We've only just started learning the amazing things we can do with 3-D printing. So forgive us if we can't quite get our heads around this new idea from MIT, which researchers call "4-D printing."

Here's what they're saying about it: Instead of printing out a full shape, the 4-D printer creates a strand of multiple materials--and that strand becomes whatever you want it to.

The process is sort of reminiscent of those toy dinosaurs that expand when you drop them in water. First, the printer creates a long string of materials. Then you put the string in water. At that point, the string of materials can fold into various shapes based on how the materials are placed. The resulting examples we've seen so far are simple--a cube or the letters "MIT"--but its creator and director of MIT's Self-Assembly Lab, Skylar Tibbits, has already spoken about what this self-assembly technique could mean to architecture and other fields. We're a long way from a building making itself, but it's a fun thought: laying down a skyscraper and watching it bend toward the sky like that scene in Inception. Even more interesting, the materials can potentially "transform" from one 3-D shape into another. ("Tired of that cube? Perhaps a rectangle would be preferable.")

Tibbits will be elaborating on the process at a TED Talk today, and we'll update here with any new information on the project.

With its long limbs and slender body, this new robot looks a lot like a wild cat--a leopard, maybe, or a cheetah. In comparison, the U.S. Defense Advanced Research Projects Agency's (DARPA) famed cheetah robot is practically obese.

For now, however, the DARPA cheetah is much more capable, using all four legs to run at speeds up to 28 mph. The "Pneupard," on the other hand, doesn't yet have working front legs and can only walk awkwardly. (It's like a cheetah with a walker, as one IEEE Spectrum commenter noted.)

But Pneupard's creators, a team of researchers from Osaka University in Japan, aren't looking to race against the DARPA cheetah. Instead, they hope to learn more about natural cheetahs' locomotive secrets, which in turn will help build more agile robots, Andre Rosendo, Pneupard's lead developer, told Spectrum.

Pneupard is already able to handle unevenness on the road, which researchers demonstrated by slipping blocks of metal, wood and other materials under its feet as it strode along a treadmill:

The robot's name comes from the fact that it has pneumatic, instead of mechanical, muscles. Pneumatic muscles are flexible, can handle impacts and contract the way biological muscles do, helping give the leopard-robot more "lifelike" movements, emphasis on like.

Rosendo and his team based Pneupard's leg lengths and muscle movements on data they gathered from cheetah dissections and studies of the electrical activity of real muscles at work, they wrote in a description on YouTube.

They also wrote computer code so that the Pneupard's legs don't need explicit instructions on how to take every step. Instead, the robot adjusts automatically to information it gets from pressure sensors in its feet.

[IEEE Spectrum]

So, here are the rules: To answer, follow us on Twitter and tweet at us with the hashtag #mysteryanimal. For example:

Hey @PopSci, is the #mysteryanimal a baboon?

And then I might say "if you think that's a baboon, perhaps you are the baboon!" But probably not, because this is a positive environment and all guesses are welcome and also this is not a very common animal so guess whatever you want!

The first person to get it right wins! We'll retweet the answer from @PopSci, and also update this post so your amazing animal knowledge will be permanently etched onto the internet. Show your kids! Your dumb kids who thought that was a baboon!

Update: And the winner is...Eve Hardy, who correctly guessed that this is a cacomistle! The cacomistle, native to Central America from southern Mexico down to Panama, is a member of the Procyonidae family, otherwise known as the raccoon family (although it also includes kinkajous, olingos, and coatis). It's a very solitary creature, requiring a large territory and rarely interacting with other cacomistles. It mostly lives in the forest canopy, is nocturnal, and is an opportunistic eater, much like its raccoon siblings--it'll eat everything from fruit to insects to bird eggs to lizards.

The name "cacomistle" actually means "half cat" in the Nahuatl language, though the cacomistle is not, in fact, a cat. It's commonly mistaken for the ringtail (which is also known as a miner's cat or ring-tailed cat, though it is also not a cat), which more Americans may be familiar with--it can be found throughout the southwestern states, and is in fact the state animal of Arizona. You can tell the cacomistle apart from the ringtail in a few ways; the cacomistle has pointed ears, its claws do not retract, and its tail is comparatively longer than the ringtail's. In fact, the cacomistle's tail can often be longer than the cacomistle itself. Hi cacomistle!

In general, people tend to use the phrase "force of nature" loosely, as in "she's a real force of nature." But physicists are pickier--they reserve the phrase for just four separate, universal forces they call the "fundamental forces": gravity, electro-magnetism, and the strong and weak nuclear forces, which hold the nucleus together and are involved with radioactive decay, respectively.

That doesn't mean physicists rule out the possibility that other forces exist. Since the models they have for explaining everything are incomplete, there's a fairly good chance that there's something else out there, pulling matter apart or pushing it together in a different way than all the forces identified so far.

A team of physicists at the Amherst College and the University of Texas is looking for one potential fifth force--one that might arise from the spin of electrons interacting with the spins of other subatomic particles. We experience the short-range effects of electron spin every time we snap two magnets together--a result of the fact that iron contains electrons that line up with each other--but scientists think that particles' spin may cause them to interact over very long distances, too.

The problem is, even if this long-range force, called "spin-spin force," does exist, it's incredibly weak, and therefore extremely difficult to detect. Larry Hunter, chief scientist on the Amherst team, calculates that the long-range spin-spin force must be at least a million times weaker than the gravitational attraction between a neutron and an electron. Since gravity is the most obvious force in our lives, it seems like a strong one, but on the scale of individual sub-atomic particles, it's almost completely insignificant (the electrostatic force between two electrons is a million trillion trillion trillion times stronger than their gravitational attraction).

But Hunter's team has come up with a clever way to address the difficulty: instead of trying to detect the incredibly faint force acting between two particles, they are aiming to detect the net force of all the spinning electrons locked up in iron atoms in Earth's deep interior.

Since the electrons in iron tend to line up with the magnetic field, Hunter realized it might be possible to estimate the net spin from all the iron atoms in the mantle--the thick layer between Earth's crust and core that makes up the bulk of our planet's volume.

Hunter worked with a geophysicist, Jung-Fu Lin of the University of Texas at Austin, to calculate the strength of the magnetic field in different regions of Earth's interior and the net spin of electrons throughout the mantle. The researchers realized they could use the planet's quarry of iron atoms to increase the long-range spin-spin force on the neutrons inside Hunter's lab by more than a quadrillion-fold.

Still, there are lots of challenges: the test chamber containing the atoms of mercury gas the team is studying has to be completely isolated from all interference from the four known fundamental forces, and the tools the team uses to detect changes in the gas need to be perfectly calibrated. "It's a little like playing whack-a-mole," Hunter jokes. "You fix one problem and then another one pops up."

Hunter thinks he and his team can increase the sensitivity of their set-up by at least a couple orders of magnitude. Whether that increase will be enough for the physicists to make a detection--if this force really exists--remains to be seen.

In spite of medical schools' efforts to shield budding doctors from the dark forces of the medical-industrial complex, more than half of medical students end up receiving gifts from pharmaceutical representatives by the end of their fourth year, according to an upcoming study.

The study's lead scientist, a physician and researcher at Brigham and Women's Hospital in Boston named Aaron Kesselheim, explained the problem for the hospital:

Kesselheim and a fourth-year Harvard medical student, Kirsten Austad, surveyed more than 2,000 medical school students and residents from every school in the United States. They asked students how often they interacted with pharmaceutical company reps, what kind of gifts they received and what they thought of their interactions.

Kesselheim and Austad found that even tender first-year students often interacted with pharma reps, and one-third of first-years reported getting gifts. The majority of students said they thought the pharmaceutical industry gave them "valuable education," but also opened them up to bias. The majority supported reducing how often industry members can talk with students.

The study will be published this week in the Journal of General Internal Medicine. And for an overview of how often the pharmaceutical industry talks with doctors, and how that affects what doctors choose to prescribe, check out this 2000 review.

[Brigham and Women's Hospital]

A European mission to intercept and deflect an asteroid now has a target: asteroid Didymos. The proposed Asteroid Impact and Deflection Assessment mission couldn't have had better timing, sounding a call for proposals in the days before a huge meteorite exploded above northern Russia and an even larger chunk of space rock gave Earth a close shave.

The European Space Agency has been working on its AIDA concept for a couple years, designing a two-part mission that would send two spacecraft to a double asteroid target. One small spacecraft will smash into an asteroid at 14,000 MPH, and the other will record what happens to the space rocks' orbital dance. The goal is to characterize how an object's orbital mechanics would change if it's disturbed by an impactor. This will help scientists trying to determine how space debris might affect a satellite, or it could be a first step in determining whether an asteroid deflection mission could work, should we need it.

Didymos is a binary asteroid, with two asteroids orbiting each other. One is roughly a half mile across and the other is about 500 feet across. Many asteroids have small moons or orbital companions.

It doesn't pose any threat to Earth, but it will come close enough in about 9 years for ground-based telescopes to spot it. That will help astronomers verify the impact dynamics after one of the two spacecraft smack into it. You can read more about AIDA here.

Humans have been using alcohol as a medicine since ancient times, using it as an antiseptic and a pain killer, among other things. We're not the only species that does so, apparently. According to biologists at Emory University, fruit flies force alcohol on their larvae to protect them from parasitic wasps.

Common fruit flies (Drosophila melanogaster) have adapted to be able to largely digest alcohol in their main food source, the rot on overripe and fermenting fruit. Fruit fly larvae been known to self-medicate, consuming high levels of alcohol in order to fight off endoparasitoid wasps, which lay eggs inside fruit flies that eventually hatch and eat their host from the inside out. The alcohol is still somewhat toxic for them, but the wasps, which don't have a tolerance for the toxic effects, are a bigger danger, so the flies kill the parasite by raising their own blood alcohol levels.

But it seems that the flies also try to protect the next generation from the wasp threat. When wasps are present, fruit flies sense that their children will be at risk for infection, and lay their eggs in alcoholic food to protect them.

Researchers released adult female fruit flies into a cage with parasitic wasps and a cage with no wasps and looked to see if they preferred to lay their eggs in the petri dish that contained alcohol. Overwhelmingly, they did -- 90 percent of flies in the cage with wasps laid eggs in the alcohol dish, versus only 40 percent in the wasp-free dish. They consistently chose to deposit their eggs on petri dishes that contained the highest level of alcohol that would be found in nature, despite the fact that they were bred in a lab and had never encountered parasitic wasps before.

The flies could tell the difference between wasps that infect larvae and other wasp species that infect flies a little later in their lifespan, when they are pupae. The fruit flies would only lay their eggs in alcohol in the presence of larvae-infecting species, because it wouldn't help prevent infection for pupae.

"Fly larvae usually leave the food before they pupate, so there is likely little benefit to laying eggs at alcoholic sites when pupal parasites are present," explains Todd Schlenke, one of the study's authors.

Schlenke was surprised that the flies used sight to identify danger to their larvae. "I thought the flies were probably using olfaction to sense the female wasps. The small, compound eyes of flies are believed to be more geared to detecting motion than high-resolution images."

The researchers found that a number of fly species they tested used alcohol to protect against parasites. And alcohol-seeking behavior seemed to persist for the remainder of the fly's life, even if wasps were no longer present. "Medication may be far more common in nature than we previously thought," Schlenke says.

[eScienceCommons]

Tourists vacationing on the sunny isles of Reunion and Mauritius have no idea what secrets those sandy beaches hold. The islands could be hiding the remains of an ancient micro-continent, quietly torn apart between 50 and 100 million years ago, according to a new study. Scientists think they have spotted a fragment of a continent known as Mauritia.

The small strip of continent was once tucked tightly between the lands now known as India and Madagascar, back when those areas were packed into a supercontinent known as Rodinia. (It's the older and less-famous relative of supercontinent Pangaea.) Evidence of this sandwiched continent came from sand grains on Mauritius beaches, according to Trond Torsvik of the University of Oslo in Norway and colleagues.

Rodinia would have existed from the Precambrian era, about 2 billion years ago, to around 85 million years ago when plate tectonics broke it apart. Continental breakup is usually a mantle plume's doing--hot rock from within the Earth softens up tectonic plates, which eventually split. This is how the land masses now known as Madagascar, India, Australia and Antarctica broke up and migrated to their current locations on the planet. As this took place and the Indian Ocean formed, small fragments located on the edges of the rupture zone broke off--this is how the Seychelles came to be. Mini-continent Mauritius just wasn't so lucky, and it slipped beneath the waves, disappearing with time.

Much later, volcano eruptions spewed its remnants back to the top of the Earth's crust, Torsvik and colleagues write.

They examined sands in Mauritius that formed from eroded volcanic rocks, dating to about 9 million years ago. But when the team looked at these sand grains, they found ancient zircon minerals that were far more ancient--between 660 and 1,970 million years old. The presence of these ancient zircons points to microcontinent fragments churning up due to more recent volcanic activity, the team says.

The discovery of a possible microcontinent fragment suggests continental leftovers like the Seychelles might be more common than scientists thought. A paper describing the research is published this week in Nature Geoscience.

Thanks to dozens of video reports, scientists are getting a pretty good handle on the life history of the massive meteorite that exploded above Russia earlier this month. They know it is rocky and a common type, and now they know where it probably came from. Scientists are scrambling to publish papers describing its origins in the middle of the solar system.

The asteroid chip that became the recent meteorite came from a spot in the asteroid belt near Jupiter, about 2.5 times further from the sun than Earth is, according to NASA.

At the University of Antioquia in Colombia, astronomers Jorge I. Zuluaga and Ignacio Ferrin produced a preliminary reconstruction of its orbit around the sun. It came from a well-known group of asteroids that frequently cross paths with Earth, known as the Apollo asteroids. Astronomers have seen about 240 that are larger than a kilometer in diameter, but speculate that about 2,000 similarly sized space rocks exist. As for rocks of Chelyabinsk size? There could be 80 million.

The space rock's trajectory can also be determined through infrasound, astronomers said. Infrasound ripples spread through the atmosphere as the meteorite exploded, and by examining their patterns, scientists can figure out which direction the meteor traveled and how much energy it unleashed. Elephants and homing pigeons can hear it, but all humans can do is turn to the infrasound stations monitored by the Comprehensive Test Ban Treaty Organization.

"We would like to know not only where it came from, but how big it was, how coherent it was, where it stated breaking up, where its terminal impact was," said Bill McKinnon, professor of Earth and Planetary Sciences at Washington University in St. Louis. "People have studied the entry of these sort of meteors before, but they're usually not quite so big. We haven't had a chance to have such a good instrumented look at these things ... they don't undergo terminal deceleration over a city of a million people."

Nobody could see it coming because it careened toward Earth from the same direction as the sun, so no telescopes could have detected it. But video cameras throughout Russia captured its entry, and Zuluanga and Ferrin use these to reconstruct the space rock's orbit. They used trigonometry to determine its speed, height and position--it entered at a shallow 30-degree angle--and then they calculated its height, elevation and geolocation at its so-called "brightening point," when it becomes bright enough to cast a shadow in the videos. They plugged this data into a model that computes the gravitational influence of the moon, Earth and other planets, and figured out it was an Apollo group asteroid. Their paper is posted to the physics arXiv preprint server, and McKinnon notes there are probably many more to come.

[via Technology Review, NASA]

Cockroaches can recover their footing before their nervous systems even kick in to tell them how, according to new research. This means their legs recover passively, without needing instructions from the command center--a useful lesson for people trying to design better multiple-legged robots.

Shai Revzen, an assistant professor of electrical engineering and computer science plus biology at the University of Michigan, is studying cockroaches with a goal toward building better robots. He designed an experimental setup that records high-speed imagery of the insects scurrying across a small bridge. The roaches run onto a platform that is then released from an elastic spring, sending it swinging sideways with great force. It's equivalent to Revzen running and being tackled by a sumo wrestler, according to a university news release. Watch the roaches run below.

They found that the nervous system kicks in pretty late, meaning the insects don't need their senses to recover. For whatever reason, the nervous system gives the physical system a second to figure things out before sending sensory pulses. That suggests passive robots might be better-equipped to handle surprises, rather than coded to respond to any scenario, Revzen said. This is contrary to widely held assumptions about how robots should respond.

"We shouldn't try so hard to control things actively; we should just build a good passive mechanical system and end up with a robot that's far simpler and more reliable," he said.

[via National Science Foundation]

An audacious plan to send two people looping around Mars and back has a lot of crazy components--who will pay for it? Who will design and build the special rocket and spaceship for this mission? How can it possibly be ready in just five years? And who gets to go? And why? So far, only that last question has an answer, and it's the only non-crazy part of this new plan: Why not?

We first heard about the "Mission for America" last week, when the first details emerged about space tourist Dennis Tito's Inspiration Mars program. Tito, who gained fame as the first person to pay for a round-trip ticket to the International Space Station, wants to send a two-person crew to Mars and back in 501 days, starting in 2018. The nonprofit company formed to further this goal held a press announcement Wednesday in Washington, presenting scarce new details but pretty good answers to the oft-repeated question of why. American pride is high on the list.

Someone asked Tito if he just waned to beat China to Mars, and he replied, "Wouldn't I want to do that? Wouldn't I want America to do that? Wouldn't you want America to do that?"

Since the announcement, several space exploration luminaries--not the least of whom is Apollo 11 astronaut Buzz Aldrin--have lined up to lend moral support. "The purpose is to inspire, to say we're going to do something and then we do it," he told the Washington Post. A 6-year-old boy who reportedly said "this is my Apollo" has apparently made one of the first donations, worth $10.

The Mission for America has a tight schedule because it aims to take advantage of a rare alignment between Mars and Earth during the 2018 launch window. The trajectory is so carefully designed that the spacecraft wouldn't need to fire its engines to get around Mars and back; instead it would just use the planet as a slingshot. It would gain immense speeds for the return leg and would need no de-orbit burn. But as we learned with Apollo 13, there's a really tiny window for error.

It will be cramped, uncomfortable, scary and lonely, which is one reason why the mission's supporters think the crew should be a married couple. You'd want two people no matter what, if for no other reason than contingency--in case something happened to one person, you'd have a backup pilot. But anyone making the trip would also be subject to crushing loneliness, especially while watching our planet fade to a pale blue dot as the odometer ticks into the hundreds of millions. Being there with your spouse would make it a little easier.

The Inspiration Mars team clearly has a ton of work to do--and very soon--before this dream gets anywhere near reality. But it's definitely exciting to think about it.

Those music files -- be they MP3, AAC or WMA -- that you listen to on your portable music players are pretty crap when it comes to accurate sound reproduction from the original recording. But just how crap they really are wasn't known until now.

Audio data compression, at its heart, is pretty simple. A piece of software compresses a piece of digital audio data by chopping out redundancy and approximating the audio signal over a discrete period of time. The larger the sample time-period, the less precise the approximation. This is why an MP3 with a high sampling rate (short sample times) is of higher quality than an MP3 with a low sampling rate.

To test if the human ear was accurate enough to discern certain theoretical limits on audio compression algorithms, physicists Jacob N. Oppenheim and Marcelo O. Magnasco at Rockefeller University in New York City played tones to test subjects. The researchers wanted to see if the subjects could differentiate the timing of the tones and any frequency differences between them. The fundamental basis of the research is that almost all audio compression algorithms, such as the MP3 codec, extrapolate the signal based on a linear prediction model, which was developed long before scientists understood the finer details of how the human auditory system worked. This linear model holds that the timing of a sound and the frequency of that sound have specific cut-off limits: that is, at some point two tones are so close together in frequency or in time that a person should not be able to hear a difference. Further, time and frequency are related such that, a higher precision in one axis (say, time) means a corresponding decrease in the precision in the other. If human hearing follows linear rules, we shouldn't hear a degradation of quality (given high enough sampling rates -- we're not talking some horrible 192kbps rip) between a high-quality file and the original recording.

The experiment was broken up into five tasks that involved subjects listening to a reference tone coupled with a tone that varied from the reference. The tasks tested the following:

1) frequency differences only
2) timing differences only
3) frequency differences with a distracting note
4) timing differences with a distracting note
5) simultaneously determining both frequency and timing differences

I don't think it will come as a surprise to a lot of audiophiles, but human hearing most certainly does not have a linear response curve. In fact, during Task 5 -- what was considered the most complex of the tasks -- many of the test subjects could hear differences between tones with up to a factor of 13 more acuity than the linear model predicts. Those who had the most skill at differentiating time and frequency differences between tones were musicians. One, an electronic musician, could differentiate between tones sounded about three milliseconds apart -- remarkable because a single period of the tone only lasts 2.27 milliseconds. The same subject didn't perform as well as others in frequency differentiation. Another professional music was exceptional at frequency differentiation and good at temporal differentiation of the tones.

Even more interesting, the researchers found that composers and conductors had the best overall performance on Task 5, due to the necessity of being able to discern the frequency and timing of many simultaneous notes in an entire symphony orchestra. Finally, the researchers found that temporal acuity -- discerning time differences between notes -- was much better developed than frequency acuity in most of the test subjects.

So, what does this all mean? The authors plainly state that audio engineers should rethink how they approach audio compression -- and possibly jettison the linear models they use to achieve that compression altogether. They also suggest that revisiting audio processing algorithms will improve speech recognition software and could have applications in sonar research or radio astronomy. That's awesome, and all. But I can't say I look forward to re-ripping my entire music collection once those codecs become available.

The Karma is a very small revolution in tech: it's a gadget with a data plan that makes sense, is transparent, and doesn't try to screw you. This should not be a crazy great thing. And yet it is.

Portable Wi-Fi hotspots are, for the most part, great to use and awful to pay for. They're tiny little devices that gives you fast internet access no matter where you are, by tapping into the same fast networks used by Verizon, AT&T, Sprint, and T-Mobile. Until all our laptops have little SIM-card slots in them, this is the best way to get online in places without a Wi-Fi connection. Great! Except it costs an arm and a leg, and requires a contract, and forces you to ration yourself every tiny little megabyte. So, yeah, Wi-Fi hotspots are trying to screw you.

Karma isn't the most high-tech hotspot out there, but unless somebody else is footing the bill, it's the one I'd recommend, because not only is it not trying to screw you, it actually rewards you for un-screwing (AKA helping) other people. That help? Free data, both for you (for being nice enough to share your connection with someone) and for the lucky person who's found your generous connection. Hence, "karma," kind of.

The Hardware

The Karma is probably the best-looking Wi-Fi hotspot on the market--since it's independent of all of the carriers, it doesn't have to have violent branding from Verizon or AT&T or whoever, and the three Dutch founders were all formerly designers. It's very small and light, a rounded-off square like a reverse Oreo, with a white top and bottom sandwiching black plastic. On the back is a standard microUSB port for charging--that's the same cable that your Android phone, Windows phone, Kindle, and about a billion other devices use.

Karma says the battery lasts between 6 and 8 hours. Compare that to the Verizon Jetpack 4G LTE MiFi 4620L, one of the best hotspots on the market, which, with its standard battery, only gets 3 hours of battery life. And, of course, since the Karma charges over USB, you can plug it into your laptop and keep it going that way.

Speed: The Karma uses Clearwire's 4G network, just like Sprint. It's not an LTE network, like Verizon's or AT&T's, but it was fast enough for my uses, averaging about 8.35Mbps download speeds in Manhattan and around 3.0Mbps in Brooklyn. My home internet, for the record, gets between 12Mbps and 15Mbps, so this isn't quite as fast, but in practice, I didn't find the speed to be a problem at all. That said, an LTE network can easily hit speeds of 15Mbps.

Free of Contracts

Verizon's Jetpack 4G LTE MiFi 4620L (lord, what a name) is faster than the Karma, yes. But it'll cost you a lot; it's designed specifically for people who will be using it all the time, and even then, it's expensive as all hell. You'll sign up for a two-year contract, then pay $50 for the hotspot, then you'll pay a minimum of $50 per month for 4GB of service. If you use 1GB of that in March, you still pay $50. If you use 6GB in April, Verizon will charge you $70, since you went over your limit--even though those two months average out to less than your limit.

See? Verizon's trying to screw you.

Here's how Karma works. You pay $80 up front. It comes with 1GB free, just for buying it. Then it's pay-as-you go. No contracts at all. No minimum to buy. Your service rolls over; if you buy 5GB in February and only use 1GB? You'll have 4GB left to use in March. Or April. Or whenever. It's a flat fee; since it never expires, it doesn't really make sense for Karma to offer it in bulk. But it's reasonably priced, at $14 per GB. That means 4GB of service costs $56, compared to $50 at Verizon, but you'll save money in the long run, since you'll only pay for the data you use and none will go to waste on less data-heavy months.

Karma is not trying to screw you. Robert Gaal, one of the founders of the company, told me that the goal was to create a "simple and honest mobile provider." As anyone who's dealt extensively with Verizon and AT&T can tell you, that's a totally different approach than most carriers. The idea of just paying for what you use--it's refreshing and crystal-clear, and, even better, will almost certainly work out to cheaper in the long run for almost every user.

That "Karma" Thing

So the reason it's called "Karma" is due to some built-in sharing features. Your Karma network is unprotected, always. Other people are encouraged to use it: they sign in using Facebook, and they'll get 100MB of free data. Even better, you'll get 100MB of free data whenever someone new signs in this way. It's a Silicon Valley startup's idea of karma, I guess. There doesn't seem to be a limit to how much free data you can get, so walking into a Starbucks and shouting "Hey everyone, sign into my Wi-Fi network!" would seem to be a way to get out of ever paying for internet again. (Though you can only host eight connections simultaneously.)

Except! Karma relies on Facebook to authenticate users. If you want to use Karma, you've got to sign in on Facebook. That freaks people out. They assume someone is trying to hack them, to see their photos and post ads to their timeline or god knows what other kinds of circa-2013 horrors can be perpetrated with a Facebook login. Karma says very emphatically that the Facebook login is merely used for authentication, and that "We'll never post anything to your timeline without your explicit permission. Never, ever." But I think people will be very hesitant to log into an unprotected Wi-Fi network called something like "Dan's Karma" that requires you to give it access to Facebook before letting you online. Gaal tells me that in the coming weeks, Karma will implement some kind of alternative to Facebook authentication, using an email address paired with perhaps a credit card number or phone number, though I'm not sure people will be any more likely to hand over a credit card number to a strange Wi-Fi network than they'd be to type in their Facebook password.

I was concerned about security; this is by default an open network. Gaal noted that most major sites--all Google, Facebook, any modern email sites, media sites like Netflix and Rdio--all use HTTPS, a secure communications protocol. Sharing is completely disabled, so you you don't have to worry about anyone swiping your files. Basically, it's about as secure as your local coffee shop's unprotected Wi-Fi network--which is to say, moderately secure, assuming nobody really wants to hack you.

How Does It Work?

Really well. Super seamless and easy to set up, the billing system couldn't be more simple, the hardware is tiny and attractive and easy to use, and the speeds were reliably solid. The "YourKarma" site that tracks your data use is very pretty and clear; it lets me know whenever anyone logged into my hotspot and gifted me with some data (though it doesn't let you see any Facebook info you couldn't already see) and how much data I have left. You'll also get an email when you're nearly out of data, which is nice.

There are some downsides. The Karma doesn't have some of the advanced functions that high-end hotspots have, like a microSD slot for sharing files or a display for showing data usage or battery life. Though Clearwire's 4G is pretty quick, it is definitely not top-of-the-line; it has neither the speed nor the coverage of the bigger LTE networks. It'd be a good idea to check this coverage map before picking one up, and it won't work internationally at all. And as much as Karma reassures me, there are definitely some people that shy aware from giving anyone or anything access to their Facebook account. It's a reasonable fear, though nothing in my time testing the Karma indicated that anything untoward was being done with my Facebook information.

But overall, the Karma is easily my favorite Wi-Fi hotspot. It's reasonably priced, good-looking, and doesn't seem like it's trying to pull a fast one on me, which is more than I can say for any of the hotspots you might find at your Verizon or AT&T shop. The "karma" element is kind of gimmicky and silly, but it's not hurting anyone. Matter of fact, all it does is give free stuff away, so I find it hard to have too much of a problem with it.

I think contract-free is always the way to go with something you won't necessarily use every day. The Karma is a great thing to pick up just in case; you can drop $70 on 5GB of data for a rainy day, and then the next time you're stuck without Wi-Fi--even if it's months later--you've got some data in the tank. It's great.

Nothing can escape a black hole, even light, because to wrench away from its titanic gravitational pull, you'd have to move faster than light is capable of traveling. And nothing can do that, as far as anyone knows. As matter falls into a black hole's gaping maw, it superheats to millions of degrees, screaming a final cry of X-rays as it is torn apart. At a specific point called an event horizon, the matter disappears and is never heard from again.

A pair of X-ray telescopes recently watched some of these X-ray death gasps and were able to figure out how fast a black hole is spinning. This is "hugely important" for black hole science, according to researchers working with NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR space telescope. One particularly cool finding: The black hole is spinning almost as fast as Einstein's theory of gravity says it possibly could. It's spinning at almost the speed of light.

The galaxy in question is called NGC 1365, which is about twice the size of the Milky Way and located about 60 million light years away. The black hole is about 2 million times more massive than the sun. Scientists using NuSTAR and the European Space Agency's XMM-Newton satellite wanted to measure how fast it is spinning. This is a key feature of black holes that is related to their size and the way they gobble up stars, gas and even other black holes.

The problem is that black holes are hard to study, because, you know, not even light can escape them. To measure them, you have to measure their effect on their surroundings--like the X-rays emitted by dying matter. This is hard to do because objects between us and them can get in the way, however, making the X-rays look distorted. There have been two competing models explaining why the X-rays look warped: Either gravitational distortion caused by black hole gravity, or distortion caused by intervening clouds of gas and dust.

In this new study, NuSTAR and XMM-Newton set out to determine which one is right. The telescopes carefully traced the X-rays emitted at the very, very edge of the black hole, right near the event horizon, or the point of no return. By combining their distinct viewing abilities, the two telescopes were able to see a wide range of X-ray energies, and figure out that the X-rays are not actually distorted by intervening gas clouds. They look distorted because the black hole is spinning, and its immense gravity warps spacetime as it swirls around. This information was used to tell just how fast the black hole is spinning: Just below the universal speed limit.

Along with new information about this particular black hole, this study suggests that black hole observations can remove a little bit of ambiguity. This will help astronomers continue to unravel the mysteries of these galactic monsters. A paper describing the findings is published this week in Nature.

[NASA]

This fat airplane is designed to fly for four days at altitudes around 65,000 feet--but it's only taking baby steps so far. Boeing shared some video today of the Phantom Eye's second flight earlier this week, which lasted 66 minutes and reached altitudes of 8,000 feet.

The plane flew at 62 knots, equivalent to about 71 MPH. It's powered by liquid hydrogen and it has to take off using a special "ground cart," or fancy airplane skateboard. The flight was Monday at NASA's Dryden Flight Research Center at Edwards Air Force Base, Calif. Boeing updated the plane's software and hardware--including the landing gear--after its first flight. Watch Phantom Eye fly:

"The first flight was pretty incredible, because it proved that the technology and our design worked, but this second flight is a major step closer to bringing Phantom Eye to the market," said Drew Mallow, program manager at Boeing Phantom Works in St. Louis.

The plane can carry 450 pounds of payload, so it could carry a rather large suite of instruments for surveillance. It produces only water as a byproduct.

Enthusiasts of gun-law loopholes, this might be your new favorite workaround. A project at the crowd-funding site Rockethub wants to create a 3-D printed gun part for just $50. The twist: the part is only 80 percent complete, so like an Ikea desk you'll have to finish the rest of it yourself.

Started by 2nd AM Arms, the project promises to make a lower receiver for an AR-15 semiautomatic rifle. The lower receiver is what holds all the working parts in a gun. The receiver is so important that under U.S. law, a receiver on its own is still treated as a firearm, and requires a serial number. The argument made by 2nd AM Arms, however, is that an 80-percent completed receiver is just part of a gun component, not a full-blown firearm, and as a such is not subject to the same degree of federal regulation.

What that might mean: Buy it, and you could have complete anonymity. A licensed seller of complete gun parts "must maintain records of all firearms receipts and dispositions, including the name, age, and place of residence of purchasers." That's not the case when selling an 80-percent complete part. 2nd AM Arms FAQs says under facts that it will "even accept cash or gold if you like as payment for those who would like to stay completely anonymous."

So what would someone do with 80 percent of a gun part? At its Rockethub page, 2nd AM Arms links to YouTube videos detailing the kind of drilling and modification someone would need to take a part like this and make it functional.

Making the lower receiver is only one of the goals of this project. Obviously, there's a larger agenda here: to send a political message. Just look at the other donor rewards. At the lowest level of support, 2nd AM Arms will mail a copy of the 2nd Amendment to President Obama and Sen. Dianne Feinstein (D-California), both of whom have expressed interest in stricter gun laws. All higher pledge levels include T-shirts featuring the 2nd Amendment, and if you pledge anything above $50, you get a commemorative lower embossed with the 2nd Amendment. Finally, if the project meets its funding goal (which it had as of press time), 2nd AM Arms pledges to donate 2 percent of its funding to the NRA.

Earlier this week we described the continuing developments of Defense Distributed, a band of 3-D printed gun advocates, to make a 3-D printed lower receiver. Both of these 3-D printed gun projects have a political intent, and it's interesting to see the different ways they are aiming to skirt regulation. With Defense Distributed, it's about people freely downloading schematics. With 2nd AM Arms, the dodge is by offering only a mostly complete product.

Astronomers have likely caught one of the first glimpses of a planet being born.

Over the past few years, other astronomy teams have found evidence of other still-forming baby planets, but this object may be the youngest yet. "The other planets are a little older," says Sascha Quanz, an astronomer at ETH Zurich in Switzerland who led the discovery, in a phone interview.

Using the European Southern Observatory's Very Large Telescope in Chile, Quanz directly observed a planet still in the midst of a disk of gas and dust that surrounds its central star, HD 100546, located 335 light-years away from Earth. The planet hasn't had the time to gather enough mass to clear the dust around it. The other probable protoplanets, discovered in 2011 and 2012, are a step ahead. "They have already cleared a big gap in the disk of their host stars," Quanz says.

The newfound object is very bright, which Quanz thinks is because gas is actively falling on the forming planet. Right now, the planet is about as massive as Jupiter, Quanz says. Like Jupiter, it is also gas giant.

Quanz will still have to confirm that the data he and his team gathered really point to a forming planet. Another possible explanation for what they're seeing is that the object is actually being ejected from its solar system, he says. There are data, although not direct observations, that suggest HD 100546 has another planet orbiting closer to it. Interactions between two planets closer to the star could shoot one of the planets out into the dust ring.

Observations made about five years from now should help astronomers differentiate between the two scenarios. Why five years? From its location, astonomers expect the new object to make a full orbit every 360 years. So after five years, the planet should move five degrees, if it's truly in orbit as forming planet.

Quanz and his team will make some observations far before that, however. In April, they'll get another turn at the Very Large Telescope, during which they'll make measurements that will help them determine the object's temperature. If they're lucky, Quanz says, they may be able to observe the object accreting gas--growing like any healthy baby would.

Quanz and his team published a paper today about their discovery, in the journal Astrophysical Letters.