Ars Technica - The Scientific Method

Study: Solitary electric eels sometimes hunt in groups with synchronized zaps

Mon, 18 Jan 2021 20:06:44 GMT

Volta's electric eels can gather in groups, working together to corral smaller fish in shallower waters, a new study finds. Then, smaller groups of about 10 eels attack in unison with high-voltage discharges.

Electric eels were long believed to be solitary predators, preferring to hunt and kill their prey alone by sneaking up on unsuspecting sleeping fish at night and shocking them into submission. But according to a recent paper published in the journal Ecology and Evolution, there are rare circumstances in which eels employ a social hunting strategy instead. Specifically, researchers have observed more than 100 electric eels in a small lake in the Brazilian Amazon River basin forming cooperative hunting parties to capture small fish called tetras.

"This is an extraordinary discovery," co-author C. David de Santana, of the Smithsonian National Museum of Natural History, said. "Nothing like this has ever been documented in electric eels. Hunting in groups is pretty common among mammals, but it's actually quite rare in fishes. There are only nine other species of fishes known to do this, which makes this finding really special."

Electric eels are technically knife fish. The eel produces its signature electric discharges—both low and high voltages, depending on the purpose for discharging—via three pairs of abdominal organs comprised of electrocytes, located symmetrically along both sides of the eel. The brain sends a signal to the electrocytes, opening ion channels and briefly reversing the polarity. The difference in electric potential then generates a current, much like a battery with stacked plates.

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Virgin Orbit just earned the orbit part of its name

Mon, 18 Jan 2021 17:44:26 GMT

Enlarge / LauncherOne heads to orbit after dropping from its carrier aircraft on Sunday. (credit: Virgin Orbit)

On Sunday afternoon, Virgin Orbit joined the rare club of companies that have privately developed a rocket and successfully launched it into orbit. Moreover, with its LauncherOne rocket dropped from a 747 aircraft, the California-based company has become the first to reach orbit with an air-launched, liquid-fueled rocket.

"This magnificent flight is the culmination of many years of hard work and will also unleash a whole new generation of innovators on the path to orbit," said Sir Richard Branson, the founder of the company. "Virgin Orbit has achieved something many thought impossible."

Sunday's flight, which included multiple firings of LauncherOne's upper stage engine and successful deployment of several small satellites for NASA, caps a development program that has spanned about eight years and myriad technical challenges.

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A curious observer’s guide to quantum mechanics, pt. 2: The particle melting pot

Sun, 17 Jan 2021 14:00:04 GMT

One of the quietest revolutions of our current century has been the entry of quantum mechanics into our everyday technology. It used to be that quantum effects were confined to physics laboratories and delicate experiments. But modern technology increasingly relies on quantum mechanics for its basic operation, and the importance of quantum effects will only grow in the decades to come. As such, physicist Miguel F. Morales has taken on the herculean task of explaining quantum mechanics to the rest of us laymen in this seven-part series (no math, we promise). Below is the second story in the series, but you can always find the starting story here.

Welcome back for our second guided walk into the quantum mechanical woods! Last week, we saw how particles move like waves and hit like particles and how a single particle takes multiple paths. While surprising, this is a well-explored area of quantum mechanics—it is on the paved nature path around the visitor’s center.

This week I’d like to get off the paved trail and go a bit deeper into the woods in order to talk about how particles meld and combine while in motion. This is a topic that is usually reserved for physics majors; it's rarely discussed in popular articles. But the payoff is understanding how precision lidar works and getting to see one of the great inventions making it out of the lab, the optical comb. So let's go get our (quantum) hiking boots a little dirty—it'll be worth it.

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AI-powered text from this program could fool the government

Sun, 17 Jan 2021 11:55:17 GMT

Enlarge (credit: Elena Lacey | Getty Images)

In October 2019, Idaho proposed changing its Medicaid program. The state needed approval from the federal government, which solicited public feedback via Medicaid.gov.

Roughly 1,000 comments arrived. But half came not from concerned citizens or even Internet trolls. They were generated by artificial intelligence. And a study found that people could not distinguish the real comments from the fake ones.

The project was the work of Max Weiss, a tech-savvy medical student at Harvard, but it received little attention at the time. Now, with AI language systems advancing rapidly, some say the government and Internet companies need to rethink how they solicit and screen feedback to guard against deepfake text manipulation and other AI-powered interference.

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After a decade, NASA’s big rocket fails its first real test

Sun, 17 Jan 2021 03:57:07 GMT

At 4:27pm central time, the SLS rocket core stage ignited its four RS-25 engines at NASA's Stennis Space Center. The test was to last up to eight minutes. [credit: Trevor Mahlmann for Ars ]

STENNIS SPACE CENTER, Miss.—For a few moments, it seemed like the Space Launch System saga might have a happy ending. Beneath brilliant blue skies late on Saturday afternoon, NASA’s huge rocket roared to life for the very first time. As its four engines lit, and thrummed, thunder rumbled across these Mississippi lowlands. A giant, beautiful plume of white exhaust billowed away from the test stand.

It was all pretty damn glorious until it stopped suddenly.

About 50 seconds into what was supposed to be an 8-minute test firing, the flight control center called out, “We did get an MCF on Engine 4.” This means there was a “major component failure” with the fourth engine on the vehicle. After a total of about 67 seconds, the hot fire test ended.

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What motivates the motivated reasoning of pro-Trump conspiracists?

Sat, 16 Jan 2021 18:54:09 GMT

Enlarge / January 7, 2021 - St. Paul, Minn. — Trump supporters gather at the Minnesota Governor's Residence after a "Storm The Capitol" event at the Minnesota State Capitol. (credit: Chad Davis / Flickr)

Motivated reasoning is the idea that our mental processes often cause us to filter the evidence we accept based on whether it's consistent with what we want to believe. During these past few weeks, it has been on display in the United States on a truly grand scale. People are accepting context-free videos shared on social media over investigations performed by election officials. They're rejecting obvious evidence of President Donald Trump's historic unpopularity, while buying in to evidence-free conspiracies involving deceased Latin American dictators.

If the evidence for motivated reasoning is obvious, however, it's a lot harder to figure out what's providing the motivation. It's not simply Republican identity, given that Trump adopted many policies that went against previous Republican orthodoxy. The frequent appearance of Confederate flags confirms some racism is involved, but that doesn't seem to explain it all. There's a long enough list of potential motivations to raise doubts as to whether a single one could possibly suffice.

A recent paper in PNAS, however, provides a single explanation that incorporates a lot of the potential motivations. Called "hegemonic masculinity," it involves a world view that places males from the dominant cultural group as the focus of societal power. And survey data seems to back up the idea.

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Hackers alter stolen regulatory data to sow mistrust in COVID-19 vaccine

Fri, 15 Jan 2021 22:40:48 GMT

Enlarge (credit: Getty Images)

Last month, the makers of one of the most promising coronavirus vaccines reported that hackers stole confidential documents they had submitted to a European Union regulatory body. On Friday, word emerged that the hackers have falsified some of the submissions’ contents and published them on the Internet.

Studies of the BNT162b2 vaccine jointly developed by pharmaceutical companies Pfizer and BioNTech found it’s 95 percent effective at preventing COVID-19 and is consistently effective across age, gender, race, and ethnicity demographics. Despite near-universal consensus among scientists that the vaccine is safe, some critics have worried it isn’t. The hackers appear to be trying to stoke those unsupported worries.

Data unlawfully accessed by the hackers “included internal/confidential email correspondence dating from November, relating to evaluation processes for COVID-19 vaccines,” the European Medicines Agency based in Amsterdam said in a statement. “Some of the correspondence has been manipulated by the perpetrators prior to publication in a way which could undermine trust in vaccines.”

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With Trump’s vaccine rollout in chaos, Biden unveils five-point plan

Fri, 15 Jan 2021 22:30:54 GMT

Enlarge / US President-elect Joe Biden delivers remarks on his plan to administer COVID-19 vaccines in Wilmington, Delaware on January 15, 2021. (credit: Getty | Angela Weiss)

President-elect Joe Biden on Friday unveiled a five-point plan to try to rescue the country’s beleaguered COVID-19 vaccination campaign and achieve his stated goal of reaching 100 million shots in his first 100 days in office.

The five steps include, in brief:

Working with states to open and clarify eligibility for vaccination
Help set up additional vaccination sites
“Fully activate” pharmacies to act as vaccination sites
Ramp up manufacturing of vaccine and supplies
Commit to transparency and rollout a massive public information campaign to combat disinformation

“The vaccine rollout in the United States has been a dismal failure thus far,” Biden said in speech. These five things are an attempt to turn things around, to “turn frustration into motivation.”

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As it turns out, the Biden administration will listen to scientists

Fri, 15 Jan 2021 20:46:32 GMT

Enlarge / Co-Founder & CEO of 23andMe, Anne Wojcicki President & Founding Director Broad Institute of MIT and Harvard Professor, Eric Lander, speak onstage during the TIME 100 Health Summit in 2019. (credit: Brian Ach/Getty Images)

During the height of the presidential election last October, President Trump warned voters that if Joe Biden was elected president, he would "listen to the scientists." Now, as the president-elect is about to be inaugurated as the 46th president of the United States, Biden appears to be leaning into this attack line.

On Friday, the incoming Biden administration announced that it would name Eric Lander to become director of the Office of Science Technology and Policy. As is customary in this role, Lander will also serve as chief "science advisor" to the president. In addition, Biden announced that he is making the science advisor a cabinet-level position. This is a first for this role.

“Science will always be at the forefront of my administration—and these world-renowned scientists will ensure everything we do is grounded in science, facts, and the truth," President-elect Biden said in a news release announcing the appointments.

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FDA blindsided as Trump Admin cripples agency on its way out

Fri, 15 Jan 2021 20:40:47 GMT

Enlarge / Stephen Hahn, commissioner of the US Food and Drug Administration. (credit: Getty | Bloomberg)

The US Food and Drug Administration is under siege from the Trump Administration, which is forcing through a steady stream of changes in its final days that threaten the remaining independence of the regulatory agency.

Perhaps the most dramatic meddling came on Monday, when FDA officials were blindsided as the agency cycled through three different top lawyers. FDA’s Chief Counsel, Stacy Cline Amin—a Trump appointee—resigned Monday, which FDA Commissioner Stephen Hahn announced in an email. Hahn’s email also included the news that career civil servant Mark Raza, the FDA’s principal deputy chief counsel, would serve as Cline Amin’s replacement on an acting basis. But that decision was abruptly overturned Monday night when the Department of Health and Human services tweeted that James Lawrence, deputy general counsel for the HHS, would serve as the FDA’s new chief counsel until January 20.

"We were all very surprised," a senior FDA official told Politico. "But it's consistent with all the fire bombs that keep getting thrown over the fence."

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There is no COVID vaccine reserve. Trump admin already shipped it

Fri, 15 Jan 2021 16:58:27 GMT

Enlarge / Alex Azar, secretary of Health and Human Services (HHS), who allegedly deceived states on the vaccine supply, receives the Moderna COVID-19 vaccine during an event at the NIH Clinical Center on Tuesday, December 22, 2020. (credit: Getty | Bloomberg)

The Trump administration announced Tuesday, January 12, that it would begin shipping reserved vaccine supplies, raising hopes that states may see their vaccine supply potentially double as they work to accelerate the sluggish immunization campaign. But according to a report by The Washington Post, that promised vaccine stockpile doesn’t actually exist—it was already shipped out—and the limited vaccine supply available to states will remain as it is for now.

The news has not only left state health officials angry and confused by the false promises, they’re also left scrambling to sort out distribution changes. In addition to claiming they would release the (non-existent) stockpile, Trump administration officials told states to expand access to vaccines—now allowing anyone over age 65 to get vaccinated and people under 65 who have a documented underlying health condition that makes them more vulnerable to COVID-19.

The expanded eligibility covers around 152 million people in the US. But administration officials had previously estimated that it wouldn’t be until the end of March before they would have 200 million doses—enough to vaccinate only 100 million people—as STAT noted earlier.

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Trump tries to claw back billions from COVID vaccine distributor

Fri, 15 Jan 2021 15:55:02 GMT

Enlarge / A picture taken on January 15, 2021, shows a pharmacist holding with gloved hands a vial of the undiluted Pfizer-BioNTech vaccine for COVID-19. (credit: Getty | JEAN-FRANCOIS MONIER)

With mere days left in office, President Donald Trump has proposed $27.4 billion in brutal budget cuts—including clawing back 5.1 billion from global public health amid a raging pandemic. Of the proposed health cuts, $4 billion would be slashed from a vaccine alliance playing a central role in helping to distribute COVID-19 vaccines to low-income countries.

The proposed cuts are part of a rescission request, which has no chance of being enacted by Congress, as Politico reports. However, the proposed cuts—particularly to the vaccine alliance—are likely to add insult to injury to the global public health community, which continues to battle the out-of-control pandemic.

Worldwide, the total number of COVID-19 cases is over 93 million, and deaths are approaching 2 million. In the US alone, the seven-day rolling average of daily new cases is over 235,000, with 129,000 people currently hospitalized. Around 4,000 people have died each day for the past three days, bringing the US death toll to around 380,000.

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This painted pig is the world’s oldest figurative art

Fri, 15 Jan 2021 15:08:10 GMT

Enlarge (credit: Brumm et al. 2021)

A pig painted on the wall of an Indonesian cave is the world’s oldest figurative art—that is, it’s the oldest known drawing of something, rather than an abstract design or a stencil.

The 45,500-year-old ocher painting depicts a Sulawesi warty pig, which appears to be watching a standoff between two other pigs. If that interpretation is correct, the painting is also a contender for the world’s oldest narrative scene. And it hints at how much the earliest Indonesians observed and recorded about the animals and ecosystems around them. A growing pile of evidence tells us that the first people to reach the islands of Indonesia carried with them a culture of art and visual storytelling, as well as the means to cross the expanses of water between the islands, eventually reaching Australia.

Painted pig’s feet, anyone?

Griffith University archaeologist Adam Brumm and his colleagues used uranium-series dating to measure the age of a mineral deposit that had formed above one of the pig’s rear feet. As water flows through a limestone cave, it leaves behind small deposits of minerals, which gradually build up into layers of calcite, like the one atop the pig painting. The minerals in the water contain trace amounts of uranium, which gradually decays into different uranium isotopes and eventually into a completely different element, thorium. By measuring the amounts of uranium-234 and thorium-230 in a cave deposit (also called a speleothem) and then comparing that to the local groundwater, archaeologists can measure how long ago the speleothem formed.

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NASA gives up on taking Mars’ temperature

Fri, 15 Jan 2021 12:30:45 GMT

Enlarge / A selfie taken by the InSight Lander. (credit: NASA/JPL-Caltech)

Today, NASA announced that it was giving up on its attempts to place a temperature sensor several meters under the Martian surface. Part of the agency's InSight lander, the hardware was supposed to be placed deep enough to avoid the influence of Mars' weather, seasons, and daily temperature changes. But because of the unusual conditions at the landing site, the hardware never made it below the surface.

The InSight lander carried several instruments meant to provide a clearer picture of Martian geology. One of those instruments, the SEIS seismometer, has been successfully tracking marsquakes to provide a better perspective on Mars' structure and the local composition under the surface near the landing site. A second measures the wobbling of Mars' axis of rotation, which will be influenced by a combination of the red planet's composition and the gravitational influences of the rest of the Solar System.

InSight's other major experiment is the Heat Flow and Physical Properties Package, or HP³. While previous landers hadn't put any hardware deeper than about 20 centimeters, HP³ was designed to operate several meters below the Martian surface. From there, the fluctuations on the surface would be somewhat averaged out, and HP³ could measure the heat flow from the Martian interior to the surface. This would allow an estimate of the energy still left in the Martian core from a combination of its formation and radioactivity, a key element in understanding what geological activity might still be possible there.

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Rocket Report: NASA dishes on small rockets, Jeff buys a ride on a Falcon 9

Fri, 15 Jan 2021 12:00:57 GMT

Enlarge / Image of the first AR1 engine built by Aerojet Rocketdyne. (credit: Aerojet Rocketdyne)

Welcome to Edition 3.29 of the Rocket Report! What a wild weekend we're heading toward in the world of rockets and launch, with seemingly too much news to cover:

• Electron, Saturday, 07:38 UTC

• SLS Hot Fire, Saturday, 22:00 UTC

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US grid will see 80 percent of its new capacity go emission-free

Fri, 15 Jan 2021 11:45:34 GMT

Enlarge (credit: US EIA)

Earlier this week, the US Energy Information Agency (EIA) released figures on the new generating capacity that's expected to start operating over the course of 2021. While plans can obviously change, the hope is that, with its new additions, the grid will look radically different than it did just five years ago. The report includes the details of where a new nuclear plant may be started up, although it will be dwarfed by the capacity of new batteries. But the big picture is that, even ignoring the batteries, about 80 percent of the planned capacity additions will be emission-free.

New nukes?

The EIA's accounting shows that just under 40 Gigawatts of capacity will be placed on the grid during 2021, but there are a number of caveats to this. First and foremost is the inclusion of batteries, which account for over 10 percent of that figure (4.3GW). While batteries may look like short-term generating capacity from the perspective of "can this put power on the grid?" they're obviously not actually a net source of power. Typically, they're used to smooth over short-term fluctuations in supply or demand rather than a steady source of power.

Still, given the rarity of grid-scale batteries even a few years ago, 4.3GW of them is striking.

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Craft brewers now have a new tool for sniffing out trace flavor compounds

Thu, 14 Jan 2021 21:28:41 GMT

Enlarge / In dry hopping, hops are added during or after the fermentation stage of the brewing process. (credit: Natasha Breen/Getty Images)

Craft-beer aficionados relish the endless flavor variations that can be achieved by mixing and matching different varieties of hops, whether one favors refreshing citrus or fruity notes or something a bit more earthy or pine-scented. But some of the chemical compounds that contribute to those flavors are present in such trace amounts that it's difficult for brewers to measure and track them during the brewing process. Now German scientists have devised an automated, efficient method for doing just that, according to a recent paper published in the Journal of Agricultural and Food Chemistry.

As we've previously reported, all beer contains hops, a key flavoring agent that also imparts useful antimicrobial properties. (Without them, beer spoils quickly.) Brewers mash and steep grain in hot water, which converts all that starch into sugars. This is traditionally the stage when hops are added to the liquid extract (wort) and boiled to give the beer that hint of bitterness. During the boiling process, a certain portion of the resins (alpha acids) in hops isomerize into iso-alpha acids. That chemical rearrangement of the molecules is what produces bitterness. Yeast is then added to trigger fermentation, turning the sugars into alcohol.

But a little hops goes a long way. Add too many hops, and the beer will be so bitter as to be undrinkable.

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2020 ties 2016 as the warmest year on record

Thu, 14 Jan 2021 18:16:43 GMT

Enlarge / Intense wildfires were one of the climate impacts linked to the recent string of very hot years. (credit: Bloomberg/Getty Images)

Today, NASA and NOAA are announcing that 2020 was one for the record books, tying with 2016 for the warmest year since we've been tracking temperatures. NASA rates 2020 as the warmest ever, although by a margin that's not large enough to reach statistical significance; NOAA reverses the order, also without a significant difference between the two years. Whatever its precise rank, 2020 was the continuation of a worrying trend—the past seven years are all on the list of the seven warmest years on record, regardless of which source you turn to for your global temperatures.

While there is a lot of year-to-year variability (black), the overall trend (red) is hard to miss. (credit: NASA)

Another reason for concern is that 2020 saw the El Niño-Southern Oscillation (ENSO) in a state that, in the absence of human-driven climate change, would have produced relatively cool conditions. NASA's Gavin Schmidt said that, in the absence of the influence of the ENSO, 2020 would have been the warmest year on record. As shown in the chart below, strong El Niño years tend to be associated with warm records, while the cycle's opposing conditions, called La Niña, are typically associated with cooler conditions. 2016 was notable for having the strongest El Niño since the 1990s, an event that pushed temperatures far above the baseline where they'd spent most of the start of the century.

Since then, the ENSO has been largely stuck in neutral, shifting back and forth between weak El Niños and La Niña tendencies. Temperatures dropped slightly, but not back to the conditions that were typical of the decade prior. 2020 saw temperatures match those of 2016's strong El Niño despite remaining stuck in neutral. "The previous record warm year, 2016, received a significant boost from a strong El Niño," Schmidt said in a statement. "The lack of a similar assist from El Niño this year is evidence that the background climate continues to warm due to greenhouse gases.”

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China tosses more obstacles at WHO team investigating pandemic’s origin

Thu, 14 Jan 2021 18:01:59 GMT

Enlarge / Health workers in personal protection suits stand next to buses at a cordoned-off section of the international airport in Wuhan on January 14, 2021, following the arrival of a World Health Organization (WHO) team investigating the origins of the COVID-19 pandemic. (credit: Getty | NICOLAS ASFOURI )

Chinese authorities have held up two scientists sent to Wuhan, China, by the World Health Organization to investigate the origins of the novel coronavirus—yet another obstacle the Chinese government has thrown at the health agency’s efforts to understand how the devastating pandemic began.

The two scientists were traveling as part of an international team of 15 that has long been working to gain access to the city where the virus first emerged in late 2019. Thirteen of the scientists—who all repeatedly tested negative for the coronavirus, SARS-CoV-2, in their home countries—were allowed to travel on. They have now arrived in Wuhan, the WHO said on Twitter earlier today. However, China is still requiring the 13 scientists to undergo a 14-day quarantine in Wuhan.

The two scientists held back also tested negative for the virus multiple times prior to traveling. But while in Singapore en route to Wuhan, they tested positive for SARS-CoV-2 antibodies, suggesting past exposure to the virus. Despite their negative PCR tests, Chinese authorities had them remain in Singapore for additional testing.

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SpaceX hot fire tests its Starship vehicle three times in four hours

Thu, 14 Jan 2021 00:46:11 GMT

Enlarge / The Sun glints around the lower fin of Starship SN8 on Dec. 9, 2020. (credit: Trevor Mahlmann )

On Wednesday, in South Texas, SpaceX fired up its newest Starship prototype not once or twice. Rather, engineers and technicians fueled and test fired their SN9 prototype and its Raptor rocket engines three times in less than four hours.

After the first of three tests, SpaceX founder and chief engineer said on Twitter, "Today at SpaceX is about practicing Starship engine starts. Ship is held down by massive pins while engines are fired." After the third test, Musk confirmed that all three tests were completed without a major issue.

Performing three tests like this in rapid succession is a notable achievement, and it points to maturing spaceship hardware, ground systems, and procedures for SpaceX's Starship launch program. Musk said the goal is to reach a point where one could "hop in and go" to Mars. Such a capability remains years into the future, if it is ever realized. But the company appears to be making progress toward a robust launch system.

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