Author: John Timmer

A natural gas fracking well near Shreveport, Louisiana. (credit: Daniel Foster)

Fracking has mostly been studied because of what it can potentially do to the surface environment. The chemicals used in fracking fluid, as well as the gas and brines that can come back up the wells, all pose environmental risks that have to be managed. What's often not considered is that the well is a bit like a two-way street. The fracking fluid, which is anything but sterile when injected, also contaminates the environment deep under the Earth's crust.

A new study, released this week by Nature Microbiology reveals that fracking creates an entire ecosystem 2.5km below the Earth's surface, one that can persist for at least a year after the frack. And the microbes that thrive there may actually have implications for the production and durability of the fracking wells.

The people behind the work (14 of them at three different institutions) took a relatively simple approach: sample the fracking fluid at a couple of wells before it's sent underground, then sample the fluid that comes back up the wells at various time points, including over 300 days after the fracking. The sampling included a look at the organic chemicals in the fluids, and DNA sequencing that's sufficient to reconstruct entire genomes from anything present.

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On Thursday, Science released a half-dozen papers that analyzed data the Dawn mission sent home from the largest body in the asteroid belt, a dwarf planet called Ceres. Headlines will focus on signs of water ice and a possible ice-powered volcano, but the reports themselves really end up emphasizing how much we still don't know about the strange world. Despite all of Dawn's imaging, many features don't add up to a coherent picture of the body as a whole.

Before Dawn got there, our impression of Ceres was dominated by what we'd measured of its density. Those measurements suggested the dwarf planet has a substantial amount of water and is large enough to have differentiated, allowing rocky material to sink to the core. So we expected Dawn to find an icy world where viscous ice has gradually wiped away many of the indications of the impacts every Solar System body has suffered.

That's not at all what Dawn found. Instead, only the largest impact craters on Ceres seem to show any sign of viscous changes. This lack of viscous change suggests that Ceres' crust is much more rigid than it would be if it were comprised of water ice.

Enlarge (credit: Dennis Schroeder, National Renewable Energy Lab)

As the US transitions to an increased reliance on renewable energy, most of the action has been on the West Coast, where both Hawaii and California have set targets of 50 percent renewable energy by 2030. But, in an effort to keep the pace, New York recently announced that it, too, would be aiming to get to 50 percent renewables by that date.

As in California, that level of intermittent renewable energy can pose a challenge for the grid. While New York has its own grid and is able to regulate the power there, the state is heavily integrated into the surrounding grids (including in Canada) and the Eastern Interconnection, which extends as far west as Kansas and Saskatchewan. This means New York's grid management challenge will probably create strains that extend well beyond its borders. A new study from the National Renewable Energy Lab (NREL), however, indicates that the Eastern Interconnection is probably up to the task, but may require new incentives and regulations in order to function efficiently.

NREL didn't look at New York's case specifically; rather, it focused on getting the entire Eastern Interconnection at 30 percent wind and solar power. But that turns out to be in keeping with New York's goals. Unlike California, the Empire State counts hydropower toward its 50 percent goal, and it currently gets a bit under 20 percent of its power from hydro. So, 30 percent wind and solar is about what New York plans to do; NREL simply applied it to the entire Eastern Interconnection.

Enlarge / "Who's a good puppy?!" (credit: Enikő Kubinyi)

In most tests of general intelligence, dogs rate as reasonably clever, but nothing like primates. The one place where dogs beat primates is in interacting with humans. It's not clear whether dogs are better at reading human intentions or simply more motivated to act on them, but dogs truly seem to get us.

Now, researchers in Hungary have tested dogs' willingness to cooperate with us by getting them to sit still in an MRI machine. By tracking the dogs' brain activity, the researchers were able to determine that dogs can recognize not only words, but the emotional tone behind them. Dogs recognize when both words and tone indicate praise. That's when they feel rewarded.

The work was performed by a group of researchers based in Budapest, which becomes important when we get to the words the dogs were responding to. The hypothesis behind their work: dogs can recognize both the meaning of what's being said (technically, its lexical content) as well as the intonation used in saying it. In other words, it's not enough to say "good boy" to your dog—you have to sound like you mean it.

One of a set of three new mouse lemur species described this year. Microbus ganzhorni hails from Madagascar—as do all lemurs. (credit: Giuseppe Donati.)

Read any estimate of the number of species present on Earth, and you'll notice two things: the numbers vary wildly, and they're always well above the number of species we actually know about. It's tempting to think we've exhausted the exploration of the Earth, that there's nothing new to see. But one area that we've barely scratched the surface of is the biological diversity that we're a part of.

There are several reasons for this. One is that some habitats, like the deep ocean, are both vast and hard to get to. Others, like caves and islands, isolate populations and generate species at a phenomenal rate. Finally, there's just a tendency to view, say, all ants as being roughly the same. That can allow species to hide in plain sight, with nobody taking the time to look for the details that distinguish them from their close relatives. DNA sequencing is also telling us that some populations that look identical to us haven't actually interbred in a very long time, and may be separate species.

As researchers gradually look more closely, the results are a steady stream of new discoveries. We thought we'd share some with you. We set a few simple guidelines for inclusion. The first is that the species had to be discovered this year. The second is that it has to be still living—paleontologists find new species almost as often as biologists do. The final thing is that we had to be able to come up with a decent photo of it.

Enlarge / The octobot, with some of its reaction system highlighted in color. (credit: Ryan Truby, Michael Wehner, and Lori Sanders, Harvard University.)

While the current generation of industrial robots is primarily made of metal, the research community has been getting interested in the potential for soft-bodied robots. These have a number of advantages, such as being easy to customize via 3D printing and providing a flexibility that lets them squeeze through tight spaces.

Many of the research demonstrations created so far, however, have required some compromises. For some iterations, this has meant the control hardware and power sources have been kept separate, connected to the robot via a tether. For other attempts, this has meant the final product is a mixture of hard and soft pieces.

In today's issue of Nature, however, researchers are reporting the creation of a soft-bodied robot that carries its own fuel supply, which powers the robot through an on-board chemical reaction. Soft, flexible on-board logic then directs the reaction products to control the movement of the robot. While the result is pretty limited in what it can do, its creators make up for that with a certain cool factor, making their creation look a lot like an octopus.

Enlarge / The solar sail used to accelerate the craft provides a large target for dust grains. (credit: Breakthrough Starshot)

Breakthrough Starshot is one of the more exciting scientific ideas that has popped up in the past decade, with its promise to deliver hardware to the nearest star in time for many people currently alive to see it. While the idea would work on paper as an extrapolation of existing technology, there are a lot of details that need to be thoroughly checked out, because it's possible that one of them could present a show-stopper.

There's a bit of good news there: Breakthrough Starshot is apparently funding the needed research to give its concept a thorough vetting. A recent posting to the arXiv describes a careful look at the odds of a spacecraft surviving an extended journey at the speeds planned for the trip. Overall, things look good, but a bit of shielding will be needed, and there's the potential for a catastrophic collision with a speck of dust.

The work, done by a team of four astronomers, focuses on one of the most basic issues: spacecraft survival. The goal of Breakthrough Starshot is to accelerate its craft to about 20 percent the speed of light. At that speed, even individual atoms can damage the vehicle, and a collision with a bit of dust could be catastrophic. So the team set out to quantify just how risky these collisions could be.

Enlarge / Like this, but one-dimensional and only trapping sound. (credit: NASA)

One of the common descriptions of black holes is that their gravitational pull is so strong, not even light can escape it. Stephen Hawking is famous for (among other things) showing that this isn't actually true. The Hawking radiation that bears his name allows matter to escape from the grip of a black hole. In fact, Hawking's work suggests that an isolated black hole would slowly evaporate away and cease to exist.

But his work remains entirely theoretical. Hawking radiation is expected to be so diffuse that we could only detect it if we could somehow find or create a black hole isolated from all other matter. But Jeff Steinhauer of Israel's Technion has been on a sometimes single-handed quest to develop a system that can accurately model a black hole's behavior. And, in a recent paper in Nature Physics, Dr. Steinhauer describes how his model system generates what appears to be Hawking radiation.

Searching for the horizon

A feature called the event horizon plays a central role in both Hawking radiation and the new model system. At a real black hole, the space-time outside the event horizon may be distorted by the intense gravity, but the distortion is relatively limited. Inside the event horizon, however, space-time is stretched at a rate that's faster than the speed of light. Photons can't escape because the space-time they occupy is getting stretched away from the event horizon faster than the photon can move.

Enlarge / An un-strung recurve bow, showing the recurved limbs and the central riser. (credit: John Timmer)

A lot of us have only seen archery on episodes of Game of Thrones, or maybe we have hazy memories of a simple fiberglass bow at summer camp. If that's your picture of the technology, than a modern bow probably looks like it was dropped off by aliens.

To find out how this equipment actually functions, we took a subway ride to Gotham Archery, where Anjalie Field walked us through all the moving (and, hopefully, stationary) parts of a bow that's fit for competitive archery. Field got hooked on the sport while young, and she loved it so much that when she ended up at a college without an archery team, she founded one.

Field explained that there are two classes of bows. The string on a compound bow is threaded through a series of pulleys. These pulleys rotate off-center as the string is drawn back, changing the forces involved. Typically, this means that the initial draw requires considerable force, but once it's fully drawn, less effort is involved in holding it there.

(credit: Tao lab, Emory University)

When evolution hits on a solution that works, that solution tends to get reused. Researchers have found that genes that play key roles in development typically get deployed over and over again in different tissues. Once this happens, however, it can create a problem: you can't make major changes to the gene without messing up a whole lot of essential processes.

This week, however, a team of researchers from the Janelia Research Campus describe a case in which an essential gene that's critical for neural activity was tweaked in an incredibly subtle and specific way. The new version of the gene changed only a single feature of the species it evolved in: the details of the male courtship song.

You might not think fruit flies would do much in the way of singing, and they don't in the traditional sense. But their courtship behavior involves a song created by rapid vibrations of their wings. The song is a mixture of repeated chirps interspersed with longer, buzzing vibrations. The details of this song—the frequency of the buzzing, the space between the chirps, etc.—often varies among the dozens of species of Drosophila we've identified.