New Yorkers of the future will be better watched and have less privacy than they do today, Mayor Michael Bloomberg predicts in an interview on Christian talk radio station WOR 710.

His foretelling came after host John Gambling asked what he thought of the New York Police Department and other agencies using drones in the future. A local CBS report in January found signs that the NYPD is considering the machines. "It's not a question of whether I think it's good or bad, I just don't see how we're going to stop that," Bloomberg said.

In fact, that future may not as different from the situation now as some may think. As PopSci has reported before, folks in the U.S. have already accepted a lot of privacy loss just to use smartphones. Many drone capabilities mimic the location tracking and facial recognition that smartphones and their apps (think Facebook) already do.

Meanwhile, Bloomberg compared drone surveillance to security cameras already installed around the city. "What's the difference whether the drone is up in the air or on the building?" he said.

Bloomberg advocated for careful thinking about new legislation to regulate what drones can and can't do. A judiciary hearing last week got the conversation started, though few lawmakers have any concrete ideas yet.

[WOR 710 via the Verge]

With Google's recent announcement that it would be discontinuing the cultishly beloved Google Reader, some people are understandably wary about other Google products. How long until it's decided they're "underperforming" and need to be cut? Does this stuff have an expiration date?

Well, kinda. It's at least possible to crunch the numbers and approximate the shelf-life of a service. The Guardian took a look at the lifespans of 39 services that didn't survive, then plotted them to determine a mean. The magic number? 1,459 days. So Google Keep, a service released just last week, would be terminated on March 18, 2017.

This isn't an exact time of death for any products, of course: it still has a standard deviation, in this case 689 days, although all of the services studied except iGoogle fall within two standard deviations of the mean. But that does still mean there's a 68 percent chance Google Keep will be put out to pasture between April 2015 and February 2019.

Of course, all of this works under the assumption that Google's actually going to stop supporting a product. After all, there's still a lot of stuff it created and stuck with. (Ever heard of something called Gmail?) But you never can tell, so it might be nice to at least have a guess about how many days of use you're getting out of something.

Check out more over at The Guardian.

[The Guardian]

Last year, we wrote about Flu Trends, Google's search engine-based influenza barometer. The takeaway: after calibrating its results against the numbers from the Centers for Disease Control--which are based on emergency-room visits--Google did a pretty good job of predicting a flu outbreak, and did so quickly, without having to wait for all those hospital reports to reach the CDC and be compiled into a weekly report.

But how did Google's algorithm fare during this year's fierce outbreak? Flu reached epidemic levels in January and--pertinent for the Flu Trends algorithm--was widely covered in the news. Would the widespread news coverage cause healthy people to enter influenza keywords into their search bars, thereby skewing Google's results? We updated our graphic from last year to find out. Indeed, Google's methods seem to wildly overstate the outbreak's severity, outstripping the CDC's figures by nearly a factor of two. It's worth noting that we're assuming sick people visited the hospital at the same rate as in previous years--in other words, that the CDC isn't suddenly under-reporting influenza.

The result provides a cautionary tale for big data: if the data set doesn't cleanly map the underlying terrain--that is, if people search for "flu symptoms" because they've heard flu is going around, not only because they have it--that data won't yield reliable conclusions.

Neither Google nor the CDC could be reached for comment.

Welcome to round four of the world's nerdiest bracket! To recap: we've compiled a list of some of the strongest, fastest, and strangest landbots and sky drones around. Your job: vote for your favorites.

We're down to the penultimate matchup. If you need a quick guide to what's what, go here.

Polls close Wednesday, March 27, at 9 a.m. Check back later that day for the winners and the final round's matchup, which will determine the greatest land robot/ flying drone in all the internet. Will it be DARPA's BigDog? The fearsome X-47B? The clawed "Eagle" drone? Or Petman, the bipedal gym rat? Only vote once per poll in each matchup, please. And play nice in the comments. Or don't.

Ready? Go!

The retraction count for former psychology professor Diederik Stapel just hit 50: Social Psychology is revoking a 2008 paper by the Dutch researcher after an investigation found "strong indications" that the results had been manipulated and faked. Stapel, who has had 49 other papers retracted since December 2011, said he wasn't sure whether the study was fraudulent or not. Suppose it's hard to keep count!

All of Stapel's 130 articles and 24 book chapters are under investigation by his former employer, Tilburg University in the Netherlands. The university suspended him in September 2011 and later discovered that, in addition to making up data, Stapel had allowed many of his students to graduate without ever completing an experiment.

The co-author of the 2008 paper, titled "The impact of comprehension versus self-enhancement goals on group perception," said he was unaware of Stapel's actions and was not involved in data collection.

Other results faked by Stapel include the widely reported findings that meat eaters are more selfish than vegetarians and that chaotic environments promote stereotyping and discrimination. The New York Times and TIME were both fooled by fake Stapel experiments in 2010, and in May 2008, Popular Science posted an article about one of Stapel's later-retracted studies. (Sorry readers!)

Last November, Stapel published a memoir called "Derailed," in which he admitted to years of scientific fraud and apologized to his former colleagues. Dutch reviewers described the book as "revealing" but noted the last chapter contains lines plagiarized from James Joyce and Raymond Carver.

At least one high-stakes idea for reversing the effects of global warming might not work, according to a new study.

Over the past few years, some scientists have brought up the idea of "geo-engineering" the Earth with enormous projects to mitigate some of the ill effects of climate change. Examples include building space mirrors or creating big clouds to reflect away excess heat. No one is sure how well such projects would work, however, in part because it's not easy to test them without exposing everyone involved to a lot of risk. Now, a new study of a natural mirror to one popular geo-engineering idea has shown that iron fertilization of the ocean might have only short-lived effects.

Here's how iron fertilization is supposed to work. Extra iron added to the sea is supposed to feed the growth of plant-like phytoplankton, which in turn would absorb more carbon dioxide from the air. When the phytoplankton died, they would fall to the bottom of the ocean.

Especially compared to space mirrors, iron fertilization is one of the easiest-to-implement of the geoengineering ideas. Last year, California businessman Russ George dumped more than 100 tons of iron sufate into the Pacific Ocean, in violation of two United Nations conventions, apparently without telling anyone his plans.

To study the effectiveness of iron fertilization without causing any international problems, researchers from the U.K., Norway and South Africa studied the aftermath of the 2010 eruption of the volcano Eyjafjallajökull in Iceland. Like George's dumping, the researchers found that clouds of iron from Eyjafjallajökull triggered a lush phytoplankton bloom.

The bloom soon died, however, because the plankton ran out of the nitrogen they needed. Climate News Network called the results a blow for geoengineering supporters.

The Eyjafjallajökull researchers published their work earlier this month in the journal Geophysical Research Letters.

[Climate News Network]

The Mars rover Curiosity is back in action after solar radiation interrupted its mission a few weeks ago. It even swallowed some more dirt last weekend and is performing new analysis on it, according to NASA.

A computer glitch prompted engineers to switch the rover to its B-side computer on Feb. 28. Curiosity has a backup computer for just such events, but it's been operating on its A-side computer for most of its mission. It used the B-side during part of its journey from Earth to Mars. Now the A-side is officially the benchwarmer. There's actually a benefit to this switchover, though--Curiosity can check out the eight cameras that are hard-linked to that computer.

The rover has 17 cameras, and 12 of them are for engineering and planning. The 3-D Hazcams and navigation cams have two stereo pairs of cameras, with one pair linked to each computer. So now NASA can make sure the B-side cameras work, and they checked out OK.

All this is just in time for an upcoming blackout between Earth and Mars. The sun is going to be in between the two planets for much of April, so the rover team is putting communications on hiatus just to be cautious.

In some ways, Curiosity has already fulfilled its goals. It is in the beginning of a two-year (on Earth) mission to find out whether Gale Crater could ever have been home to life--and earlier this month, the rover's science teams on Earth said the answer was yes. But countless more discoveries are still to come.

Researchers at the Mind Research Network in New Mexico--a non-profit, partially government-funded neuroscience facility--have discovered a way to predict whether released convicts will return to their own ways. Sort of.

The study, published in the Proceedings of the National Academy of Sciences, found a correlation between activity in the anterior cingulate cortex of the brain and criminal activity. Researchers used fMRI machines on a population of 96 male convicts, then "followed" them for the next four years (we assume this means "checked their criminal records" and not "skulked after them while wearing balaclavas) to see whether they'd relapse. Many did, of course; the US is not a friendly place for an ex-convict, and there's a high rate of relapse. But the correlation between the findings from the fMRI is what's interesting here.

The anterior cingulate cortex is the section of the brain that circles around the corpus callosum, in the central-front part of the brain. It's responsible, we think, for some involuntary functions like regulating heart rate and blood pressure, but there's also some evidence that it has an impact on emotional response, motivation, and error detection, among other functions. In one study, increased activity in the anterior cingulate cortex was seen when study participants were shown particularly emotional video clips.

But in this study, men with lower activity in the anterior cingulate cortex were found to be significantly more likely to commit crimes after their release. It's a significant correlation: men in the bottom half of anterior cingulate cortex activity were 2.6 times more likely to be arrested for violent crimes and 4.3 times more likely to be arrested for nonviolent crimes.

This is a noteworthy finding, and a fascinating link between a not-very-well-understood section of the brain and a certain human behavior--though we're not at the point (nor, many argue, should we be) when we can use brain scans to predict crimes.

[via Nature]

This is a shark fetus, with two heads. Sharks, according to Michael Wagner, MSU assistant professor of fisheries and wildlife, who confirmed the discovery, usually have only one head (I'm paraphrasing).

This is a bull shark fetus, a very common shark found throughout the warmer waters of the world. Bull sharks are among the most aggressive sharks on the planet; they can survive in brackish (part-freshwater) environments, were probably the inspiration for the movie Jaws, and apparently once mauled a horse in Australia. Which is to say, if you had to pick one shark species that'd be the scariest if it had two heads, it'd probably be a bull shark. I am not sure what kind of shark was the basis for the movie 2-Headed Shark Attack, starring Carmen Electra and Hulk Hogan's daughter, but the bull shark would have been a good choice.

This particular shark had two distinct heads on a single body; dissection found that it had separate heads, hearts, and stomachs, but that the remainder of its body was that of a single shark. Yeah, dissected: the shark was found in the uterus of a mother bull shark caught in the Gulf of Mexico, and died shortly after it was cut out. It almost certainly would not have survived birth, had it been birthed naturally.

There's no evidence that the two-headed shark is the result of pollution, even though it was found relatively soon after the Gulf oil spill. Abnormalities like this are not unheard of in nature, though this is the first two-headed shark ever found. The article was published in the Journal of Fish Biology.

A year after his record-setting deepest dive, film director James Cameron is donating his submarine to science. The Woods Hole Oceanographic Institution, one of the premier research institutes on the planet, will take the helm of the Deepsea Challenger. WHOI plans to incorporate the custom-built sub's technology into its existing submersibles and future research platforms.

Last March, Cameron made a solo dive to 35,787 feet in the Challenger Deep of the Mariana Trench, the deepest spot on Earth. His daring trip made him the first person to reach the bottom of the Mariana in 50 years, and the first to ever do it alone. After a two-hour controlled dive, he spent several hours at the seafloor, looking for new species. Around 68 specimens he saw may be new to science.

This new partnership with WHOI comes at a crucial time for scientific research, which is hampered by funding shortfalls. Cameron himself wanted to make a second dive, but funding was too scarce, he said. The sub took seven years to design and build, and now all that research and development will benefit the scientific community, he said.

"WHOI is a place where the Deepsea Challenger system will be a living, breathing and dynamic program going forward," Cameron said in a statement.

Cameron's reps sent us some early sketches, doodled on lined paper, that he produced after a 2003 conversation with oceanographer Don Walsh. The designs evolved during the next decade, but some early concepts remained throughout.

Meanwhile, WHOI will get to work incorporating the Deepsea Challenger's cameras and lights on its robotic divers, and potentially exploring their use on the refurbished Alvin and possibly other subs.

The HPV vaccine may be the only vaccine in the U.S. that significantly fewer white Americans have received than minority Americans, the New York Times' Well Blog reported. The reasons are not clear, but the Times suggests that white parents might be more likely to worry about the vaccine's safety and moral implications.

About a third of teenage white girls and a third of teenage black girls have had all three doses of the vaccine. Forty-two percent of teenage Hispanic girls have had all the doses. Those numbers are especially surprising because they seem to have little to do with health insurance rates among kids in the U.S.: One in ten white children don't have health insurance, compared to one in six black children and one in four Hispanic children.

"I can't remember a vaccine where I saw a pattern like this," the Walter Orenstein, the former director for the U.S. Centers for Disease Control and Prevention's immunization program, told the New York Times. As recently as a decade ago-check out this article, which cites a 2002 survey-minority kids were consistently less likely to get their immunizations. Since then, the trend has been toward greater equality. CDC numbers for 2010 generally show no significant differences in vaccination rates between kids of different races for diseases such as measles, polio and pertussis.

The two Food and Drug Administration-approved HPV vaccines available in the U.S. are Glaxo-Smith-Kline's Cervarix and Merck's Gardasil. Cervarix protects against two human papillomaviruses that cause 70 percent of cervical cancers, while Gardasil protects against those two viruses, plus an additional two viruses that cause 90 percent of genital warts. The Centers for Disease Control and Protection recommend the vaccines for girls and women ages 11 through 26, plus boys and men ages 11 through 21. Usually kids get the shots at age 11 or 12.

Since Gardasil first came out in 2006, however, doctors seem to have had a tough time convincing parents to get their kids vaccinated. Especially white and black parents. Compare the numbers above with the rates for common childhood immunizations such as the DTaP, MMR and polio vaccines, which 90 percent or more of kids of all races get.

The Times mentioned a couple possible reasons for the disparity among Americans of different races. For one, the vaccine may cost white families more. White families are more likely to have private insurance, but private insurance may or may not cover the vaccine. Meanwhile, a federal program gave the vaccine for free to clinics serving poor patients.

And another? One survey showed that people who go to private clinics are more likely to think their kids don't need the vaccine. Patients at publicly funded clinics would rather take the precaution, Rebecca Perkins, a professor of obstetrics and gynecology at Boston University School of Medicine, explained to the Times. In reality, however, rates of sexual behavior in all of the teenage girls in the survey were pretty equal.

[New York Times Well]

Ouya might be one of the biggest gadget-funding success stories in recent memory. A Kickstarter raised almost $8.6 million for the Android-based console, and it's shipping to those backers this week. The idea is to create an "open" platform, where anyone who wants to build a game can, unlike in the AAA world of PlayStation and Xbox. The question now: What are the limits of what can be played on it?

There are a few interesting titles being released at launch on Thursday, but an experimental console with a dearth of brand power will need more than just a few good titles to draw people in. On its forum, Ouya recently announced that developers will be able to bring emulators to the console. Emulators are software that can be used to play games on hardware they weren't intended for. Want to relive the glory days of Super Mario on your phone? Play a round of Street Fighter II through Ouya? No problem. Note:

The problem is, even though it's easy enough to find emulators, downloading the game files, called ROMS, wanders into some tricky legal territory. Nintendo would much rather you shop and download (and pay for) Zelda on the Wii U than do it through a shady website on your PC.

Ouya told Kotaku that they will only accept emulation software, not ROMs, through the Ouya store. To submit games, developers need to show proof of intellectual property rights. But the emulations coming to the console are definitely intended to play games for IPs they don't have: EMUya, a popular NES emulator, should be available Thursday, and SuperGNES, a Super Nintendo emulator, is coming, too.

That doesn't put Ouya in any legal trouble beyond what Google Play, which is full of emulators, would presumably be in already: they might be providing a platform and the software, but going beyond the law and downloading the copyrighted games themselves? That, at least technically, is a decision Ouya users would make on their own.

Pictures like the one above, showing Hurricane Sandy, are captured by satellites owned and operated by our federal government. But we may be facing a looming gap in American weather-watching abilities. Could a private company fill it?

Bethesda, Md.-based PlanetIQ wants to launch 12 small satellites into low-Earth orbit, where they would collect weather data that could be used for forecasts and climate models. It could be cheaper and lower-risk than other publicly-funded satellites, the company recently argued before Congress.

PlanetIQ, which has never launched a satellite before, would sell its data to government weather services around the world. It would also like to sell info to the U.S. Air Force.

Why is this an issue? The United States has a whole fleet of weather satellites in various orbital positions, which are used to inform long-term climate models as well as the computers that predict our daily weather. (Some are polar-orbiting satellites that show the whole Earth every morning and afternoon, and others are geostationary satellites that stare constantly at the U.S.) But they're getting old, and new equipment has been plagued by delays and political problems.

Depending on launch schedules and how long our existing equipment lasts, we're looking at a data collection gap of between 17 and 53 months, according to a recent report. That means less accurate and less timely forecasts. The government is sufficiently worried about it to include weather satellites in a "high-risk report" to Congress, provided every two years by the Government Accountability Office.

"Such degradation in forecasts and warnings would place lives, property, and our nation's critical infrastructures in danger," the GAO says. You can read the report here.

The recently launched Suomi National Polar-orbiting Partnership satellite, which captured that amazing Blue Marble image of Earth, is supposed to mitigate this gap. Suomi NPP started out as a demo satellite for a new partnership between civilian agencies and the Defense Department. But a decade of cost overruns and other problems turned it into a civilian project between NASA and NOAA. It's only supposed to last five years, and might only last three--at a cost of $1.5 billion. Meanwhile, next-generation equipment is still languishing in warehouses.

Suomi NPP has been crucial in helping forecasters accurately predict storms like Sandy several days in advance, however. Without it, Sandy forecasts would have been wrong, according to testimony from PlanetIQ's CEO, Anne Hale Miglarese: "Without observations from satellites that orbit our planet from pole to pole, we now know that the computer model which predicted Hurricane Sandy would slam into the Northeast U.S. five days in advance would have instead showed the storm staying out to sea," Miglarese testified.

So should private companies send satellites to space and sell the data to our cash-strapped government? The private yet popular/populist site Weather Underground asked the weather service: "We welcome any reliable data that helps the National Weather Service meet its mission requirements, while also being cost-effective and properly reflected in our budget," NWS spokesman Chris Vaccaro told them in an e-mail.

Especially under sequestration, government science agencies could probably use all the help they can get. But selling weather data, presumably for a comfortable profit, is definitely uncharted territory.

[via Weather Underground]

Today T-Mobile announced that it will begin selling the iPhone 5, which is nice for T-Mobile customers, because that is a nice phone. But what's more interesting is the new "Uncarrier" plan, whereby T-Mobile is attempting to shake up how Americans buy smartphones.

The Uncarrier plan is a half-step towards contract-free plans. You aren't roped into a contract, as you are with other carriers. Instead, you buy a phone at full price (or pay it off incrementally) and thus get a (slightly) cheaper monthly bill. It isn't enough; American smartphone plans are still pretty bad. But at least it's movement towards something a little more transparent and consumer-focused.

Here's how you normally buy a smartphone in the U.S. You pay $199 "for the phone," up front, and you sign up (or renew) a two-year contract with that carrier. Over the course of those two years, you pay a monthly fee for your voice and data. The total price varies, but over two years, you'll probably pay somewhere between $1,800 and $2,400, depending on your plan. Rolled into this fee, secretly, you're paying the carrier back for giving you a discount on your phone. This is the "subsidization" setup.

It is a very dumb setup.

The iPhone 5 doesn't really cost $199. It costs $649. Your carrier is eating the difference, in exchange for a two-year contract. With that two-year contract, you can't switch carriers, because 1) you've signed a contract, which will cost you a fee if you want to break it, and 2) your phone has been "locked" to your carrier. (This is done by the manufacturer; it's a software lock, so it can be unlocked, but it's not easy to do.) That reduces competition between the carriers; people often stick with their carriers for years and years, because you only get one chance to switch every other year, and your old phone won't work with your new carrier anyway. That means that it also encourages you to throw your phone away and get a new one every two years. After all, you're paying $80 or $100 a month for this plan--why not spring for a new one if it's being offered, since it's subsidized to be only another $199?

This is designed to feed a cycle of consumption, and to provide the wireless carriers with stability. It's difficult and expensive for the customer to stop being a customer, so the carrier is assured to keep getting your money.

Another problem: Half of the smartphone-owning American populace is going to buy a new phone each year. So Apple, Samsung, HTC, and the rest are on once-a-year (or less!) cycles. The manufacturers have a huge, consistent, guaranteed market. The next time you think "man, this phone sure looks like last year's," remember this. This is why.

T-Mobile's new plan is marginally different. There's no two-year contract involved, but there's still a subsidy option. You can either pay that $649 up front, or you can pay only $99, and then fold an overt $20 a month into your monthly bill for two years. After two years, you'll have paid a total of $579, which is cheaper than the $649 you'd pay up front. The cheaper price and installment plan are T-Mobile's replacement for the contract--a bribe to stay with them for two years, rather than a monetary punishment if you leave (though there might be a monetary punishment if you leave as well; T-Mobile hasn't said, yet.) The monthly fees for voice and data are cheaper than Verizon, AT&T, and Sprint, but not by much. You'll spend a minimum of $50 a month for 500MB of data--that won't be enough for anyone who does more than the occasional email--and they won't charge you for going over, but they'll throttle your speed so it'll be real unpleasant.

So at the bare minimum, in which you pay $50 a month and get the installment plan on the phone, by the time your not-quite-but-almost-a-contract time is up, you've paid $1,780. Compare that to Verizon Wireless, the nation's most popular carrier. The cheapest individual plan for the iPhone 5 you can get is a 1GB plan, which costs $50 per month--except, you also have to get a "monthly line access fee," which is nonsense, and that's an extra $40 per month. Your total price over those two years, with a nice new 16GB iPhone 5? A whopping $2,360.

The alternative, here, is to just pay up front what the phone really costs, and then pay a carrier for voice and data. No contracts necessary. No subsidizing. The plans would be cheaper, because, theoretically, the price of the phone doesn't have to be built into your monthly fee--because you've already paid for the phone in full.

And! No nearly-new phones thrown in the garbage just because they're one generation old. Smartphones, especially the batteries, have to be disposed of properly; they contain metals which can cause damage to the environment. And, you know, it's wasteful.

I'll go even further: Your monthly fee should be pay-as-you go. Pay for what you use, not what you might use. The Karma Wi-Fi hotspot has the right idea: when you need more data, you buy more data. The idea that you need to sign up for a 2GB plan or a 4GB plan is ridiculous. Imagine if all of your bills worked that way! Pay the grocery store $500 per month, every month. If you eat out a lot that month and spend less on groceries, well, too bad! That's just money down the drain. If you have a big dinner party and need to pay more than $500 one month, well, you guessed wrong, so the grocery store will charge you a penalty for going over.

If you paid by the GB, rather than trying to guess how much you'll use next month, you'd pay more some months and less some months. Whether this would work out mostly depends on your usage; for heavy users, like myself, it makes sense to just spring for an unlimited plan. But not for everyone! It's the low-data users who get screwed here; on T-Mobile's plan, I'd use, say, 7GB a month, and pay $70 for the unlimited plan. So my cost per GB is $10. But if somebody only uses 500MB, they're paying $50, so their cost per GB is a hundred dollars.

Installment plans for phones, like T-Mobile's, aren't a terrible idea. Not everyone has $649 up front that they can spend on a phone. But that's a pretty expensive phone; our favorite smartphone of last year, Google's Nexus 4, is sold contract-free, unlocked, just the way it should be--and it starts at $300. That's barely more expensive than the subsidized phones.

The American system of selling smartphones discourages consumer freedom, stifles competition between the carriers, rewards reckless consumerism, and costs customers more money than necessary, all to pad profits for the enormous carriers and phone manufacturers. It is bad! Ban it, and let's everyone just buy what we want and pay for what we use.

About 4 billion years ago, something caused Jupiter and the other gas giant planets to shift in their orbits, shoving countless space rocks out of their positions in the asteroid belt. Tugged inward by the sun, these asteroids migrated toward Earth and the moon, ultimately bombarding our young planet and its satellite.

In a cataclysmic shower of destruction, Earth, Mars, Venus and Mercury suffered gigantic impact craters, though on our planet much of the evidence was lost to time and tectonics. The moon, however, still bears the scars of this period, known as the Late Heavy Bombardment or lunar cataclysm. And so does the giant asteroid known as Vesta.

Vesta, which was visited by a NASA spacecraft last year, suffered the same high-speed impacts as the moon and the terrestrial planets, according to new research. This points to a common history for the rocky worlds and larger non-world rocks. That's interesting because it gives scientists a new way to study this early period of our solar system. Before now, the only way to study this bombardment was with Apollo moon rocks.

By studying chunks that fall to Earth as meteorites, scientists have recently been able to figure out the ages of main belt asteroids, which gives a glimpse of their history. Certain meteorites called howardites and eucrites have also been used for comparative studies of Vesta, which is their parent body. Vesta is the second-biggest asteroid in our solar system and is technically considered a minor planet, with a diameter of 326 miles. It lives in the asteroid belt.

In a new study, scientists from NASA's Lunar Science Institute analyzed the howardites and eucrites, plus new data from the Dawn spacecraft, which orbited Vesta for a while last year. Crunching many numbers and computer simulations, the team determined the population of objects that hit Vesta also hit the moon during the lunar cataclysm.

"Although the moon is located far from Vesta, which is in the main asteroid belt between the orbits of Mars and Jupiter, they seem to share some of the same bombardment history," said Yvonne Pendleton, NLSI director.

This helps bolster the theory that the gassy planet repositioning is what triggered the bombardment. It also shows that the cataclysm affected many objects beyond our planet. And maybe best of all, it means scientists can study that tumultuous time in new ways: With the howardites and eucrites delivered from Vesta to us. The new research is published in Nature Geoscience.

The United States has killed more than 3,000 people in Pakistan with drone strikes. Breaking down who died and when into a clear and useful way can be tricky. Pitch Interactive, which has worked with Popular Science in the past, and its latest on drone casualties provides a straightforward look at a relatively murky war. At least, as clear a portrait as one can get from a contested area with biased witnesses, reporters, and governments all trying to shape the debate.

By email, I asked Wesley Grubbs of Pitch Interactive about the data.

Popular Science: Victims are categorized as children, civilians, "high-profile," and "other." Did you consider breaking up the "other," and if so, was that a problem of unclear information? Or was it something else, like wanting to avoid assuming a clear answer when the data isn't so much unclear as politically contested?

Popular Science:More than 75 percent of the victims fall into the "other" category. That means you're working with a data set three-fourths of which is unclear. Is it challenging to make a visualization for something so unknown?

The visualization does an excellent job conveying the sheer scale of collateral damage from strikes used to kill only a few high-value targets, and uses information on those high-value targets from the reputable New America Foundation. The real challenge of covering and analyzing the United States' drone war over Pakistan is getting the sourcing right, and disentangling fact from a series of disparate interests trying to manipulate truth, as Christine Fair, a Georgetown professor who has long questioned Pakistan's official account of the drone war, suggests.

Some skepticism over any answer claiming to be conclusive about drone strikes is warranted. That healthy skepticism of sources shouldn't detract from the simple utility of Pitch Interactive's visualization. Instead, for me at least, it prompted another late night at home checking facts.

Check out this contender for the title of "world's lightest solid." To demonstrate just how light it is, Zhejiang University in China, where the material's creators are based, has published pictures of chunks of it perched on small leaves, held aloft by grass seedheads and floating on the stamen of a cherry blossom. Ah, springtime.

It's still in its earliest stages of development, but in the future, the new material could be designed to soak up oil spills or clean other pollutants, Gao Chao, the lead scientist in creating the material, told China Daily. The materials used now to clean up spills absorb 10 times their weight in oil, but the new stuff can handle 900 times its weight in oil. And it absorbs quickly, Chao said, with each gram of material sucking up 69 grams of oil a second.

The material is about one-sixth the density of air.
The material is made with one-atom-thick sheets and fibers of carbon, so Chao and his colleagues have dubbed it a carbon aerogel. The researchers say they've found simple ways of making the carbon aerogel in various shapes and sizes ranging from bottle-stopper-size to tennis-ball-size.

The material has a density of 0.16 milligrams per cubic centimeter, or about one-sixth the density of air, so it beats out previous world's lightest materials such as this metal lattice, which has a density of 0.9 milligrams per cubic centimeter. Both are lighter than NASA's famed polymer-based aerogels, which were developed to cradle delicate dust from comets for scientists to study.

In the end, it doesn't really matter too much which material is the lightest in the world. They're all quite different in composition and can do different jobs in the world. And they all look amazing floating on flower stamen, eyelashes or whatever else.

Chao and his team published their work in February in the journal Advanced Materials.

[China Daily via IEEE Spectrum]

Though they're primarily used in speakers and hard drives, ferrofluids -- liquids that respond to a magnetic field like a solid -- also make awesome art installations. When in the presence of a magnetic field, tiny particles of metal (usually iron) suspended in oil become magnetized and move in crazy ways.

Determined to make an ferrofluid art installation you could put in your house, Russell Garehan invented Ferrocious, a "moving liquid sculpture that responds to sound." It's sort of like a lava lamp that dances in response music, made with ferrofluid.

The electromagnet at the top of the cylinder responds to sounds at frequencies at 250hz and lower -- like your voice, a cello or a bass guitar -- moving the fluid to the beat. You just plug it in to a DC power source and watch it dance "like a salsa dancer on a sugar rush."

From the Kickstarter page:

The project is looking to raise $5,000 by late April. For the pleasure of owning the mesmerizing conversation starter, you'll have to shell out $139, but if you're of the tinkering variety, an $85 pledge will get you a DIY Ferrocious kit to solder yourself.

[Kickstarter]