax that had a mutant flower. He likened it to a calf born with a wolf’s head. Perhaps sometimes a cow does produce a dog after all. Linnaeus eventually conceded that species created by God could occasionally cross with each other to generate new forms – hybrids. But for Darwin, that was an unsatisfactory solution. Nature may seem to comprise distinct species – killer whales, koalas, capybaras, Galapagos tortoises, blue-footed boobies, and all the rest – but his research emphasised that organisms form populations, and that these populations sometimes fragment, evolving into separate entities, or lineages. Species, he believed, are these lineages. “That was arguably the most original thing about his work,” says Brent Mishler at the University of California, Berkeley. “Lineages diverge and at some point, for convenience, we call them different species.

CHEN WHOOLI

Where we draw the line between one species and another profoundly influences our view of nature and ourselves, finds Colin Barras

But nothing magical has happened at that point.” In other words, Darwin considered it arbitrary to choose a single point in the gradual evolution of a distinct form and claim a new species has appeared. Darwin recognised that his ideas posed a profound problem for the way biologists define species. Curiously, though, his work didn’t lead to a reappraisal of the concept. Rather, the “modern synthesis” of evolutionary biology – a mid-20th century effort to pull together Darwin’s work on evolution and Gregor Mendel’s on heredity – saw species as a real and distinct level of biological organisation, as valid as the molecule, cell or organism. The synthesis was so influential that it still shapes the way many of us think of species. It is why we tend not to see them as arbitrary. And it explains the popularity of the biological species concept. “That made it into the textbooks,” says Zachos. And from there into the popular imagination. Behind the scenes, however, a different story was playing out. In the past century, scientists have redefined what a species is time and again, heaping confusion upon confusion (see “Parsing nature”, page 38). Zachos identifies no fewer than 32 competing definitions in his 2016 book on the subject, Species Concepts in Biology, and notes that two more have been added since then. This partly reflects the distinct ways that researchers in different subsets of biological science see the living world. Ecologists, for example, focus on environment, resources and adaptations, whereas palaeontologists are more interested in the shape of the fossils they study. It also reflects developments in science, with advances in genetics now making it possible to decode the DNA of individual organisms and reconstruct family trees. The upshot is often acrimonious, with players championing their favoured species concept while simultaneously taking pot-shots at rival ideas.

Specious arguments The profusion of definitions also causes practical problems because different types of biologists use different species concepts. Put simply, an insect species might not be equivalent to a mammal species or a flower species – even though most of us assume they are. “A lot of research is based on counting species,” says Zachos. “It’s as if we think we’re all using US dollars, but in reality we’re lumping together Japanese yen, euros, US dollars and pounds.” These problems are exposed whenever > 26 January 2019 | NewScientist | 37

PARSING NATURE If you think you know what a species is, think again. There are 34 competing definitions, including the six below. BIOLOGICAL SPECIES CONCEPT A species is a population of individuals that can reproduce to generate fertile offspring, and that is reproductively isolated from other populations. GENETIC SPECIES CONCEPT A species is a population of individuals that can reproduce and has a distinct genetic profile. Occasional interbreeding with other populations can occur if it doesn’t compromise the species’ genetic fingerprint. MORPHOLOGICAL SPECIES CONCEPT A species is a group of organisms whose physical features are consistently and persistently distinct from those of other groups. ECOLOGICAL SPECIES CONCEPT A species is a set of organisms adapted to a particular niche, whose distinct behaviours and morphology result from that adaptation. RECOGNITION SPECIES CONCEPT A species is a group of organisms that recognise each other as potential mates. UNIFIED SPECIES CONCEPT All separately evolving branches in an evolutionary tree are individual species.

38 | NewScientist | 26 January 2019

researchers change their definition of species – something that is happening increasingly often. For instance, in 2011, some biologists studying hoofed mammals shifted from a biological species concept approach to one based on heritable differences. Instantly, the number of species in the group rose from 143 to 279. Zachos and others worry about the consequences of such “taxonomic inflation” for conservation. Inflation, he points out, is often associated with a devaluation of the currency. Society might care a little less about losing a few species to extinction.

Rethinking hybrids Worse still, as biologists change the way they define species, conservation efforts can come in for criticism. This happened in 2018 when a team used DNA studies to conclude that the Chinese giant salamander fell into five distinct “species-level” groups, where just one had previously been recognised. The critically endangered salamanders are bred in farms and some are released back into the wild to boost population numbers. What is now clear is that if their parents are from different species, these offspring will be hybrids. Releasing them risks destroying the fragile genetic distinctions between the five species, and sending some of them extinct. The researchers called the conservation management approach “well-intentioned, but misguided”. One argued that we should now focus on identifying and saving the few remaining “unhybridised” salamanders. The International Union for Conservation of Nature’s Red List of Threatened Species recognises that species integrity is an issue in conservation. But its head, Craig Hilton-Taylor, feels that biologists need to rethink their attitudes towards hybrids. He cites the example of the northern white rhino, which is now down to just two individuals, both female. We can either accept that the species is effectively extinct or try to breed them with southern white rhinos. “You’ll have a hybrid – but you’ll save some of those genes from the northern white rhino,” he says. That may be a compromise too far for some, because the general attitude is that hybrids are in some way unnatural and of lower intrinsic value. But this view is outdated. It arises from the assumption that species, at least in the animal kingdom, are distinct once formed. In the past few decades, however, biologists have been astonished to discover that the opposite is true: hybridisation between animal species is common. Genetic analysis reveals, for

example, that the critically endangered red wolf is a cross between the grey wolf and coyote. Likewise, one of the world’s rarest fish, the Devil’s Hole pupfish, seems to be a hybrid. The hybrid issue extends all the way to our doorstep. Today, most of us are familiar with the discovery that there is Neanderthal or Denisovan DNA in the cells of many living humans. If we consider these other hominins to be distinct species, then that would make many of us “unnatural” or “valueless” hybrids, which is absurd. But the fact that such a conclusion could be reached might help explain why some experts in human evolution are cautious about using the term “species”. These include geneticist Johannes Krause of the Max Planck Institute for the Science of Human History in Jena, Germany, who with his colleagues first identified the Denisovans. They didn’t – and still haven’t – claimed Denisovans to be a distinct species. They prefer the less loaded term “population”. Language matters. Reporting one of the most astonishing science news stories of 2018, the cover of Nature read: “Ancient Human Hybrid”. It referred to research by Krause’s colleagues, who discovered that an ancient human, dubbed Denny, had a Neanderthal mother and a Denisovan father. “The research paper is so careful not to use the word hybrid,” says John Hawks at the University of Wisconsin-Madison. “And yet it is there on the cover of the journal: hybrid found!” He points out that the genetic difference between Denny’s father and mother may reflect a history of divergence that lasted no longer than that seen between some human populations that happily interbreed today. “But it would be wrong to look at a living person and say: hybrid,” he says. “We don’t use that term for a reason.”

“Biologists have been astonished to discover that hybridisation between animal species is common”

SALWAN GEORGES/THE WASHINGTON POST VIA GETTY IMAGES

that arises becomes another species. At this early stage, its members might lack distinct genetic and physical features, but, gradually, they begin to diverge in such ways. Every time the species gains another distinct feature, such as reproductive isolation, it becomes easier for us to recognise it as something different. Yet it has been a species from the very start, he argues.

RADIM BEZNOSKA/ALAMY STOCK PHOTO

Arbitrary divisions

How we define a species impacts the conservation of red wolves and Chinese giant salamanders

Given that the species concept is so divisive and so nebulous, what is to be done? One step might be to bring more rigour to the process of recognising new species. Stephen Garnett at Charles Darwin University, Australia, thinks that the ease with which new species are now recognised has led to “taxonomic anarchy”. In 2017, he and Les Christidis at Southern Cross University, Australia, argued that a formal process should be set up to judge the merit of any putative new species before it is officially adopted. “It gives the process legitimacy,” says Garnett. Immediate reaction to the proposal was negative, he admits, but he has since found common ground with some critics. “They do realise there is an issue that needs dealing with,” he says.

This could aid conservationists struggling with taxonomic inflation. It might also help focus thinking about our own ancestors when we come to classify new hominin fossils and ancient “ghost” populations – mysterious ancestors currently known only from the distinct traces they have left in our DNA. But it still leaves the problem that we have multiple definitions of what constitutes a species. One way to solve this might be to go back to Darwin and his emphasis on species as lineages, which is actually a common feature of most of the competing species concepts, according to Kevin de Queiroz at the Smithsonian Institution in Washington DC. De Queiroz’s “unified species concept” recognises that the moment a population fragments, the lineage

Problem solved? Not even close, according to some. Zachos points out that we must still make an arbitrary choice about which populations are species and which are not, unless we want to name every one of them a species. That would be socially unacceptable if it ever led to different living human populations being recognised as distinct species. Besides, we would need a crystal ball to see whether fragmenting populations will remain truly separated or whether it is just a blip before they come back together again. Perhaps, instead, the ultimate solution is simply to remove the word “species” from the scientific lexicon. In 2018, Mishler and John Wilkins at the University of Melbourne, Australia, set out this argument. They suggested that we should focus on another division of life, the “clade”, a group sharing a common ancestor and so comprising a separate twig on the tree of life. They say we could classify organisms as the Smallest Named and Registered Clade, or SNaRC, rather than as species. So, for example, Neanderthals, Denisovans and living humans would be three distinct SNaRCs. There is nothing intrinsically special about SNaRCs, according to Mishler: they might interbreed or not, and the groups that fit the classification would vary across the tree of life, forcing us to accept that there is no common currency. By abandoning “species” and turning to “SNaRCs”, he argues, biologists would have a blank slate for thinking about biodiversity. Needless to say, the idea has critics. “Darwin’s book was on the origin of species, and that’s because species are a real problem,” says Hawks. “To say ‘Oh, we’re not going to deal with species anymore’ – it’s actually a cop out.” But Zachos reluctantly concedes that Mishler’s idea might be part of a lasting solution to the species problem. “If I could think of something that would prove his thinking is wrong, I’d be a happy man,” he says. “So far I can’t.” ■ Colin Barras is a science writer in Ann Arbor, Michigan 26 January 2019 | NewScientist | 39

40 | NewScientist | 26 January 2019

COVER STORY A machine of incredible power is set to rip empty space apart and see what lurks within, finds Jon Cartwright

Something from nothing MAGINE a place far from here, deep in the emptiness of space. This point is light years from Earth, vastly distant from any nebula, star or lonely atom. We have many words for what you would find in such a place: a void, a vacuum, a lacuna. In fact, this nothingness is a sea of activity. According to quantum theory, empty space is filled with virtual particles. They are always there, keeping reality ticking over smoothly. They are also completely undetectable – unless, that is, you have an incredibly powerful searchlight. “Usually when people talk about a vacuum, they mean something that’s empty,” says theorist Mattias Marklund at the Chalmers University of Technology in Gothenburg, Sweden. “But a laser can show you the vacuum’s secrets.” To expose virtual particles, to transform them into something tangible, takes one serious laser. But that is exactly what physicists are putting the finishing touches to in Romania. Switched on for the first time a few months ago, this machine could not only reveal the truth about empty space, but also teach us about another big mystery: dark energy, the unknown entity accelerating the expansion of the cosmos. It is time to rip nothingness apart and see what is inside. The notion that nothingness is full of virtual particles might sound fanciful. After all, no astronaut swims in a virtual sea, no satellite is hindered by virtual drag. Virtual particles just aren’t tangible. The reason we believe they exist goes back to the foundations of quantum electrodynamics (QED), the branch of quantum theory used to calculate what happens when photons, particles of light, interact with electrons.

SIMON PRADES

I

When physicists developed QED in the 1930s, their calculations only worked properly if they took into account all ways in which the particles could approach and ricochet off each other, including routes that normal particles couldn’t take because they break the laws of physics. The travellers of these impossible routes can’t have been strictly real, then. There has been a lingering question over how to interpret things that are mathematically necessary, yet not entirely there, ever since (see “What is a virtual particle?”, page 40). QED also left open an alluring possibility. If you had an electrical field strong enough, you could “break the vacuum” and make the virtual particles real. Virtual electrons always exist alongside their antimatter equivalent, virtual positrons, and the two usually

“With enough energy, a vacuum ceases to be a void. Its emptiness is broken” annihilate on contact. But create a monumental electrical field and the virtual particles could escape one another and become particles proper, ones we could detect. The energy threshold where this should happen is known as the Schwinger limit, named after the QED theorist and Nobel laureate Julian Schwinger, though actually predicted by others before him. At this limit, the vacuum’s defining property, its emptiness, is broken. “The vacuum ceases to be a void,” says theorist Sergei Bulanov, based in Dolní Brežany in the Czech Republic. Getting to the Schwinger limit would require bombarding virtual particles with

an incredible number of photons in order to transfer the requisite energy. How much energy would you need? It is equivalent to cramming a billion times the output of all the world’s power plants into a space not much bigger than an atom. Not a likely proposal, unless you can gradually store up energy and then emit it all in one enormous flash. Which is where lasers come in. Inside them, a chain reaction produces many photons of the same frequency, before releasing them in a narrow beam that can be powerful enough to cut though steel. It took a while to get to that stage. The intensity of early lasers was limited while we struggled to find materials for their innards that didn’t waste away in such blinding conditions. Then in 1985, physicists Gérard Mourou and Donna Strickland, while at the University of Rochester in New York, came up with a turbo boost. They found a way of pre-stretching and thus pre-weakening a laser pulse. It could then be amplified without burning through the material inside the laser’s chamber before being compressed to its original form, intensifying the energy it had gained in the amplification stage. It was this that earned Mourou and Strickland the 2018 Nobel prize in physics. Even then, however, Mourou was setting his sights on a more ambitious target. “The laser power was at gigawatts, then terawatts, and then even petawatts were a possibility,” he says. “So naturally we thought, could we actually break the vacuum?” In 2005, Mourou began to conceive of a laser behemoth that could, by the sheer intensity of its light, generate electrical fields at the Schwinger limit. His idea became the Extreme Light Infrastructure project (ELI), > 26 January 2019 | NewScientist | 41

CTK/ALAMY STOCK PHOTO SCIENCE & TECHNOLOGY FACILITIES COUNCIL

LLNL

Testing has begun on what will be the world’s most intense laser at ELI in Romania (above and top right). At peak strength, it will be 1000 times stronger than the UK’s Gemini laser (bottom right)

and within a few years, 40 laboratories from 13 European countries were on board, with a European Union-backed budget of more than €850 million. The project now spans three sites. These include the ELI Nuclear Physics facility near Bucharest, Romania, which houses two 10-petawatt lasers that, when working at peak strength, will be the most intense in the world. Tests are being performed at gradually higher intensities. The lasers could do more than just break the vacuum. Transforming virtual particles into real ones may also tell us about dark energy, perhaps the biggest mystery in cosmology. We know something is driving the expansion of the universe faster and faster, but what? Some suspect that the mysterious factor could be the energy inherent in ever-present virtual particles. That probably isn’t the whole story – add up the energy of those particles and you would expect the universe to be expanding much faster. But probing virtual particles directly could shed light on the mystery. ELI could also help us understand the fast, bright bursts of gamma rays and radio waves that astronomers keep seeing in the night sky. These sometimes explode with thousands of times more energy than the sun produces in a year. No one knows how these explosions happen, only that they probably involve the generation of plasmas made of electrons and 42 | NewScientist | 26 January 2019

positrons, which twist and gyrate violently, throwing off photons as they do so. ELI’s lasers could create a cloud of electron-positron plasma, letting us study the material that makes these cosmic flashes so bright. The biggest prize would be finding out what lies beyond the limits of QED. In everyday conditions, the theory successfully predicts experimental outcomes involving electrons and photons to extreme levels of precision. A little beyond the Schwinger limit, however, the methodology breaks down, as the routes

taken by virtual particles get more and more convoluted, until the calculations become meaningless. “What happens is an open question,” says Bulanov. With all this potential, it is no surprise ELI’s experiments are hotly anticipated. Yet despite Mourou’s grand vision, none of the lasers will be able to reach the Schwinger limit on their own. Even a mooted fourth ELI laser facility with an intensity 10 times greater than any of the other three would be 10,000 times too dim. “Nothing being built currently gets

WHAT IS A VIRTUAL PARTICLE? Quantum electrodynamics (QED) can be used to calculate the probability that a

Ethereal they may be, but QED wouldn’t work without these virtual

photon or electron starting off at point A ends up at point B with astonishingly

particles. And there are hints of their existence in the Casimir effect, in

high precision. Doing so requires taking into account myriad possible particle routes, many of which don’t follow basic physical laws. Regular particles always abide by the law, so we call the rule-breakers virtual particles. But what actually are they? One way of picturing all particles is as invisible ripples, or fields, in space. When these fields are strong and lively, they manifest as particles. These are what make up all the tangible stuff around us, from the air we breathe to the ground we walk on. But in a vacuum, fields peter out to almost nothing. Here, there are the faintest shimmers of fields – not quite proper particles, but still something.

which two mirrors brought to within nanometres of each other will suddenly begin to attract. One explanation is that virtual particles between the mirrors are squeezed out, and can no longer balance the pressure of virtual particles striking the outsides. Picturing virtual particles is always going to be tricky, though. The most precise thing we can say is that there exists everywhere a quantum wave function, a mathematical description of space and time, says Sean Carroll at the California Institute of Technology. “It’s something our classical intuition isn’t always great at making sense of, so we reach for vivid metaphors to describe what’s going on.”

there,” says Michael Donovan, manager of the Texas Petawatt Laser in Austin. Fortunately, that doesn’t rule out any magic. For one thing, the Schwinger limit is thought to be less a cliff face than a steep ascent. In other words, there is a chance virtual particles could start transforming into real ones at lower laser intensities (see diagram, right).

The power of light As the intensity of lasers has increased over the years…

Our best physics theories can no longer describe reality

Fatal avalanche? 1030

Focused intensity of laser (watts per cm2)

That would be quite a discovery, although there could be a sting in the tail. In 2010 Mourou, now at the École Polytechnique in Paris, and his colleagues worked out that these newly materialised pairs of virtual particles would spiral around the laser beam, flinging off photons that subsequently transform into more electron-positron pairs, until there is an electron-positron avalanche. This might be welcome for astrophysicists wanting to study electron-positron plasmas, but the avalanche would mask the transformation of the original virtual particle pair. Worse, it would sap the laser’s energy, preventing it from reaching the true Schwinger limit. “It might be one of those instances where we say, OK, we can’t reach this limit,” says Jonathan Wheeler, a collaborator of Mourou’s at the École Polytechnique. “But in not reaching it, we’ve learned something.” Time to give up then? Not yet. Shortly after the publication of Mourou’s paper, Bulanov and his colleagues realised that the avalanche effect should only occur if the laser beam is circularly polarised, with its electrical field rotating in a corkscrew fashion as it travels along the beam. They calculated that, if the laser is instead linearly polarised, so the electrons and positrons zigzag along the beam, they generate far fewer photons, containing the avalanche. “In fact, we can reach the Schwinger limit,” says Bulanov. He isn’t alone in his optimism. To get over that thousandfold deficit in ELI’s intensity, laser theorists have begun to get creative. One option is to cross two or more laser beams, to double, or more, the laser intensity at the intersection. This Ghostbusters-style approach sounds easy, but Wheeler and others believe the practical details quickly get complicated. A better option might be something more outlandish: a mirror flying near the speed of light. If a laser beam reflects off such a mirror, its wavelength is compressed, allowing it to be focused on a smaller spot. The smaller the spot, the more intense the light. First proposed by Bulanov back in 2003, the concept couldn’t employ a regular bathroom

Schwinger limit, where virtual particles become real

Exotic concepts, like colliding a laser with a mirror flying at the speed of light or a particle beam, could reach this intensity and above 1025

A future ELI laser, unconfirmed ELI’s laser in Romania, when at peak intensity

HERCULES at the University of Michigan is the most intense laser in the world today 20

10

Gemini laser at the Rutherford Appleton Laboratory, UK

1015

Lasers reached this level in the 1970s

… we have been able to probe ever stranger physics A vacuum is broken, and virtual particles are easily transformed into real ones One or two virtual particles may be transformed into real ones. Quantum electrodynamics struggles to describe real particles’ behaviour Particles can be accelerated to near the speed of light, and used to drive new types of particle accelerator Particles behave normally, and quantum electrodynamics describes their behaviour with incredible precision

mirror – the energy required to accelerate it would be unthinkable. But Bulanov says a mirror consisting of a wave in an electron plasma would reflect the light just as well. Five years ago, Bulanov reported the first results of an experiment to demonstrate the principle of the flying mirror. He now leads ELI’s High Field Initiative, which explores ways of maximising laser intensity. “I’m absolutely sure that my idea works,” says Bulanov. In the meantime, Wheeler and Mourou are probing similar concepts to break the Schwinger limit. “We will find a way,” says Mourou. Some are boosting the intensity of lasers already, by other means, and seeing strange effects. In February 2018, an international group led by Stuart Mangles at Imperial College London directed a beam from the Gemini laser at the UK’s Central Laser Facility straight into an oncoming electron beam. Just as a car crashing into oncoming traffic makes a bigger bang than a car crashing into a wall, colliding the two beams boosted the intensity. The team saw the electrons emitting photons, and recoiling in the process. For this to happen, the electrons in the experiment had to absorb a barrage of photons in a

“One outlandish idea to up laser intensity is a mirror flying at the speed of light” complex process nearing the edge of QED’s descriptive powers. “It is physics on the way to the Schwinger limit,” says Mangles. Meanwhile, other laser facilities with similar powers to ELI are in development, including the Exawatt Center for Extreme Light Studies in Russia, and the Station of Extreme Light in Shanghai. David Reis, a laser physicist at Stanford University in California, says the Shanghai facility is being built near another big laser, perhaps allowing one beam to be collided into the other. “That would really be spectacular,” he says. The future is looking bright for laser physics. Mourou’s desire to see another surge in laser intensity has been boosted by the Nobel he shared with Strickland. Wheeler recalls hearing the laureate’s prediction for exceeding the Schwinger limit at a recent conference. “Mourou said it would be within five years, and I laughed nervously,” he says. “But let’s just say the next few years should be a very exciting time.” ■ Jon Cartwright is a science journalist based in Bristol, UK 26 January 2019 | NewScientist | 43

CULTURE

A virtual voyage begins What discoveries await an epic player mission to the Milky Way’s edge, asks Douglas Heaven

FRONTIER

ON 13 January, 10,000 people fired up Elite Dangerous, charged their ship’s faster-than-light drive and set off on an epic, eight-month journey to the outer edges of the Milky Way. The 200,000 light-year round-trip voyage to Beagle Point, one of the galaxy’s most distant star systems, will take the giant fleet across vast regions of uncharted space, including the Galactic Aphelion and the Abyss. “It’s a challenge in endurance and navigation,” says mission leader Erimus Kamzel. Don’t worry, you haven’t slept through 1300 years. Set in the early 3300s, Elite Dangerous (by Frontier Developments) is a video game that drops players into the cockpit of a spaceship and lets them loose in a 1:1 simulation of the Milky Way, based on our latest understanding of star and planet formation. The players can organise themselves into ambitious, informal missions: the latest is called Distant Worlds 2 because it retraces the steps of a learn about the astronomical mission three years ago, which objects they find in much more had only a few hundred players detail, including the mass, spectral and was largely a sightseeing tour. class and luminosity of stars. There are 400 billion solar This means that much of the systems, each with its own time during the journey will be planets, moons and asteroids, spent doing science. Although the and with such mind-boggling simulation is extremely accurate, stretches of nothing between any “discoveries” will be limited them that it would take some “Anything could be there, 40,000 years to see them all. civilisations, unimaginable Since the game’s 2014 release, alien life, stellar bodies roughly 160 million systems breaking scientific laws” have been visited by at least one player. But that barely scratches the surface. “There is an to revealing “genuine” things unfathomable amount out there,” about the simulated galaxy. according to a mission organiser Everything there has been called Qohen Leth (all names in conjured from first principles: this piece are player names). stars and planets begin as clouds An upgrade now lets players of matter that slowly aggregate 44 | NewScientist | 26 January 2019

Elite Dangerous lets players loose in a 1:1 simulation of the Milky Way

into different solid forms according to their chemical composition, angular momentum and gravitational pull. Satsuma, the organiser of the mission’s scientific side, is interested in the metallicity of stars: the ratio of the heavier to lighter elements they contain. In the real Milky Way, astronomers spotted a correlation between a star’s metallicity and the number of gas giants orbiting it. Using statistical analyses carried out during the voyage, Satsuma hopes to learn how the simulated galaxy compares to the real one. A lot of what the mission

discovers will make its way back to players not on the trip. “We will make ourselves available to answer questions,” says Satsuma. “I know many people who became interested in astronomy after playing this game.” But strange stars and black holes are not all the mission is preparing for. The game is already known to contain two alien races: the Thargoids and the Guardians. Given the amount of unexplored space, there are likely to be others. “Anything could be out there,” says Dr Kaii, who co-leads the expedition, “new civilisations, unimaginable alien life, stellar bodies breaking the laws of science as we know them.” But will the thrill of discovery be enough? One big challenge is to keep people online for several hours a week during those long stretches of empty space. Players will be able to distract themselves by chatting or listening to an ingame radio station broadcasting music and interviews. There is some safety in numbers, too, with players relying on the fleet not only for refuelling and repairs, but also for motivation. “The most dangerous thing to run out of is sanity and that’s why we’re going out there as a community,” says Olivia Vespera, who is responsible for supplies. “But the truth is, none of us knows what we will face,” says Valen Zendaris, another organiser. It could be hostile regions of space, alien archaeological sites harbouring dangerous tech, or a giant living organism. “How will we act? How will it react? We will never know until we go there.” ■ Douglas Heaven is a consultant for New Scientist

For more books and arts coverage, visit newscientist.com/culture

DON’T MISS

Images of the digital world reveal little, Lydia Nicholas finds

THESE days, half the news cycle is fake news, half is about the fake news, and a third half bemoans the impact of this circus on our health, politics and culture. We are addicted to likes, manipulated by media platforms and bamboozled by images whipped up by uncanny new AI or oldfashioned fraudsters. We are being entertained, sure – and we are being exploited. Think pieces, master’s degrees and consulting jobs spring from this rich manure of media anxiety, and with them exhibitions like All I Know Is What’s on the Internet, a worthwhile, although not groundbreaking, exhibition about the systems and infrastructures that underpin our image culture. The journey begins in empty space. Winnie Soon’s Clone invasion: Constant Dullaart’s SIM-card art features fake identities

Unerasable Images consists of 300 screenshots taken in China in 2017. They display the results obtained when Google’s image search was tasked with finding the moment in 1989 outside Tiananmen Square in Beijing when a protester faced down a tank. Most of these screenshots are white fields, left barren by Chinese state censorship. There is a Lego version of the scene, though, which survived for months before a change in the algorithm, or human intervention, rooted it out. In Stéphane Degoutin and Gwenola Wagon’s installation World Brain, two videos play amid tree stumps. Each film puts the reality of the web into question. In one, sharks chew on transatlantic fibre-optic cables – so much for the internet as cloud. In the other, researchers attempt to survive in a forest using only Wikipedia. Much work in the show is about the people who facilitate online exchanges of imagery and information. The hands of those digitising pages for Google Books, caught accidentally in some of

CONSTANT DULLAART, PVA FORMATION

All I Know Is What’s on the Internet, The Photographers’ Gallery, London, to 24 February

their scans, populate Andrew Norman Wilson’s ScanOps. The faces of Google Street View operators are captured as they adjust equipment in Emilio Vavarella’s The Google Trilogy 3: The driver and the cameras. Eva and Franco Mattes’s stories of internet content moderators lift the lid on a world of horrors. The assumption throughout is that art brings hidden systems into the light of day. The truth is, though, they weren’t so hidden in the first place. And if we worked in India, say, or the Philippines, getting PTSD from days spent vetting obscene and brutal videos, we would know in our bones how real these systems are. All I Know Is What’s on the Internet is interesting, certainly, but at this stage in the media cycle, revelation is not enough. Brigading_Conceit by Constant Dullaart is a sculpture made from hundreds of SIM cards that the artist used to create an “army” of fake identities, aping the acts of hundreds of political parties around the world in recent years. There is a military metaphor to be read in the sculpture’s large, mirrored surface, where SIM cards are arranged in battle formations. It is a highly Instagrammable piece; the perfect backdrop for a selfie. But the mirror reflecting the narcissism of social media and the metaphor of the bot army are fairly familiar artistic strategies. There is nothing wrong with a gorgeous picture, but it brings us uncomfortably close to where we started: mesmerised by a cycle of entertaining, consumable shocks. ■

At the Barbican Centre’s Curve gallery in London from 31 January, film-maker Daria Martin’s exhibition Tonight the World combines gaming technology and film to immerse visitors in her grandmother’s memories of fleeing the Holocaust.

Play Escape a ravaged Earth on your own starship when Team17 and Radiation Blue launch video game Genesis Alpha One on 29 January. You’ll have to build your ship first, though, and maintain it, and manage the crew…

Watch Last year Jodie Whittaker fell to Earth as the first female in the title role of Doctor Who and split opinion among fans. All the more reason to get her first series on DVD, out on 29 January.

Last chance Science Gallery Dublin’s Intimacy (pictured below), an exhibition full of neuroscience, original art and behaviour-studies mischief, ends on 3 February. Take a friend.

Read Physicist Paul Davies hunts for the secret of life in his book The Demon in the Machine: How hidden webs of information are finally solving the mystery of life (Allen Lane), while Our Universe: An astronomer’s guide  (Pelican) is astrophysicist Jo Dunkley’s thrilling new paperback guide to our cosmos “and how it works”. No pressure there, then.

SCIENCE GALLERY DUBLIN

Unveiling the obvious

Visit

Lydia Nicholas is a researcher in ethics and culture 26 January 2019 | NewScientist | 45

CULTURE

A world of pain This unsung story of slave women in gynaecology deserves a wide audience, says Chelsea Whyte

PHILOMENA. Sally. Betty. Mary. Dinah. These are the women at the heart of new play Behind the Sheet. They speak for slaves used by a 19th-century doctor, James Marion Sims, in experimental surgeries to cure painful vaginal fistulas. These were often caused by complicated childbirth, and resulted in loss of bladder control, incontinence, infections, inflammation and infertility. Over four years, Sims rented slaves from their owners and operated on them without anaesthetic until he found a way to suture these holes. His work ended that suffering, but what of the women he practised on? They are the focus of this play, and despite the faithful portrayal of their pain, they brighten a dark tale set against a backdrop of racism and misogyny. It is a story for our time: the furthering of modern gynaecology by a male doctor driven to help women as he disregards their humanity. The production is one of the latest from a partnership between Ensemble Studio Theatre and the Alfred P. Sloan Foundation. One of the most acclaimed plays from this association is Anna Ziegler’s Photograph 51, which had a successful run in London’s West End. Nicole Kidman starred as Rosalind Franklin, whose work on the structure of DNA was only celebrated posthumously. An excellent, if mostly unknown, cast star in the new play. Together, Female slaves share their painful surgical experiences 46 | NewScientist | 26 January 2019

the actors produce fine, layered The women did not. I wanted to portrayals of female relationships tell their story,” says playwright and of the power dynamics of life Charly Evon Simpson. on a plantation. Their scenes take She deviates in places from the place in the “sick house” set up by historical record that forms much Sims for them to recover from of the story to underscore key surgeries. Here, they speak freely ironies. For example, the fictional about painful wounds and grief Sims has sex with his slaves, over losing a child. They call each which lead to pregnancies and to other out, show jealousy towards the very disease he aims to fix. the slave master’s favourite, Sims named three slaves in his and literally lean on each other. notes: Anarcha, Betsey and Lucy. They are imprisoned by their He operated on them repeatedly, pain, but even when set free from Anarcha perhaps as many as 30 that, they aren’t free. Jehan O. times. Anaesthesia was not widely Young, who plays Dinah, voices available when Sims started, but this in a striking moment, when it became more common as his she says she and the others are work continued. On stage, Sims being fixed so they can bear more children and produce more slaves. “Can we celebrate the good It is rare to see a woman’s inner someone does for society while recognising their life shown with such nuance. human failings?” “Sims wrote an autobiography.

JEREMY DANIEL

Behind the Sheet by Charly Evon Simpson, an EST/Sloan Project, Ensemble Studio Theatre, New York City, to 3 February

echoes what the real doctor expressed in medical journals: the procedure caused so little pain anaesthesia was too much bother. When asked why he used it on white women, Sims tells Philomena that she and the other slaves were stronger and didn’t need it. But in the play’s most haunting moment, each woman bends over, clutching her stomach and crying out as she counts out the number of her surgeries, a dramatic device I won’t forget. Early in the play, Sims – played by actor Joel Ripka as more zealot than monster – shows off one of his many medical inventions, the speculum. As Sims says, you can’t solve a problem until you see it. The same could be said for the play. Re-examining history with lenses other than those of the dominant white male, we have to ask: can we celebrate the good someone does for society while recognising their human failings? Yes, says Simpson, and her work is a fine example of navigating the two currents. “I can be grateful for the innovation and critical about how it came to be,” she says. “I thought a lot about that balance when researching and writing.” Until last year, a monument to Sims stood on the edge of Central Park. In 2018, the statue was moved to Green-Wood Cemetery, Brooklyn, where Sims is buried. But at the curtain call, the actors paused the applause, and Naomi Lorrain, who plays Philomena, said: “There is no monument to the women.” The lights dimmed, showing her in silhouette as if to refute that. Behind the Sheet is also a living monument – and as important a message as Photograph 51. Let’s hope it too gets a global airing. ■

Postdoctoral position in chemical biology The incumbent will develop complimentary skills in preclinical drug discovery through the rapidly growing, highly collaborative program in Chemical Biology at the Dana-Farber. 4XDOLˉFDWLRQV 'DQD)DUEHU&DQFHU,QVWLWXWHLVDQHTXDORSSRUWXQLW\HPSOR\HUDQGDIˉUPV WKH ULJKW RI HYHU\ TXDOLˉHG DSSOLFDQW WR UHFHLYH FRQVLGHUDWLRQ IRU employment without regard to race, color, religion, sex, gender identity or expression, national origin, sexual orientation, genetic information, disability, age, ancestry, military service, protected veteran status, or other groups as protected by law. Drs. Jarrod Marto and Nathanael Gray are seeking an exceptional and highly motivated postdoctoral candidate to advance their joint program for development and proteome-wide characterization of covalent kinase inhibitors targeting disease-relevant pathways. The successful candidate for this position will have a recent Ph.D. in chemistry, chemical biology, or UHODWHGˉHOGZLWKWKHUHTXLVLWHFRPPLWPHQWDQGVNLOOVWRLQWHJUDWHUHVHDUFK activities in advanced mass spectrometry and structure-guided inhibitor design. Candidates can augment their career development through an expanding portfolio of interactions with the greater Boston pharma and biotechnology community. Additional requirements for this position include: strong interpersonal, organizational, and writing skills. This position is available immediately. Interested candidates should email a FRYHUOHWWHUVWDWLQJVSHFLˉFLQWHUHVWTXDOLˉFDWLRQVDQGFDUHHUJRDOVDORQJ with CV to: Dr. Jarrod Marto c/o Ms. Nicholle Wurie The Dana-Farber Cancer Institute 450 Brookline Avenue, Longwood Center, Rm 3115, Boston, MA 02215-5450 Email: [email protected]

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'HSXW\'LUHFWRU6FLHQFH'LUHFWRU(QHUJ\ Australia

7KH2SSRUWXQLW\ ‡$OHDGLQJUROHLQSURYLGLQJWKHVFLHQWLÀFYLVLRQOHDGHUVKLSDQGGLUHFWLRQ WRWKH&6,52(QHUJ\%XVLQHVV8QLW ‡&RPELQH\RXUHVWDEOLVKHGUHSXWDWLRQDQGOHDGHUVKLSH[SHULHQFHWR GHYHORSVWUDWHJLFFDSDELOLW\DQGHIIHFWLYHO\DFKLHYH&6,52·VVWUDWHJ\ ‡-RLQ&6,52$XVWUDOLD·VOHDGLQJVFLHQWLÀFUHVHDUFKRUJDQLVDWLRQ The Energy Business Unit is one of nine impact science Business Units in CSIRO with over 450 staff working across Australia. Our goal is to deliver solutions that will enhance Australia’s economic competitiveness and regional energy security while enabling the transition to a lower emissions energy future. In the role of Deputy/Science Director you will work closely with the Business 8QLW'LUHFWRUSDUWQHULQJWRDFKLHYHWKHVFLHQWLÀFYLVLRQDQGGHPRQVWUDWH\RXU OHDGHUVKLSZKLOHHQVXULQJWKH%XVLQHVV8QLWDQG&6,52UHPDLQVFLHQWLÀFDOO\ competitive. You will lead the development and implementation of a strateJLFFDSDELOLW\SODQLQFOXGLQJSHRSOHDQGVFLHQWLÀFHQJLQHHULQJLQIUDVWUXFWXUH ensuring appropriate evolution with the Energy Business Unit and CSIRO’s strategic direction. At CSIRO you can be part of helping to solve big, complex problems that make a real difference to our future. We spark off each other, learn from each other, trust each other and collaborate to achieve more than we FRXOGLQGLYLGXDOO\LQDVXSSRUWLYHUHZDUGLQJLQFOXVLYHDQGWUXO\ÁH[LEOH environment. We’re working hard to recruit diverse people and ensure all our people feel VXSSRUWHGWRGRWKHLUEHVWZRUNDQGHPSRZHUHGWROHWWKHLULGHDVÁRXULVK See full details and apply online with a CV and cover letter outlining your suitability and motivation for the role. # 59516. KWWSVMREVFVLURDXMRE 1HJRWLDEOH'HSXW\6FLHQFH'LUHFWRU(QHUJ\%XVLQHVV8QLW Applications Close -DQXDU\

Albert Einstein College of Medicine Departments of Medicine and Molecular Pharmacology

Postdoctoral Opportunity:

Mechanistic Studies of the Proton-Coupled Folate Transporter (PCFT) A postdoctoral position is available for studies on the structure-function, molecular genetics, regulation and biological/ pharmacological role of PCFT. This transporter, discovered in this laboratory, is mutated in the autosomal recessive disorder, hereditary folate malabsorption, also a focus of study. PCFT mediates intestinal folate absorption, folate transport across the choroid plexus and transport of antifolate chemotherapeutics.

The Albert Einstein College of Medicine is located in a residential area of Northeast Bronx in close proximity to City Island and Westchester County with easy access to Manhattan. The Albert Einstein College of Medicine is an Equal Opportunity/Affirmative Action Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, age, protected veteran or disabled status, or genetic information. Candidates should have a strong background in molecular biology and a track record of productivity during their doctoral training. Experience in physiology and modeling is desirable. This is a participating laboratory in the Experimental Therapeutics Program of the NCI-designated Albert Einstein Cancer Center. Email resume and the names of three references to: I. David Goldman, MD, ([email protected]), Departments of Medicine and Molecular Pharmacology, Albert Einstein College of Medicine, Jack and Pearl Resnick Campus, Bronx, New York 10461.

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2019

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POSTDOCTORAL OPPORTUNITIES Find these and many more postdoctoral opportunities on our New Scientist Jobs online jobs board! Go to www.NewScientistJobs.com Enter the Job ID# listed below to read about the position. Find more jobs by entering your criteria into the grey search box.

1401660798

Postdoctoral Opportunity: Mechanistic Studies of the Proton-Coupled Folate Transporter (PCFT) Bronx, New York - Albert Einstein College of Medicine

1401660776

Research Fellow Boston, Massachusetts (US) - Dana-Farber Cancer Institute

1401660709

Postdoctoral Research Opportunities Bronx, New York - Albert Einstein College of Medicine

1401660560

Postdoctoral Research Fellow – Alzheimer’s Disease Chicago, Illinois Rush University Medical Center

1401656605

NASA Postdoctoral Program – Application Deadline March 1, 2019 NASA Centers throughout the US - NASA / Universities Space Research Association

1401656602

Research Fellow -Chemical Biology Boston, Massachusetts (US) - Dana-Farber Cancer Institute

1401656502

Postdoctoral Research Fellowship Position Ann Arbor, Michigan - University of Michigan School of Medicine, Department of Internal Medicine

1401656497

RESEARCH ASSOCIATE/ INSTRUCTOR Memphis, Tennessee - University of Tennessee Memphis Health Science Center

1401656319

Postdoctoral Fellows Memphis, Tennessee - University of Tennessee Memphis Health Science Center

1401656231

Postdoctoral Fellowships in Computational Chemistry and Physics New York City, New York (US) - D. E. Shaw Research

1401646848 NRC Research Associateship Programs - February 1 Deadline Washington D.C. - National Academy of Sciences 1401654338

Biopharma Innovation Cup 2019 Seeking US and Canadian Postdocs and Postgrads for 1 Week Paid Event - Merck KGaA

1401660586

Postdoctoral Training Fellow in Cancer Immunology London (Central), London (Greater) (GB) - The Francis Crick Institute

26 January 2019 | NewScientist | 51

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LETTERS EDITOR’S PICK

We need to remember some old lessons about genetic testing

From John Warre, Bondleigh, Devon, UK You raise the question of whether all newborns might benefit from DNA testing (12 January, p 19). I see at least two problems that you didn’t mention. If 140 out of 159 babies tested had one or more genes associated with disease, many parents will surely

conclude that there is something wrong with their baby. It will take a great deal of careful counselling to counteract this conclusion. Very few fully qualified doctors could cope with providing this, let alone a start-up sequencing company. I came across the second issue when I was a final-year medical student in 1970. Our teaching hospital was researching rhesus incompatibility in newborn babies. At the time, it was an almost untreatable, unpreventable condition. It arises when a mother whose blood group is rhesus negative has a baby with a rhesus-positive man. Their first child might be only mildly affected by a reaction between the two incompatible blood groups, but the mother may develop antibodies that affect a second child, sometimes with grave, if not fatal, results.

The most obvious thing to do was to ascertain the blood groups of the parties involved – mother, baby and father. It soon emerged that around 25 to 30 per cent of the babies had blood groups that could not possibly have arisen if the “father” was who he thought he was. The percentage was rumoured among colleagues to be higher in the babies of mothers who had had a problem with a first or second pregnancy. The research project ground to a halt. DNA testing will reveal much more detailed results. In several published cases, such results have brought adults to the realisation that their parentage isn’t quite what they thought. Discovering this with newborn babies may open another counselling headache, to put it mildly.

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Some first class solutions to air travel pollution From Iain Climie, Whitchurch, Hampshire, UK Paul Marks mentions replacing aviation kerosene with biofuels (5 January, p 32). One problem with this is that aircraft engines will still generate various oxides of nitrogen at the high temperatures involved. Another is that emissions, including carbon dioxide and water vapour, occur at altitude, where they have a disproportionate effect on climate. Flying lower and slower could reduce emissions, as could stopping to refuel on long flights. The high weight of fuel carried on these causes higher consumption. From Julian Goodkin, London, UK Another measure for reducing the environmental impact of air

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“Many women return to work ‘part time’ but do their previous job in less time for less money” EDgypsy responds to the suggestion that flexible working is more productive and healthy (12 January, p 39)

travel is curtailing or abolishing first class and business class. I have seen estimates that a firstclass seat takes between five and seven times as much space as an average economy seat, and this doesn’t take into account extra crew to service these passengers. It seems to be an accepted premise that as long as you have the money, you can pollute six times more for the same activity. From Brian Tagg, Taunton, Somerset, UK Marks mentions electric vertical take-off and landing (eVTOL) aircraft. To suggest that these might replace commuter trains is, frankly, frightening. According to figures from the UK Department for Transport, there were some 1.7 billion rail journeys in the country in 2017-18, of which over half were commutes or for business purposes. If just

1 per cent of these journeys were switched, we would see at least 10 million eVTOL flights per year. For what purpose? This solves nothing and creates new problems, not least for those under their random flight paths. To reduce emissions, we need jobs to be available where people live, to minimise travel. All new major housing developments should come with mandatory business space to attract work that people can travel to on foot, bicycle or local transport. We don’t need more crazy ways to perpetuate the daily commute.

An iguana’s view on land mass evolution From Richard Crane, Brighton, East Sussex, UK Zoologist Peter Grant suggests naming the chain of sunken islands near the Galapagos

“Iguania” and Felipe OrellanaRovirosa, whose work you report, suggests “Darwinia” (5 January, p 15). I propose calling them all the Galapagos Chain. Humans may think they see one archipelago of seven islands and a nearby chain of submarine mountains. But iguanas survived a sea crossing to reach the area and have bred there for more than 10 million years. Islands keep popping up and going down, but that is no problem for iguanas because each new island is close to the old ones before these are eroded, slide off the hotspot and sink beneath the sea. Extending the window for evolution of the Galapagos flora and fauna from 3 million years to a more useful 15 million years or more was the viewpoint I proposed 40 years ago when plate tectonics was in its infancy and I was a geologist from the

University of Durham, UK, and working at the Galapagos National Research Centre.

Where children have play, adults have art From Richard Hind, York, UK David Robson talks about the extended infancy in humans that allows us time to develop cognitive skills through play and its role in enabling innovation (22/29 December 2018, p 65). This brought to mind an insight expressed by musician Brian Eno in his 2015 John Peel Lecture (bit.ly/EnoLecture). He says children learn through play, but adults play through art. Could this help explain our need for artistic endeavour? Eno suggests that adult play – engaging with art – is how we rehearse for life events. He notes that by immersing >

Spectacular wall art from astro photographer Chris Baker

Available as frameless acrylic or framed backlit up to 1.2 metres wide. All limited editions

www.galaxyonglass.com +44 (0) 7814 181647 [email protected] 26 January 2019 | NewScientist | 53

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LETTERS yourself in art, you are not only increasing your ability to imagine and flex your mental muscles in other worlds, but you are also looking back at the world you are actually in.

Most bacteria aren’t as large as that From Guy Cox, St Albans, New South Wales, Australia Leah Crane describes a BoseEinstein condensate of caesium atoms 26 micrometres across as “the size of some bacteria”. A few bacteria are this size, and I’ve spent a large part of my career researching them. But your average bacterium is less than a tenth as large.

A chromosome puzzle in human ancestry From Harry Phillips, Morayfield, Queensland, Australia You frequently discuss humans interbreeding with Neanderthals and Denisovans (for example 22/29 December 2018, p 35). Presumably this was going on further back in the lineages.

All these species have 23 pairs of chromosomes; other great apes have 24. Each of one certain pair of our chromosomes consists of two ancestral units stuck end to end with “telomere” end sequences in the middle. How did the first ancestor with 23 chromosome pairs have offspring with others that had 24? What advantages do 23 chromosome pairs give over 24?

I detect some politics happening here From Philip Ledger, Carlton, Bedfordshire, UK For several months, I have detected an increased number of New Scientist articles covering our dire position with respect to climate change. You appear to have taken the position that global warming is a fact and that extreme measures will have to be taken for us to be successful to combat it. We should ask ourselves whether this is a proper attitude for an impartial journal. And of course, the answer is a resounding yes. Thank you. Keep up the good work. Tell it like it is. If science

becomes politics, then so be it. We will only get one chance at the experiment of dealing with this.

Thank you for the help coping with Parkinson’s From Graham Legg, Ragged Appleshaw, Hampshire, UK I thank Mike Aris for sharing his technique for handwriting with Parkinson’s disease (Letters, 22/29 December 2018). My wife Brenda was most distressed to lose her writing abilities. Using Aris’s method of sounding the letters, she has regained a lot. She was amazed that she could produce a recognisable set of initials on a delivery driver’s pad, something most of us struggle with at the best of times.

Beware the lure of young blood treatments From Roger Lord, Brisbane, Queensland, Australia Early indications that protein in blood from younger individuals can offer hope for people with Parkinson’s and Alzheimer’s are promising (5 January, p 6). I hope

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the proteins responsible are isolated quickly for clinical use. I fear that if they are not, limited stocks of young blood may promote young people being abducted as a source of blood for the old. Vampire devotees and authors of medical horror will have plenty of scope.

A sideways look at the carbon dividend plan From Rick Jefferys, Berkhamsted, Hertfordshire, UK Matthew Benton highlights the potential benefits of a carbon tax and dividend scheme (Letters, 22/29 December 2018). This returns the proceeds to taxpayers and encourages spending on low-carbon purchases. The concept ought to be particularly attractive to US conservatives once they realise that it is effectively a tax on noncitizens, including illegal residents, who will pay the tax on purchases but will not receive the dividend.

For the record Q Vitamin B12 supplements may be synthesised from scratch, derived from animal products or extracted from bacteria (The Last Word, 5 January). Q We are still in the Quaternary Ice Age, and the previous interglacial period within it ended 115,000 years ago (22/29 December 2018, p 54). Q The image by artist Dan Holdsworth was in fact of the Argentière glacier in the Chamonix region of France (15 December 2018, p 28). Q Data point: statistician Joshua Loftus is at New York University (12 January, p 7).

Letters should be sent to: Letters to the Editor, New Scientist, 25 Bedford Street, London, WC2E 9ES Email: [email protected] Include your full postal address and telephone number, and a reference (issue, page number, title) to articles. We reserve the right to edit letters. New Scientist Ltd reserves the right to use any submissions sent to the letters column of New Scientist magazine, in any other format.

54 | NewScientist | 26 January 2019

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1 Split resistor into four terminal leads (4) 3 Star desiccates small objects (8) 9 Boston University to organise most of excavation in African country (7) 10 School revolutionary Asian country about hydrogen (5) 11 The air and climate changed, losing energy, to do with numbers (12) 13 Journalist is working for inventor (6)

15 Pelt church after escape (6) 17 Resistance in devil’s grid is apparent (12) 20 Robot finished covering radius (5) 21 Let room get messy to produce vibration effect (7) 22 After winter blues study, Edward is depressed (8) 23 Inverted central aspect of fungi (4)

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12 Kind piece of DNA somewhat awoken (8) 14 Put topping on carbon, ancient and frigid (3-4) 16 Disease carrier starts to torment statistical epidemiologists twice (6) 18 Community of organisms said to be next to cockney’s house (5) 19 Chances of 6-1, say, or 3-0? (4)

Answers to Quick crossword No26 ACROSS: 1 ERBIUM, 4 OPENCAST, 9 HUXLEY, 10 BURBIDGE, 12 DIAZEPAM, 13 MEGOHM, 15 AXES, 16 METATARSAL, 19 HEAVY METAL, 20 CYAN, 23 SHADOW, 25 WAVEFORM, 27 TRIGONAL, 28 CHROME, 29 GOODYEAR, 30 COSMOS. DOWN: 1 ECHIDNA, 2 BOX CAMERA, 3 USENET, 5 PLUG, 6 NOBLE GAS, 7 AUDIO, 8 THERMAL, 11 LA JETEE, 14 FARADAY, 17 STYROFOAM, 18 CYTOLOGY, 19 HASHTAG, 21 NUMBERS, 22 TECHNO, 24 AMINO, 26 LAVA.

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Answers and the next Quick crossword will be in the 9 February issue.

26 January 2019 | NewScientist | 55

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FEEDBACK

fog filled with angry wasps, a flood of poison frogs, tornadoes of electric eels. Brazilians are cordially reminded that there is no bad weather: just insufficiently plague-proof clothing.

SHE has drawn admiring glances from all over the world, and is said to repay them in kind: visitors to the Louvre often claim Mona Lisa’s gaze seems to follow them around the room. But science is here to show that this isn’t strictly true. A study published in i-Perception

PAUL MCDEVITT

recounts how volunteers looked at the famous painting straight on,

70 newtons of force with its bite, making it 320 times as powerful, pound for pound, as T. rex. Humans, however, have an exceptionally weak bite because our big brains take up the space where larger biting muscles would be. Hopefully the resultant smarts are enough to keep us out of any strong sets of jaws.

IT FEELS like only last week that we were discussing the travails of Dutch whizz-kid Boyan Slat’s plastic collecting boom [It was last week –Ed]. Having recovered it from the Pacific, he may need to deploy the boom closer to home, after a cargo ship spilled some 280 containers off the coast of the Netherlands. The contents of these huge boxes washed ashore across the country’s northerly islands, offering enthusiastic residents a smorgasbord of free shoes, toys, IKEA furniture and slightly sodden large-screen TVs. Which just goes to show that attitudes to ocean plastic vary greatly depending on what that plastic is. Feedback offers a novel means to clean up ocean litter: sprinkle a few high-value items into the Pacific to entice bargain hunters. There is nothing like the lure of a free ODGER dining room chair to get beachcombers out in force.

TWO weeks after declaring war on

Christine Akre – informs us that the discombobulated lyrics offered by

On average, the participants judged her gaze to be looking 15.4 degrees to

the Amazon, Brazil’s new far-right president Jair Bolsonaro was blessed

Google for The Twelve Days Of Christmas are in fact taken verbatim

their right – in other words, just over their shoulder. Perhaps she is

by mother nature with a rain of spiders. Residents of the town of

from an acapella group called Straight No Chaser (22/29 December 2018).

admiring Veronese’s Wedding Feast at Cana, which is hung opposite her?

Espírito Santo do Dourado – named after the patron saint of horrifying arachnid portents, we believe – could only watch as millions of hairy omens fell like soft, eight-legged hail. Hopefully this will be enough of a warning for the current administration to shelve plans for greater development of the rainforest. If not, it is only a matter of time before more threatening meteorological phenomenon are unleashed:

Mystery solved!

A roadside sign tells Julia Butler “Witness littering? Report offenders”. She says “And I thought suborning them was bad.” 56 | NewScientist | 26 January 2019

FINALLY, Jim Logan reports an unlikely discovery in a hotel gift shop. “It was very posh,” he says, the sort where souvenirs come with five-year payment plans. “One item was a ballpoint pen priced at £125.” Querying the value of such a pen, the assistant told him they are made in Switzerland, and the clear piece on the end of the cap was ice chipped from a genuine Swiss glacier. This prompts a very obvious question, which Jim dutifully asked. He was breezily informed that the Swiss use “a special process” to keep the ice solid at room temperature.

ONE of Santa’s little elves – or rather,

then marked the direction of her gaze on a carpenter’s rule in front of them.

TYRANNOSAURUS REX may have had a fearsome bite, but in relation to body size, it was nothing special. After adjusting for size, Darwin’s finches have a more powerful bite, according to a comparative analysis of living and extinct species. A 33-gram finch generates

environmentally damaging crops would fade. If only it were so! The team also found that those who knew the least about GM foods were convinced they knew the most. It is perhaps a lovely example of the Dunning-Kruger effect, in which those with little expertise think they know it all. The only way for these people to be more confidently sceptical of GM technology would be if they had never heard about it at all. Which might be happier for everyone involved.

A STUDY published in Nature Human Behaviour has grilled US residents on their attitudes towards genetically modified foods. It turns out that those most concerned about the dangers of GM foods also knew the least about GM foods. As the authors say: “the less people know, the more opposed they are to scientific consensus.” On the face of it, this ought to be good news, suggesting that by sharing more information about GM foods, opposition to these more nutritious, less

Feedback isn’t sure what is worse: that the great minds behind this Vonnegutian invention have gone unrecognised by the Nobel committee, or that it is being used to sell novelty pens rather than, say, stop the ice caps melting. Then again, you can’t sign a five-year payment plan with an ice cap.

You can send stories to Feedback by email at [email protected]. Please include your home address. This week’s and past Feedbacks can be seen on our website.

Last words past and present at newscientist.com/lastword

THE LAST WORD A key question We keep the key to our holiday cottage in a four-digit key safe by the door. Because of my poor eyesight, I move only one of the digit rotors when I leave, so it is easier to open next time. Most visitors rotate all rotors on leaving. Is my behaviour riskier?

only one rotor means the other three are left in the “open” position. Of course, this assumes the thief knows you have only moved one rotor and indeed that they know which one you moved. But it is you who tells them this. Let us say the thief sees the code is 8519 the first time they visit and 6519 the second. As three digits are identical, they now know that the first rotor is the one to focus on and that the correct digit is not 8 or 6. If you change a different rotor when you leave the second time, you actually make it easier for the thief. Under this condition, they see 8519 the first time and 4517 the second. The clever thief knows

QIf all the rotors were scrambled, a would-be intruder would have a one in 10,000 chance of success at each attempt using only trial and error. However, if they guess that only one rotor has been moved, then their chances improve dramatically. The safe-cracker would choose one rotor and test it at each of the nine other positions. If that didn’t work, “If you move just one rotor they would return the rotor to on the key safe, a thief its original position and repeat could gain access to your the process with the other three. cottage after two visits” The intruder would succeed after a maximum of 36 attempts. We have a key safe and our not to bother with the middle two children also tend to move only rotors, and also that the correct one rotor. It gets worse: they combination is either 8517 or 4519. always move one of the end ones. Sorry, but you need a better I suspect this behaviour is quite security system. common and it would be Pauline Keyne surprising if characters less Beaconsfield, scrupulously honest than myself Buckinghamshire, UK haven’t already worked that out. Having thought this through, QThe rotor type of key safe it looks like it is time for us to generally requires all the numbers switch to a new key system. to be aligned precisely before it Tim McCulloch will open. I would guess that if Hurlstone Park, New South Wales, you are moving only one rotor Australia and your eyesight is poor, you might not align it precisely to QA potential thief will gain easy another number. A careful access to your property after just observer will spot this – so if two visits. That is because moving they experiment with the poorly

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aligned rotor, they will soon be inside your cottage. You may also wish to bear in mind that many people use the year of their birth, or the birth year of one of their children, as their security code. From 15 years of working in social services, I would estimate that about 90 per cent of people do this. Liz Haigh Cardiff, UK QA thoughtful intruder might apply a little psychology and realise that most people don’t scramble the rotors very efficiently. If we assume that each rotor is left within plus or minus two digits of its correct position, that leaves only five positions of each rotor to try. The potential intruder could be in the house within 15 minutes. David Walmsley Wokingham, Berkshire, UK QAs a detective, formerly specialising in burglaries, I know that most burglars have their preferred modus operandi. This is the method they feel confident and competent at, roughly where the potential reward outweighs their perceived risk of getting caught. Some burglars might try rotating just one number, giving up and walking away if this is unsuccessful. If there is a burglar employing this method in your area, your behaviour certainly is riskier than moving all the rotors. Adam Hewitt Guildford, Surrey, UK

The Eagles Are there any large birds that sing melodiously? If not, why not?

QSinging is used to attract mates and assert territorial ownership. The largest birds, such as emus and ostriches, are flightless. Advertising their location by singing would be a poor survival strategy. The largest flying birds tend to be raptors. These have large territories, so singing is an impractical way to communicate. Other large flying birds such as geese and ducks tend to be nonterritorial and often congregate in flocks. Here it would be harder to distinguish the sound of one bird, again making singing impractical. For smaller territorial birds that don’t gather in large numbers, the two major tactics for attracting mates and guarding territory are either song or colourful displays of plumage. Few birds do both well, although the superb lyrebird of Australia, which is about the size of a pheasant, is a candidate. Simon Iveson Callaghan, New South Wales, Australia

This week’s question DUNNY ROAMING

Many workplaces I visit have a row of three toilets. If all three are available and I want to use the least visited – and hopefully cleanest – which should I choose? Maria Clemens Williamstown, Victoria, Australia