A fungus that recently evolved to infect humans is spreading rapidly in health care facilities in the United States and becoming harder to treat, a study from the U.S. Centers for Disease Control and Prevention finds.

Candida auris infections were first detected in the United States in 2013. Each year since, the number of people infected — though still small — has increased dramatically. In 2016, the fungus sickened 53 people. In 2021, the deadly fungus infected 1,471 people, nearly twice the 756 cases from the year before, researchers report March 21 in Annals of Internal Medicine. What’s more, the team found, the fungus is becoming resistant to antifungal drugs.
The rise of cases and antifungal resistance is “concerning,” says microbiologist and immunologist Arturo Casadevall, who studies fungal infections. “You worry because [the study] is telling you what could be a harbinger of things to come.” Casadevall, of Johns Hopkins Bloomberg School of Public Health, was not involved in the CDC study.

In tests of people at high risk of infection, researchers also found 4,041 individuals who carried the fungus in 2021 but were not sick at the time. A small percentage of carriers may later get sick from the fungus, says Meghan Lyman, a medical epidemiologist in the CDC’s Mycotic Diseases Branch in Atlanta, possibly developing bloodstream infections that carry a high risk of death.

Starting in 2012, C. auris infections popped up suddenly in hospitals on three continents, probably evolving to grow at human body temperature as a result of climate change (SN: 7/26/19). The fungus, typically detected through blood or urine tests, usually infects people in health care settings such as hospitals, rehabilitation facilities and long-term care homes. Because people who get infected are often already sick, it can be hard to tell whether symptoms such as fevers are from the existing illness or an infection.
Those most at risk of infection include people who are ill; those who have catheters, breathing or feeding tubes or other invasive medical devices; and those who have repeated or long stays in health care facilities. Healthy people are usually not infected but can spread the fungus to others by contact with contaminated surfaces, including gowns and gloves worn by health care workers, Lyman says.

Growing drug resistance
Infections can be treated with antifungal drugs. But Lyman and colleagues found that the fungus is becoming resistant to an important class of such medications called echinocandins. These drugs are used as both the first line and the last line of defense against C. auris, says Casadevall.

Before 2020, six people were known to have echinocandin-resistant infections and four other people had infections resistant to all three class of existing antifungal drugs. That resistance developed during treatment using echinocandin. None of those cases passed the resistant strain to others. But in 2021, 19 people were diagnosed with echinocandin-resistant infections and seven with infections resistant to multiple drugs.

More concerning, one outbreak in Washington, D.C., and another in Texas suggested people could transmit the drug-resistant infections to each other. “Patients who had never been on echinocandins were getting these resistant strains,” Lyman says.

Some health care facilities have been able to identify cases early and prevent outbreaks. “We’re obviously very concerned,” Lyman says, “but we are encouraged by these facilities that have had success at containing it.” Using those facilities’ infection control measures may help limit cases of C. auris, she says, as well as reducing spread other fungal, bacterial and viral pathogens.

Uracil, a building block of life, has been found on the asteroid Ryugu.

Yasuhiro Oba and colleagues discovered the precursor to life in samples collected from the asteroid and returned to Earth by Japan’s Hayabusa2 spacecraft, the team reports March 21 in Nature Communications.

“The detection of uracil in the Ryugu sample is very important to clearly demonstrate that it is really present in extraterrestrial environments,” says Oba, an astrochemist at Hokkaido University in Sapporo, Japan.
Uracil had been previously detected in samples from meteorites, including a rare class called CI-chondrites, which are abundant in organic compounds. But those meteorites landed on Earth, leaving open the possibility they had been contaminated by humans or Earth’s atmosphere. Because the Ryugu samples were collected in space, they are the purest bits of the solar system scientists have studied to date (SN: 6/9/22). That means the team could rule out the influence of terrestrial biology.

Oba’s team was given only about 10 milligrams of the Ryugu sample for its analysis. As a result, the researchers were not confident they would be able to detect any building blocks, even though they’d been able to previously detect uracil and other nucleobases in meteorites (SN: 4/26/22).

Nucleobases are biological building blocks that form the structure of RNA, which is essential to protein creation in all living cells. One origin-of-life theory suggests RNA predated DNA and proteins and that ancient organisms relied on RNA for the chemical reactions associated with life (SN: 4/4/04).
The team used hot water to extract organic material from the Ryugu samples, followed by acid to further break chemical bonds and separate out uracil and other smaller molecules.

Laura Rodriguez, a prebiotic chemist at the Lunar and Planetary Institute in Houston, who was not involved in the study, says this method leaves the possibility that the uracil was separated from a longer chain of molecules in the process. “I think it’d be interesting in future work to look at more complex molecules rather than just the nucleobases,” Rodriguez says.

She says she’s seen in her research that the nucleobases can form bonds to create more complex structures, such as a possible precursor to the nucleic acid which may lead to RNA formation. “My question is, are those more complex structures also forming in the asteroids?”

Oba says his team plans to analyze samples from NASA’s OSIRIS-REX mission, which grabbed a bit of asteroid Bennu in 2020 and will return it to Earth this fall (SN: 10/21/20).

SAN DIEGO — Marijuana use during teenage years may change the brain in key decision-making areas, a study in rats suggests.

“Adolescence is a dangerous time to be insulting the brain, particularly with drugs of abuse,” study coauthor Eliza Jacobs-Brichford said November 7 at the annual meeting of the Society for Neuroscience.

Jacobs-Brichford and colleagues gave adolescent male and female rats a marijuana-like compound. Afterward, the researchers found changes in parts of the brain involved in making decisions.
Normally, many of the nerve cells there are surrounded by rigid structures called perineuronal nets, sturdy webs that help stabilize connections between nerve cells. But in male rats that had been exposed to the marijuana-like compound in adolescence, fewer of these nerve cells, which help put the brakes on other cells’ activity, were covered by nets. Drug exposure didn’t seem to affect the nets in female rats.

“Males look more susceptible to these drugs,” said Jacobs-Brichford, a behavioral neuroscientist at the University of Illinois at Chicago.

There’s something big lurking beneath Greenland’s ice. Using airborne ice-penetrating radar, scientists have discovered a 31-kilometer-wide crater — larger than the city of Paris — buried under as much as 930 meters of ice in northwest Greenland.

The meteorite that slammed into Earth and formed the pit would have been about 1.5 kilometers across, researchers say. That’s large enough to have caused significant environmental damage across the Northern Hemisphere, a team led by glaciologist Kurt Kjær of the University of Copenhagen reports November 14 in Science Advances.
Although the crater has not been dated, data from glacial debris as well as ice-flow simulations suggest that the impact may have happened during the Pleistocene Epoch, between 2.6 million and 11,700 years ago. The discovery could breathe new life into a controversial hypothesis that suggests that an impact about 13,000 years ago triggered a mysterious 1,000-year cold snap known as the Younger Dryas (SN: 7/7/18, p. 18).
Members of the research team first spotted a curiously rounded shape at the edge of Hiawatha Glacier in northwest Greenland in 2015, during a scan of the region by NASA’s Operation IceBridge. The mission uses airborne radar to map the thickness of ice at Earth’s poles. The researchers immediately suspected that the rounded shape represented the edge of a crater, Kjær says.
For a more detailed look, the team hired an aircraft from Germany’s Alfred Wegener Institute that was equipped with ultra-wideband radar, which can send pulses of energy toward the ice at a large number of frequencies. Using data collected from 1997 to 2014 from Operation Icebridge and NASA’s Program for Arctic Regional Climate Assessment, as well as 1,600 kilometers’ worth of data collected in 2016 using the ultra-wideband radar, the team mapped out the inner and outer contours of their target.

The object is almost certainly an impact crater, the researchers say. “It became clear that our idea had been right from the beginning,” Kjær says. What’s more, it is not only the first crater found in Greenland, but also one of the 25 or so largest craters yet spotted on Earth. And it has held its shape beautifully, from its elevated rim to its bowl-shaped depression.

“It’s so conspicuous in the satellite imagery now,” says John Paden, an electrical engineer at the University of Kansas in Lawrence and a member of the team. “There’s not another good explanation.”

On the ground, the team hunted for geochemical and geologic signatures of an asteroid impact within nearby sediments. Sampling from within the crater itself was impossible, as it remains covered by ice. But just beyond the edge of the ice, meltwater from the base of the glacier had, over the years, deposited sediment. The scientists collected a sediment sample from within that glacial outwash and several from just outside of it.

The outwash sample contained several telltale signs of an impact: “shocked” quartz grains with deformed crystal lattices and glassy grains that may represent flash-melted rock. The sample also contained elevated concentrations of certain elements, including nickel, cobalt, platinum and gold, relative to what’s normally found in Earth’s crust. That elemental profile points not only to an asteroid impact, the researchers say, but also suggests that the impactor was a relatively rare iron meteorite.
Determining when that iron meteorite slammed into Earth is trickier.
The ice-penetrating radar data revealed that the crater bowl itself contains several distinct layers of ice. The topmost layer shows a clear, continuous sequence of smaller layers of ice, representing the gradual deposits of snow and ice through the most recent 11,700 years of Earth’s history, known as the Holocene. At the base of that “well-behaved” layer is a distinct, debris-rich layer that has been seen elsewhere in Greenland ice cores, and is thought to represent the Younger Dryas cold period, which spanned from about 12,800 to 11,700 years ago. Beneath that Younger Dryas layer is another large layer — but unlike the Holocene layer, this one is jumbled and rough, with undulating rather than smooth, nearly flat smaller layers.

“You see folding and strong disturbances,” says study coauthor Joseph MacGregor, a glaciologist with Operation IceBridge. “And below that, we see yet deeper, complex basal ice.” Radar images of that bottommost ice layer within the crater show several curious peaks, which MacGregor says could represent material from the ground that got incorporated into the ice. “Putting that all together, what you have is a snapshot of an ice sheet that looked fairly normal during the Holocene, but was quite disturbed before that.”

Those data clearly suggest that the impact is at least 11,700 years old, Kjær says. And the rim of the crater appears to cut through a preexisting ancient river channel that must have flowed across the land before Greenland became covered with ice about 2.6 million years ago.

That time span — essentially, the entire Pleistocene Epoch — is a large range. The team is working on further narrowing the possible date range, with more sediment samples, simulations of the rate of ice flow and possibly cores collected from within the crater.

The date range does include the possibility that the impact occurred near the onset of the Younger Dryas. “It’s the woolly mammoth in the room,” MacGregor says.
Planetary scientist Clark Chapman of the Southwest Research Institute in Boulder, Colo., notes that “there are plenty of roughly circular landforms on Earth of many different sizes, most of which are not impact craters.” Still, he says, the paper presents several lines of evidence that strongly support the conclusion that the object is a crater, including the shocked quartz and the topography.

As for the idea that a crater may have formed within the last couple of million years, Chapman says, it’s “quite unlikely.” Such strikes are rare in general, he adds, and asteroids barreling into Earth are far more likely to land somewhere in an ocean. “[And] it would be at least a hundred times less likely that it could have happened so recently as to have affected the Younger Dryas.”

Regardless of when the crater formed, it is “a straight-up exciting discovery,” MacGregor says. “And we’re just happy not to have to keep it a secret anymore.”

DENVER — Three jugs placed as offerings in a roughly 3,600-year-old tomb in Israel have revealed a sweet surprise — evidence of the oldest known use of vanilla.

Until now, vanilla was thought to have originated in Mexico, perhaps 1,000 years ago or more. But jugs from the Bronze Age site of Megiddo contain remnants of two major chemical compounds in natural vanilla extract, vanillin and 4-hydroxybenzaldehyde, said archaeologist Vanessa Linares of Tel Aviv University in Israel. Chemical analyses also uncovered residues of plant oils, including a component of olive oil, in the three jugs.
“Bronze Age people at Megiddo may have used vanillin-infused oils as additives for foods and medicines, for ritual purposes or possibly even in the embalming of the dead,” Linares said. She described these findings at the annual meeting of American Schools of Oriental Research on November 16.

Vanillin comes from beans in vanilla orchids. About 110 species of these flowers are found in tropical areas around the world. The chemical profile of the vanillin in the Megiddo jugs best matches present-day orchid species in East Africa, India and Indonesia, Linares said.

Extensive Bronze Age trade routes likely brought vanillin to the Middle East from India and perhaps also from East Africa, she suggested.

“It’s really not surprising that vanillin reached Bronze Age Megiddo given all the trade that occurred between the [Middle East] and South Asia,” says archaeologist Eric Cline of George Washington University in Washington, D.C. But no evidence exists of trade at that time between Middle Eastern societies and East Africa, says Cline, who did not participate in the Megiddo research.
Vanilla orchids or their beans probably reached Megiddo via trade routes that first passed through Mesopotamian society in southwest Asia. However Bronze Age Middle Easterners ended up with those products, discoveries at Megiddo challenge the idea that vanilla use originated only in Mexico and then spread elsewhere, Cline says.

The vanillin-containing jugs at Megiddo came from a tomb of three “highly elite” individuals who were interred with six other people of lesser social rank, said archaeologist Melissa Cradic of the University of California, Berkeley, a member of the current Megiddo research team. Excavations uncovered the tomb in 2016, Cradic also reported at the ASOR meeting.

Primary burials in the tomb consist of an adult female, an adult male and an 8- to 12-year-old boy. Elaborate types of bronze, gold and silver jewelry were found on and around the three skeletons. Exact replicas of several pieces of jewelry appeared on each individual.

The tomb lies in an exclusive part of Megiddo near a palace and a monumental city gate.

“We can’t definitively say that these three people were royals,” Cradic said. “But they were elites in Megiddo and may have belonged to the same family.”

The next NASA Mars rover will hunt for signs of ancient life in what used to be a river delta, the agency announced on November 19.

The rover is expected to launch in July 2020 and to land on Mars around February 18, 2021. It will seek out signs of past life in the sediments and sands of Jezero crater, which was once home to a 250-meter-deep lake and a river delta that flowed into the lake.
“This is a major attraction from our point of view for a habitable environment,” said Mars 2020 project scientist Ken Farley of Caltech in a news conference discussing the site. “A delta is extremely good at preserving biosignatures.” Any evidence of life that may once have existed in the lake water, or even evidence that came from the river’s headwaters and flowed downstream, could be preserved in the rocks that are there today.

The 2020 rover’s design is similar to that of the Curiosity rover, which has been exploring a different ancient crater lake, Gale crater, since 2012 (SN: 5/2/15, p. 24). But where Curiosity has an onboard chemistry lab for studying the rocks and minerals in its crater, Mars 2020 will have a specialized backpack for sample storage. A future mission will pick up the cached samples and return them to Earth for more detailed study, possibly sometime in the 2030s.

“The samples will come back to the best labs — not the best labs we have today, but the best labs we will have then,” said science mission directorate administrator Thomas Zurbuchen of NASA headquarters in Washington, D.C.

Mars 2020 will also use a souped-up version of Curiosity’s landing system called Sky Crane, in which a hovering platform lowers the rover onto the ground with a cable. Mars 2020’s version will include a navigation system that will help it avoid hazards on the ground, like cliff faces and boulders.
Jezero crater is within striking distance of another site on scientists’ wish list. That region, called Midway, is just 28 kilometers away from Jezero and contains some of the most ancient rocks on Mars. At the final landing site selection workshop in October, scientists floated the idea of visiting both sites in one mission, a feat seen as ambitious but achievable. But a decision on that will have to wait until after the rover is safely on Mars, Farley said.

Mysterious particles called neutrinos constantly barrel down on Earth from space. No one has known where, exactly, the highest-energy neutrinos come from. This year, scientists finally put a finger on one likely source: a brilliant cosmic beacon called a blazar. The discovery could kick-start a new field of astronomy that combines information gleaned from neutrinos and light.

It began with one high-energy neutrino spotted on September 22, 2017, by the IceCube observatory, a giant particle detector with thousands of sensors buried deep in the ice at the South Pole. Alerted by IceCube, astronomers soon spotted a flare from a blazar about 4 billion light-years away. The neutrino had come from the same area of the sky. With that matchup in time and space between the neutrino and the blazar’s light, scientists in 2018 pegged the blazar as the particle’s probable source (SN: 8/4/18, p. 6).

“People have been hoping for this kind of discovery for decades,” says astrophysicist Meg Urry of Yale University.
Blazars are active regions at the centers of galaxies that spew jets of high-energy matter and light toward Earth. Both the Earth-orbiting Fermi Gamma-ray Space Telescope and the Major Atmospheric Gamma Imaging Cherenkov, or MAGIC, telescopes in the Canary Islands reported that the blazar was violently flaring up in gamma rays, a type of high-energy light, at about the same time the neutrino was detected.

After combing through old data, IceCube researchers found evidence of even more neutrinos from near the blazar’s location in the sky. With those extra neutrinos, the researchers were finally convinced that the blazar birthed neutrinos.
Not only did the detection hint at the source of at least some high-energy spacefaring particles, it also taught physicists a few things about blazars. Scientists weren’t sure what kinds of particles blazars emit, but the detection reveals that the jets contain protons. That’s because scientists know that any neutrino from a blazar would have to be produced in combination with protons.

The discovery, scientists say, could invigorate a nascent field, dubbed multimessenger neutrino astronomy, to reveal secrets of the cosmos, whether from blazars or other sources. Now, says astrophysicist Kohta Murase of Penn State, “we can use neutrinos as very important probes” to learn more about the objects that spit them out. For example, researchers might spot neutrinos from a collision of two neutron stars, like the one detected by the Advanced Laser Interferometer Gravitational-Wave Observatory, LIGO, in 2017 (SN: 11/11/17, p. 6). IceCube didn’t see any neutrinos from that event, but astrophysicists are hopeful that future neutron star smashups will produce a neutrino bounty.

Before scientists are fully confident that blazars can blast out high-energy neutrinos, researchers need to spot more of the wily particles, Murase says. To improve detection, an upgrade to IceCube will make the detector 10 times bigger in volume and should be ready by the mid-2020s, says Francis Halzen, leader of IceCube and an astrophysicist at the University of Wisconsin–Madison. If all goes well, the tiny particles may soon be revealing secrets from new corners of the cosmos.

Cleaning up ocean pollution is no simple task, as an effort to fish plastic out of the Pacific Ocean is revealing.

In September, scientists launched a 600-meter-long boom meant to herd plastic debris from the great Pacific garbage patch into a net (SN Online: 9/7/18). The trash accumulation, which is twice the size of Texas, swirls in waters between California and Hawaii.

But some scientists worry the system, designed by a Dutch organization called Ocean Cleanup, could harm marine wildlife. Others aren’t convinced it will even work. Four months in, some of those concerns appear to be founded: Wind and currents have pushed trash into the rig, but the setup hasn’t kept the trash corralled as planned. Now part of the rig has broken off, and the device is being towed back to shore for repairs and design tweaks.
Whether the system will eventually help remove garbage from the Pacific remains to be seen. But it’s not the only option for reducing how much plastic is dumped in the oceans — now at some 5 trillion pieces, per some estimates. Here are a few other approaches seeing success.

1. Meet Mr. Trash Wheel and friends
   It’s easier to collect trash from rivers and streams than from the open ocean. Baltimore has deployed three giant waterwheels that trap river plastic before it flows into the harbor.
   The first installation, adorned with googly eyes and dubbed Mr. Trash Wheel, debuted in 2014, followed by Professor Trash Wheel in 2016 and Captain Trash Wheel in 2018. Collectively, the wheels so far have removed more than 680,000 kilograms of trash.

Mr. Trash Wheel wasn’t immediately successful, though, says Adam Lindquist, director of Baltimore’s Healthy Harbor Initiative. A waterwheel installed in 2008 didn’t work well. He suggests that the Ocean Cleanup group, in tweaking its device, could also see improvements — though clearing plastic from the ocean is certainly a bigger job than cleaning a river, he says.

2. Snag it on land
   Collecting debris as it’s washed onto beaches is another way to tackle the plastic problem. “Lots of published papers show the ocean spits out trash really quickly,” says Marcus Eriksen, an environmental scientist and cofounder of the 5 Gyres Institute based in Los Angeles.

The U.S. National Oceanic and Atmospheric Administration’s Marine Debris Program, for example, has collected more than 450 tons of garbage from the Alaska shoreline since 2006.

3. Rise of the bans
   Using less plastic in the first place is the most straightforward way to cut down on ocean pollution. Many cities and 127 countries have imposed regulations on single-use plastic, such as grocery bags or plastic straws, according to a December report from the U.N. Environment Program.

These restrictions can make a difference. In 2010, thousands of volunteers collecting and tallying garbage along the California coast found that 7 percent of the trash consisted of plastic bags. In 2017, after multiple California cities imposed plastic bag bans or restrictions, the bags made up less than 2 percent of trash gathered.

Bans can also fight debris that the Ocean Cleanup’s system won’t snag — microplastics, tiny fragments that can harm the health of people and other animals. The United States banned microbeads in personal care products starting in 2017; the European Union has voted to enact a similar ban by 2020.

4. Rethink the cycle
   Plastic can take decades or even centuries to break down, so some scientists are working on alternatives that are easier to recycle. For example, a type of recyclable plastic described in Science in 2018 can be broken down into component pieces and rebuilt again and again (SN: 5/26/18, p. 12). But if recyclable plastic ends up in a landfill or in the ocean, those special properties won’t matter.

“There’s a really big gap between what can be recycled in a perfect world, and what actually gets recycled,” says Miriam Goldstein, the director of ocean policy at the Center for American Progress, a research and lobbying organization in Washington, D.C. Bridging that gap isn’t as simple as telling people to use less plastic, she says. “You cannot opt out of single-use plastics in most of the country,” and lots of products are designed in ways that make them challenging to properly recycle.

That’s one reason why an approach called extended producer responsibility is gaining popularity — essentially, holding companies that make plastic products responsible for the cost of proper disposal. “If you’re going to make anything, you need to think of the recovery,” Eriksen says. Putting a financial burden on the producer provides an incentive for designing products that are easier to recycle or reuse. One example: using just one type of plastic instead of combining plastics that would then need to be separated for proper recycling.

The fishing industry also needs incentives to join in the cleanup, Eriksen says. Surveys of detritus that washes ashore suggest that a substantial portion is left by fishers. Giving them a financial reason to retrieve old nets and buoys could help keep our oceans clean.

Quantum physics has earned a reputation as a realm of science beyond human comprehension. It describes a microworld of perplexing, paradoxical phenomena. Its equations imply a multiplicity of possible realities; an observation seems to select one of those possibilities for accessibility to human perception. The rest either disappear, remain hidden or weren’t really there to begin with. Which of those explanations pertains is debated by competing interpretations of the quantum math, pursued in a field of study known as quantum foundations.

Numerous quantum interpretations have been proposed — and an even greater number of books have been written about them. Two of the latest such books offer very different perspectives.
Philip Ball, in Beyond Weird, argues that much of the famous quantum weirdness lies in the popular descriptions of it, rather than in the math itself. Adam Becker’s What is Real? insists that the traditional “Copenhagen interpretation” is misguided; he extols the work of several physicists who reject it. Becker writes with exuberance and self-assuredness, often focusing on the personal stories of the scientists he discusses. Ball’s approach is less personal but more conversational, although he does not try to evade the sticky technicalities that illustrate and partially explain the quantum mysteries.
Ball contends that many of the analogies and illustrations used by popularizers (and physicists) to convey the weirdness of quantum theory (like a particle being in two places at once) are actually misleading. With less flamboyant phrasing, in Ball’s view, quantum physics can seem less perplexing, even almost understandable.

Without fully endorsing it, Ball gives a fairly sound presentation of the Copenhagen interpretation, based on the ideas of the Danish physicist Niels Bohr. Bohr held that quantum reality cannot be described apart from the experiments designed to probe it. A particle has many possible locations before you experimentally observe it; once observed, the location is established and the other possibilities vanish. And an electron will seem to behave as a particle or wave, depending on what sort of experimental apparatus you use to observe it.

Bohr expressed these truths by a principle he called complementarity — mutually exclusive concepts (such as wave or particle) are required to explain reality, but both concepts cannot be observed in any individual experiment. Bohr’s elaborations on this idea are famously convoluted and expressed rather obscurely. (When asked what is complementary to truth, Bohr replied, “clarity.”)

Bohr’s lack of clarity has led to many misinterpretations of what he meant, and it is those misinterpretations that Becker criticizes, rather than Bohr’s actual views. Becker’s main argument insists that the Copenhagen interpretation embraces the philosophy known as positivism (roughly, nothing unobservable is real, and sensory perceptions are the realities on which science should be based), and then demonstrates positivism’s fallacies. He does a fine job of demolishing positivism. Unfortunately, the Copenhagen interpretation is not positivistic, as its advocates have often pointed out. Bohr’s colleague Werner Heisenberg said so quite clearly: “The Copenhagen interpretation of quantum theory is in no way positivistic,” he wrote. And the philosopher Henry Folse’s 1985 book on Bohr’s philosophy thoroughly dispelled the mistaken belief that Bohr’s view was positivistic or opposed to the existence of an underlying reality.

Becker’s book commits many other more specific errors. He says Heisenberg found his famous uncertainty principle “buried in the mathematics of [Erwin] Schrödinger’s wave mechanics.” But Heisenberg despised wave mechanics and did his work on uncertainty wholly within his own matrix mechanics. Becker claims that physicists Murray Gell-Mann and James Hartle “had long been convinced that the Copenhagen interpretation had to be wrong.” But Gell-Mann and Hartle are on record stating that the Copenhagen view is not wrong, merely limited to special cases and not general enough to tell the whole quantum story.

Becker’s book does offer engaging discussions of the physicists who have questioned Bohr’s ideas and proposed alternate ways of interpreting quantum physics. But he allows the opponents to frame Bohr’s position rather than devoting any effort of his own to examining the subtlety and depth of Bohr’s philosophy and arguments. And Becker fails to address the important point that every quantum experiment’s results, no matter how bizarre, are precisely what Bohr would have expected them to be.

Becker does not engage deeply with the more recent body of work on quantum foundations, an area where Ball excels. Ball especially favors the perspective on quantum physics offered by the notion of quantum decoherence. Very roughly, the decoherence process dissipates various possible quantum realities into the environment, and only those versions of reality that are robustly recorded in the environment present themselves to observers. It’s of course much more complicated than that, and Ball admirably conveys those complications even at the occasional expense of clarity. Which puts his account closer to the truth.

Like a quantum version of a whirling top, protons have angular momentum, known as spin. But the source of the subatomic particles’ spin has confounded physicists. Now scientists have confirmed that some of that spin comes from a frothing sea of particles known as quarks and their antimatter partners, antiquarks, found inside the proton.

Surprisingly, a less common type of antiquark contributes more to a proton’s spin than a more plentiful variety, scientists with the STAR experiment report March 14 in Physical Review D.
Quarks come in an assortment of types, the most common of which are called up quarks and down quarks. Protons are made up of three main quarks: two up quarks and one down quark. But protons also have a “sea,” or an entourage of transient quarks and antiquarks of different types, including up, down and other varieties (SN: 4/29/17, p. 22).

Previous measurements suggested that the spins of the quarks within this sea contribute to a proton’s overall spin. The new result — made by slamming protons together at a particle accelerator called the Relativistic Heavy Ion Collider, or RHIC — clinches that idea, says physicist Elke-Caroline Aschenauer of Brookhaven National Lab in Upton, N.Y., where the RHIC is located.

A proton’s sea contains more down antiquarks than up antiquarks. But, counterintuitively, more of the proton’s spin comes from up than down antiquarks, the researchers found. In fact, the down antiquarks actually spin in the opposite direction, slightly subtracting from the proton’s total spin.

“Spin has surprises. Everybody thought it’s simple … and it turns out it’s much more complicated,” Aschenauer says.
Editor’s note: This story was updated April 3, 2019, to correct the subheadline to say that up antiquarks (not up quarks) add more angular momentum than do down antiquarks (not down quarks).