North America was a crazy place a few million years ago. The megafauna alone would make the world's most awesome zoo collection: giant sloths! Mastodons! Nine-foot saber-toothed salmon! Dire wolves! And, believe it or not, camels. Yes, camels originally arose in North America 45 million years ago and lived there until human migrated into the area around 16,000 years ago.

So, we might expect to find camels somewhere in North America, sure. But researchers just found fossils on Ellesmere Island, in the northern territory of Nunavut, Canada, far above the Arctic Circle. Nobody knew that camels could live so far north, and now researchers have begun to wonder: was the camel's hump -- which is basically a judicious redistribution of fat -- an adaptation to deal with a cold climate? And identifying the fossils as camels is a feat unto itself -- they are all small shards, discovered in digs in 2006, 2008 and 2010, rather than the giant bones one usually imagines.

After painstaking reconstruction following 3-D laser scanning, scientists discovered that the bone fragments came from a large tibia. Further, this tibia came from a large cloven-hoofed animal called an artiodactyl. Carbon dating revealed that the bones were about 3 million years old, and the only large artiodactyl in North America back then was...drum roll please...the camel.

Full confirmation of the identity of the fossil animal came from a new technique called collagen fingerprinting. Researchers first extract some of the collagen still left in the bones--collagen sticks around for a long time--by drilling a small hole in the bone and collecting the accrued dust. After demineralization of the bone dust and gelatinization, researchers digested the collagen protein using the protease trypsin. The trypsin digestion results in peptide fragments. Researchers put those peptides into a mass spectrometer to determine the different fragment lengths; each species has its own particular fragment signature. When the researchers compared the fossil signatures to known current species, they corroborated that the High Arctic Camel is closely related to both dromedaries (modern single-humped camels) and to another older species of camel whose fossils have been found in the Yukon Territory.

Finally, while temperatures in that region during that time period were warmer than they are now (up to 10 degrees Celsius warmer in the Arctic), it was still a harsh environment. From their recent paper on the high arctic camel: "Other specialized traits seen in modern camels may also have served well in an Arctic realm. For example their wide flat feet function well on soft substrates, such as sand or snow. Their iconic hump(s), containing fat, also may have been adaptive. As seen in high-latitude ungulates today, fat deposits could have been critically important for allowing populations to survive and reproduce in harsh climates characterized by 6-month long, cold, winters." So, there you go. Arctic camels.

You can read the full article in the journal Nature Communications.

Smithsonian magazine has chosen its top picks for its 10th annual photography contest, which draws submissions from amateurs and professionals around the world. This year's finalists for best nature photo include an unforgettably soulful gorilla from the Bronx, a jaw-dropping galaxy rise behind Mt. Ranier, and the delicate wings of a juvenile Spectacled Spiderhunter perched on a branch in a dense green jungle in Malaysia.

Check out our gallery below, and then head over to Smithsonian's site and vote for your favorites.

The porn industry has always been on the forefront of technological progress, pushing us into the world of video chat, streaming media, broadband access and online payment systems. It appears they're also getting into the e-book business.

Both Amazon and Barnes & Noble have clear content policies against porn in self-published titles, and Amazon employs both automated and human filters to keep sexxy content out of their marketplace. Yet porn is flourishing on both sites.

A quick search for "erotica" in the Kindle Store brings up 400 pages worth of titles, despite the fact that Amazon refuses to oblige me by autofilling the search bar. Those books range from poorly-written short erotica to pages of low-resolution still images, both often snagged from easily available sources around the internet. It gets us wondering--it might be tricky to navigate the porn world on an E-Ink Kindle, but it's very easy to do on a smartphone or a tablet. So who's actually buying six pages of misspelled erotica for the train ride to work? Especially when they're often as algorithmically-composed as a @Horse_ebooks tweet?

CNET has the down-low on Amazon's dirty self-published secret:

Sounds like the perfect content to download over something called the "Whispernet."

[CNET]

Click to enter the gallery

This month, our top new gadget picks include a smarter bike trainer, a credit-card size USB charger, and a new Arduino controller for serious DIY gamers. Check out the gallery for more great ideas in gear.

A new mortality index calculates people's chances of dying in the next 10 years if they're over 50.

This index is not for you, the index's lead creator, a physician at the University of California, San Francisco, School of Medicine, told the Associated Press. Marisa Cruz and her team intended for doctors to use the index to help them decide whether to recommend expensive, long-view tests and procedures that aren't expected to benefit patients until years after they're taken. If it's needed, doctors can discuss the index's results with their patients, taking into account each patient's personal medical history, the AP reported.

Nevertheless, if you're still curious, UCSF has made the whole checklist available online. A lower score means a lower likelihood of dying. You gain points for things like memory problems, smoking, being man and not being able to push a living room chair around. The highest possible score is 26, which corresponds to a 95 percent chance of dying over the next decade.

The index is based on a data from about 20,000 adults over the age of 50, whom researchers followed from 1998 to 2008. The same research team previously developed a test for older people's likelihood of dying within four years. In this new study, published this week in the Journal of the American Medical Association, the researchers checked that the same index worked on a 10-year time scale, too.

[AP, UCSF]

Just days after waking up from a self-imposed safe mode, the Mars rover Curiosity is getting some extra shuteye as it waits for a solar storm to calm down. On Tuesday, a huge solar flare erupted from the sun's far side as viewed from Earth. But it was right toward Mars, and it also hurled a cloud of superheated gas toward the Red Planet.

Mars doesn't have a magnetic field like Earth's, so any spacecraft (or future people) hanging out on the surface will be exposed to this solar radiation. In 2003, the long-running Odyssey orbiter lost its radiation detector after a solar blast.

This particular eruption was pretty ordinary, just a run-of-the-mill 2 million degree explosion. NASA is not anticipating any major problems, but the scientists working with Curiosity and its cousin, Opportunity, are stopping science operations just to be safe.

That means Curiosity can't continue analyzing the tablespoon of pulverized rock it drilled a couple weeks ago. It also means the rover's radiation detector is shut off, the AP noted. "It's just bad timing," project manager Richard Cook told AP.

The sun is extra active at this stage in its 11-year cycle, so more blasts are certainly possible in the coming months. Keep an eye on the Solar Dynamics Observatory for some great views.

Not that you need an additional reason to watch a cat video, but this clip of a cat looking at an optical illusion could be scientifically valuable, too.

YouTube user rasmusab posted the clip of a cat attacking a version of the rotating snakes illusion like it just saw a laser pointer aimed at the ground, suggesting the cat might've seen the wheels "spinning" and tried to get a paw on them. Now rasmusab's created a Google doc for people to replicate the experiment and report their findings. (We could get so many cat videos out of this experiment, you guys.) For the record, other studies have found that animals--owls, in particular--might see and respond to optical illusions the same way people do.

We love citizen science projects, and love them even more when they involve cats. Still, this might be a tough experiment to get accurate results for--cats, after all, sort of seem to like paper in general, so it's tough to say if they're reacting to stimuli. But it's not like we could be against watching cat videos for science.

[YouTube via io9]

Something is making the universe expand at an ever-faster rate, and since no one knows what it is or how it works, we call it dark energy. A new super-precise observation of a nearby galaxy could help shed some light on it, however. Astronomers have measured the distance to the Large Magellanic Cloud better than ever, and this is a crucial step in a special calculation called the Hubble constant, which helps scientists figure out how quickly the universe is speeding apart.

To measure the universe, you need to start with a point of reference--a cosmic yardstick, if you will. Astronomers measure the distance to nearby objects, which are dubbed "standard candles," and use these objects and their brightnesses to measure objects that are farther away. But if the original yardstick is mis-calibrated, then so are the rest of your measurements. The Large Magellanic Cloud is one such standard candle, but its distance from us has been hard to pin down. Astronomers have been trying for more than a century.

Telescopes in Chile, Hawaii and elsewhere around the world observed tight pairs of stars known as eclipsing binaries. (These stars also figure prominently in the Kepler mission, celebrating its planet-hunting anniversary this week.) In an eclipsing binary system, stars orbit a common center of mass, and they eclipse each other as viewed from Earth. When this happens, their combined brightness drops a bit, as one star blocks the other. By tracking their variable brightnesses, and watching how fast they circle each other, scientists can figure out the stars' size. Combining that with color and other data gives you a remarkably accurate distance measurement.

This new work used 16 years' worth of observations to construct a newly precise distance to the Large Magellanic Cloud: 163,000 light years away. All told, the new numbers dramatically reduce the inaccuracy of cosmological distance measurements, according to the authors of a new paper describing the work.

"For extragalactic astronomers, the distance to the Large Magellanic Cloud represents a fundamental yardstick with which the whole universe can be measured," said Fabio Bresolin, an astronomer at the University of Hawaii, in a statement.

And so too can dark energy. Astronomers can now further nail down the number known as the Hubble constant, the rate at which the universe is expanding. This will help them investigate the physical properties of the cause of that accelerated expansion: Dark energy. The paper is published this week in Nature.

At an event this morning, Facebook took the wraps off the service's latest design. The idea is, as Facebook says, to "pull back the chrome," simplifying the way the site works and looks. That means cutting down on all the boxes and lines and shading and sidebars and lord knows what else litters your homescreen right now. It's more like a mobile app than ever before; just the stream of news.

And it actually is similar to a news site in a few ways; it now has different sections, so you can check out what your friends have been doing in specific categories like music, photos, and games. They're all kind of individual feeds, which is clever; services like Instagram (which Facebook owns), plus Vine and Twitter, are much more concise, and this is a way for Facebook to not be quite so bulky.

And it looks great! Facebook has not always been the nicest-looking service, but the cleaner design, paired with larger images and videos, make it perhaps the most aesthetically appealing version of Facebook yet. Of course, big photos also mean big ads, which could be irritating.

Facebook's new design will begin rolling out today, though not all at once.

A new 3-D model of ancient Mars depicts how ancient mega-floods carved channels into the planet within the last 500 million years. While Curiosity roves across Gale Crater in search of other watery evidence, this new map will help scientists trying to understand how water shaped the planet earlier in its life.

Mars has several channels embedded in its surface, which were carved by ancient gigantic floods larger than anything known to have happened on Earth. The flood channels are distinct from alluvial fans and other drainage areas, like the one Curiosity is exploring in Gale Crater--they're much larger, and must be the result of some catastrophically huge displacement of water. It could be from some underground reservoir that was loosed either by volcanic activity, or maybe an impact. Some of the evidence of these floods has been erased, however, including a region near the Martian equator called Elysium Planitia.

Lava plains cover Elysium Planitia, burying evidence of its older geologic past. Among the buried evidence is the source of the flood channel called Marte Vallis, which extends about 620 miles across the Elysium plain and 60-odd miles wide. Marte Vallis is an important flood channel in part because it's so big, and in part because it's so young, especially compared to other flood channels that are more well-studied. Understanding Marte Vallis will help scientists understand Mars' recent hydrologic history, which is especially important because when this flood channel was carved, the planet was cold and dry. But to study it, scientists have to peel back the lava layers.

They did it using the Shallow Radar (SHARAD) sounding instrument and the Mars Orbiter Laser Altimeter (MOLA) on the Mars Reconnaissance Orbiter. Radar images helped scientists reveal erosion in buried Martian bedrock, and they realized the erosion was far more pronounced than anyone thought. The channel is at least twice as deep as earlier research suggested, according to the research team, which includes scientists from NASA's Goddard Space Flight Center and Jet Propulsion Laboratory, the Planetary Science Directorate in the Southwest Research Institute, and the Smithsonian Institution.

The team was also able to map these buried channels and figure out where they came from. The great Elysium flood originated from a fracture system known as Cerberus Fossae, the radar showed. This means the floodwaters probably came from a deep aquifer, which breached because of tectonic activity.

Its deepest part compares to the largest-known megaflood on Earth, the Missoula floods, which carved out much of the western United States, the researchers say.

"This work demonstrates the importance of orbital sounding radar in understanding how water has shaped the surface of Mars," said Gareth A. Morgan, a Smithsonian scientist who led the work. Their paper is published this week in Science.

What's the future of journalism? It's pretty grim if you ask the writer Nate Thayer or pretty much anyone else working in digital media today. The technological tools that make it possible to post news online, instead of on paper, have gone hand in hand with a crippling depletion of the ad revenue that supports journalism. Publishing platforms are cranking out more and more content, and advertisers are spending fewer and fewer dollars.

There's a sunnier side to the future of publishing, however. Digital tools, such as increasingly sophisticated computer programs, can make certain kinds of reporting possible that weren't before. The Knight Prototype Fund funds some of these potential tools, and it announced its latest projects today. Here are some of my favorites:

The Open Gender Tracking Project
The Open Gender Tracking Project seeks to automatically scour news outlets for how many women versus men are quoted in, and write for, an outlet. Remember that crazy study that found that major news sources quote men four to seven times more often than women in stories about abortion? The tracking project's developers hope their program will help news companies realize the imbalances they have.

The Rashomon Project
The Rashomon Project is making software that lets users pull together pictures and videos people have posted about news events such as protests. The software uses metadata stored in the digital files to arrange everything chronologically. In the end, what you get is a timeline of videos, probably from a lot of different angles and people. It sounds like it could be a great way for journalists and non-journalists to get a fuller view of what actually happened during an event.

Data Toys
It's hard to tell exactly what they're doing from their description on the Knight Foundation's website, but this sounds like it could be pretty fun. Public Radio International and Radiolab are teaming up to make "data toys" for people to play with. The data will show "physical and digital models of complexity in the news," according to the Knight Foundation's blog.

Truthteller
And here's a favorite of mine from a previous round of Knight funding. The Washington Post Company is working on a computer program that listens to political speeches and automatically fact-checks the speech as it occurs. The project is called Truthteller, and I cannot wait for it to start laying down the law on national TV.

Each of these ideas received up to $50,000 in funding over six months, plus they'll get support for expansion if they work out. Check out the Knight blog for descriptions for the other recent winners. Anything in there that you'd be especially excited to use?

Plutarch was practically the worst, Edith Wharton was right on, and Shakespeare was about average.

That's all in terms of the balance of pronouns they used in their writing. Plutarch used nearly 16 masculine pronouns for every feminine one in his books, while Shakespeare had a 3:1 ratio of pronouns. Edith Wharton's books, on the other hand, talked about men and women in nearly equal measure.

All these numbers and more come from an analysis by Benjamin Schmidt, a grad student in history at Princeton University. Schmidt helped make Bookworm, a program for mining the text in digitized books, then ran a pronoun analysis on the books of 1,000 authors using his program.

The vast majority of authors use far more masculine pronouns than feminine ones, he found. The 25-just a thimbleful-that skew feminine include Jane Austen and Louisa May Alcott.

Schmidt poked around at some other analyses, too. Check out his blog for more graphs and breakdowns.

P.S. Curious why some authors don't seem to be assigned either male or female in Schmidt's graphs? That's because Bookworm automatically determines authors' genders by comparing their first names with first names in the U.S. Census. If a name is associated with either men or women 97 percent of the time in the census, Bookworm says, "Aha, this author is a [lady/gent]." If the name is not associated with one sex 97 percent of the time (Frances, Marion, Ollie, Allie), Bookworm says it cannot determine the author's gender. Schmidt describes more of Bookworm's limitations here.

P.P. S. Don't worry, Schmidt writes that he hand-coded George Eliot as a woman.

When an unmanned aerial vehicle reportedly flew within about 200 feet of an airliner earlier this week, outlets like Time and CNN chose to accompany their stories with a picture of the RQ-9 Reaper--this, despite that initially, there was no concrete description of the unmanned aircraft.

It's not terribly surprising that news outlets would default to an image of the Reaper; it's perhaps the most widely recognized drone in operation. But as more details of the incident surfaced, this simplification proved incredibly wrong. The unmanned craft is now described as a 3-foot-long quadrotor--a four-blade copter--which is wildly distinct from the 36-foot-long Reaper; a bit like the difference between a Johnny Seven O.M.A and an AK-47. That's when I realized: drones are really confusing. Even to people who get paid to write about them! So here's a primer on what is and isn't a drone, the differences between common types of drones, and a bunch of other stuff you need to know to sound smart talking about these things:

Where does the term drone come from?

When unmanned flying vehicles were first introduced to the U.S. military, the ability to control them from afar wasn't very sophisticated. So the first drones flew along pre-set paths, operating off an internal navigation system. This led to servicemen informally referring to any machine that flew without human control a "drone," and Germany still has some like this in service today. That said, the "not being controlled by a human" part of the definition has since been lost to everyday use.

What exactly are drones?

"Drone" as a category refers to any unmanned, remotely piloted flying craft, ranging from something as small as a radio-controlled toy helicopter to the 32,000-pound, $104 million Global Hawk. If it flies and it's controlled by a pilot on the ground, it fits under the everyday-language definition of drone.

Wait, does that mean model airplanes are drones?

Almost! Actually, under the law as it stands, any unmanned, remotely piloted vehicle in the United States flown for hobby or recreational purposes is a model airplane, thanks to the 2012 FAA re-authorization act. In 2015, the FAA will suggest new, drone-specific regulations, at which point model airplane law and drone law will probably diverge. Until then, though, all small drones used by private citizens in the U.S. are legally model airplanes.

So is the military using model airplanes?

No. The military is not considered a private citizen, so it plays by different rules, and uses different terminology.

Okay, so what terms does the military use?

The military has described drones, variously, as Unmanned Aerial Vehicles (UAVs), Remotely Piloted Vehicles (RPVs), Unmanned Aerial Systems (UASs), and Remotely Piloted Systems. (The FAA uses some of these terms, too.) The difference between UAV/RPV and UAS/RPS is that the former terms refer to the vehicle itself, and the latter terms describe the vehicle as well as the pilot and support staff. These are useful distinctions for specialists, but not for regular people.

What are the different types of drones the military uses?

The United States military alone maintains three different classifications, one each for the Air Force, Army, and Marines. Part of the confusion in drone terminology is overlapping and competing definitions. The Air Force files drones under five different tiers; the Army and the Marines file drones under three tiers, and none of those tiers perfectly overlap. That's boring and technical. Instead, here are some of the most commonly used or iconic drones:

RQ-11 Raven
The RQ-11 Raven weighs 4 pounds, is launched with a throw, and is piloted with a hand-held unit that resembles a video-game controller. The Raven isn't the most iconic military drone, but it is probably the most used: more than 19,000 have been built. It's mainly useful for seeing around corners and sending footage of rooftops back to troops moving through a city.

It also looks like an awkward model airplane, and it breaks apart like LEGOs when it lands:

RQ-7 Shadow
The RQ-7 Shadow is approximately man-sized, and can fly almost 80 miles away from its commander while providing near-instant video to give a good picture of the battlefield.

MQ-1 Predator and MQ-9 Reaper
The MQ-1 Predator and MQ-9 Reaper are the most iconic drones, and odds are if there's a news story about a drone, it's going to have a picture of one of these. These guys can be armed so that makes them largely, though by no means exclusively, the preferred tool for what we call drone strikes. The main difference between them is that the newer Reaper is larger, has a more powerful engine, and can carry much, much more. They still both look like someone slapped a giant wing on a match, though.

Rq-4 Global Hawk
The Rq-4 Global Hawk is the leviathan of the drone fleet. As mentioned above, it weighs more than 32,000 pounds, has a 130-foot wingspan, and can fly for more than a day. It can reach up to 60,000 feet, and from high elevation it can take high-resolution images of the land below, as well as detect and track moving targets.

Aeryon Scout
Though not in use by the United States, let's take a look at the Aeryon Scout. It's a small quadrotor that NATO allies supplied to the Libyan rebels in the recent campaign to overthrow Gaddafi. The scout weighs less than 3 pounds and can fly for about 25 minutes, making it useful for checking around corners. It's operated with a touch screen, too.

That's by no means a comprehensive list of military drones, but it should get you through a dinner party.

What about private industry? Does it use simpler terms?

As of last week, yes! Not because the drone industry doesn't have weird or obscure terms, but on Friday the drone lobbyist Association for Unmanned Vehicle Systems International (AUVSI) conceded that "drone" is what people are calling unmanned aerial vehicles, so "drone" is now begrudgingly the industry term.

So what should I call them?

Ultimately, depends on your audience. In everyday conversation or casual writing, "drone" is fine. If the audience is military or industry, or knowledgeable policy makers, it might be best to skip the informal terms, crack open Google, and figure out exactly how these people are going to talk about flying robots.

In 2011, the European Space Agency launched Earth's weirdest creature, the tardigrade, into orbit for twelve days on an unmanned spacecraft. And I mean on the spacecraft--scientists attached the organisms to the outside of the rocket to test just how alien-like the very alien-looking tardigrade is.

Of course, it isn't just their looks that make them seem well-suited to the ET lifestyle; as NASA explains, the millimeter-long tardigrades are "known to be able to go for decades without food or water, to survive temperatures from near absolute zero to well above the boiling point of water, to survive pressures from near zero to well above that on ocean floors, and to survive direct exposure to dangerous radiations." Oh, and "they can repair their own DNA and reduce their body water content to a few percent."

Which is why NASA selected this picture of a tardigrade as their "Astronomy Picture of the Day." The image is a color-enhanced electron micrograph.

[NASA]

A new radio telescope that can hear the faintest heartbeats in the universe--colder and farther back in time than anything to come before it--is about to be officially switched on in the Chilean Andes. The Atacama Large-Millimeter/sub-millimeter Array, or ALMA, is the grandest ground-based observatory ever built.

The National Radio Astronomy Observatory, which is one of the partners that built ALMA, is taking a group of journalists to the Chajnantor Plateau next week. I'm headed down with them to see the 66 radio dishes that make up the array, clustered together at 16,400 feet. (I hear we might also see some alpacas.)

ALMA will study the birth of stars and planets, the evolution of galaxies, and even detect the origin of molecules in the far-flung reaches of the cosmos. There will be a lot to share as the governments of Chile, the U.S., and several European nations gather to officially get it started--so stay tuned for the latest, live from South America.

That guy up there is a Kittlitz's murrelet, a small bird in the auk family native to the rocky southern coast of Alaska, from Anchorage out to the Aleutian Islands, and also along the coast on the Russian side of the Bering Sea. It's one of about 25,000 Kittlitz's murrelets in the world, we think. The species has had a very difficult time in the past few decades; it's dependent on glaciers, which are melting due to global warming, for one thing. It's estimated that the Exxon Valdez oil spill back in 1989 killed as many as 10 percent of the global population. Its population has been rapidly, disastrously declining.

The Endangered Species Act, signed into law in 1973 by President Nixon, is designed to protect animals just like Kittlitz's murrelet. The law has had some success; several species, including the bald eagle, grey wolf, and whooping crane, have all come back from the brink of extinction thanks to the Endangered Species Act. But the Kittlitz's murrelet isn't on that list, because it's not officially a protected species. Instead, it's been a candidate for consideration...since 1994.

While the Kittlitz's murrelet has sat on the candidate list, waiting to be considered for federal protection, its population has decreased by an estimated 80 to 90 percent.

And it's just one of several hundred species that have sat on the wildly backlogged candidate list. The Dakota skipper butterfly has been on the candidate list since 1975. It's now extinct in Indiana and Iowa. The eastern massasauga rattlesnake has been a candidate since 1982. The list goes on, for hundreds of species of birds, reptiles, plants, insects, and every other corner of the natural world.

The problem of the backlog isn't due to a single cause; the individual departments in the United States Fish and Wildlife Service and the National Oceanic and Atmospheric Administration tasked with doing this kind of work are extremely underfunded. Sometimes they have to choose between spending money to protect species that are on the list, or deciding whether to go into the backlog and add new species--and choose the former. Management issues have plagued the efforts; during President Bush (43)'s two terms, control of the program was taken away from the department heads and given to political appointees. Pressure from lobbyists, especially from the oil industry, has also slowed the program's progress.

The dunes sagebrush lizard, for example, is native to a very tiny part of New Mexico and Texas. It's been on the candidacy list since 1982, and has never actually been considered because if it was protected, its range would be off-limits for oil drilling. And the Independent Petroleum Association of American doesn't want that. The IPAA has fiercely lobbied the government to keep the dunes sagebrush lizard off the list--and has been successful.

It took two lawsuits from conservation groups to actually force the program to review the backlog of candidates. A settlement was reached in 2011, and the specifics were announced this week. By September of this year, Fish and Wildlife Services will evaluate 97 species. The entire backlog, more than 800 species, will be evaluated by 2018. It's a victory for conservationists (and the flora and fauna in question) but it's already attracted criticism from the oil and housing industries, which can be forced to change drilling and building plans in accordance with the law.

Read more at the New York Times.

Across most industries, women are paid on average significantly less than men, and science is no exception. In 2008, the median salary for women in science and engineering was $60,000, a full $24,000 less than the equivalent male salary.

And as much as it sucks that women make less than men, this is symptomatic of an even larger problem within the sciences: an institutionalized sexism that prevents women from achieving as much similarly qualified men.

As the introduction to Nature's awesome special issue this week on the topic puts it:

According to the White House's Office of Science and Technology Policy, women in STEM (science, technology, engineering and mathematics) careers experience a smaller wage gap in relation to their male colleagues than women in non-STEM fields. That's less reassuring after playing with Nature's fun-to-fiddle-with but depressing interactive graphic quantifying the scientific gender gap. (Augh, lady friends, careful -- numbers are scary!)

You can choose to narrow the data by various scientific fields, ages and types of degrees, but the gap persists. On the bright side, if you're a female computer and information scientist under 29, your median annual salary will only fall a $1,000 short of your male colleagues' -- unless you're comparing master's degrees holders, in which case the gap widens to $9,000 a year. For psychologists and biological life scientists under 29, women actually make a little more than men.

Of course, salary isn't the only marker of how science has remained a boys club, and differences in pay aren't necessarily the result of overt discrimination. Women disproportionately drop out of scientific careers early on, possibly because of the demands of raising a family, a lack of female role models and a perception that these careers are "not for them," as Hannah Valantine, dean of leadership and diversity at the Stanford School of Medicine, says.

Despite the fact that almost half the doctorates in science engineering the U.S. and Europe go to women, only about a fifth of full professors are female. There's also the lack of women invited to speak at conferences, the lack of women on high-level committees, and the lack of women serving on corporate scientific advisory boards.

So how do we fix it? Eight experts from around the world weighed in on the best ways to zip the gender gap shut in Nature's Comment section. From beyond the paywall, here are a few of the ones we can all take to heart:

Pay attention to what's not happening:

Liisa Husu, a gender studies professor at Örebro University in Sweden, brings up the point that outright discrimination and belittlement aren't the only reasons for a Petri-dish glass ceiling. It's also what we're not doing:

Invite women to speak at conferences and events:

As Virginia Valian, a psychologist at Hunter College and City University of New York, points out, it's rare to see women giving plenary or keynote speeches at scientific conferences. Some organizations strive to bring speakers from non English-speaking countries to diversify their lineup. The same should go for women:

Modify tenure timelines:

Child-rearing responsibilities still affect women more than men. Ben Barres, a neurobiologist at Stanford University, says we can encourage more women to choose tenure-track jobs by granting extensions to scientists who have babies, whether that's during their graduate or postdoc training or as an assistant professor:

Institute gender-bias training.

Jo Handelsman and Corinne Moss-Racusin of Yale University published a study in 2012 showing that scientists of all ranks and genders were complicit in gender discrimination. It found that a male candidate is more likely to be hired (and paid more) and mentored than a female. A little diversity training couldn't hurt, and, failing that, "we could paint murals of admired female scientists throughout the halls of universities," Handelsman and Moss-Racusin write. Yes.

This could be helpful no matter what side of the wheel you normally find yourself on. Volvo has built a system that automatically detects bicyclists. If the driver is on a collision course, the system sounds an alarm and brakes, the BBC reported.

The cyclist-detector works with a similar, pedestrian-avoiding feature that Volvo began offering as as an option in 2010. A radar in the car's grille calculates the distance between the car and objects in front of it, while a camera in the rearview mirror figures out what type of objects are in front of the car.

Spotting cyclists is more difficult than detecting pedestrians, however, so the new system uses a more powerful processor, the BBC reported. That means those who already own people-sensing Volvos can't simply get a software upgrade. The cyclist feature will be built into certain new models of Volvos that will be available starting in mid-May. It'll cost at least $2,787 (1,850 British pounds).

Next up, the company wants to make a system that's able to detect deer and other animals.

[BBC, Volvo]