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Enlarge / Air pollution in China apparently includes a dash of banned ozone-depleting CFCs. (credit: NASA Earth Observatory)

A couple months ago, an atmospheric study revealed that someone had started producing an ozone-depleting pollutant that had been banned under an international agreement to protect the ozone layer. The new source was preventing the chemical from dissipating on schedule. Although the researchers were careful about what they could conclude from regional measurements, they found that eastern Asia was likely the source.

Now, a UK-based NGO called the Environmental Investigation Agency (EIA) says that it has uncovered a number of Chinese companies that are responsible. If you’re expecting an elaborate infiltration and undercover sting... adjust your expectations. The investigation seems to have been shockingly easy, with the culprits’ representatives strangely amenable to detailing their illegal operations.

Mystery solved through Google

The EIA started with a simple Internet search, which turned up a few companies that were apparently advertising sales of the banned chemical, known as CFC-11. Like other CFCs, 11 can be used as a refrigerant or a propellant in aerosol spray cans. But it was also widely use to “inflate” foam insulation, and that seems to be the market where at least some of its illicit use has continued.

Enlarge (credit: DeepMind)

New research from Google's UK-based DeepMind subsidiary demonstrates that deep neural networks have a remarkable capacity to understand a scene, represent it in a compact format, and then "imagine" what the same scene would look like from a perspective the network hasn't seen before.

Human beings are good at this. If shown a picture of a table with only the front three legs visible, most people know intuitively that the table probably has a fourth leg on the opposite side and that the wall behind the table is probably the same color as the parts they can see. With practice, we can learn to sketch the scene from another angle, taking into account perspective, shadow, and other visual effects.

A DeepMind team led by Ali Eslami and Danilo Rezende has developed software based on deep neural networks with these same capabilities—at least for simplified geometric scenes. Given a handful of "snapshots" of a virtual scene, the software—known as a generative query network (GQN)—uses a neural network to build a compact mathematical representation of that scene. It then uses that representation to render images of the room from new perspectives—perspectives the network hasn't seen before.

Enlarge (credit: Aaron Jacobs)

Anyone who has tried to pull a late-night study session and wound up rereading the same pages of their textbook because they couldn't focus has experienced it. And countless studies confirm it: if you're sleep deprived, your brain starts functioning poorly. Your reaction times slip, you are more prone to careless actions, and you generally just get bad at things. But how is it your body registers "too little sleep"? It could be after you spend too much time awake. Or it could be the amount of sleep you get in a 24-hour period. Or it could be tracked in relationship to your body's internal 24-hour circadian clock.

A new study out this week suggests it's not just one of these things, and different aspects of our mental capacities are either more sensitive or less sensitive depending on how we end up short on sleep.

Deprived

The challenge with separating out different aspects of sleep deprivation in the real world is that anything you do will involve multiple aspects of sleep. Get too little sleep during a 24-hour cycle, which means more awake time—and awake at times your circadian clock says you shouldn't be. So, the researchers behind the new work messed with people's clocks. They got a small group of people (because it would be hard to recruit a large one) to live at a sleep center for 32 days, cut off from any indication of outside time.

Enlarge / The latest satellite measurements of ozone from May 14 show the "hole" that still exists over the South Pole. (credit: NASA Ozone Watch)

The Montreal Protocol—a 1987 international agreement to end production of ozone-destroying chemicals like freon—seems miraculous compared to the long struggle to achieve meaningful action on climate change. Even more astonishing is that the agreement has worked. Those chemicals (known as CFCs) take a long time to flush out of the atmosphere, but monitoring has shown that the flushing is proceeding largely according to plan.

That keeps the hole in the ozone layer on track to shrink over the coming decades. However, a new study shows that someone has been cheating in the last few years.

A group of researchers led by Stephen Montzka of the US National Oceanic and Atmospheric Administration had been tracking the progress of CFCs and noticed something off with CFC-11. This chemical has been used as a refrigerant, solvent, and propellant for aerosol spray cans, as well as in the production of styrofoam. As with the other CFCs, nations agreed to end production of CFC-11 entirely. While there may still be some older machines leaking CFC-11, these sources should gradually disappear over time, allowing the decline of its atmospheric concentration to accelerate.

NASA/JPL-Caltech/SwRI/ASI/INAF/JIRAM

Scientists studying data from NASA's Juno spacecraft have published a trove of papers in Nature this week, making a number of intriguing and surprising findings about the atmosphere of the largest planet in our Solar System. The papers are summarized and linked in this NASA news release.

Some of the most striking discoveries come from visible and infrared observations made by Juno during its first five science passes in its elongated orbit around Jupiter. (The spacecraft entered Jupiter's orbit on July 4, 2016. It will make its 11th pass on April 1.) In these initial passes, scientists found clusters of strange and long-lasting cyclones orbiting the north and south poles of Jupiter.

Enlarge / But nobody can explain Welsh. (credit: flickr user: Groundhopping Merseburg)

A funny thing happens to languages that have huge numbers of speakers: over time, they seem to simplify. They lose all the fiddly bits that make languages like Hungarian so incredibly hard to learn, and instead become more regular and grammatically simple.

But at the same time that the grammatical challenge of these languages shrinks, their vocabulary explodes. This leaves a mystery for researchers who study how language structures emerge in humans: why does population size seem to drive increased complexity in vocabulary but reduced complexity in grammar? There are some intuitive answers to this question, but we need to confirm whether those intuitions are backed up by data.

Evolutionary linguists Florencia Reali, Nick Chater, and Morten Christiansen have used a computational simulation to suggest an answer: the two different kinds of complexity are very different in how easy they are to learn, and they're passed on to others through conversation. Their results imply that “language, and possibly other aspects of culture, may become simpler at the structural level as our world becomes increasingly interconnected,” they write.

Enlarge / Sequence on a stick. (credit: Oxford Nanopore)

A few years back, a company called Oxford Nanopore announced it was developing a radically different way of sequencing DNA. Its approach involved taking single strands of the double helix and stuffing them through a protein pore. With a small bit of current flowing across the pore, the four bases of DNA each created a distinct (if tiny) change in the voltage as it passed through. These could be used to read the DNA one base at a time as it wiggled through the pore.

After several years of slow progress, Oxford Nanopore announced that its sequencing hardware would be as distinctive as its wetware: a USB device that could fit comfortably in a person's hand. As the first devices went out to users, it became clear that the device had some pros and cons. On the plus side, the device was quick and could be used without requiring a large facility to support it. It could also read very long stretches of DNA at once. But the downside was significant: it made lots of mistakes.

With a few years of experience, people are now starting to learn to make the most of the devices, as demonstrated by a new paper in which researchers use it to help sequence a human genome. By using the machine's long reads—in one case, nearly 900,000 bases from one DNA molecule—the authors were able to get data out of areas of the human genome that resisted characterization before. And they were able to distinguish between the two sets of chromosomes (one from mom, one from dad) and locate areas of epigenetic control in many areas of the genome.

Enlarge (credit: Brigham Young University)

All sorts of 3D-imaging technologies tend to get lumped under the label "hologram." But there's actually a variety of distinct technologies that can create the appearance of depth. Now, we can add another to the list: the photophoretic-trap volumetric display. The device uses one set of optical hardware to control the motion of a tiny sphere and a second set to illuminate the sphere as it travels. Provided the sphere can be kept moving fast enough, the result is a true-color image that has real depth since it's built from light reflected from different locations.

The downside is that a single sphere can't cover all that much ground in the amount of time our brain needs to construct an image. As a result, photophoretic-trap volumetric display is currently limited to either small images or showing only part of an image at a time.

The recent work, from a team at Brigham Young University, is a variation on volumetric displays. These involve projecting a changing image onto a moving reflective surface. If the change in the image is properly matched to the changing location of where it's projected, the result will be the appearance of depth, since the light you see will actually be reflected at different locations. On the plus side, this doesn't require the viewer to wear any hardware, and multiple people can view the image at the same time, each seeing it from the appropriate perspective.

Enlarge / Picture shows a woman about to sneeze holding a handkerchief in her hand. (credit: Getty | Bettmann)

Ah… AHHH… Choose wisely when it comes to handling that impending sneeze. Holding one in can lead to some serious damage, British doctors report Monday in BMJ Case Reports.

In their rare-disease case report, they relay the tale of an otherwise healthy 34-year-old male who managed to tear a hole in the back of his throat trying to extinguish a snot explosion.

The man showed up in an emergency room with an alarming popping sensation and swelling in his throat. He was also in terrible pain and could barely talk. Subsequent X-rays and CT scans revealed that he had bubbles of air throughout his neck, including along his spine. The doctors also noted a crackling, grating sound coming from both sides of his throat down to his chest, which is a sign of gas trapped inside tissue.

Enlarge / The Voyager team is able to use a set of four backup thrusters, dormant since 1980. They are located on the back side of the spacecraft in this orientation. (credit: NASA/JPL-Caltech)

At present, the Voyager 1 spacecraft is 21 billion kilometers from Earth, or about 141 times the distance between the Earth and Sun. It has, in fact, moved beyond our Solar System into interstellar space. However, we can still communicate with Voyager across that distance.

This week, the scientists and engineers on the Voyager team did something very special. They commanded the spacecraft to fire a set of four trajectory thrusters for the first time in 37 years to determine their ability to orient the spacecraft using 10-millisecond pulses.

After sending the commands on Tuesday, it took 19 hours and 35 minutes for the signal to reach Voyager. Then, the Earth-bound spacecraft team had to wait another 19 hours and 35 minutes to see if the spacecraft responded. It did. After nearly four decades of dormancy, the Aerojet Rocketdyne manufactured thrusters fired perfectly.

Enlarge (credit: Adapted from an image created by Dennis Sun, Mezarque Design)

To the best of our ability to tell, everything on Earth shares a few common features. It encodes information in DNA using four bases, A, T, C, and G. Sets of three consecutive bases are used to code for a single amino acid, and most organisms use a set of 20 amino acids to build proteins. These features appear everywhere, from plants and animals to bacteria and viruses, suggesting that they appeared in the last common ancestor of life on Earth.

This raises a question that comes up a lot in evolutionary studies: are these features used because they're in some way efficient, or did we end up stuck with them as a result of some historic accident?

A team of California-based researchers has been building an argument that it's an accident. And it's doing so by expanding life beyond the limitations inherited from its common ancestor. After having expanded the genetic alphabet to six letters, the team has now engineered a bacterial strain that uses the extra letters to put an unnatural amino acid into proteins.

Enlarge / Don't mind us, just performing some alchemy here. (credit: NOAA)

Thunderstorms have a lot of overt indications of power, from the thunder and lightning to torrential rains and hail. But the full extent of their power wasn't obvious until recent years, when we discovered they generate antimatter. Now, researchers in Japan have looked at this phenomenon more closely and determined that a lightning bolt generates a zone that contains unstable isotopes of oxygen and nitrogen, leading to series of radioactive decays over the next minute.

Transformative

All of these phenomena are powered by the fact that the electric fields within thunderstorms are able to accelerate electrons to extremely high energies. Whenever these electrons move along a curved path, they emit radiation that's proportional to their energy. As a result, a storm can be associated with bursts of gamma rays, extremely high-energy photons.

Gamma rays rays are primarily noted for their interaction with the electrons of any atoms they run into—it's why they're lumped in the category of ionizing radiation. But they can also interact with the nucleus of the atom. With sufficient energy, they can kick out a neutron from some atoms, transforming them into a different isotope. Some of the atoms this occurs with include the most abundant elements in our atmosphere, like nitrogen and oxygen. And, in fact, elevated neutron detections had been associated with thunderstorms in the past.

Enlarge / Those dark streaks come and go with the seasons. We still don't know what causes them. (credit: NASA/JPL-Caltech/Univ. of Arizona)

Mars clearly had extensive water in the past, and there's still plenty of it locked up as ice in glaciers and the polar ice caps. But the atmosphere is too thin and cold to allow liquid water to exist on the surface, which makes prospects for life on the Red Planet far less likely.

Back in 2011, however, researchers suggested that, contrary to our expectations, there might still be some water seeping out onto Mars' surface. Darkened features were identified on a variety of slopes, and they seemed to appear during warmer seasons and vanish as temperatures plunged again. The Mars Reconnaissance Orbiter appeared to detect water at the site. But other researchers proposed a physical mechanism that didn't involve water that could account for the seasonal changes.

Now, a review of the evidence in Nature Geoscience argues that there are problems with almost all of the potential causes for these seasonal features. And, in the absence of a compelling case for water, it's best to assume that the harsh conditions mean what we typically thought they did: Mars is a dry planet.

Enlarge / An artist’s impression of the oddly shaped interstellar asteroid `Oumuamua. (credit: ESO/M. Kornmesser)

Since mid-October, the astronomy community has been buzzing about what might be our Solar System’s first confirmed interstellar visitor. An automated telescope spotted an object that appeared as if it had been dropped on the Solar System from above, an angle that suggests it arrived from elsewhere. Now, a team of astronomers has rushed out a paper that describes the object's odd properties and gives it the name “1I/2017 U1 ‘Oumuamua.” In Hawaiian, ‘Oumuamua roughly means “first messenger,” and the 1I indicates that it’s the first interstellar object.

‘Oumuamua was first spotted on October 19 by the Pan-STARRS1 automated telescope system. Pan-STARRS1 turned out to have captured images of the object the day previously, but the automated analysis software hadn’t identified it. Further images over the next few days allowed researchers to refine its travel through our Solar System, confirming that ‘Oumuamua was making the most extreme approach toward the inner Solar System of any object we’ve ever seen. In essence, it appeared to have been dropped onto the Solar System from above, plunging between the Sun and the orbit of Mercury. It was also moving extremely quickly.

The Solar System was formed from a flattened disk of material, and all of the planets orbit roughly in the plane of that disk. Smaller objects, like dwarf planets and comets, may take somewhat more erratic approaches with orbits tilted out of that plane, but they still roughly aligned with it. We had literally never seen anything like ‘Oumuamua.

Enlarge / A nori farm off the coast of Japan. (credit: H. Grobe)

The tasty Japanese seaweed nori is ubiquitous today, but that wasn't always true. Nori was once called “lucky grass” because every year's harvest was entirely dependent on luck. Then, during World War II, luck ran out. No nori would grow off the coast of Japan, and farmers were distraught. But a major scientific discovery on the other side of the planet revealed something unexpected about the humble plant and turned an unpredictable crop into a steady and plentiful food source.

Nori is most familiar to us when it's wrapped around sushi. It looks less familiar when floating in the sea, but for centuries, farmers in Japan, China, and Korea knew it by sight. Every year, they would plant bamboo poles strung with nets in the coastal seabed and wait for nori to build up on them.

At first it would look like thin filaments. Then, with luck, it grew into healthy, harvestable plants with long, green leaves. The farmers never saw seeds or seedlings, so no one could cultivate it. The filaments simply appeared every year. That is, they appeared until after World War II, when pollution, industrialization along the coast, and a series of violent typhoons led to a disastrous drop in harvests. By 1951, nori production in Japan had been all but wiped out.

Enlarge (credit: Getty | ullstein bild)

Your next romp with a paramour may blow your mind, but it’s unlikely to stop your heart, according to research presented this weekend at the American Heart Association’s Scientific Sessions 2017 in Anaheim, California.

That’s the good news. The bad news is that if you do suffer cardiac arrest from an amorous encounter, there’s a decent chance your partner will just let you croak.

In an analysis of 4,557 adult cases of cardiac arrest in a Northwestern US community between 2002 and 2015, only 34 of them occurred during or within an hour of sexual intercourse. Of those, 32 were in men. That means that sex is linked to only about one in a hundred cases of cardiac arrest in men. For women, the rate is around one in a thousand.

Enlarge (credit: Sci-Hub)

First came the $15 million fine a New York federal judge imposed on Sci-Hub, a scientific research piracy site that has freed tens of thousands of research papers from behind paywalls. That was in June, and the site's overseas operator, Alexandra Elbakyan, said she'd never pay plaintiff Elsevier or stop the infringing behavior.

Elbakyan

Now on Friday, a Virginia federal judge dinged the site for another $4.8 million for the same infringing behavior, this time from a lawsuit brought by the American Chemical Society.

The latest Friday order (PDF), like the previous order (PDF), demands that domain providers stop servicing Sci-Hub. The site has been playing a game of domain Whac-a-Mole for years in a bid to skirt US judicial orders.

ScanPyramids mission

Though the Great Pyramid at Giza in Egypt is one of the ancient world's biggest and most elaborate monuments, we still know very little about how it was constructed. We also don't know how many chambers are hidden inside it. Now, an international research team has identified what appears to be a large empty space or void above the pyramid's famed "Grand Gallery." The scientists report in the journal Nature that they used a cutting-edge technique for detecting cosmic radiation to make their discovery.

The Pharaoh Khufu (2509-2483 BCE) ordered the Great Pyramid to be built at Giza roughly 4,500 years ago. The structure remained sealed until 820 CE, when the Caliph al-Ma'mun broke open one of its walls and discovered three chambers inside, arranged vertically. These chambers are connected by the "Grand Gallery," a large corridor. Since that time, many have tried to find additional rooms and failed. Part of the problem is that we have no remaining plans for the pyramid's design, so it's impossible to know where to look. Plus, archaeologists today can't explore the pyramid using invasive techniques that might damage the structure. So explorers have to get creative. That's why Heritage Innovation Preservation Institute's (HIP) Mendhi Tayoubi organized a team of engineers and physicists who would use cosmic radiation to map the interior of the pyramid to look for empty spaces.

Enlarge (credit: DeepMind)

While artificial intelligence software has made huge strides recently, in many cases, it has only been automating things that humans already do well. If you want an AI to identify the Higgs boson in a spray of particles, for example, you have to train it on collisions that humans have already identified as containing a Higgs. If you want it to identify pictures of cats, you have to train it on a database of photos in which the cats have already been identified.

(If you want AI to name a paint color, well, we haven't quite figured that one out.)

But there are some situations where an AI can train itself: rules-based systems in which the computer can evaluate its own actions and determine if they were good ones. (Things like poker are good examples.) Now, a Google-owned AI developer has taken this approach to the game Go, in which AIs only recently became capable of consistently beating humans. Impressively, with only three days of playing against itself with no prior knowledge of the game, the new AI was able to trounce both humans and its AI-based predecessors.

Enlarge / Mmmmm, plastic-y. (credit: Getty | Cate Gillon)

Tiny bits of plastic commonly come rushing out of water taps around the world, according to a new survey of 159 water samples collected from more than a dozen nations.

Overall, 83 percent of the 159 samples contained some amount of microplastics. Those samples came from various places in the US, Europe, Indonesia, Uganda, Beirut, India, and Ecuador. No country was without a plastic-positive water sample. In fact, after testing a handful of samples from each place, the lowest contamination rate was 72 percent. The highest—found in the US—was 94-percent positive rate.

The microplastic pieces found are tiny, as small as 2.5 micrometers in size. The amounts were tiny, too. When researchers looked at the average number of plastic bits per 500mL water sample in each nation, the highest average was from US water samples—with 4.8 plastic scraps per sample. A sample taken from the US Capitol had 16 plastic fragments in it, for instance. The lowest average was 1.9 microplastic shards per 500mL sample, seen in those from Indonesia and Europe.