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Over 10,000 years ago, weapons at White Sands were aimed at giant sloths

Thu, 04/26/2018 - 08:33

Enlarge (credit: Bustos et al. 2018)

More than 10,000 years ago, a band of hunter-gatherers chased a group of giant ground sloths along the shores of an ancient lake, and their footprints still preserve the story. West of the sparkling white gypsum dunes of White Sands National Monument, at a site called Alkali Flat, layers of mud and sand left behind by a long-vanished lake hold more than 100 human and giant ground sloth tracks—rare evidence of Pleistocene hunters stalking, and sometimes cornering, giant sloths.

Most of them are so-called “ghost tracks,” visible only under very specific conditions.

“Most of the time they are invisible. There is a lot of salt in ground, and when it rains, the salt dissolves. And, crucially, as it dries out, the fill dries at a different rate and the difference between the fill (footprint) and the surrounding sediment makes the track visible for a brief time while it dries out,” explained paleoecologist Sally Reynolds of the UK’s Bournemouth University, a co-author on the paper. The team, led by the US National Parks Service’s David Bustos, used aerial photography to spot the tracks and then selected a few groups for careful excavation and study.

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California can look forward to more extreme dry-wet “climate whiplash”

Wed, 04/25/2018 - 16:00

Enlarge / Don Pedro Reservoir was down to 61 percent of its normal level in 2015 but filled to 134 percent by early 2017 after a very wet winter. (credit: NASA Earth Observatory)

As the last few years have reminded us, California weather means you have to be prepared for anything. From 2012 to 2016, the Golden State saw a historic drought that led to water restrictions—and saw land areas sinking as groundwater use increased to compensate. But the winter of 2016 brought too much rain, producing flooding and evacuations below the Oroville Dam.

Variable rainfall is a natural component of California’s climate, but what will happen as climate change continues to play out? That’s the question a team led by UCLA’s Daniel Swain recently set out to answer.

Sim California

Though climate change projections show a warmer California, total rainfall isn’t expected to change much. But in this case, the researchers used climate model simulations to analyze precipitation variability, specifically, rather than just annual totals. They compared historical weather records, an 1,800-year-long simulation of the climate pre-Industrial-Revolution, and 40 simulations of climate change from 1920 to 2100 (assuming high future greenhouse gas emissions). These long simulations allowed them to accumulate meaningful statistics for different weather patterns.

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Researchers edit coral genes, hope to understand how to save them

Wed, 04/25/2018 - 11:50

Enlarge (credit: NOAA)

Coral reefs are the poster-organisms for ecosystem services, aiding fisheries, promoting biodiversity, and protecting land from heavy waves. Unfortunately, we seem to be repaying them by killing them. Our warming oceans are causing coral bleaching and death, rising sea levels will force them to move, and the acidification of our oceans will make it harder for them to form reefs. It would be nice if we could help them, but interventions are difficult to design when you don't know enough about coral biology.

Now scientists have announced a new tool is available to study corals: genetic editing provided by the CRISPR/Cas9 system. The ability to selectively eliminate genes could help us understand how corals function normally and could eventually provide a tool that lets us help them ride out climate change.

Coral complexities

You might think that we'd have a pretty good grasp of coral biology, given the amount of study that reefs receive. But much of that study has focused on coral reefs as an ecosystem, rather than coral as an organism. And that's a big barrier to helping these reef-builders survive in our changing world. To give one example, coral bleaching is caused by a heat-driven breakdown in the symbiosis between coral and a photosynthetic algae that provides the coral with food. Corals that live in warmer waters are clearly able to form partnerships with heat-tolerant algae, but the precise mechanics of which species partner with what algae aren't well understood.

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A short, new movie of a comet’s surface is pretty incredible

Wed, 04/25/2018 - 09:38

Enlarge / False-color image showing the smooth Hapi region connecting the head and body of comet 67P/Churyumov-Gerasimenko. (credit: ESA)

The European Space Agency's Rosetta spacecraft arrived at Comet 67P/Churyumov–Gerasimenko in 2014 and subsequently became the first mission to ever orbit around a comet. Additionally, its small Philae lander became the first to touch down on a comet’s surface—although it was subsequently lost after it was unable to deploy its solar panels in a proper configuration to capture enough energy to continue operations.

During its two years in varying orbits around the comet, which is about 4km on its longest side, Rosetta captured some unprecedented imagery of these Solar System interlopers. Now, a Twitter user named landru79 has combed through the Rosetta image archives and found a striking series of 12.5-second exposure photos taken from about 13km away from the comet. The images from June 1, 2016, are combined into the short video below.

The bright dots travelling from the top of the frame to the bottom, which look something like snow, are in fact background stars. They have that apparent motion as the spacecraft moves and the comet rotates. The more rapidly moving streaks are thought to be dust particles illuminated by the Sun. There also appear to be a few streaking cosmic rays.

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On his first day, NASA’s new administrator sets an inclusive tone

Tue, 04/24/2018 - 08:56

Enlarge / Jim Bridenstine, standing with his family, takes the oath of office from Vice President Mike Pence. (credit: NASA)

During his lengthy confirmation process to become NASA's new administrator, Oklahoma conservative Jim Bridenstine got pilloried for being a divider rather than a uniter. Noting Bridenstine's attacks on Marco Rubio during the 2016 presidential election, Florida Senator Bill Nelson characterized Bridenstine's politics as "divisive and extreme." Given that the space agency was apolitical, Nelson asked, “How do you keep NASA from being dragged down in a divisive political background?”

Nelson, a Democrat, was never satisfied with Bridenstine's answers and opposed his nomination to become administrator until the end. As a result, so did the entire Democratic party, and this forced a tense, party-line vote on Bridenstine when in the past NASA administrators have largely been approved by unanimous consent.

Truthfully, no one knows how Bridenstine will lead NASA. Critics have painted him as a climate change denier and against gay rights. However, the former congressman struck a moderate tone during his confirmation hearing, and as a pilot with a background in the US Navy, he has shown leadership on key aerospace issues during this five-and-a-half years in Congress.

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Interest in science, not ability, builds trust in climate science

Tue, 04/24/2018 - 07:15

Enlarge (credit: Carrie Martin/LLNL)

Studies of how people perceive climate science paint a depressing picture—one in which ideology overwhelms evidence. Not only does opinion about the science break down along ideological lines, but knowledge of science seems to make matters worse, accentuating the partisan divide.

Those studies have always been somewhat dissatisfying, though, as they leave little room for anyone to dispassionately evaluate the evidence or voice trust in the researchers who have. And, in fact, they don't explain how exceptions come to exist—the significant conservative voices that are calling for action on climate change.

A study done by Matthew Motta of the University of Minnesota delves in to how people might escape ideological blinders. Motta found that people with a long-term interest in science tend to trust scientific authorities like NASA and the IPCC when it comes to climate, regardless of what their political persuasions may be. It's the latest result that indicates that a "scientific curiosity" can get people past their ideology.

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“I feel whole again:” Wounded vet receives first penis-scrotum combo transplant

Mon, 04/23/2018 - 14:34

Enlarge / Doctors performing surgery. (credit: Getty | BSIP)

A young military veteran severely maimed by an improvised explosive device (IED) received a transplant of a large section of tissue, including the penis, scrotum, and a portion of the abdominal wall, from a deceased organ donor, according to The New York Times.

The 14-hour operation took place at Johns Hopkins Hospital last month. It marks the third successful penis transplant and the first complex penis transplant, which is to say it involved the scrotum and surrounding tissue as well as the penis. For ethical reasons, surgeons removed the testicles prior to the transplantation to prevent the possibility that the recipient could father children genetically belonging to the donor.

Though doctors expect his recovery and nerve regrowth to take some time, they’re hopeful that the patient will eventually recover the ability to urinate and have spontaneous erections and orgasms. In fact, they expect urination to be possible within a few months.

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Are we sure there wasn’t a coal-burning species 55 million years ago?

Mon, 04/23/2018 - 12:11

Enlarge (credit: Getty / Aurich Lawson)

If you’ve ever wished that a new study came packaged with some science fiction exploring the implications, this is your lucky day. Of course, not every research paper lends itself to a short story, but a manuscript by NASA’s Gavin Schmidt and the University of Rochester’s Adam Frank asks a fun question: are we sure that humans built the first industrial civilization in Earth’s history?

In recent years, scientists have debated defining a new geologic epoch—the “Anthropocene”—based on the idea that humans have done enough to leave a recognizable mark in Earth’s geologic archives. Theoretically, if another world harbored life that produced an industrial civilization, we could find the proof written in that world’s rocks, too.

To examine that idea, Schmidt and Frank pawed through the pages of Earth’s history—after all, it’s not impossible that some earlier species built a civilization that was subsequently wiped out, right? By looking for funky signals in the rock record, you can think about how clear the signs might be on another world.

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NASA’s new planet finder is in space. Now what?

Sun, 04/22/2018 - 10:00

Trevor Mahlmann

Most everyone reading this story will probably know that a SpaceX Falcon 9 rocket launched on Wednesday carrying a NASA spacecraft into orbit—the Transiting Exoplanet Survey Satellite—that will further the space agency's mission of searching for exoplanets.

Less well known is the TESS spacecraft's clever orbit, which will enable an on-a-budget but robust science mission of searching for planets transiting in front of nearby stars. This "lunar resonant" orbit, which has never been used by a spacecraft, will allow TESS to both observe nearby stars and transmit data back to Earth with a minimal energy expenditure. (The useful lifetime of a spacecraft is often determined by its amount of onboard propellant).

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White House reportedly exploring wartime rule to help coal, nuclear

Sat, 04/21/2018 - 10:00

(credit: Kym Farnik)

According to reports from Bloomberg and E&E News, the Trump Administration has been exploring another way to help coal and nuclear generators: the Defense Production Act of 1950.

The Act was passed under President Truman. Motivated by the Korean War, it allows the president broad authority to boost US industries that are considered a priority for national security. On Thursday, E&E News cited sources that said "an interagency process is underway" at the White House to examine possible application of the act to the energy industry. The goal would be to give some form of preference to coal and nuclear plants that are struggling to compete with cheap natural gas.

Third time's the charm?

This appears to be the third attempt to use policy to keep coal and nuclear operators afloat. The main focus is coal generators, which Trump promised to rescue during his campaign. Although Trump's campaign rhetoric often blamed environmental regulations, the problem has been economic more than regulatory; cheap natural gas has been the biggest threat to coal and nuclear.

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Here are the types of marijuana best for stress and anxiety, according to users

Fri, 04/20/2018 - 13:20

Enlarge / Inventory including "Merry N'Berry" is on display at a medical marijuana dispensary (credit: Getty | Tom Williams)

By passively monitoring user-generated data from medical cannabis patients, researchers have glimpsed the types and amounts of marijuana that seem effective for relieving symptoms of stress, anxiety, and depression. The findings could direct more detailed research into the best strains for specific conditions. But the data also hints at a danger of using marijuana to manage depression symptoms in the long term.

The study, published this week in the Journal of Affective Disorders by researchers at Washington State University, is based on data from a medical cannabis app called Strainprint, which lets patients track symptom severity after medical cannabis use. Before that, users enter detailed information about the strain of marijuana used, including selecting specific products from a list of those sold by licensed medical cannabis distributors in Canada. Health Canada has uniquely strict production and quality control guidelines for products sold there. But if a patient is using a product not on the list, they can manually input information about the strain, including cannabinoid content.

The researchers looked at data from nearly 1,400 medical cannabis users, analyzing outcomes from almost 12,000 inhalation sessions. The researchers kept their analysis just to sessions involving inhalation (smoking, vaping, concentrates, dab bubbler, dab portable), to try to control—at least a little—for efficacy and timing of the onset of effects.

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Tiny krill appear to mix up the ocean

Fri, 04/20/2018 - 10:04

Enlarge / Differences in the density of water reflect light to show the complex mixing generated by a moving brine shrimp. (credit: Isabel Houghton, image obtained with the assistance and facilities of R. Strickler)

If you've heard of krill at all, it's probably in the context of their role as whale food. Nature programs love to point in amazement to the fact that the largest animals on the planet subsist on some of the smallest, namely the krill. But these tiny animals exist independently of their function as food, and a new study suggests that they and their peers may have a significant role in their ecosystems: mixing up the top layers of the ocean.

Krill are crustaceans, as a careful look at them will indicate (although Wikipedia tells us that the cool-sounding name "krill" is simply Norwegian for "small fry of fish"). They don't tend to grow much larger than a couple centimeters in length, and they feed on even smaller creatures, taking tiny photosynthetic plankton and moving them up the food chain.

But what they lack in size, they make up for with truly astonishing numbers, with some species estimated as having one of the largest total biomasses of anything on Earth. It's these vast numbers that make them a viable food for the world's largest creatures and give them the ability to replace the vast numbers gulped down by whales. It's also at the heart of the new results.

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Netflix film examines why NASA shunned women astronauts in early days

Fri, 04/20/2018 - 08:00

Enlarge / An undated file photo of some of the Mercury 13 candidates. (credit: Mercury 13 / Netflix)

This June, the world will mark the 55th anniversary of the first woman flying into space. Valentina Tereshkova, an amateur Russian skydiver, spent nearly three days in orbit inside a spherical Vostok 6 capsule. The first American woman, physicist Sally Ride, would not follow Tereshkova into space for another two decades.

A new documentary on Netflix, Mercury 13, examines the question of why NASA did not fly women in space early on and, in particular, focuses on 13 women who underwent preliminary screening processes in 1960 and 1961 to determine their suitability as astronauts. The film offers a clear verdict for why women were excluded from NASA in the space agency's early days—"good old-fashioned prejudice," as one of the participants said. Mercury 13 will be released Friday.

The film admirably brings some of these women to life, all of whom were accomplished pilots. There is Jerrie Cobb, who scored very highly in the preliminary tests and gave compelling testimony before Congress in an attempt to open NASA's early spaceflight programs to women. Another key figure is pilot Jane B. Hart, married to a US Senator from Michigan, whose experience in the project compelled her to become one of the founders of the National Organization for Women.

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Mammals are smaller than they used to be, and it’s our fault

Thu, 04/19/2018 - 14:00

Enlarge / They were big, but we showed up, and they're now gone. (credit: Mauricio Anton)

When the first modern humans ventured beyond Africa during the late Pleistocene, roughly 120,000 years ago, they stepped into a world filled with giants: the 6-ton giant ground sloth in South America, the 2- to 3-ton wooly rhino in Europe and northern Asia, the 350- to 620-pound sabertooth cat in North America, and the 6-ton wooly mammoth in Eurasia and North America. It's hard to imagine a world filled with animals that large: the giants of the Pleistocene quickly vanished, and the animals that survived were, in general, two or three times smaller than those that went extinct. A new study indicates that the late Pleistocene decrease in mammal size coincided with the geographical spread of humans around the world—and the authors say that's not just happenstance.

Human involvement in the disappearance of the Pleistocene megafauna is still the subject of intense debate, but this is hardly the first time we've been implicated. To provide a different perspective on these extinctions, a team of biologists led by Felisa Smith of the University of New Mexico, Albuquerque, decided to look for changes in the pattern of extinctions since the beginning of the Cenozoic period 65 million years ago—the end of the dinosaurs and the beginning of the rise of mammals. Species go extinct all the time at a steady background rate of about one to five species per year. If that rate or the kinds of animals dying off changed after humans started colonizing the world beyond Africa, that could imply that we had something to do with it.

The biologists examined two large datasets. One listed the global distribution and body size of animal species in the late Pleistocene and Holocene, starting 125,000 years ago. The other listed similar information for species spanning the whole Cenozoic. Starting at around 125,000 years ago, the datasets traced a decrease in both the mean and the maximum body size of mammals on every continent, coinciding with the spread of humans into each region. Wherever humans went, mammals got smaller, and big ones tended to die off.

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Doctors tried to lower $148K cancer drug cost; makers triple price of pill

Thu, 04/19/2018 - 12:48

(credit: Wellness GM)

A drug that treats a variety of white blood cell cancers typically costs about $148,000 a year, and doctors can customize and quickly adjust doses by adjusting how many small-dose pills of it patients should take each day—generally up to four pills. At least, that was the case until now.

Last year, doctors presented results from a small pilot trial hinting that smaller doses could work just as well as the larger dose—dropping patients down from three pills a day to just one. Taking just one pill a day could dramatically reduce costs to around $50,000 a year. And it could lessen unpleasant side-effects, such as diarrhea, muscle and bone pain, and tiredness. But just as doctors were gearing up for more trials on the lower dosages, the makers of the drug revealed plans that torpedoed the doctors’ efforts: they were tripling the price of the drug and changing pill dosages.

The drug, ibrutinib (brand name Imbruvica), typically came in 140mg capsules, of which patients took doses from 140mg per day to 560mg per day depending on their cancer and individual medical situation. (There were also 70mg capsules for patients taking certain treatment combinations or having liver complications.) The pills treat a variety of cancers involving a type of white blood cell called B cells. The cancers include mantle cell lymphoma, which was approved for treatment with four 140mg pills per day, and chronic lymphocytic leukemia, approved to be treated with three 140mg pills per day. Each 140mg pill costs somewhere around $133—for now.

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Massive bleaching event may be permanently changing the Great Barrier Reef

Wed, 04/18/2018 - 16:48

Enlarge / Although these corals are colored, they've been bleached, in that they have lost their photosynthetic symbiotes. (credit: ARC Centre of Excellence for Coral Reef Studies / Gergely Torda)

The intense El Niño event that started in 2015 drove global air temperatures to new records, helped by the long trend of human-driven warming. But the air wasn't the only thing affected. El Niño is fundamentally about Pacific Ocean temperatures, and those were exceptionally hot as well. One of the unfortunate results of this was a massive bleaching of the corals of the Great Barrier Reef.

While the damage to corals looked dramatic at the time, appearances aren't the same as data, and they don't give a comprehensive view of the damage, much less the corals' ability to recover from the bleaching. Now, a large Australian-US team of researchers has provided a comprehensive overview of the damage to and recovery of the Great Barrier Reef. The results are grim, showing that mass coral die offs started at lower temperatures than we had expected. The overview also shows that the entire composition of sections of the Great Barrier Reef have changed and are unlikely to recover any time soon.

Bleached to death

The corals that build reefs are actually a collaboration between animals (the coral proper) and single-celled algae that form a symbiotic relationship with corals, providing them with nourishment. At high temperatures, this relationship breaks down and causes the corals to lose their photosynthetic guest. The reefs turn white, giving bleaching its name. And, if recovery doesn't happen quickly enough, the corals will starve, causing a mass die off. Complicating matters, different species of coral will bleach at different temperatures and recover at different rates.

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Meteorite’s diamonds tell of Earth’s baby sister, which died young

Wed, 04/18/2018 - 13:15

Enlarge / Microscope image showing diamond (blue), graphite (black/gray), and blobs of iron-sulfur minerals (yellow). (credit: Dr. F. Nabiei/Dr. E. Oveisi/Prof. C. Hébert, EPFL, Switzerland)

On Earth, diamonds are time capsules with fascinating stories to tell. After all, they form at great depths—below the tectonic plates that make up Earth’s crust. It's only because they travel to the surface with the volcanic equivalent of a jet pack that we're able to see them at all.

But there's another way to get your hands on a diamond: wait for one to crash to Earth inside a meteorite. And in the case of a new study published this week, it might even tell a story of a different planet, one that died in the early days of our Solar System.

Diamonds from space

The meteorite in question fell in 2008 in Sudan and contained a type of meteorite rock called “ureilite” that is composed of minerals you’d only find in the deep mantle of the Earth. Among those minerals were microscopic crystals of diamond and graphite—two minerals composed entirely of carbon atoms.

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Russia appears to have surrendered to SpaceX in the global launch market

Wed, 04/18/2018 - 10:01

Enlarge / A Russian 3-stage Proton rocket blasts into the sky in 2000. (credit: NASA)

As recently as 2013, Russia controlled about half of the global commercial launch industry with its fleet of rockets, including the Proton boosters. But technical problems with the Proton, as well as competition from SpaceX and other players, has substantially eroded the Russian share. This year, it may only have about 10 percent of the commercial satellite launch market, compared to as much as 50 percent for SpaceX.

In the past, Russian space officials have talked tough about competing with SpaceX in providing low-cost, reliable service to low-Earth and geostationary orbit. For example, the Russian rocket corporation, Energia, has fast-tracked development of a new medium-class launch vehicle that it is calling Soyuz-5 to challenge SpaceX.

On Tuesday, however, Russia's chief spaceflight official, Deputy Prime Minister Dmitry Rogozin, made a remarkable comment about that country's competition with SpaceX.

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Despite alien theories and novel mutations, the real Ata puzzle may be ethical

Wed, 04/18/2018 - 08:15

Enlarge (credit: Bhattacharya et al. 2018)

In 2003, Oscar Munoz found a mummy in the Atacama Desert ghost town of La Noria. The six-inch-long mummy, now called Ata, has an elongated skull, oddly shaped eye sockets, and only ten pairs of ribs... which helped fuel wild speculation that she was an alien hybrid. Ata was sold several times—probably illegally—and ended up in the private collection of Barcelona entrepreneur and UFO enthusiast Ramón Navia-Osorio. A 2013 documentary called Sirius soon helped immortalize Ata, focusing heavily on the alien hybrid claims.

When a team led by University of California, San Francisco bioinformatics researcher Sanchita Bhattacharya recently sequenced the tiny mummy’s genome, however, it revealed only a girl of Chilean descent. There were a complicated set of genetic mutations, including some usually associated with bone and growth disorders and a few more that have never been described before. Those mutations, the researchers claim, may help explain her unusual appearance.

It’s easy to see why the team's March paper attracted so much interest: a high-profile urban legend was fully debunked at last, but now there were hints at compelling medical discoveries. Most press outlets presented the results as conclusive, cut-and-dried science—except for a few UFO fan sites that loudly insisted the study was part of a cover-up. But even beyond the extraterrestrial exchanges, things have gotten very complicated, both in terms of the scientific claims and in terms of whether the research should have been done at all.

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Homeopath “treated” 4-yr-old boy’s behavior problems with saliva from rabid dog

Wed, 04/18/2018 - 07:30

Enlarge / Insanity dog's got nothin' on homeopaths. (credit: Getty | Agency-Animal-Picture)

“Hair of the dog” remedies may do the trick for some hangover sufferers. But health experts say that a Canadian homeopath took the idea too far—way, way too far.

Homeopath and naturopath Anke Zimmermann used diluted saliva from a rabid dog to “treat” a four-year-old boy, according to a blog post she published earlier this year. Zimmermann claims that the potentially infectious and deadly concoction successfully resolved the boy’s aggressive behavior, which she described as a “slightly rabid-dog state.”

The tail fits with the scientifically implausible principles of homeopathy. These ruffly state that substances that produce similar symptoms of a particular ailment can cure said ailment (“like cures like”) and that diluting a substance increases its potency (“law of infinitesimals”).

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