Enlarge / Whales and their kin evolved from land-dwelling mammals, a transition that entailed major physiological and morphological changes—which geneticists have begun to parse. (credit: Hayes Baxley/National Geographic for Disney+)

Around 400 million years ago, the ancestor of all four-limbed creatures took its first steps onto dry land. Fast-forward about 350 million years, and a descendant of these early landlubbers did an about-face: It waded back into the water. With time, the back-to-the sea creatures would give rise to animals vastly different from their land-trotting kin: They became the magnificent whales, dolphins, and porpoises that glide through the oceans today.

Going back to being aquatic was a drastic move that would change the animals inside and out, in the space of about 10 million years—an eyeblink in evolutionary terms. Members of this group, now called cetaceans, dropped their hind limbs for powerful flukes and lost nearly all their hair. For decades, their bizarre body plans perplexed paleontologists, who speculated they might have arisen from creatures as varied as marine reptiles, seals, marsupials like kangaroos, and even a now-extinct group of wolf-like carnivores.

“The cetaceans are on the whole the most peculiar and aberrant of mammals,” one scientist wrote in 1945.

Enlarge (credit: CHRISTOPH BURGSTEDT/SCIENCE PHOTO LIBRARY)

Ryan Grant was in his 20s and serving in the military when he learned that the numbness and tingling in his hands and feet, as well as his unshakeable fatigue, were symptoms of multiple sclerosis. Like nearly a million other people with MS in the United States, Grant had been feeling his immune system attack his central nervous system. The insulation around his nerves was crumbling, weakening the signals between his brain and body.

The disease can have a wide range of symptoms and outcomes. Now 43, Grant has lost the ability to walk, and he has moved into a veterans’ home in Oregon, so that his wife and children don’t have to be his caretakers. He’s all too familiar with the course of the illness and can name risk factors he did and didn’t share with other MS patients, three-quarters of whom are female. But until recently, he hadn’t heard that many scientists now believe the most important factor behind MS is a virus.

For decades, researchers suspected that Epstein-Barr virus, a common childhood infection, is linked to multiple sclerosis. In January, the journal Science pushed that connection into headlines when it published the results of a two-decade study of people who, like Grant, have served in the military. The study’s researchers concluded that EBV infection is “the leading cause” of MS.

Enlarge / Getting those few last dollops of ketchup out of the bottle can lead to unexpected splattering. (credit: Getty Images)

Ketchup is one of the most popular condiments in the US, along with mayonnaise, but getting those few last dollops out of the bottle often results in a sudden splattering. "It's annoying, potentially embarrassing, and can ruin clothes, but can we do anything about it?" Callum Cuttle of the University of Oxford said during a press conference earlier this week at an American Physical Society meeting on fluid dynamics in Indianapolis, Indiana. "And more importantly, can understanding this phenomenon help us with any other problems in life?"

The answer to both questions, per Cuttle, is a resounding yes. Along with his Oxford colleague, Chris MacMinn, he conducted a series of experiments to identify the forces at play and develop a theoretical model for ketchup splatter. Among the most interesting findings: squeezing the bottle more slowly and doubling the diameter of the nozzle helps prevent splatter. There is also a critical threshold where the flow of ketchup shifts suddenly from not splattering to splattering. A preprint paper has been posted to arXiv and is currently undergoing peer review.

Isaac Newton identified the properties of what he deemed an "ideal liquid." One of those properties is viscosity, loosely defined as how much friction/resistance there is to flow in a given substance. The friction arises because a flowing liquid is essentially a series of layers sliding past one another. The faster one layer slides over another, the more resistance there is, and the slower one layer slides over another, the less resistance there is.

Enlarge / No, those donut tracks aren't mine, officer. (credit: NASA/JPL-Caltech/MSSS)

The Perseverance rover landed in Mars' Jezero Crater largely because of extensive evidence that the crater once hosted a lake, meaning the presence of liquid water that might once have hosted Martian life. And the landing was a success, placing the rover at the edge of a structure that appeared to be a river delta where the nearby highlands drained into the crater.

But a summary of the first year of data from the rover, published in three different papers being released today, suggests that Perseverance has yet to stumble across any evidence of a watery paradise. Instead, all indications are that water exposure in the areas it explored was limited, and the waters were likely to be near freezing. While this doesn't rule out that it will find lake deposits later, the environment might not have been as welcoming for life as "a lake in a crater" might have suggested.

Putting it all together

Perseverance can be considered a platform for a large suite of instruments that provide a picture of what the rover is looking at. Even its "eyes," a pair of cameras on its mast, can create stereo images with 3D information, and offer information on what wavelengths are present in the images. It also has instruments that can be held up to rocks to determine their content and structure; sample-handling hardware can perform a chemical analysis of materials taken from rocks.

Enlarge (credit: Getty | DeAgostini)

Officials in Wisconsin found a series of failures and federal violations at a nursing home where a renegade nurse cut off a man's foot without his consent and wanted to have it stuffed in her family's taxidermy shop and put on display to warn children to "wear your boots" in cold weather.

The nurse, Mary Brown, 38, of Durand, has since been charged with two felony counts of elder abuse in connection with the illegal amputation, which occurred on May 27. She is scheduled to appear in court on December 6.

The man died on June 2, six days after losing his foot. A nursing aide who spoke with state investigators said the man "really declined after his foot was gone," according to the Milwaukee Journal Sentinel, which reviewed a state inspection report.

Enlarge / The jets of material ejected from around black holes can be enormous. (credit: NASA, ESA)

Active galactic nuclei, powered by the supermassive black holes they contain, are the brightest objects in the Universe. The light originates from jets of material hurled out at nearly the speed of light by the environment around the black hole. In most cases, these active galactic nuclei are called quasars. But, in rare instances where one of the jets is oriented directly toward Earth, they're called a blazar and appear brighter.

While the general outline of how a blazar operates has been worked out, several details remain poorly understood, including how the fast-moving material generates so much light. Now, researchers have turned a new space-based observatory called the Imaging X-ray Polarimetry Explorer (IXPE) toward one of the brightest blazars in the sky. The data from it and other observations combined indicate that light is produced when the black hole jets slam into slower-moving materials.

Jets and light

The IXPE specializes in detecting the polarization of high-energy photons—the orientation of the wiggles in the light's electric field. Polarization information can tell us something about the processes that created the photons. For example, photons that originate in a turbulent environment will have an essentially random polarization, while a more structured environment will tend to produce photons with a limited range of polarizations. Light that passes through material or magnetic fields can also have its polarization altered.

Enlarge / Artist's concept of the Rosalind Franklin ExoMars rover on Mars. (credit: Adrian Mann/Stocktrek Images)

The more than two dozen nations that make up the European Space Agency concluded their high-level "ministerial" meeting on Wednesday, establishing a budget and priorities for the next three years.

A German delegate chosen to chair the meeting, Anna Christmann, said the space agency's plans reflect a bold agenda for Europe to lead in climate science and maintain independent and launch capability. The goal is for Europe to stand alongside the United States and China as a major space power. "We've shown Europe is ambitious," said Christmann at a media conference to discuss results of the meeting.

Germany, France, and Italy remain the major players in ESA, combining to contribute nearly 60 percent of its overall funding. The member nations agreed to contribute 16.9 billion euro ($17.5 billion) to agency programs over the next three years. This is less than the 18.5 billion euro sought by ESA Director General Josef Aschbacher but still significantly higher than the total for the previous three-year period of 14.5 billion euro.

Enlarge / Dr. Anthony Fauci, White House chief medical adviser, speaks alongside COVID-19 Response Coordinator Dr. Ashish Jha during a briefing on COVID-19 at the White House on November 22, 2022, in Washington, DC. Fauci spoke on the updated COVID-19 booster shots and encouraged individuals to get their vaccines. (Photo by Win McNamee/Getty Images) (credit: Getty | Win McNamee)

The updated bivalent COVID-19 booster vaccine increased protection against symptomatic disease compared with the original monovalent vaccine given as recently as two months ago.

That's the takeaway from a study released Tuesday morning from the Centers for Disease Control and Prevention, which offered the first clinical efficacy data for the bivalent shot since its national rollout in September.

In adults, the relative effectiveness of the bivalent vaccine's protection against symptomatic infection ranged from about 30 percent to up to 56 percent compared with that of the monovalent vaccine, with the relative efficacy estimated to be larger the more time had passed since a person's last monovalent shot.

Enlarge / Pumpkin pie isn't complete without a dollop of whipped cream. Danish scientists concocted a fat-free analog from bacteria. (credit: Getty Images)

The human love affair with whipped cream dates back to at least the 16th century, and it's a staple of all our favorite holiday desserts. Is that slice of Thanksgiving pumpkin pie truly the same without a dollop of whipped cream on top? But whipped cream also contains 38 percent saturated fat. That's one reason it's so delightfully fluffy and pleasurable to eat, but it's also not great for our health, and dairy farming is a major source of greenhouse gases. So food scientists at the University of Copenhagen decided to explore possible low-fat, sustainable alternatives. They successfully created a fat-free prototype based on bacteria, according to a recent paper published in the journal Food Hydrocolloids. Someday, per the authors, the whipped topping on our holiday desserts could be made from beer-brewing residues or plants.

"We usually associate bacteria with something to keep away from food," said co-author Jens Risbo, a food scientist at the University of Copenhagen. "But here, we base a beloved food product on good bacteria found in nature. This has never been seen before. This is advantageous, both because it is a renewable resource grown in a tank, and because it creates a healthier, less energy-dense, fat-free product."

Whipped cream is a type of liquid foam, a category that also includes hair styling mousse and shaving cream. Such foams are created by beating air into a liquid formula that contains, among other ingredients, some kind of a surfactant (active surface agent)—a collection of complex molecules that link together to stiffen the resulting froth into a substantial foam. The surfactant—usually fats or proteins in edible foams, or chemical additives in shaving cream or styling mousse—keeps surface tension from collapsing bubbles by strengthening the thin liquid film walls that separate them. Cream, with its high-fat content, serves as the surfactant in whipped cream.

Enlarge (credit: Michael Schamis/Flickr/CC)

Spider monkeys don’t live anywhere near the central Mexican highlands, including the area around what’s now Mexico City, once the home of Teotihuacan. So when University of California, Riverside, archaeologist Nawa Sugiyama and her colleagues found the 1,700-year-old skeleton of one buried alongside other offerings in a pyramid in the city’s ceremonial center, they knew it must have come from far afield—such as somewhere in the territory of what was then a neighboring political power, the Maya. And the little primate hints at a previously unsuspected history of diplomatic links between Teotihuacan’s rulers and Maya kingdoms further south.

A diplomatic gift

Sugiyama and her colleagues found the skeleton interred as part of a ritual offering deep inside one of the three pyramids that make up the Plaza of the Columns complex in the ceremonial district of ancient Teotihuacan. It was found alongside a trove of jade figurines that were traced by their chemical makeup to the Motagua Valley in what’s now central Guatemala. There were also finely worked obsidian blades and shell ornaments, along with the remains of other animal sacrifices, including an eagle, a puma, and several rattlesnakes.

No primates (other than humans) live in the region around what’s now Mexico City, and a spider monkey would have been “an exotic curiosity, alien to the high elevations of Teotihuacan,” as Sugiyama and her colleagues describe it in their paper.

Enlarge / An astronomical clock in Prague, Czech Republic. (credit: Getty Images)

There are not many things you can get Facebook, Google, the United States, France, and Linus Torvalds to agree on, but one of them has come to pass.

A near-unanimous vote on Friday in Versailles, France, by parties to the International Bureau of Weights and Measures (BIPM in its native French) on Resolution 4 means that starting in 2035, the leap second, the remarkably complicated way of aligning the earth's inconsistent rotation with atomic-precision timekeeping, will see its use discontinued. Coordinated Universal Time, or UTC, will run without them until 2135. It was unclear whether any leap seconds might occur before then, though it seems unlikely.

The assumption is that within those 100 years, time-focused scientists (metrologists) will have found a way to synchronize time as measured by humans to time as experienced by our planet orbiting the Sun. But most people will not notice any difference at all, even as the time difference could reach up to one minute by the end of that 100 years.

Enlarge / The Orion spacecraft approaches the Moon on Monday. (credit: NASA)

So far, NASA's ambitious Artemis I mission seems to be going swimmingly. The Orion spacecraft has performed a number of propulsive burns, flying smoothly past the Moon, and will now test out its capabilities in deep space.

On Monday evening, after flying around the Moon, the spacecraft returned images of the flyby back to Earth via the Deep Space Network. While no humans are on board Orion during this test flight, they will be during its next mission. The views of the Moon from human spacecraft—the first in more than half a century—were brilliant.

"Today was a terrific day," said Howard Hu, program manager for the Orion spacecraft, speaking about the spacecraft's performance and its images. "This is a dream for many of us who work at NASA. We were like kids in a candy store."

Enlarge / "Opportunity was our brave, intrepid explorer so we could see this unchartered world that we'd never seen before." (credit: Prime Video)

For over 14 years, space nerds and the general public alike were riveted by the parallel journeys of Spirit and Opportunity, twin intrepid Mars rovers who launched and landed on the red planet three weeks apart and surpassed their original 90-day missions by many years. We watched from Earth as they explored the Martian surface and dutifully collected samples before finally giving up the ghost in 2010 and 2018, respectively. Now we can relive that journey all over again—while others can discover it for the first time—in Good Night Oppy, a dazzling, feel-good new documentary from Prime Video directed by Ryan White.

It's easy to forget that the triumphant story of Spirit and Opportunity began against a backdrop of two previous failed missions to Mars: the Mars Climate Orbiter, a robotic space probe that lost communication as it went into orbit insertion, and the Mars Polar Lander, which never re-established communication after what was likely a crash landing. While the orbiting 2001 Mars Odyssey mission was a success, there was still tremendous pressure on the teams at NASA's Jet Propulsion Laboratory to finally land an autonomous solar-powered robotic rover on Mars. Another failure could have jeopardized the future of NASA's Mars Exploration Rover program.

Fortunately, both launches went off without a hitch. There was a moment of terror when Spirit bounced dramatically upon impact, resulting in a nail-biting delay until the signal was re-established. (The engineers in Good Night Oppy joke that Spirit was always a bit of a drama queen.) But Spirit was fine, and Opportunity landed safely a few weeks later. Each rover spent the next several years exploring their respective regions of Mars, overcoming steep hills, getting stuck in the loose Martian soil, and bracing against dust storms to deliver oodles of valuable scientific insights back to mission control on Earth.

Enlarge / Pfizer CEO Albert Bourla talks during a press conference with the European Commission president after a visit to oversee the production of the Pfizer-BioNtech COVID-19 vaccine at the factory of US pharmaceutical company Pfizer, in Puurs, on April 23, 2021. (credit: Getty | John Thys)

Pfizer CEO Albert Bourla claimed at a news event last week that the company's COVID-19 vaccines will continue to be "free to all Americans," despite the company's plan to raise the price of the vaccine roughly 400 percent—a price difference that will be picked up by health insurers.

The company said in October that it plans to raise the price of a dose of its COVID-19 vaccine from about $30 to somewhere between $110 and $130 as it moves the shots to the commercial market next year.

Until now, all COVID-19 vaccines in the US have been bought by the US government, which paid $30.48 per dose in its latest vaccine supply agreement from June. The US government had previously paid $24 per dose in July 2021 and $19.50 per dose in July 2020. The government offered all the doses to Americans for free.

Enlarge / This image taken by NASA's Orion spacecraft shows its view just before the vehicle flew behind the Moon. (credit: NASA)

NASA's Orion spacecraft flew to within 130 km of the Moon's surface on Monday morning after executing one of the most demanding maneuvers of its 25-day mission.

Since launching on top of the Space Launch System rocket last Wednesday, Orion's European Service Module had conducted four "trajectory correction burns" on the way to the Moon. These were brief firings of the service module's main engine, an Aerojet-built AJ10 engine. However, the propulsion system faced a stiffer test on Monday as part of a maneuver to enter orbit around the Moon. It passed with flying colors.

The AJ10 engine burned for 2 minutes and 30 seconds as Orion passed behind the Moon, out of contact with NASA back on Earth. When Orion reemerged from the lunar shadow, all was well, and the spacecraft was positioned to reach its temporary destination—a distant retrograde orbit around the Moon.

Enlarge / The Adidas Al Rihla ball during the international friendly match between Japan and United States at Merkur Spiel-Arena on September 23, 2022 in Duesseldorf, Germany. (credit: DeFodi Images via Getty)

As with every World Cup, at the 2022 FIFA World Cup in Qatar the players will be using a new ball. The last thing competitors want is for the most important piece of equipment in the most important tournament in the world’s most popular sport to behave in unexpected ways, so a lot of work goes into making sure that every new World Cup ball feels familiar to players.

I am a physics professor at the University of Lynchburg who studies the physics of sports. Despite controversies over corruption and human rights issues surrounding this year’s World Cup, there is still beauty in the science and skill of soccer. As part of my research, every four years I do an analysis of the new World Cup ball to see what went into creating the centerpiece of the world’s most beautiful game.

The physics of drag

Between shots on goal, free kicks, and long passes, many important moments of a soccer game happen when the ball is in the air. So one of the most important characteristics of a soccer ball is how it travels through air.

Enlarge / Cement works, Ipswich, Suffolk, UK. (Photo by BuildPix/Construction Photography/Avalon/Getty Images) (credit: Construction Photography/Avalon via Getty Images)

Nobody knows who did it first, or when. But by the 2nd or 3rd century BCE, Roman engineers were routinely grinding up burnt limestone and volcanic ash to make caementum: a powder that would start to harden as soon as it was mixed with water.

They made extensive use of the still-wet slurry as mortar for their brick- and stoneworks. But they had also learned the value of stirring in pumice, pebbles, or pot shards along with the water: Get the proportions right, and the cement would eventually bind it all into a strong, durable, rock-like conglomerate called opus caementicium or—in a later term derived from a Latin verb meaning “to bring together”—concretum.

The Romans used this marvelous stuff throughout their empire—in viaducts, breakwaters, coliseums, and even temples like the Pantheon, which still stands in central Rome and still boasts the largest unreinforced concrete dome in the world.

Enlarge / Elizabeth Holmes (C), founder and former CEO of blood testing and life sciences company Theranos, walks with her mother Noel Holmes and partner Billy Evans into the federal courthouse for her sentencing hearing on November 18, 2022, in San Jose, California. (credit: Getty | Amy Osborne)

Elizabeth Holmes has been sentenced to 11.25 years in federal prison, plus three years of supervision for her conviction in January on four counts of defrauding investors of her failed blood-testing company, Theranos. Restitution in the case will be determined at a later hearing, not yet set.

The sentencing is less than the maximum of 20 years set by federal sentencing guidelines, but still more than the nine-year prison sentence recommended by the probation officer in Holmes' case.

Federal prosecutors had sought 15 years of imprisonment and for Holmes, 38, to pay roughly $804 million in restitution to defrauded investors. Holmes' lawyers, meanwhile, requested just 18 months of house arrest and argued that she has "essentially no assets" and could not pay a nine-figure fine.

Enlarge / Each one of the silvery squares includes a small sheet of an atomically thin material. (credit: Dodda, et. al.)

Since the isolation of graphene, we've identified a number of materials that form atomically thin sheets. Like graphene, some of these sheets are made of a single element; others form from chemicals where the atomic bonds naturally create a sheet-like structure. Many of these materials have distinct properties. While graphene is an excellent conductor of electricity, a number of others are semiconductors. And it's possible to tune their properties further based on how you arrange the layers of a multi-sheet stack.

Given all those options, it shouldn't surprise anyone that researchers have figured out how to make electronics out of these materials, including flash memory and the smallest transistors ever made, by some measures. Most of these, however, are demonstrations of the ability to make the hardware—they're not integrated into a useful device. But a team of researchers has now demonstrated that it's possible to go beyond simple demonstrations by building a 900-pixel imaging sensor using an atomically thin material.

Making pictures

Most image sensors currently consist of standard silicon semiconductors, manufactured using the usual complementary metal–oxide semiconductor (CMOS) processes. But it's possible to replace the silicon with another semiconductor. In this case, the researchers used molybdenum disulfide, an atomically thin material that has seen a lot of use in experimental devices.

Enlarge / Forensic facial reconstruction of the "Connecticut vampire" (aka JB55), accounting for known tooth loss and inferred health issues. Hair is based on 19th century styles. Skin, hair, and eye color are based on phenotype predictions (credit: Parabon NanoLabs )

Thanks to the efforts of Parabon NanoLabs and the Armed Forces DNA Identification Laboratory, we now know what the so-called "Connecticut vampire" probably looked like. Using DNA analysis and a 3D scan of the skull, the two labs collaborated to digitally reconstruct the face of the 19th century man whose remains were discovered more than 30 years ago. The image was revealed earlier this month at the International Symposium on Human Identification conference in Washington, DC. The work also builds on earlier DNA analysis to strengthen the evidence that the man in question was a former resident named John Barber.

As we've reported previously, back in 1990, children playing near a gravel pit in Griswold, Connecticut, stumbled across a pair of skulls that had broken free of their graves in a 19th century unmarked cemetery. Subsequent excavation revealed 27 graves—including that of a middle-aged man identified only by the initials "JB55," spelled out in brass tacks on his coffin. Unlike the other burials, his skull and femurs were neatly arranged in the shape of a skull and crossbones, leading archaeologists to conclude that the man had been a suspected "vampire" by his community.

Analysis of JB55's bones in the 1990s indicated the man had been a middle-aged laborer, around 55 when he died. The remains also showed signs of lesions on the ribs, so JB55 suffered from a chronic lung condition—most likely tuberculosis, known at the time as consumption. It was frequently lethal in the 1800s due to the lack of antibiotics, and symptoms included a bloody cough, jaundice (pale, yellowed skin), red and swollen eyes, and a general appearance of "wasting away." And the sickness often spread to family members. That could be why local folklore suspected some victims of being vampires, rising from the grave to sicken the community they left behind.