On September 19th, 2017 we learned about

Squirrels’ food storage strategies classify nuts by type and location

Researchers at the University of California, Berkeley have been trying to recreated the maps that their local squirrels keep in their heads. In a variety of different experiments, biologists have followed eastern fox squirrels (Sciurus niger) around the Berkeley campus, keeping track of every place the furry critters hide their nuts and seeds. The researchers aren’t after the food directly, but are hoping that by mapping out every cache in the area, they’ll be able to better understand how these scatter-hoarders decision-making and overall cognitive abilities.

Snacks worth saving

When a squirrel obtains a peanut or acorn, their first task is to asses if it’s worth burying or not. They inspect it by looking it all over, sampling a bit of the husk, and then shaking their head while clutching their prize. It’s not clear what the head-shaking measures exactly, but researchers have found that more movement usually corresponds with a higher chance that that nut will be saved for later, rather than eaten on the spot. For the nuts that pass this test, the squirrels will scurry off to bury them someplace safe. Some nuts are lost, but the squirrels generally remember exactly where they hid their stored food, even taking the time to organize it when possible.

In one experiment, researchers offered nuts to squirrels to see if the way food is acquired influences what the squirrels do with it. Each squirrel had a ration of 16 nuts of varying types, but some squirrels were given them randomly, while others received them according to type, such as four almonds followed by four peanuts. The squirrels did seem to value organization, but not on the researcher’s part. Regardless of how the nuts were received, the squirrels would move back and forth to four distinct caches, sorting their food like you sort your groceries. Researches assume that, like your cupboards or refrigerator, this sorting allows the squirrels to find the precise type of food they want faster, since all the almonds will be in one place, and the peanuts all in another. It seems to be a balance between efficiency while avoiding leaving all their winter food stores vulnerable in one location.

Nuts in new locations

The squirrels have shown one other limitation, which is that they generally try to stay within 330 feet of where the food was found when they hide it. So when a researcher offered nuts from one location, the squirrels could pick their own locations to organize things. When researchers were handing nuts out from multiple locations, the squirrels instead focused on diversifying their hiding places. Instead of taking the time to sort by type, the squirrels seemed to simplify their strategy, focusing more on finding novel hiding places for each item.

It may be tempting to write this off as a cap on the squirrels’ cognitive abilities. Maybe adding new locations to pick up nuts was too mentally taxing to make the effort to organize them at the same time. However, it could be that they were making other mental anchors to remember new hiding places, and organization wasn’t as necessary to keep track of things. Researchers at Berkeley have already found that these squirrels are persistent problem solvers, spending plenty of time and energy to figure out locked puzzle boxes, so it seems unlikely that sorting their snacks is necessarily too demanding a task.

Source: Fox squirrels use ‘chunking’ to organize their favorite nuts by Yasmin Anwar, UC Berkeley News

On September 19th, 2017 we learned about

Speculation about why the ancient Greeks repeatedly rebuilt on earthquake fault lines

Despite what housing prices in the San Francisco Bay area may suggest, most people have an understanding of how dangerous living on an earthquake fault-line can be. It helps that since San Francisco’s historic quake in 1906, a lot of research has been done on what causes earthquakes, leading to more safely engineered buildings that can survive a tremblor. Of course, before people even considered the notion of plate tectonics, seismically active locations have been surprisingly active real estate markets. In fact, there’s a chance that the occasional shake-up actually attracted people, since they interpreted earthquakes as being divine in origin.

Guessing why the ground shakes

Geologist Iain Stewart from the University of Plymouth noticed an odd trend in building locations in ancient Greece, as many cities, temples and monuments were built directly on active fault lines. On it’s own that’s not that odd, but the fact that ancient people’s repeatedly rebuilt ruined structures at these locations indicates that there was a strong motivation to do so. Without scientific explanations and predictions to help shape people’s reactions, Stewart suspects that the ground’s spontaneous movement was likely understood to be an expression of the gods’ will. Even if a building was shaken to dust, knowing that a deity had taken an interest in a particular plot of land boosted its prestige as a sort of ‘holy’ site.

In some cases, the intersection of geology and faith is fairly clear. The famed Oracle of Delphi described visions that foretold the future and explained the actions of the gods. While the accuracy of those interpretations may be up for debate, a biochemical component has been found for the seer’s visions, as ethylene gas was likely produced underground, and released with each bit of seismic activity. The priestess was then probably subject to hallucinations, and would share the her descriptions of these sights as guidance for her visitors. Similarly, an oracle at Perachora Heraion may have lost their divine gift after a quake blocked off a water supply to vision-inducing hot springs in 300 BC.

Picking fault lines on purpose?

Even ignoring these more mind-altering interactions with fissures in the rock, Stewart believes that the ancient Greeks weren’t rebuilding on fault lines at random. It’s hard to move a city to avoid seismic activity, but it should have been possible to a least move a broken temple off a fault. Instead, Stewart things the Greeks rebuilt at the same locations on purpose, possibly to harness the inexplicable energy of that spot. While Stewart has a list of at least four more cities that seem conspicuously located along active fault lines, he admits that he’s looking at this from a geologist’s perspective. He’s hoping that archaeologists will look for evidence of people’s intent to build where the ground shook, helping answer how they rationalized living in such a risk-prone place.

As for the Bay Area… the weather really is lovely most of the year, and the local produce is hard to beat, plate tectonics be damned.

Source: Ancient Greeks May Have Deliberately Built Sacred Sites on Earthquake Faults by John Dyer, Seeker

On September 18th, 2017 we learned about

Cuckoos copy the sounds of bigger animals to keep their eggs, and themselves, safe from harm

As hundreds of years of clocks have taught us, the cry of a cuckoo sounds like “coo-coo, coo-coo,” unless that cuckoo chooses to sound more like a hawk or peccary. The call used as an hourly chime is actually only used by certain male cuckoos, and while it’s striking enough to inspire the birds’ name, it’s certainly not the most strategic sound they can make. Two studies have found that in addition to passing their eggs off as belonging to other birds, cuckoos are also rather adept at mimicking the sounds of other animals to keep their eggs, and themselves, safe from discovery.

Sounding like a predator to startle parents

While male cuckoos’ calls helped name the birds, the behavior of the females is what really made them famous. The common cuckoo (Cuculus canorus) is a brood parasite, which means they hide their own eggs in the nests of other species like reed warblers (Acrocephalus scirpaceus) or blue tits (Cyanistes caeruleus). If the egg is recognized, the would-be surrogate parents will generally destroy it, as they don’t want to accidentally invest resources in caring for the cuckoo’s offspring. However, if the warbler or tit parents don’t detect the parasite, they will raise and care for it as their own offspring.

Cuckoos have adopted a number of strategies to help get their own eggs into other birds’ nests, including pushing other eggs out or evolving to lay eggs with a similar appearance as the host’s. Now researchers have found that the females will make a sound imitating a hawk or sparrowhawk right after laying their own egg. It appears that this call is meant to scare and distract the nests’ owners around the time they might discover the new egg so that they don’t scrutinize it’s appearance as closely. Once they realize no hawk is bearing down on them, they’ve already started to get used to the new addition to their clutch.

To confirm this hypothesis about the cuckoo’s hawk impression, scientists conducted experiments with various wild birds. They played recordings of different species of birds in proximity to brooding reed warblers and tits, then measured the intensity of the birds’ reactions. The nesting parents paid little mind to the sound of a dove or male cuckoo, but both hawks and female cuckoos were found to be quite alarming, spurring them to observe the area around, but not in, their nests very closely. In a second phase of testing, researchers looked at how well nesting warblers noticed balsa wood eggs when distracted by these sounds, and found that a well-timed distraction was very effective at helping an egg get assimilated in a nest.

Sounding like a peccary to scare predators

In Central South America, Neomorphus ground cuckoos have evolved a very different sort of audio mimicry. These birds have been found to trail herds of wild peccaries that plow through underbrush, eating the insects the foraging mammals stir up. As they travel, the peccaries often make a distinct clacking sound with their teeth, which is thought to warn off would-be predators. From the sounds of things, the cuckoos have picked on this strategy, and now clack their own beaks to sound like the peccaries.

Clicking a beak isn’t unheard of in the larger cuckoo family, as birds like roadrunners also make percussive sounds with their mouths. However, close analysis of the cuckoo clacks found they were much more similar to the sound of a peccary than the birds’ own relatives. This suggests that imitating the peccaries offer’s some advantage, which is probably to ward off predators that may mistake the cuckoo for a more dangerous herd of peccaries. Alternatively, the birds may be clacking to communicate with the peccaries themselves, and are sounding off as guards for the foraging mammals in exchange for protection. Researchers hope to follow up on this study, specifying which goal is motivating the cuckoos.

My third grader asked: Do the ground cuckoos also hide their eggs in other birds’ nests?

Nope. While the common cuckoo draws a lot of attention, their brood parasitism isn’t actually the most common parenting strategy. Most members of the Cuculidae family tend for their own eggs. For better or for worse, it should also be noted that there are other brood parasites out there. Cowbirds, for example, even bother to scout potential parents before hiding their eggs in their nests.

Source: Female cuckoo calls misdirect host defences towards the wrong enemy by Jenny E. York and Nicholas B. Davies, Nature Ecology & Evolution

On September 18th, 2017 we learned about

Super-heated exoplanet is dark due to its atmosphere’s energy absorption

There is a dark object closely orbiting the star WASP-12A, circling it close to every 24 hours. This object reflects almost no light, making it as dull and black as new asphalt, and thus rather difficult to see in the visible spectrum. It’s not dark matter, nor is it a black hole in the making. Instead, it’s simply an extremely overcooked planet. Rather than reflecting light off its atmosphere into space so we can see it, the hydrogen and helium miasma that surrounds planet WASP-12B absorbs nearly every bit of energy its star throw at it, further fueling its extreme temperatures and eventual destruction.

WASP-12B is what’s known as a “hot Jupiter,” because it’s two-times larger than our solar system’s premier gas giant, while also holding above average temperatures in its atmosphere. However, that title really doesn’t capture the nature of WASP-12B’s atmosphere, which is 4,600° Fahrenheit one side, and around 2,600° Fahrenheit on the other. The large disparity is because the planet is tidally locked, meaning the “day” side of the planet is always facing its star, while the “night” side always dark. This arrangement means that temperatures have a harder time equalizing, since winds flowing from one side to the other can only do so much to mitigate the effects of constant heat exposure. At this point, the molecules in the atmosphere are thought to have been broken down to more basic atomic states, leaving no molecules to bond into materials that could potentially reflect any of the incoming solar energy.

Minimal registered reflection

The amount of light an object reflects is called albedo, and WASP-12B never gets higher than 0.064. To put it another way, this means that 94 percent of the energy from the star WASP-12A gets trapped in the planet’s increasingly shattered atmosphere. For comparison, the Earth only absorbs around 70 percent of the Sun’s energy each day, and our rotation helps keep that from being overly concentrated in a single location.

Some energy is reflected though, which is how the Hubble space telescope was able to see the bleak ball of heat in the first place. Once the planet was in it’s brief but daily position where it’d be illuminated by its star, the telescope was able to see and measure the energy reflected off WASP-12B’s daytime side. The light that came back was appropriately slightly red, compatible to the glow of red-hot metal.

My third grader asked: How does the planet exist close to the star at those temperatures? Why wouldn’t it be destroyed like we would be?

Well, the short answer is that WASP-12B is being destroyed, just slowly. Hubble’s Cosmic Origins Spectrograph has found that material from the black ball of heat is being cooked off the atmosphere and absorbed into the star. There aren’t estimates on how long this will continue, but as planet shrinks its inertia will likely decrease, making it even more likely to be consumed by WASP-12A.

Source: Hubble observes pitch black planet, Hubble Space Telescope

On September 17th, 2017 we learned about

Researcher personally confirms electric eels’ airborne defense against potential predators

210 years ago, Prussian naturalist Alexander von Humboldt learned that the preferred bait for catching electric eels was horses. Not horse meat, which the eels don’t eat, but live horses or mules themselves, which the eels treat as a threatening predator. Humboldt had hired locals living along the Amazon river to catch eels on his behalf for study, and was rather astonished when he saw the eels leaping out of the water to butt their faces into 30 panicking horses and mules. The eels were apparently shocking the large mammals, causing two drownings in the dramatic procedure that netted Homboldt five live eels. When describing the scene later on, most audiences dismissed the entire idea as “tommyrot,” but a dedicated biologist from Vanderbilt University has now confirmed the plausibility of the story, even though it meant getting repeatedly electrocuted himself.

Attacking in the air

Like many of Humboldt’s detractors, professor Ken Catania wasn’t interested in the use of horses as much as the supposed behavior of the eels. Electric eels (Electrophorus electricus) normally use their manipulation of electric currents to find their way through the murky waters of the Amazon river, stunning or paralyzing the small fish they consider prey for easy capture. The idea that eels might also throw themselves out of the water towards a threat seemed bonkers, at least until Catania was able to demonstrate this behavior in his lab. Using a plastic crocodile head, Catania was able to trigger a defensive response from captive eels. As the dummy predator lunged into the water, the eels would leap up, then touch their chin to the plastic lure to deliver a sizable shock. This behavior was demonstrated again using a plastic replica of a human hand that contained LEDs. When the eels felt they were in danger, from a horse hoof or a plastic hand, they did indeed jump up and shock their pursuers.

Now Catania has gone further, and found a way to more directly measure how much of a charge the eels can deliver to the terrestrial animals that threaten them. He did this by wiring up sensors to his own arm, then slamming his arm into an eel’s aquarium. The juvenile eel, named Finless, treated Catania’s arm as dangerous, leaping up to tag it with a shocking touch of the chin. By punching into a submerged ammeter, Catania could then measure exactly how much power the eel delivered, specifically looking at the amount of resistance in the temporary circuit that was tied to either air, water or flesh. He was also able to give some qualitative evaluation of the feeling of being shocked, which he said was akin to the zap delivered by electric fencing to livestock. He estimates that a larger, adult eel may be able to hit a predator with as much as nine-times the charge delivered by a taser, which is certainly enough to make a harassing crocodile think twice about eating an eel.

Registering resistance

The precise measurements Catania gathered help explain why the eels bother leaping up out of the water. A zap delivered underwater would be subject to the water’s conductivity, dissipating the shock delivered to the predator. The air acts more like an insulator, helping ensure all of a shocks stopping power be delivered to the larger animal’s body directly. This behavior has probably evolved slowly over time, starting with zaps in the water, then chin touches, and then getting out of the water. At this point, eels have refined the process to deliver a considerable amount of pain very efficiently, assuming they feel cornered enough to lash out in the first place.

As bold (and painful) as Catania’s research may be, he admits his arm isn’t a perfect proxy for all eel-predator interactions. Scales or thick fur may create different amounts of resistance to the flow of electricity, possibly making this defense less effective against actual crocodiles or shaggy dogs. That said, Humboldt’s account already shows that it’s apparently plenty painful for creatures as large as a horse.

Source: Biologist reaches into electric eel tank, comes out with equation to measure shocks by Heidi Hall, News at Vanderbilt

On September 17th, 2017 we learned about

Determining what makes microbes more drug resistant in microgravity

Future human endeavors in space may run into problems with bacteria from Earth. The microbes that cover our planet seem to be surprisingly resilient to being in space, a concern that has pushed NASA to extreme measures like destroying spacecraft to avoid contaminating new environments. Experiments on the International Space Station (ISS) suggest that we may need to develop some new medical strategies as well, as bacteria in microgravity may inadvertently make themselves more resistant to antibiotics.

Absorbing less, clumping more

In a series of experiments on the ISS, researchers observed a number of changes in Escherichia coli samples adapting to microgravity. On Earth, forces like buoyancy and sedimentation help push nutrients through bacterial cells with the help of the planet’s gravity. But in the perpetual free-fall of the ISS, these mechanisms didn’t function, leading to bacteria taking in fewer nutrients from their environments. That also meant that they had a smaller surface area to absorb medicines like antibiotics, and larger doses were needed to kill them than on Earth.

This might sound manageable, but collapsing into a more tightly packed ball wasn’t the only effect of microgravity. The E. coli on the ISS also tended to grow in clumps, which researchers worry will lead to the formation of more biofilms, which are defensive structures bacteria use to repel both medicines and immune systems. Beyond that, the microbes also grew extra outer membrane vesicles, which are small structures bacteria use to communicate with each other. This can often lead to faster infections in a body, as well as mitigate the effects of antibiotics to a degree.

Silver lining?

This may sound like the first bacterial outbreak in space will be unstoppable, but researchers are still optimistic. Understanding what microgravity does to bacteria can help us develop new techniques beyond simply increasing the doses of antibiotics. There’s a chance that further study will reveal the underlying principles that shape bacteria that may normally be obscured by the Earth’s gravity. If weaknesses can be found, this may allow us to fight bacterial infections in space and at home in new ways. It should also help us understand what happens to the bacteria we want in our bodies, since they’re needed for our immune health, digestion and more.

Source: Why bacteria 'shapeshift' in space by Jim Scott, Phys.org

On September 14th, 2017 we learned about

How Cassini’s 13 years of study transformed our understanding of Saturn’s natural satellites

Friday, September 15, 2017, will be the first time my kids wake up without a spacecraft near Saturn. Launched in 1997, the Cassini spacecraft has had its mission extended twice, but a dwindling fuel supply is requiring that the orbiter be permanently added to Saturn’s atmosphere in a “disassembly” procedure expected to rapidly occur at around 70,000 miles-per-hour. This fiery end will give Cassini a unique shot at collecting a final bit of data, but is driven primarily to avoid the risk of the spacecraft accidentally damaging some of the moons we now know might be home to life. It should be expected that spending 13 years around Saturn would enhance our understanding of that part of the solar system, but it’s fair to say that Cassini revealed more than anyone was expected when the mission was first planned in the early 1980s. For now, my kids asked that I mainly focus on the moons.

Imperfect views before Cassini’s visit

Again, from our current vantage point that’s been filled with years of daily snapshots of a great gas giant and it’s ever growing list of moons, it may be hard to remember how little we knew of the outer solar system in the past. To back up a bit further, it’s worth mentioning the spacecraft’s namesake, Jean-Dominique Cassini, an astrologer-turned-astronomer that discovered gaps in Saturn’s rings, as well as the moons Iapetus, Rhea, Tethys and Dione. At the behest of King Louis XIV, Cassini joined the Acadèmie Royale des Sciences in 1669, going on to become the director of the Observatoire de Paris in 1671. Beyond the connections to Saturn, it was thought that invoking Cassini for this mission to space would help garner support from the European Space Agency (ESA), which did indeed prove instrumental in getting the project off the ground.

Our view of Saturn didn’t change much until the Voyager 1 spacecraft flew by the planet in 1980. Instead of the inert lumps of icy rock people had once imagined, we saw hints of a diverse group of moons, begging for more investigation. Titan, for instance, was covered in a thick atmosphere, but Voyager 1 didn’t have any instruments that could see through the clouds to know what was below. This became a key part of the Cassini mission design, with the ESA taking the lead in designing the Huygens lander that would later be dropped on the surface of Titan. This collaboration, and some of the aforementioned goodwill that lead to some influential lobbying efforts by the ESA, became critical to seeing Cassini completed, as the project was almost canceled multiple times before it’s launch in 1997.

Surveying Saturn’s many moons

Touching down on Titan

Once launched, Cassini started sending back mountains of data that opened our eyes to all kinds of new possibilities around Saturn. The Huygens probe successfully visited Titan, revealing that the mix of surface liquids and organic molecules covering the moon might potentially be home to some form of life. In retrospect, dropping a lander into that environment wouldn’t be allowed today, but that’s only because we have now seen the surface of the moon, complete with lakes, riverbeds, dunes, weather and more.

Enceladus’ great geysers

The next eye-popping moon was less expected. Enceladus was observed in 2005 spraying saltwater geysers out of its surface into space. This unexpected site has since catapulted this small moon to the top of researchers’ wish-list of locations to revisit, as these geysers indicate that the moon is even more likely to be home to life than Titan. The salty spray has also been linked to Saturn’s giant “E” ring, which is now believed to be made primarily of ejected ice from Enceladus.

Rings’ debris mashes into moons

Beyond potentially habitable satellites, Cassini has had time to fill in gaps about other strange moons around Saturn. Iapetus had been a mystery for some time, as it seemed to be half white and half black. The detailed data from Cassini helped explain this appearance, and it was determined that dark red debris from another moon, Phoebe, was essentially painting Iapetus’ surface. So the dark side was heat-collecting dirt, and the light side was ice that hadn’t been painted enough to melt. The moon also had an odd ridge around it’s equator which is now thought to be the result of bombardment and debris collection. It’s not the only moon to exhibit this strange shape, as Daphnis and Pan seem to also have equatorial build-ups of their own.

Six moons seen for the first time

Daphnis has caught scientists’ eyes for more than it’s slightly oblong shape. The tiny moon is one of many that have been found in gaps between Saturn’s rings, although it still interacts with them. As the small bits of rock and debris move by Daphnis, the moon’s gravity creates waves in the rings shape. Other moons’ interactions aren’t quite so graceful though. In 2013, a moonlet tentatively known as “Peggy,” after the discoverer’s mother-in-law, was observed forming on the edge of Saturn’s “A” ring, only to have apparently been smashed by another object by the time researchers checked again in 2015. Even with that loss, Cassini has nonetheless discovered six new named moons around Saturn, including Methone, Pallene, Polydeuces, Daphnis, Anthe, and Aegeon, bringing the count up to 53, with a few still lingering as “provisional.”

Carrying on after Cassini’s crash

All of the above barely scratches as the surface of the research Cassini has made possible (especially since this post basically ignores what was learned about Saturn itself!) Nearly 4,000 papers have been published using data from the spacecraft, with more yet to come. It will wind down though— as I write this, the final photos have already been taken so the spacecraft can prioritize more easily streamed data, like individual measurements, in its final moments above Saturn. For our next look at Saturn and its moons, we may have a wait on our hands. New missions to Saturn are still in early planning stages at best, but hopefully running out of interplanetary postcards from Cassini will help spark demand for further exploration, just as the Voyager 1 mission sparked ideas for Cassini itself. After 13 years of amazing exploration, we’ve seen too much to never visit again.

My kids asked: Why are you crying, Daddy?

It’s hard to explain, but this feels much more intense than when MESSENGER was crashed into Mercury, or even when Rosetta was permanently parked on Comet 67P. The fact that Cassini has been in space for over half my life, and my children’s entire lives, has definitely made it seem like a significant change in the world, er, solar system. Saying goodbye sucks. The fact that many of the reports on Cassini’s Grand Finale mission are framed as tear-jerking, heroic sacrifices certainly doesn’t help. It certainly didn’t help my kids, who both decided to start crying when hearing about exactly how Cassini would break up, with my four-year-old repeatedly asking “but why are they breaking the satellite?!”

Beyond that, reading about the success of this product of cooperation and curiosity is really heartening, and it’s always good to have examples of humanity being awesome. (And make no mistake— this has been awesome.) However, having no plan for a return yet makes me very nervous. It’s not that I have a line of research I need investigated or investments in aerospace, but that I want to know that our society will still invest in broadening our horizons, simply as an affirmation of our values. I do take some solace in the fact that Cassini was almost canceled, and yet has beat expectations right and left, so I have to believe that I’ll get to see better close-ups of Enceladus before too long. In the mean time, it’s probably time to check in with Juno

Source: Cassini's Grand Tour by Nadia Drake and Brian T. Jacobs, National Geographic

On September 14th, 2017 we learned about

Bilingual brains work more on math when it’s presented in a second language

If you’re reading this website, there’s a good chance you do your math in English. As concepts, numbers can obviously exist in any language, but research has shown that dealing with quantities over four require parts of our brains normally reserved for language. For monolingual people, this isn’t a concern, but a study has now found how math can get harder if it’s not in your mother tongue.

The study took students from Luxembourg who went to primary school speaking German, but attended secondary school in French. They were all considered to have a high degree of proficiency in both languages, hopefully eliminating any kind of basic comprehension as a variable. The participants were then asked to do math presented in either German or French so that their time, accuracy and brain activity could be observed in either scenario.

Spotting the right brain structures

It had been previously established that people tend to make more mistakes and take longer to complete math problems that require their second language. These test participants followed that trend, having an easier time with math problems they read in German than French. These tests were conducted in an fMRI machine, so that researchers could also monitor what regions of the brain were activated for each task, hopefully giving insight as to why these differences in performance exist.

When doing math in a first language, a small language-oriented region in the left temporal lobe was seen supplementing efforts to solve the quantitative task. When things got trickier in French, the brains showed activity in new regions that weren’t directly related to either language or numbers, specifically visual centers associated with figurative identification. Interestingly, there were no signs that the test subjects were trying to translate problems back to their first language- they were instead relying on more abstract cognition to help work through tasks complicated by less ingrained grammar and vocabulary. This all may seem very intuitive, but the study aims to help us understand and measure the effects of making calculations in a second language in a time when more and more people are expected to do just that.

Source: The Bilingual Brain Calculates Differently Depending On The Language Used, Scienmag

On September 13th, 2017 we learned about

Jerboas rely on two long legs to hop, skip and jump out of harm’s way

Jerboas are small, herbivorous rodents native to Asian deserts. Like many other fuzzy critters their size, their life is spent trying to find a balance between finding food and finding shelter, particularly from airborne predators like owls. A key difference between jerboas and their kin is that these rodents run around primarily on their hind legs, and researchers believe that their bipedal movement is what allows them to more safely explore the world.

To be objective about how hopping about on two legs makes a difference to the jerboa, researchers first had to figure out how to quantify their movement. The type of steps they take, or the gait, was categorized as either hopping, skipping or running. Those categories still left a lot to the imagination, so researchers had to also find a way to measure how fast the jerboas traveled, how often they changed speeds, and what direction this movement took place in. Since hopping and jumping were part of the jerboa’s evasive maneuvers, the traditional treadmills that are often used to measure an animal’s speed weren’t sufficient. To capture the full range of motion, the six-inch rodents were tracked in a special enclosure, complete with simulated raptor attacks.

Unpredictable paths

Once specific attributes about the jerboa’s gaits were analyzed, it became clear that their movement simply much more randomized than their quadruped peers. Rather than avoiding danger by running faster, jerboas leveraged their bipedal flexibility to change speeds, hop, and more in a way that made their paths very unpredictable. For the flying predators the jerboas are most concerned about, this would be very difficult to compensate for when diving out of the air in a straight line.

Researchers also found that on some level, the jerboas were aware of their relative safety. Jirds, a gerbil-like rodent native to Asia, were observed in a similar space as a quadrupedal control group, and they demonstrated much stronger thigmotaxis, or desire to remain in contact with sheltering objects. The jirds explored their enclosures, but always kept close to the walls, presumably to feel less exposed to danger. The jerboas seemed much happier to explore the entire space, in the process gaining access to more potential food sources. In addition to getting access to new food sources, the jerboas would also be competing less with their four-legged brethren who stay under cover, essentially helping both species in the process.

Source: Hop, Skip, Run, Leap: Unpredictability Boosts Survival For Bipedal Desert Rodents, Scienmag

On September 13th, 2017 we learned about

Fiber-optics under Stanford can feel every car tire and footstep

Every moment has repercussions, a fact my neighbors are no doubt acutely aware of on Saturday mornings when the kids wake up. Every step, thumb and bump not only hits the floor (or wall, or… ceiling), but transmits energy through those materials, much of which we end up noticing as sound. Thankfully, many of these vibrations are either too faint or the wrong frequency to be detected by our ears, but that doesn’t mean they’re not there. In fact, if you really wanted to, it turns out that it’s possible to detect and decipher almost every vibration a person’s movement might make— right down to individual footsteps along a busy sidewalk.

Wired for sound

This kind of listening is already underway at Stanford University in a project called the Big Glass Microphone. Three miles of fiber-optic cables have been laid in a loop under part of the campus, originally to investigate seismic activity. Seismographs around the world already rely on vibrations being transmitted through the ground in order to sense and triangulate activity like earthquakes, but the fiber-optics have proven to be especially sensitive. Like more traditional seismographs, the fiber-optics can measure small changes in electrical current as it’s mechanically perturbed by vibrations, but the scale of the vibrations detected provide previously unknown resolution in those readings.

As a foot steps on the ground, a relatively small, low-frequency vibration is transmitted through the sidewalk and dirt. This then hits the fiber-optic cable, which at the length of a hair is small enough to stretch slightly as the vibration passes through. With light running through the cable, these fluctuations are measured, and in most applications, thrown out as background noise that would muddy data on earthquakes or explosions. In this case, engineers are looking the other way, seeing how well they can track footsteps and cars, possibly even identifying the source of those sounds by unique vibration “signatures.”

Uses for more electronic ears

This effectively means that any material that can house a fiber-optic cable could conceivably serve as a mechanical sensor for nearby activity. In the case of a sidewalk or road, it could track the movement of people or specific cars driving by. In a building, vibrations could reveal what floor people are on to trigger changes in lighting and heating, or detect when a pipe is leaking in the wall. Or just track you even more than your phone already does.

The fact that this kind of system isn’t terribly difficult to set up is seen as both a good and a bad thing, depending on how it’s applied. It could be a relatively cheap way to get better data on how traffic operates, or to make buildings more efficient. However, any system that can track people without their knowing it is certainly open to abuse, and so many of the questions surrounding the project are now about when it should be used, rather than just if it could work.

Source: Is the ground beneath the Stanford campus listening to you? by Yasemin Saplakoglu, The Mercury News