Amazing Science

The convergence of 5G, augmented reality, sensors, distributed computing and blockchain, and artificial intelligence is giving rise to the spatial web.

Welcome to Web 3.0, or the Spatial Web. In version 1.0, static documents and read-only interactions limited the internet to one-way exchanges. Web 2.0 provided quite an upgrade, introducing multimedia content, interactive web pages, and participatory social media. Yet, all this was still mediated by two-dimensional screens.

Today, we are witnessing the rise of Web 3.0, riding the convergence of high-bandwidth 5G connectivity, rapidly evolving AR eyewear, an emerging trillion-sensor economy, and powerful artificial intelligence.

As a result, we will soon be able to superimpose digital information atop any physical surrounding—freeing our eyes from the tyranny of the screen, immersing us in smart environments, and making our world endlessly dynamic.

In the third post of our five-part series on augmented reality, we will explore the convergence of AR, AI, sensors, and blockchain and dive into the implications through a key use case in manufacturing.

Rolls-Royce plans on building mini nuclear reactors, which could be in operation by 2029. They are less the size of traditional nuclear reactors and they do not take as many years to build.

How mini is that? Roger Harrabin and Katie Prescott reporting in the BBC: "They are about 1.5 acres in size - sitting in a 10-acre space. That is a 16th of the size of a major power station such as Hinkley Point."

The company has stated that this is a low-cost alternative for a global market. "With a modular design that's built in a factory, it can improve certainty of delivery, reduce complexity, optimize safety."

Currently, they said, "nuclear power stations are large scale sites that typically cover an area of over 400,000m2. This is because traditionally once a company has gone through the time and expense of securing an appropriate site, it was more cost effective to build as much capacity on that site as possible. Construction of these sites can take years to complete and their complexity can lead to significant delays and escalating costs."

Why are they building them, you might ask? These would serve as nuclear reactors to generate power in the UK, said designboom. They would be delivered "in chunks," said Forbes, via trucks.

Massive gas giants called "hot Jupiters"—planets that orbit too close to their stars to sustain life—are some of the strangest worlds found beyond our solar system. New observations show that the hottest of them all is stranger still, prone to planet-wide meltdowns so severe they tear apart the molecules that make up its atmosphere. In the scorching atmosphere of exoplanet KELT-9b, even molecules are torn to shreds.

Called KELT-9b, the planet is an ultra-hot Jupiter, one of several varieties of exoplanets—planets around other stars—found in our galaxy. It weighs in at nearly three times the mass of our own Jupiter and orbits a star some 670 light-years away. With a surface temperature of 7,800 degrees Fahrenheit (4,300 degrees Celsius) - hotter than some stars—this planet is the hottest found so far.

Now, a team of astronomers using NASA's Spitzer space telescope has found evidence that the heat is too much even for molecules to remain intact. Molecules of hydrogen gas are likely ripped apart on the dayside of KELT-9b, unable to re-form until their disjointed atoms flow around to the planet's nightside.

Though still extremely hot, the nightside's slight cooling is enough to allow hydrogen gas molecules to reform—that is, until they flow back to the dayside, where they're torn apart all over again.

"This kind of planet is so extreme in temperature, it is a bit separate from a lot of other exoplanets," said Megan Mansfield, a graduate student at the University of Chicago and lead author of a new paper revealing these findings. "There are some other hot Jupiters and ultra-hot Jupiters that are not quite as hot but still warm enough that this effect should be taking place."

The findings, published in Astrophysical Journal Letters, showcase the rising sophistication of the technology and analysis needed to probe these very distant worlds. Science is just beginning to peer into the atmospheres of exoplanets, examining the molecular meltdowns of the hottest and brightest.

KELT-9b will stay firmly categorized among the uninhabitable worlds. Astronomers became aware of its extremely hostile environment in 2017, when it was first detected using the Kilodegree Extremely Little Telescope (KELT) system—a combined effort involving observations from two robotic telescopes, one in southern Arizona and one in South Africa.

Computers can now drive cars, beat world champions at board games like chess and Go, and even write prose. The revolution in artificial intelligence stems in large part from the power of one particular kind of artificial neural network, whose design is inspired by the connected layers of neurons in the mammalian visual cortex. These “convolutional neural networks” (CNNs) have proved surprisingly adept at learning patterns in two-dimensional data — especially in computer vision tasks like recognizing handwritten words and objects in digital images.

But when applied to data sets without a built-in planar geometry — say, models of irregular shapes used in 3D computer animation, or the point clouds generated by self-driving cars to map their surroundings — this powerful machine learning architecture doesn’t work well. Around 2016, a new discipline called geometric deep learning emerged with the goal of lifting CNNs out of flatland.

Now, researchers have delivered, with a new theoretical framework for building neural networks that can learn patterns on any kind of geometric surface. These “gauge-equivariant convolutional neural networks,” or gauge CNNs, developed at the University of Amsterdam and Qualcomm AI Research by Taco Cohen, Maurice Weiler, Berkay Kicanaoglu and Max Welling, can detect patterns not only in 2D arrays of pixels, but also on spheres and asymmetrically curved objects. “This framework is a fairly definitive answer to this problem of deep learning on curved surfaces,” Welling said.

Already, gauge CNNs have greatly outperformed their predecessors in learning patterns in simulated global climate data, which is naturally mapped onto a sphere. The algorithms may also prove useful for improving the vision of drones and autonomous vehicles that see objects in 3D, and for detecting patterns in data gathered from the irregularly curved surfaces of hearts, brains or other organs.

The world is getting warmer, the weather is getting worse. Here's everything you need to know about what humans can do to stop wrecking the planet.

The world is probably already busted. For decades, scientists have carefully accumulated data that confirms what we hoped wasn’t true: The greenhouse gas emissions that have steadily spewed from cars and planes and factories, the technologies that powered a massive period of economic growth, came at an enormous cost to the planet’s health. Today, we know that absent any change in our behavior, the average global temperature will rise as much as 4 degrees Celsius by the end of the century. Global sea levels will rise by up to 6 feet. Along with those shifts will come radical changes in weather patterns around the globe, leaving coastal communities and equatorial regions forever changed—and potentially uninhabitable.

Strike that. We are already seeing the effects of a dramatically changed climate, from extended wildfire seasons to worsening storm surges. Now, true, any individual weather anomaly is unlikely to be solely the result of industrial emissions, and maybe your particular part of the world has been spared so far. But that’s little solace when the historical trends are so terrifyingly real. (Oh, and while it used to take mathematicians months to calculate how the odds of specific extreme weather events were affected by humans, they’ve knocked that data-crunching time down to weeks.)

Thankfully, it seems most of the world’s nation-states are beyond quibbling over the if of climate change—they’re moving rapidly onto the what now? The 2015 Paris climate agreement marked a turning point in the conversation about planetary pragmatics. Renewable energy in the form of wind and solar is actually becoming competitive with fossil fuels. And the world’s biggest cities are driving sustainable policy choices in a way that rival the contributions of some countries. Scientists and policymakers are also beginning to explore a whole range of last-ditch efforts—we’re talking some serious sci-fi stuff here—to deliberately, directly manipulate the environment. To keep the climate livable, we may need to prepare for a new era of geoengineering.

Climate change by numbers:

• 407.6 parts per million: The concentration of CO2 in the lowest layer of our planet’s atmosphere. Compare that to 380 ppm just a decade ago.
• 75 percent: The portion of humanity that could face deadly heat waves by 2100 if major cuts to CO2 emissions are not made. By the middle of this century, the American South could see a tripling of days per year that hit 95 degrees.
• 2 degrees Celsius: The goal for maximum global temperature rise from pre-Industrial levels, as outlined in the Paris agreement. Unfortunately, a study published last summer determined that the chance of hitting that goal by 2100 is a mere 5 percent. The reality is, the rise could be as much as 4.9 degrees Celsius.
• 1.5 degrees Fahrenheit: The rise in sea surface temperature between 1901 and 2015. Warming seas are a particular problem for coral, which release the photosynthetic algae they use to extract energy from sunlight when they’re stressed and bleach to death.

The multi-hued, three-foot-long squirrels currently taking the internet by storm are no Photoshopped mythical creatures.

As Jason Bittel reports for National Geographic, the colorful four-pound critters—enjoying a renewed burst of attention thanks to a series of snapshots posted on Instagram by amateur photographer Kaushik Vijayan—not only roam the forests of southern India, but also, in the words of wildlife conservation biologist John Koprowski, look “exactly” like the majestic orange-, purple- and maroon-colored animals seen on Vijayan’s feed. (Give or take a few filters, that is: Evolutionary biologist Dana Krempels points out that the photographer may have enhanced the squirrels’ natural coloring by applying a “vibrance” setting.)

Officially known as Ratufa indica, or the Malabar giant squirrel, the species is one of four relatively hefty rodents in the squirrel family. The colorful creatures can measure up to three feet long from head to tail and weigh in at around four pounds.

University of Queensland researchers have combined quantum liquids and silicon-chip technology to study turbulence for the first time, opening the door to new navigation technologies and improved understanding of the turbulent dynamics of cyclones and other extreme weather.

Professor Warwick Bowen, from UQ’s Precision Sensing Initiative and the Australian Research Council Centre of Excellence for Engineered Quantum Systems said the finding was “a significant advance” and provided a new way to study turbulence.

“Turbulence is often described as the oldest unsolved problem in physics,” Professor Bowen said. “Our finding allows us to observe nanoscale quantum turbulence, which mirrors the sort of behavior you see in cyclones.

“This advance is enabled by the properties of quantum liquids, which are fundamentally different to everyday liquids.” Professor Bowen said it was postulated more than 50 years ago that the turbulence problem could be simplified using quantum liquids. “Our new technique is exciting because it allows quantum turbulence to be studied on a silicon chip for the first time,” he said.

The research also had implications in space, where quantum liquids are predicted to exist within dense astrophysical objects. “Our research could help to explain how these objects behave,” Dr. Bowen said.

Dr. Yauhen Sachkou, the paper’s lead author, said rotating neutron stars lost angular momentum in fits and starts. “The way this occurs is thought to hinge on quantum turbulence,” Dr. Sachkou said. Dr. Christopher Baker, who co-led the research, said the finding made possible silicon-chip based accelerometers with sensitivity far beyond current state of the art. “In quantum liquids, atoms behave more like waves than particles,” Dr. Baker said. “This allows us to build laser-like sensors from atoms.”

A single bright star in the constellation of Indus, visible from the southern hemisphere, has revealed new insights on an ancient collision that our galaxy the Milky Way underwent with another smaller galaxy called Gaia-Enceladus early in its history.

The animation shows a schematic of the orbits of three stars within our Galaxy the Milky Way – whose extent is marked by the dashed line -- as viewed from above and side-on, projected over the next half a billion years. The three stars are: nu Indi, the subject of the Nature Astronomy paper; a star accreted from Gaia-Enceladus (after its collision with the Milky Way); and the Sun. The accreted star came from outside the Galaxy, as part of the Gaia-Enceladus collision, and so has a very elongated orbit. The collision affected the motion and orbit of nu Indi.

Notice how its orbit is quite different to that of the Sun. This research was funded by the Science and Technology Facilities Council and the European Research Council. Acknowledgements: J. T. Mackereth, supported by the European Research Council (https://www.asterochronometry.eu)

In the immediate aftermath of the explosion on 26 April, 1986, few were prepared to endure the massive radiation levels and document the disaster, but Russian photographer Igor Kostin did.

In the years that followed, he continued to monitor the political and personal stories of those impacted by the disaster, publishing a book of photos called Chernobyl: Confessions of a Reporter. His images of a deformed boy even led to adoption of the ‘Chernobyl Child’ in UK.

Here is a selection of his finest photographs

Recover from dengue once, and you’re not necessarily free and clear. The mosquito-borne disease marked by fever, rash, and debilitating pain results from any of four genetically distinct versions of the dengue virus. Previously infected people who get hit with a second of these “serotypes” can face more severe, even life-threatening symptoms.

Now, by endowing a line of mosquitoes with an antibody against the virus, researchers have for the first time made insects that—at least in lab tests—appear unable to spread any form of the disease. In theory, these mosquitoes could be released into the wild to suppress the circulation of the virus. “This is right on the money,” says Alexander Franz, a biologist at the University of Missouri, Columbia, who studies insect-borne viruses. “This is what you need to do if you really want to have a strong effect on dengue prevalence.”

Conventional control strategies for dengue, such as removing stagnant water where mosquitoes breed, spraying insecticides, and protecting people with bed nets, have failed to defeat the virus, which infects up to 400 million people a year in regions near the tropics. So some researchers are trying to defeat dengue from inside the mosquito that has just drunk infected blood. The goal is to keep the virus from spreading to the insect’s saliva, where it can be injected into the next person bitten.

One strategy is to fight infection with an infection—give mosquitoes a virus-blocking bacterium called Wolbachia pipientis. Releasing Wolbachia-carrying insects into the wild has reduced rates of human dengue infection in preliminary experiments. Other approaches tinker with the mosquito genome—for example, inserting the gene for a synthetic RNA molecule that destroys the virus’s genetic material. But no approach has effectively combatted all four varieties—or serotypes—of the virus.

In 2013, researchers uncovered a new possibility. In the blood of a person who had been infected with dengue multiple times, researchers at Vanderbilt University found an antibody that could strongly bind to all four dengue serotypes and prevent them from infecting new cells. Mosquitoes don’t make antibodies to target pathogens like we do, but giving them the ability to make one of these immune proteins could help them fight off an infection that they would otherwise pass on to people. In previous studies, researchers endowed mosquitoes that carry the malaria parasite Plasmodium with an antibody that kept the pathogen out of their saliva.

The new study applies a similar principle to the dengue virus. Molecular biologist Omar Akbari of the University of California, San Diego, and colleagues reengineered the human antidengue antibody to simplify its structure, making its gene easier to insert into the mosquito genome. They injected the slimmed-down antibody gene into the embryos of Aedes aegypti mosquitoes, which spread dengue. Then, they bred the resulting insects to make offspring with two copies of the new gene, which is activated only when blood enters the gut. After the engineered mosquitoes drank blood infected with any one of the four dengue serotypes, they had no detectable dengue virus in their saliva, the researchers report now in PLOS Pathogens.

UC San Diego researchers studied nearly 900 vertebrate species and found that bats have unusual gut microbiomes that more closely resemble those of birds than other mammals, raising questions about how evolutionary pressures change the gut microbiome.

Diet and host phylogeny drive the taxonomic and functional contents of the gut microbiome in mammals, yet it is unknown whether these patterns hold across all vertebrate lineages. Now, researchers assessed gut microbiomes from ∼900 vertebrate species, including 315 mammals and 491 birds, assessing contributions of diet, phylogeny, and physiology to structuring gut microbiomes. In most nonflying mammals, strong correlations exist between microbial community similarity, host diet, and host phylogenetic distance up to the host order level. In birds, by contrast, gut microbiomes are only very weakly correlated to diet or host phylogeny. Furthermore, while most microbes resident in mammalian guts are present in only a restricted taxonomic range of hosts, most microbes recovered from birds show little evidence of host specificity. Notably, among the mammals, bats host especially bird-like gut microbiomes, with little evidence for correlation to host diet or phylogeny. This suggests that host-gut microbiome phylosymbiosis depends on factors convergently absent in birds and bats, potentially associated with physiological adaptations to flight. These findings expose major variations in the behavior of these important symbioses in endothermic vertebrates and may signal fundamental evolutionary shifts in the cost/benefit framework of the gut microbiome.

Researchers from NUS have synthesized the world’s first one-atom-thick amorphous material. Previously thought to be impossible, the discovery of monolayer amorphous carbon (MAC) could finally settle a decades-old debate of exactly how atoms are arranged in amorphous solids, and open up potential applications.  This major research breakthrough was led by Professor Barbaros Özyilmaz, Head of the NUS Materials Science and Engineering. The results were published in the prestigious scientific journal Nature on 8 January 2020. 

The NUS team grew the material and studied its properties and potential areas of application. In addition, atomic resolution imaging was performed by the group of Professor Kazu Suenaga from the National Institute of Advanced Industrial Science and Technology (AIST), Japan, and Professor Junhao Lin from Southern University of Science and Technology (SUSTECH), China.

Furthermore, theoretical simulations were carried out by the group of Professor Sokrates Pantelides from Vanderbilt University, USA. “With MAC, we have shown for the first time that fully amorphous materials can be stable and free-standing in single atomic layers.

Amorphous materials are of great technological importance, but surprisingly, they remain poorly understood from a basic science point of view. This breakthrough allows for direct imaging to reveal how atoms are arranged in amorphous materials, and could be of commercial value for batteries, semiconductors, membranes and many more applications,” said Prof Özyilmaz, who is also from NUS Physics and the NUS Centre for Advanced 2D Materials. 

Mechanoluminescence (ML) is a type of luminescence induced by any mechanical action on a solid, leading to a range of applications in materials research, photonics and optics. For instance, the mechanical action can release energy previously stored in the crystal lattice of phosphor via trapped charge carriers. However, the method has limits when recording ML emissions during a pressure-induced event. In a new study, Robin R. Petit and a research team at the LumiLab, Department of Solid State Sciences at the Ghent University—Belgium devised a new technique to add a memory function to pressure-sensitive phosphors. Using the method, the scientists obtained an optical readout of the location and intensity of a pressure event three days (72 hours) after the event.

The team noted the outcome using Europium-doped barium silicon oxynitride (BaSiO2N2:Eu2+) phosphor, which contained a broad trap depth distribution or depth of defect distribution—essential for the unique memory function.

The excited electrons of phosphor filled the 'traps' (or defects) in the crystal lattice, which could be emptied by applying weight to emit light. The research team merged optically stimulated luminescence (OSL), thermoluminescence (TL) and ML measurements to carefully analyze the influence of light, heat and pressure on trap depth distribution. Based on the memory effect, the materials remembered the location at which pressure had occurred, helping researchers to develop new pressure sensing applications and study charge carrier transitions within energy storage phosphors. The work is now published on Light: Science & Applications.

When specific materials are subjected to mechanical action, light emission can be observed as mechanoluminescence (ML). The process can be induced through different types of mechanical stress including friction, fracture, bending, impact of a weight and even ultrasound, crystallization and wind.

The phenomenon can be used to identify stress distribution, microcrack propagation and structural damages in solids, while allowing a variety of applications in displays, to visualize ultrasound and even map personalized handwriting. However, the technique is limited by the range of emission colors, restriction of real-time measurements and restricted signal visibility.

Researchers from the Moscow Institute of Physics and Technology teamed up with colleagues from the U.S. and Switzerland and returned the state of a quantum computer a fraction of a second into the past. They also calculated the probability that an electron in empty interstellar space will spontaneously travel back into its recent past. The study is published in 

Scientific Reports.scientists from the U.S. and Russia have experimentally demonstrated time reversal—sending a qubit from a more complicated state to a simpler one. The algorithm they suggest changes the quantum developed state so it starts to develop back in time. "Doing this magic with the developed state of ink we will see that after the same time (time needed for the dissolving of ink in the water) the ink will again combine back into the original drop," study author Andrei Lebedev told Newsweek.

"This is exactly what we did in our work where the drop of ink is state of three qubits, and the water is a Hilbert state of the quantum computer." Lead author Gordey Lesovik said in a statement: "This is one in a series of papers on the possibility of violating the second law of thermodynamics. That law is closely related to the notion of the arrow of time that posits the one-way direction of time: from the past to the future."

In the experiment, researchers set the state of each qubit to what you would think of as zero. From this point, the order is lost and the qubits became more and more complex, changing to a pattern of zeros and ones. Next, time was reversed by a specially developed program that allows the quantum computer to go from a state of chaos to order—going from complex to simple. As a result, the qubits are sent backwards in time.

The program was successful in a two qubit quantum computer around 85 percent of the time. When a third qubit was introduced, more errors occurred and the success rate fell to around 50 percent. So developing a quantum computer that can reverse time on a large scale is not going to happen any time soon. Furthermore, it indicates time reversal in nature is unlikely because it is too complex.

"Jumping genes"—bits of DNA that can move from one spot in the genome to another—are well-known for increasing genetic diversity over the long course of evolution. Now, new research at Washington University School of Medicine in St. Louis indicates that such genes, also called transposable elements, play another, more surprising role: stabilizing the 3-D folding patterns of the DNA molecule inside the cell's nucleus.

The study appears Jan. 24, 2020 in the journal Genome Biology. The DNA molecule inside the nucleus of any human cell is more than six feet long. To fit into such a small space, it must fold into precise loops that also govern how genes are turned on or off. It might seem counterintuitive that bits of DNA that randomly move about the genome can provide stability to these folding patterns. Indeed, the discovery contradicts a long-held assumption that the precise order of letters in the DNA sequence always dictates the broader structure of the DNA molecule.

"In places where the larger 3-D folding of the genome is the same between mice and humans, you expect the sequence of the letters of the DNA anchoring that shape to be conserved there as well," said senior author Ting Wang, Ph.D., the Sanford C. and Karen P. Loewentheil Distinguished Professor of Medicine. "But that's not what we found, at least not in the portions of the genome that in the past have been called 'junk DNA.'"

New research done at the University of the Witwatersrand in Johannesburg, South Africa, and Huazhang University of Science and Technology in Wuhan, China, has exciting implications for secure data transfer across optical fiber networks. The team have demonstrated that multiple quantum patterns of twisted light can be transmitted across a conventional fiber link that, paradoxically, supports only one pattern. The implication is a new approach to realizing a future quantum network, harnessing multiple dimensions of entangled quantum light.

Science Advances published the research by a team led by Professor Andrew Forbes from the School of Physics at Wits University in collaboration with a team lead by Professor Jian Wang at HUST. In their paper, titled "Multi-dimensional entanglement transport through single mode fiber," the researchers demonstrate a new paradigm for realizing a future quantum network. The team showed that multiple patterns of light are accessible after a communication link of conventional optical fiber that paradoxically can only support a single pattern.

The team achieved this quantum trick by engineering entanglement in two degrees of freedom of light, polarization and pattern, passing the polarized photon down the fiber and accessing the many patterns with the other photon.

"In essence, the research introduces the concept of communicating across legacy fiber networks with multi-dimensional entangled states, bringing together the benefits of existing quantum communication with polarized photons with that of high-dimension communication using patterns of light," says Forbes.

A world awash in plastic will soon see even more, as a host of new petrochemical plants — their ethane feedstock supplied by the fracking boom — come online. Major oil companies, facing the prospect of reduced demand for their fuels, are ramping up their plastics output.

As public concern about plastic pollution rises, consumers are reaching for canvas bags, metal straws, and reusable water bottles. But while individuals fret over images of oceanic garbage gyres, the fossil fuel and petrochemical industries are pouring billions of dollars into new plants intended to make millions more tons of plastic than they now pump out.

Companies like ExxonMobil, Shell, and Saudi Aramco are ramping up output of plastic — which is made from oil and gas, and their byproducts — to hedge against the possibility that a serious global response to climate change might reduce demand for their fuels, analysts say. Petrochemicals, the category that includes plastic, now account for 14 percent of oil use, and are expected to drive half of oil demand growth between now and 2050, 

the International Energy Agency (IEA) says.The World Economic Forum predicts plastic production will double in the next 20 years. “In the context of a world trying to shift off of fossil fuels as an energy source, this is where [oil and gas companies] see the growth,” said Steven Feit, a staff attorney at the Center for International Environmental Law, an advocacy group.

Magnesium ions have many cellular actions including the suppression of the excitability of neurons; however, the depolarization effect of magnesium ions seems to be contradictory. Thus several hypotheses have aimed to explain this effect. In this study, a quantum mechanical approach is used to explain the depolarization action of magnesium.

The model of quantum tunneling of magnesium ions through the closed sodium voltage-gated channels was adopted to calculate the quantum conductance of magnesium ions, and a modified version of Goldman–Hodgkin–Katz equation was used to determine whether this quantum conductance was significant in affecting the resting membrane potential of neurons.

Accordingly, it was found that extracellular magnesium ions can exhibit a depolarization effect on membrane potential, and the degree of this depolarization depends on the tunneling probability, the channels’ selectivity to magnesium ions, the channels’ density in the neuronal membrane, and the extracellular magnesium concentration.

In addition, extracellular magnesium ions achieve a quantum conductance much higher than intracellular ones because they have a higher kinetic energy. This study aims to identify the mechanism of the depolarization action of magnesium because this may help in offering better therapeutic solutions for fetal neuroprotection and in stabilizing the mood of bipolar patients.

Half a billion years ago, the continents were quiet. Earth’s animals—represented largely by shelled mollusks, armored arthropods, and a smattering of wriggly, jawless fish—breathed with gills, not lungs, and hunted their prey at sea.

But sometime, possibly during the Silurian (the geologic period spanning 443 million to 416 million years ago) an intrepid creature, likely equipped with sturdy limbs and a set of gas-cycling tubes that could leech oxygen from air, decided to crawl ashore. In habitually venturing out of the ocean, this animal paved a habitat-hopping path for countless lineages of land-dwellers to come—including the one that eventually led to us.

The identity of this pioneering terrestrial trekker has long perplexed paleontologists. Over the years, several candidates have come forth, all known only by their fossilized remains. Two of the most promising possibilities include many-legged millipedes, eager to snack on the predecessors of today’s plants, and stinger-tipped scorpions—one of the world’s oldest arachnids, the group that also includes spiders. But when and how these arthropods first made that crucial transition from water to land remains an unsolved puzzle.

Now, new research is pushing the scorpion timeline further back than ever before and may help pinpoint the traits that helped these pint-sized predators make a living on land. Today in Scientific Reports, paleontologists announce the discovery of the oldest known scorpions to date: a pristinely preserved pair of 437-million-year-old fossils, complete with what seem to be venom-packed tails.

Loop quantum gravity—a theory that extends general relativity by quantizing spacetime—predicts that black holes evolve into white holes.

Black holes are remarkable entities. On the one hand, they have now become familiar astrophysical objects that have been observed in large numbers and in many ways: we have evidence of stellar-mass holes dancing around with a companion star, of gigantic holes at the center of galaxies pulling in spiraling disks of matter, and of black hole pairs merging in a spray of gravitational waves. All of this is beautifully accounted for by Einstein’s century-old theory of general relativity. Yet, on the other hand, black holes remain highly mysterious. We see matter falling into them, but we are in the dark about what happens to this matter when it reaches the center of the hole.

Abhay Ashtekar and Javier Olmedo at Pennsylvania State University in University Park and Parampreet Singh at Louisiana State University, Baton Rouge, have taken a step toward answering this question [1]. They have shown that loop quantum gravity—a candidate theory for providing a quantum-mechanical description of gravity—predicts that spacetime continues across the center of the hole into a new region that exists in the future and has the geometry of the interior of a white hole.

A white hole is the time-reversed image of a black hole: in it, matter can only move outwards. The passage “across the center” into a future region is counterintuitive; it is possible thanks to the strong distortion of the spacetime geometry inside the hole that is allowed by general relativity. This result supports a hypothesis under investigation by numerous research groups: the future of all black holes may be to convert into a real white hole, from which the matter that has fallen inside can bounce out. However, existing theories have not been able to fully show a way for this bounce to happen. That loop quantum gravity manages to do it is an indication that this theory has ripened enough to tackle real-world situations.

The reason why we are in the dark about aspects of black hole physics is that quantum phenomena dominate at the center and in the future of these objects. Classical general relativity predicts that a black hole lives forever and that its center is a “singularity” where space and time end. These predictions are not realistic because they disregard quantum effects. To tackle these effects we need a quantum theory of gravity. We don’t yet have consensus on such a theory, but we have candidates, some of which are now reaching the point of allowing actual calculations on the quantum behavior of black holes. Loop quantum gravity, which has a clean conceptual structure and a well-defined mathematical formulation based on representing the fabric of space as a spin network that evolves in time, is one such theory.

During the last few years, a number of research groups have applied loop theory to explore the evolution of black holes. These efforts are building a compelling picture based on a black-to-white-hole transition scenario (1), which can be summarized as follows [2]. At the center of the black hole, space and time do not end in a singularity, but continue across a short transition region where the Einstein equations are violated by quantum effects. From this region, space and time emerge with the structure of a white hole interior, a possibility suggested in the 1930s by physicist John Lighton Synge [3].

As the hole’s center evolves, its external surface, or “horizon,” slowly shrinks because of the emission of radiation—a phenomenon first described by Stephen Hawking. This shrinkage continues until the horizon reaches the Planck size (the characteristic scale of quantum gravity) or earlier [4, 5], at which point a quantum transition (“quantum tunneling”) happens at the horizon, turning it into the horizon of a white hole (6). Thanks to the peculiar distorted relativistic geometry, the white hole interior born at the center joins the white horizon, completing the formation of the white hole.

A glance to the left. A flick to the right. As my eyes flitted around the room, I moved through a virtual interface only visible to me—scrolling through a calendar, looking up commute times home, and even controlling music playback. It's all I theoretically need to do to use Mojo Lens, a smart contact lens coming from a company called Mojo Vision.

The California-based company, which has been quiet about what it's been working on for five years, has finally shared its plan for the world's "first true smart contact lens." But let's be clear: This is not a product you'll see on store shelves next autumn. It's in the research and development phase—a few years away from becoming a real product. In fact, the demos I tried did not even involve me plopping on a contact lens—they used virtual reality headsets and held up bulky prototypes to my eye, as though I was Sherlock Holmes with a magnifying glass.

Mojo Vision is all about "invisible computing." The company, whose founders include industry veterans from the likes of Apple, Google, Amazon, and Microsoft, wants to reduce our reliance on screens. Instead of pulling out your phone to check why it buzzed in the middle of a conversation, look to the corner of your eye to activate an interface that will tell you in a split second.

"We want to create a technology that lets you be you, lets you look like you; doesn't change your appearance; it doesn't make you act weird walking down the street," said Mike Wiemer, cofounder and chief technology officer at Mojo Vision. "It's very discreet and frankly, substantially, most of the time it doesn't show you anything."

Deaths from lung cancer dropped by 51 percent among men since the early 1990s and by 26 percent among women since the early 2000s. The report also credits drops in lung cancer mortality for a 2.2 percent dip from 2016 to 2017 — the largest decline of cancer deaths in a single year ever reported. Doctors attribute the success in part to lower smoking rates but also to significant advances in treatment.

Major medical advances are continuing

"The years we have been investing in basic science of cancer therapeutics [are] now starting to pay off," said Dr. Patrick Hwu, division head of cancer medicine at MD Anderson Cancer Center in Houston.

Hwu, who was not involved with the new report, credited targeted therapies, which are drugs that work to eliminate the circuitry that turns on cancer cells.

Another of the biggest advances, experts said, has been the development of immunotherapies such as Keytruda, also known as pembrolizumab. It uses the body's immune system to fight tumors, and it is approved for lung cancer and melanoma, the most dangerous form of skin cancer.

The American Cancer Society report also found rapid declines in melanoma death rates, up to 7 percent a year from 2013 to 2017 among adults, also attributable to new treatments. The Food and Drug Administration approved two key drugs to treat melanoma: ipilimumab and vemurafenib.

"We're actually seeing the effect of those drugs reflected in the overall melanoma death rate," said Rebecca Siegel, scientific director of surveillance research at the American Cancer Society and an author of the new report. "That's really exciting." Physicians are seeing it in practice, as well.

"In the past decade, how we treat invasive melanoma has evolved so unbelievably rapidly that it is, for some, becoming more of a chronic disease than a death sentence," said Dr. Adam Friedman, a professor of dermatology at the George Washington School of Medicine and Health Sciences in Washington, D.C.

Researchers use post-mortem genetic testing to find the underlying cause of multiple sudden deaths in young people and sudden cardiac arrests in two large Amish families.

Using an exome molecular autopsy, Michael Ackerman, M.D., Ph.D., and his associates conducted genetic testing of four siblings who each died suddenly during exercise. Dr. Ackerman is a genetic cardiologist and director of the Windland Smith Rice Comprehensive Sudden Cardiac Death Program at Mayo Clinic. The findings are published in JAMA Cardiology. Dr. Ackerman is the senior author.

Based on a family history of exercise-associated sudden deaths in the young and sudden cardiac arrests, researchers suspected a recessive inheritance pattern because the parents of affected children did not show visible characteristics, or phenotype. This recessive condition requires the inheritance of the genetic variant from each parent, such that the children who are affected have two copies of the variant. If both parents carry a single copy of the genetic variant, their children have a 25% chance of inheriting two copies of the variant and are likely to express the phenotype that puts them at risk for sudden cardiac arrest or sudden death.

"Alarmingly, people with this condition often have an unremarkable clinical course and routine cardiology clinical testing, such as an electrocardiogram or even stress testing, that do not reveal an individual at risk for a sudden cardiac event," Dr. Ackerman says.

A molecular autopsy revealed a common genetic factor among all four siblings. Each had the same homozygous multiexon duplication in RYR2, as did multiple distantly related relatives who also experienced a sudden cardiac arrest during exercise.

Researchers then compared a second, unrelated Amish family that also has multiple exertion-related sudden deaths and sudden cardiac arrests in the young. Genetic testing confirmed that both families possessed the exact same gene duplication. To date, 23 family members have been identified as being affected. Of those 23 family members, 18 have tragically died suddenly at a young age.

Identifying which people in these Amish communities are at risk is important for their future, but it is difficult without genetic testing. "Now that our genetic sleuthing has revealed the underlying genetic cause for these families' tragic events, a simple genetic test can be performed to identify family members at risk for their own sudden cardiac arrest," Dr. Ackerman says. "In fact, identification of unaffected heterozygous carriers may provide potentially lifesaving premarital counseling and reproductive planning for the Amish community."