A large metallic ball has fallen from the heavens and landed in a remote region of Namibia, spurring a lot of speculation about its origins and spurring local authorities to get NASA and the European Space Agency on the horn. No one is sure where the hollow metallic object came from, but it definitely came down hard--it was found 60 feet away from its landing site, a hole more than a foot deep and 12 feet across.

Made of a "metal alloy known to man," the 13-pound ball is about 43 inches in circumference and landed roughly 480 miles from the Namibian capital of Windhoek. And it turns out it's not alone. Apparently several similar objects have fallen across the southern hemisphere (in Australia and Latin America as well as elsewhere in Africa) over the past couple of decades.

So far, it has not exploded, hatched, or started to glow with a faint, eerie white light. Nor has anyone descended from the sky looking for it. If that happens, we'll be sure to post something about it here.

[AFP]

Attentive followers of dentistry developments that we are, we've been following the story of the plasma brush for awhile now. And it seems like it's making some serious progress: human clinical trials are supposed to begin in early 2012, and there's also a video (below) of the World's Bravest Dentist shooting a plasma beam into his own mouth.

Some background, for anyone who doesn't subscribe to Dentistry Illustrated Weekly: the plasma brush isn't a toothbrush, but actually a tool dentists are hoping to use for two primary situations. The first is breaking up plaque; the plasma torch, though it's no hotter than room temperature, is excellent at breaking the bonds that adhere plaque to a tooth. The second is as a sort of primer for filling cavities.

There are certain kinds of cavities, according to Hao Li, associate professor of mechanical and aerospace engineering in the Missouri University University of Missouri College of Engineering, that need to be refilled every five or seven years using current technology--and they can only be refilled a few times before having to be pulled. The plasma brush can prime a cavity for filling in sort of the same way pavers create those divots in roads before filling them in with new asphalt: it provides more surface area for the filling to stick to, and the research team claims plasma-assisted fillings could be 60% stronger than traditional fillings.

Human clinical trials are due to begin early next year at the University of Tennessee at Memphis, with the team hoping the tool could be approved by the FDA and available to dentists by 2013.

Today in pretty space pics: Comet Lovejoy, still alive and heading back out toward the far reaches of the solar system, as seen from the International Space Station. This photograph was snapped yesterday as the ISS passed over Australia by Dan Burbank, one of the station's current crew members. And needless to say, it's one of those once-in-a-lifetime shots.

What you're seeing in the top of the shot is actually the dark side or our dear planet, with the lit up arc traversing the image being Earth's atmosphere, backlit by the sun (the thin green line is the upper atmosphere, where energized particles are tickling the edge of space). And of course, there's Comet Lovejoy, which narrowly escaped a flyby of the Sun last week and came out not so worse for wear on the other side. Burbank managed to capture it from the ISS just as it was darting behind the home planet on its way back out into interplanetary space.

Click through to Bad Astronomy for a quick primer on comets, Lovejoy, and the two tails--yes, there's actually two--that you're seeing here. And, as always, the Bad Astronomer has links up to the larger version of this pic, should you feel the need to take a closer look. And you should.

[Bad Astronomy]

No. The charm has nothing to do with the music and everything to do with the charmer waving a pungi, a reed instrument carved out of a gourd, in the snake's face. Snakes don't have external ears and can perceive little more than low-frequency rumbles. But when they see something threatening, they rise up in a defensive pose. "The movement of the snake is completely keyed in on the guy playing the toodley thing," says Robert Drewes, chairman of the department of herpetology (the study of amphibians and reptiles) at the California Academy of Sciences in San Francisco. "He sways, the snake sways."

Drewes studies how animals respond to their own calls; his specialty is frogs. Frogs have very good ears, which makes sense, since airborne sound is vital to their procreation: A croaking male calls out to a female. Every call of every frog species is distinct, and Drewes can walk blindfolded into a patch of Kenya's Arabuko-Sokoke forest and identify 15 different species by listening to their calls. Female frogs have inner ears that are attuned only to the call of their species. He likes a deep, rich pitch, and when he plays the saxophone, he prefers his alto and tenor to his soprano. Although when he travels to Africa, he brings a soprano. "I hate the damn thing, but it fits in my bag," he says. What do the frogs think of his playing? "I can't answer that," he says. "The guy who really knows this stuff is Bernie Krause."

Krause is a musician and "soundscape ecologist" who has recorded with Stevie Wonder, the Doors and George Harrison (Krause worked on Harrison's album Electronic Sound, which credits Harrison's cat for performing on one side). "Some musicians have played music to killer whales or dolphins," he says, "and what happens is initially the critters that are being subjected to this appear to be curious and want to know what it is, where it's coming from." In 1985 he was part of a team that coaxed a lost humpback whale out of the Sacramento River delta with field recordings of other humpbacks feeding.

Krause says that although animals seem to respond to what we call music, how can we know what they think? "Birds bob their heads to beats, bonobos played keyboard with Peter Gabriel," he says, "but we're ascribing our attributes to animals. Show me animals appearing to enjoy music that aren't captive, that aren't looking for something to alleviate the boredom." Krause says that we learned our music from the natural world, and in a few small pockets of the globe, groups of humans still sing with nature rather than to it. The Kaluli in Papua New Guinea, he says, "mix their voices in with the sounds of the forest, which is how we first learned polyphony"-singing with more than one voice. Snake charming also may have begun this way, singing and dancing with the snake. But that was thousands of years ago, before we knew snakes couldn't even hear that toodley thing.

A team of veterinarians have taken time away from helping fluffy animals to focus on what's really important: dinner. Specifically, what's the best way to sew your holiday bird back up after you've deboned and stuffed it?

The group tried four different surgical suture patterns to secure the bird, but all of them resulted in torn skin and a sadly scarred main course. The solution? A fifth bird, which was closed up with metal surgical staples instead of stitches, was by far the fittest for presentation at the holiday table.

Ever willing to buy in to useful culinary technology, I think I better pick up one of these quick, before the bird goes in the oven. Less than $10 and preloaded with stainless steel staples.

Oops! And one of these.

[Science]

Biometric security is often focused on the more boring anatomical parts, like the pads of the fingers (ehhh) or the eyes (who cares). So little attention has been paid to the security possibilities of the butt. Well, not anymore: researchers at the Advanced Institute of Industrial Technology in Tokyo have come up with a car seat that measures the precise contours and pressures left by your posterior.

Apparently measuring buttprints, or rear-pressure (none of the terms I just used, or will use, have been approved or sanctioned by the researchers) is a pretty decent way to identify people. The seat is comprised of a system of 360 separate sensors, which measure pressure. Those sensors communicate with a laptop to put together a precise map of the seated person. The researchers say the seat can correctly identify people with 98% accuracy--not bad at all.

The team is hoping to work with Japanese car manufacturers to implement the system as an added security measure, possibly in as few as two or three years.

[TechCrunch]

In honor of this festive holiday season, we've included in this week's roundup of amazing science and tech galleries some festive shots of our own. Pictured above is a nearby spiral galaxy that looks, if you're a NASA scientist who has been recently bonked on the head, like an outer-space wreath. There are also cute baby animals this week. Enjoy, and happy holidays!

Click to launch the gallery.

As we say goodbye to the year 2011, we reminisce on what came before us, and look forward to what is still to come. In order, according to this Baarbarian illustration, that is: Stonehenge, and giant robots.

Want to win this triumphant Baarbarian illustration on a T-shirt? It's easy! The rules: Follow us on Twitter (we're @PopSci) and retweet our This Week in the Future tweet. One of those lucky retweeters will be chosen to receive a custom T-shirt with this week's Baarbarian illustration on it, thus making the winner the envy of their friends, coworkers and everyone else with eyes. (Those who would rather not leave things to chance and just pony up some cash for the t-shirt can do that here.) The stories pictured herein:

• Japanese Roboticists Are Building the Tallest Humanoid Ever
• Geologists Pinpoint Welsh Quarry as Source of Stonehenge's Oldest Stones

And don't forget to check out our other favorite stories of the week:

• Happy Holidays From Popular Science
• The Most Amazing Images of the Week, December 19-23, 2011
• Mysterious Metallic Space Ball Falls to Earth in Africa, Baffling Authorities
• How a Decade of IEDs Has Reshaped Bomb Disposal Tech
• A Rare Last Look Inside the Space Shuttle Atlantis
• Discovered: The First Earth-Sized Worlds Outside Our Solar System
• How to Lift 3,500 Tons
• Tch Support: Vin Marshall's Favorite Chemical Tools for DIY Projects

Well, 2011 is almost over. And it's been a great year in science and tech, as our annual Best of What's New awards have shown--from portable destroyers to portable 3-D TVs, from revolutions in private aerospace to revolutions in digital photography, this year's awards are chock full of amazing stuff. So, thoughtful folk that we are, we've combined all the winners into an easy-to-navigate roundup. This is...the Best of What's New.

Check out the best, most innovative, and most futuristic products of 2011.

By day, Seok-Hyun Yun and Malte Gather are physicists at Massachusetts General Hospital. But at night, for the past four years, they worked on making a human cell behave like a laser. They built their human laser out of the same three components found in all lasers: a pump source, which provides the initial light energy; an optical cavity, which concentrates the light from the pump source into a beam; and a gain medium, a substance in which electrons are excited until they reach a higher-energy state and simultaneously release that energy as a beam of photons-laser light.

Awesome!

Yun and Gather modified a human kidney cell to produce green fluorescent protein (GFP), the substance that makes jellyfish bioluminescent. This was their gain medium. They cultured these modified cells and placed one between two mirrors, creating the optical cavity-"a cell sandwich," Yun says. They then sent pulses of blue light from a miniature laser (the pump source) through the cell, where it bounced between the mirrors. The cell glowed green, and light shot out. Through a microscope, the physicists saw a grayish mass (the cell) with luminescent spots (the laser).

Now What?

A living laser could be used to activate cancer-treating drugs using photodynamic therapy. Doctors could inject light-sensitive compounds into a patient's bloodstream to seek out tumors and diseased cells. Normally, such compounds are activated externally, but if both the drugs and the light itself were internal, treatment would be more precise. For now, though, Yun is primarily interested in the possibility of using his human laser to detect slight changes in cells. The intracavity light passes through the cells thousands or millions of times before exiting as a laser beam. Yun says that scientists could use the ricocheting light to monitor cell behavior with unprecedented sensitivity, similar to an intracellular high-speed camera. And yes, he says, his process could one day allow people to shoot laser beams from their eyes, though it would be more flashlight than death ray. "If a light source was implanted in the eye, it might be possible to control it with brain signals."

The 40-inch SUR40, co-created by Samsung and Microsoft, is a thin tabletop computer that sees and responds to whatever is placed on it. Each of the table's LCD pixels emits an infrared beam that reflects off an object back to a sensor. The processor synthesizes the sensor data to create an eight-bit image from which it can pick out shapes and large text, such as product names and numbers. Once the object is identified, the table displays related YouTube videos and other product information. Right now most apps are on the simpler side, but developers are free to program custom games and more, depending on what bar or store the table winds up in. $8,400

With enormous sets of instruments and giga-amounts of data, it's easy to have too much information in science these days, requiring the careful sifting of signals to reach a target. But researchers can just as easily share their surpluses, and they probably should - time and again, one scientist's discarded data is another researcher's treasure. This time, a seismology tool used for monitoring underwater earthquakes is being used to track the endangered fin whale.

Hydrophones used to listen to the burbling sounds of seafloor spreading also pick up the low-frequency calls of fin whales, a poorly understood species that live in deep waters far offshore. Seismologist William Wilcock of the University of Washington-Seattle spent three years using hydrophones implanted near hydrothermal vents on the ocean floor, and developed algorithms to detect and filter out the whale sounds.


Then they turned the code inside out and listened for the whales, according to a story in ScienceInsider. The team presented a paper at the American Geophysical Union's annual meeting earlier this month. Scientists traced individual whale calls through an entire network of seafloor sensors, and were able to determine whale "tracks" as the enormous animals moved above hydrothermal vents on the Juan de Fuca Ridge near Vancouver. They were even able to link calls to whale behavior and group size. Now the team plans to expand its data-extraction methods to other seismic monitoring stations in the region to paint an even clearer picture of whale activities, ScienceInsider said.

This study sounded really similar to another odd collaboration I've covered, this one between weather radar scientists and bat biologists. In their hunt for raindrops, the National Weather Service's Doppler radar stations pick up any object in the air, including bats, insects and birds. The green-and-blue precip maps on your evening news have largely been scrubbed of these objects, thanks to specialized algorithms. But last year a group of biologists and radar scientists turned the software inside out, and are looking through an extensive weather archive to watch bat and bird migrations. You can read more about that in our January issue.

The fin whale study, like the bat study, shows the promise of intrascience partnerships. In the way accidental discoveries can be the best discoveries, strange bedfellows are sometimes the best ones.

[ScienceInsider]

The hundreds of millions of bats in the U.S. are in serious trouble, threatened by such hazards as wind turbines and a fungal infection called white-nose syndrome, all while facing the uncertainty of a changing climate. Most bats hide in caves during the day and live in the air at night, making them notoriously difficult to study. But if scientists are going to help them, they need to be able to track them.

To that end, biologists Winifred Frick of the University of California at Santa Cruz and Tom Kunz of Boston University have teamed up with some unexpected allies: weather researchers Phillip Chilson, an atmospheric physicist at the University of Oklahoma, and radar scientist Ken Howard of the U.S. National Severe Storms Laboratory.

The U.S. National Weather Service's 156 Nexrad Doppler radar stations gather a tremendous amount of data. They scan the country in five- to 10-minute intervals, 24 hours a day, from 0.5 degrees above the horizon to 19.5 degrees. And in doing so, they detect much more than weather. Anything in the air bounces a signal back-insects, birds, wind turbines, low-flying planes, forest-fire smoke, falling meteors, debris from NASA disasters, and bats. Radar scientists call the signal from flying animals bioclutter. "From a meteorological standpoint, it's noise," Howard says. "It contaminates all our algorithms. It misleads people. We have examples that look like severe storms, but it's actually bats coming out of the ground."

The weather-radar images shown on TV broadcasts have mostly been scrubbed of such clutter. But unscrubbed maps are far more complex. Clear, cloudless nights are filled with flocks of animals on the wing, which appear on radar maps as a thick cloud of fuzzy green dots, similar to raindrops. If a cloud of bat-size objects appears at dusk at the location of a known bat cave, they're probably bats, which means that the Weather Service's 20-year-old, 1.2-petabyte raw radar archive is also an archive of two decades of bats in flight.

The Nexrad archive has already generated several new observations and even a new field of science: aeroecology, a term Kunz coined last year. Frick has noticed that in a dry year (when insects are less abundant), Brazilian free-tailed bats in a certain Texas cave emerged from their daytime slumber earlier in the evening to get a head start on mealtime. During a wet year, they slept in. Using the archive, Frick also spotted insects pooled along a storm front, where winds shepherded them together. On several nights, the bats gathered to feed on the wind-formed buffet line-clear evidence that weather influences foraging activities. She says she wants to study the entire two-decade archive, including looking at whether the free-tailed bats are starting to spend the winter in Texas rather than heading farther south, which would be an indication that a warming climate is changing migration patterns.

Eventually, the scientists aim to use the data to count population numbers at each cave. The algorithms that determine the identity of objects in the sky are not yet nuanced enough for a census. But they could be improved, helping both meteorologists and biologists better determine, for example, what's a cloud, what's a bat-cloud and what's an insect-cloud. (Bioclutter still sometimes contaminates weather-only maps, looking like a storm.)

Radar scientists are working to make the archive more useful for researchers. One of their goals is to produce animal-only maps and animal counts, much as they produce weather maps and rainfall counts today. In order to accurately screen for various life-forms, though, the scientists need to know more about how individual animals appear on radar. Last summer, Chilson and Frick scanned live bat swarms in west Texas with a mobile radar device (designed for tornado chasing) while also using infrared cameras to identify individuals. Chilson even put a dead bat in an anechoic chamber to precisely map its radar signature.

Howard says that the animal-tracking project could also help biologists studying insects and birds, particularly those observing nocturnal airborne behavior. The aerosphere is a habitat just like the land or the ocean, "but we never stop to look at it," he says. "Most of these things happen at night. There's a whole richness of life that's going on that is not visible, unless you are a biologist with night-vision glasses-or if you are using radars."

Some 4.6 billion pounds of used carpeting wound up in landfills last year. Raw carpet tile puts the waste to good use. It's made from a new yarn composed of a combination of reclaimed carpet fiber, salvaged fishing nets and postindustrial waste. The tiles look no different from regular carpeting, but each contains up to 29 percent post-consumer recycled content and 79 percent recycled content overall. $31 per square yard

The average smartphone user consumed 89 percent more megabytes of data in the first quarter of 2011 than in the same period last year. But the era of unlimited data is almost over as, more and more, cellular carriers are instituting tiered pricing plans. To avoid overage fees, you'll need to rein in data consumption. Cutting back doesn't have to be painful, though. A few tweaks to the phone will reduce the data stream considerably, and certain apps and browsers can bring even greater savings.

CHANGE YOUR SETTINGS

Having notifications from Facebook, Twitter and your e-mail "pushed" to you as soon as they arrive is convenient, but it eats up data. Unless you absolutely need notifications immediately, make sure that any application with a "Refresh" setting is switched to "Manual" (instead of being on a timer), and turn off push notifications for your e-mail app. Finally, check to see that auto-sync (usually found on e-mail clients and calendars) is disabled. For heavy users, these tweaks can reduce consumption by hundreds of megabytes a month. Other tips: Switch to Wi-Fi before refreshing apps that require data, as well as before updating your app library, and at home leave the phone connected to a Wi-Fi network.

USE BETTER BROWSERS

Download Opera Mini, a free, fast and compact Web browser for iPhone and Android handsets. When a user asks to view a page, the request is sent to the Opera Mini server, which downloads the page from the Internet. The server then packages the page in a neat little compressed format, called OBML, that requires less data to download. YouTube addicts should also get the Skyfire browser ($3), which has a multimedia compression feature that allows users to spend less time loading videos and less data accessing them.

LOOK FOR DATA-SAVING APPS

Onavo is a free app that acts as a proxy server for iPhones and Android phones. It compresses data sent to the user-from Facebook, Twitter and other websites-on Onavo's servers before sending it to the phone. Users also receive access to compression reports and metrics on data savings. The app doesn't compress information that the user sends, though, so image and video uploads will look as good as possible. If you're still fretting over your bill after taking these steps, the 3G Watchdog for Android ($3) and DataMan Pro for iOS ($2) apps both provide elaborate data-monitoring and notification services, helping to curb usage as your monthly limit approaches.

Thieves make off with millions of dollars' worth of laptops and mobile devices every year. Most stolen gadgets go unrecovered, but tracking software can help. The software runs in the background of the operating system or, with some services, the boot-level layer, which makes detecting the tracker much more difficult. Services like Prey provide free software for up to three laptops or Android devices. BlackBerry, iPhone or iPad owners can use GadgetTrak (from $4).

Most services can send a command from their servers to the device to disable it-or do something more dramatic. When the thief connects to the Internet, the program can erase or encrypt personal data, sound an alarm, or even snap a photo of the thief using the device's camera. The software also logs the IP addresses that the device has connected to since the theft and attempts to determine its location based on its Wi-Fi, 3G or GPS connections.

That location data is useful, but most tracking services won't actually work with the authorities to try to get the device back for you. For assistance with the recovery process, use a service such as LoJack for Laptops (from $40) or, for iPhones and iPads, Undercover ($5). Once the owner has alerted authorities to the theft, agents from these services give them the computer's probable location and the likely identity of the thief. Some laptop makers, including Dell, offer track-and-recovery services with personal assistance as well.

When you think of technology, you probably think of computers and jet engines and such. But there are other feats of engineering that are equally sophisticated, just less obviously so. Instant Kool-Aid, for example.

There are two fundamental problems in creating a small tablet that quickly turns a glass of water into a fruity drink. The first is finding a way to disperse the ingredients without forcing an impatient customer to stir them. The solution is sodium bicarbonate and citric acid, a mixture perhaps best known as the plop-plop, fizz-fizz of Alka-Seltzer. These chemicals react with water to form carbon dioxide gas, breaking up the pill, dispersing its contents, and leaving behind just a small amount of sodium citrate, a harmless substance found in citrus fruits.

The second problem-making the drink sweet enough-is more difficult. It would take far too much ordinary sugar to fit in a small pill. This part of the problem was solved in 1879 with the chemist Constantin Fahlberg's discovery of the first artificial super-sweetener, saccharin. Instant Kool-Aid (introduced by Kraft as Kool-Aid Fun Fizz last year) incorporates a more recently developed sugar substitute, aspartame, better known as NutraSweet. Aspartame is 200 times as sweet by weight as cane sugar and represents a very high level of sophistication in chemical engineering; it was discovered by a chemist who was assembling proteins into a polypeptide while trying to design a new treatment for ulcers. All the sweet needed for eight ounces of Kool-Aid fits in a pinch of aspartame.

The drink innovation I'd really like to see, though, still remains tantalizingly out of reach: a pill that heats a cup of coffee. Self-heating coffee does exist, but only in bulky containers that keep the chemicals that do the heating separate from the coffee you drink. Sadly for coffee lovers, no one has yet figured out how to make a mixture that fits in a pill and wouldn't poison you if you tried to drink it.