Giving video cameras to animals can yield some awesome results, especially underwater - remember the octopus guerrilla filmmaker? In a new video, ride on the back of a South American seabird as it captures footage of its 150-foot-deep dive.

Imperial cormorants live off the coast of Patagonia, Argentina, and are protected by various regulations. Scientists at the Wildlife Conservation Society have been tracking about 400 of them with GPS loggers and archival tags. This time, a team led by WCS researcher Flavio Quintana attached a camera to a bird's back and set it loose.

The video is the first time scientists have been able to watch the birds' feeding techniques.

The footage is choppy at first as the bird sits on the surface, but then it takes a nosedive. It finally reaches the ocean floor and looks around for a meal, snatching up a long fish and bringing it back up to eat. Watch its crazy ride below.

In other billionaire news today, a controversial and ostentatious Australian is supposedly planning a real-life Jurassic Park, complete with cloned dinosaurs. Clive Palmer, who also wants to build a modern-day Titanic replica, has held talks with the scientists who cloned Dolly the sheep, reports Australia's Sunshine Coast Daily.

Palmer, a mining magnate, owns a luxury resort on the Sunshine Coast, in southern Queensland on Australia's Pacific side. He would put the dinosaurs in his new resort there, the Daily reports. There are no named sources in the article about this effort, however, with the newspaper citing someone "close to Palmer's inner circle."

Other plans for the resort apparently call for a sky needle and a mega Ferris wheel like the London Eye, and a focus on clientele from the Middle East. But the cloned-dino idea is obviously the most eyebrow-raising. Palmer would not answer questions about it and is holding a press conference on Friday, so we'll see what he says then.

Palmer said earlier this year that he wanted to build a "Titanic II," as close a replica as possible to the fated ship but with modern technology. If all goes as he plans, the vessel would sail from London to New York in 2016, according to the BBC.

Palmer would not be the first to discuss cloning dinosaurs. The book and movie "Jurassic Park" certainly popularized the idea, but scientists really are trying to resurrect extinct animals. Researchers in Russia, Korea and Japan say they're planning to bring mammoths back by injecting their DNA into elephants. (This idea is controversial and doubted by many, to say the least.) There's not enough dino DNA to do this, but the paleontologist Jack Horner is famously trying to genetically engineer their descendants - birds - to have more dinosaur-like qualities. Perhaps a future Australian seaside resort will play host to flocks of Chickenosaurus, which you can view through self-driving Land Rovers.

[via Slashdot]

In the 1930s, U.S. Navy researchers stumbled upon the concept of radar when they noticed that a plane flying past a radio tower reflected radio waves. Scientists have now applied that same principle to make the first device that tracks existing Wi-Fi signals to spy on people through walls.

Wi-Fi radio signals are found in 61 percent of homes in the U.S. and 25 percent worldwide, so Karl Woodbridge and Kevin Chetty, researchers at University College London, designed their detector to use these ubiquitous signals. When a radio wave reflects off a moving object, its frequency changes-a phenomenon called the Doppler effect. Their radar prototype identifies frequency changes to detect moving objects. It's about the size of a suitcase and contains a radio receiver composed of two antennas ­and a signal-processing unit. In tests, they have used it to determine a person's location, speed and direction-even through a one-foot-thick brick wall. Because the device itself doesn't emit any radio waves, it can't be detected.

Wi-Fi radar could have domestic applications ranging from spotting intruders to unobtrusively monitoring children or the elderly. It could also have military uses: The U.K. Ministry of Defence has funded a study to determine whether it could be used to scan buildings during urban warfare. With improvements, Woodbridge says, the device could become sensitive enough to pick up on subtle motions the ribcage makes during breathing, which would allow the radar to detect people who are standing or sitting still.

See image above for how it'll work.

1. MOVING SUBJECT
When Wi-Fi radio waves bounce off a moving object, their frequency changes. If, for example, a person is moving toward the Wi-Fi source, the reflected waves' frequency increases. If a person is moving away from the source, the frequency decreases.

2. REGULAR OL' ROUTER
A Wi-Fi Internet router already in the room fills the area with radio waves of a specific frequency, usually 2.4 or 5 gigahertz.

3. BASELINE SIGNAL
One antenna of the radar system tracks the baseline radio signal in the room.

4. SHIFTED SIGNAL
A second antenna detects radio waves that have reflected off of moving objects, which changes their frequency.

5. PERP, SPOTTED
By comparing the two antennas' signals, the computer calculates the object's location to within a few feet as well as its speed and direction.

BREATHE EASY

It's possible to detect a person's breathing rate by surrounding him with radio waves. Neal Patwari's wireless engineering group at the University of Utah designed a network of 20 inexpensive radio transmitters that are placed around a patient's bed. Then they created an algorithm that detects a stationary person's breaths better than current detectors do. Patwari plans to upgrade the algorithm by the end of the year to filter out body movements too. The system could someday be used in hospitals in place of tubes and masks.

-Elbert Chu

The human body already has a highly efficient cooling system: As perspiration evaporates, it draws heat away from the body. Wicking fabrics facilitate this process by distributing sweat evenly over the fabric, so that it dries more quickly. Despite devising cheats, such as menthol-like chemical coatings added to fabrics, companies have never actually improved upon the body's natural cooling process. Designers at Columbia Sportswear have now made a fabric that does.

The wicking polyester base of the Omni-Freeze ZERO T-shirt is embedded with thousands of 0.15-inch hydrophilic polymer rings (a men's medium has more than 41,000 of them). As the base spreads sweat, the rings absorb moisture and expand into three-dimensional doughnuts. In order to swell, the rings require energy, which they gather as body heat. In tests, the shirt was up to 10 degrees cooler against the wearer's skin than shirts made from any other material.

Columbia Sportswear Omni-Freeze Zero Freeze Degree T-shirt

Weight: 4.8 ounces
Material: stretch polyester
Sun Protection Factor: 50
Price: $60

In Related News: The Safest Way to Jog at Dusk

Designers at Brooks worked with a team at the Loughborough University Sports Technology Institute in the U.K. to ensure runners wearing the Nightlife Jacket III remain visible to drivers in any light. The darker the surroundings, the more heavily eyes rely on contrast to pick out objects, so the team added black stripes to the arms and shoulders to offset the fluorescent base and better outline runners. Brooks NightLife Jacket III $115

Cars in Europe may soon become very much more robotic whether drivers want them to or not. New rules coming down from the European Commission will require all commercial vehicles to be fitted with autonomous emergency braking (AEB) technology by November 2013, and passenger vehicles could soon follow suit. These cars will go beyond simply sending a signal to the driver when they detect an impending collision via radar, lidar (that's like radar but with light), or video sensors and apply the brakes themselves.

Some drivers will doubtless mistrust an automated system that can interfere with the controls without prompting from the driver's seat, but proponents of the system think it could drastically curtail traffic accidents (particularly fender benders at low speeds) and save billions of euros annually across Europe by reducing the economic productivity lost to accident-related congestion. One study commissioned by the EC showed traffic accidents could be cut by more than a quarter.

Some 80 percent of the cars on sale in Europe at this moment do not possess AEB technology, and the EC doesn't wish to force it on manufacturers and citizens all at once, an official said. So instead, the European New Car Assessment Program--a seven-nation consortium that does crash-test rating for European autos--is simply gong to make it more or less impossible for a car to receive a five-star safety rating without AEB technology on board. That's called forcing without appearing to force, but hey--if the technology really can reduce accidents and improve road safety, maybe a strong nudge toward universal adoption isn't such a bad thing.

[TRL]

America's space shuttles may be settling into their retirement roles as national artifacts, but for space fans who miss their presence at Kennedy Space Center, Google has a new offering - Street View images of the entire complex, shuttles and all. The web giant unveiled the new images this morning, and we have a preview.

Google brought its Street View fleet to the KSC in January while the shuttles were being decommissioned, and snapped 6,000 panoramic images of two orbiters (Atlantis and Endeavour), the launch pads, the massive Vehicle Assembly Building, even the runway where the shuttles landed.

"It's not stuff that any normal person would get to see," said Ryan Falor, product manager for Street View Special Collections. "You can go underneath the shuttles and you can see the tiles, these really sort of fragile heat tiles, and you can look up at them. They look like they are almost close enough to touch."

The project took about a week, with NASA engineers and managers working with Google to ensure no secret space assets made their way into the field of view.

Here's the view from the top of launch pad 39A:

View Larger Map

Below is Space Shuttle Endeavour. Click here to see Space Shuttle Atlantis. You can also see some more images in the video at bottom.

View Larger Map

Or just navigate in Google Maps, and you can go inside the gigantic Vehicle Assembly Building and peer down from the 15th floor; you can meander down the road the shuttle crawler would inch along toward the launch pad; you can even walk down the gantry astronauts would use to board the shuttle cockpit. The whole experience offers some unique vantage points the public would otherwise never see, Falor said. It also presents some surprises, like the bathroom right at the top, which astronauts referred to as "the last bathroom on Earth."

"It has this sign that says ‘close before launch,' which I just thought was really funny, imagining someone up there," Falor said. "That's the fun of Street View - it's this immersive experience, where you can say, ‘Wow, I didn't realize it looked like that.'"

He was also impressed by humongous water nozzles at the base of the launch pads, which were used for noise suppression when the shuttles' main engines fired up. NASA called them "rain birds," like the sprinkler system, only ginormous.

"You can walk around them and imagine how much water is shooting out of this thing. It's one interesting technical thing to explore that normally isn't visible," Falor said.

If he sounds enthusiastic, he is - Falor used to work on the Mars Phoenix and Mars Exploration Rover missions at the Jet Propulsion Laboratory, and left for Google before work started on the Mars rover Curiosity. But his soft spot for space exploration stayed with him, prompting this Street View project.

Street View is now available on all seven continents (despite some protest in Europe), museums, the White House, even the jungles of the Amazon. The KSC is the first major government facility, aside from the museum-y parts of the presidential mansion, to get Street Viewed, Falor said.

"We are excited about how users will be able to explore all this stuff, and maybe we can inspire the next generation of people to get interested in math and science," he said.

NASA's Mars rover Curiosity, scheduled to reach the red planet this Sunday, is the size of an SUV for good reason: It's built to carry 165 pounds of scientific instruments over boulders and into gullies. But putting Hummer-size robots on other planets is not altogether practical. For one, it's expensive. (Getting a Curiosity-weight rover to Mars takes more than a million pounds of fuel.) Large rovers are also power-hungry and limited in range. For future missions, some researchers, eager to do more science with fewer resources, have begun looking to nanobots-each one about one-one-billionth as big as Curiosity.

The first nanobots to reach Mars could arrive as a cloud of "smart dust"-sand-grain-size robots that travel like a sand storm, using the Martian wind for propulsion. An orbiting spacecraft would drop a capsule of the dust motes onto the planet. From there, they would take advantage of Mars's low gravity (38 percent of Earth's) to ride the thin Martian winds. John Barker, a physicist at the University of Glasgow, says that according to his computer simulations, one release of 30,000 robots could cover thousands of square miles. Each robot would contain a nanoprocessor, an antenna for communicating with neighboring motes, a sensor for collecting data and an electrode-controlled shape-shifting polymer shell. Once on the ground, the motes would decide which would change from a smooth exterior to a dimpled silhouette that creates drag to help them catch the wind and travel. The motes would use their sensors to collect data about Mars's air currents and chemical composition and then communicate this information to the orbiter, which would relay that data back to Earth. The project might sound impossibly complex, but shape-shifting polymers already exist in the lab, and Barker has started testing the most challenging part of the concept-the communications array-with centimeter-size prototypes.

One engineer is working on what amounts to a nanobot Mars base, which would protect the ‘bots from cosmic radiation.For more complex and directed missions, such as digging under Mars's surface and collecting samples, robots will have to move autonomously and under their own power. Researchers at NASA's ANTS (Autonomous Nanotechnological Swarm) program have been developing concepts for tiny robots, called TETwalkers, capable of doing just that. Each TETwalker would be a tetrahedron of carbon-nanotube struts connected by joints. Each individual robot could move by lengthening or shortening its struts, thereby shifting its center of gravity until it tumbles in the desired direction. Together, tens of thousands of nanoscale TETwalkers could connect together to form devices such as rovers and antennas, which could travel the planet in search of signs of life and water. So far, engineers have built a two-foot-high proof-of-concept that moves in response to human commands. To shrink this prototype to nanoscale, scientists need advanced nanotubes that can both move themselves and rearrange themselves to form different kinds of materials. Program head Steve Curtis says that depending on the speed of nanotech development and funding levels, TETwalkers could land on Mars within the next 30 to 40 years.

Without shelter, any Mars-dwelling robot will eventually succumb to the planet's intense cosmic radiation and extreme weather. To enable nanobots to carry out long-term missions, Constantinos Mavroidis, an engineer at Northeastern University, is working on a theoretical plan for what amounts to a nanobot Mars base. Mavroidis calls this miles-long spiderweb of nanotube tunnels the Networked TerraXplorer concept. An orbiter would drop the TerraXplorer, preloaded with nanobots, onto the Martian surface. Once in place, the protected nanobots could make long-term measurements of the planet's weather and any seismic activity.

Although Mars is likely the first planetary destination for nanobots, scientists could eventually send them to places much more distant and extreme. Researchers at NASA's Jet Propulsion Laboratory are developing carbon nano­tubes that can survive Venus's 900°F surface. Others are studying ways to move nanobots through interstellar space. No matter what, in the decades ahead, some of the most stunning revelations about space could come from robots smaller than a toy car.

There are a lot of hurdles to accurately predicting intelligence, from the difficulty of defining exactly what it is to accurately understanding the complexities of the human brain. Some techniques are surprisingly simple, like measuring the size of the brain. But others, like a new study that suggests brain imaging could crack the IQ code, require a little more finesse.

Researchers at Washington University in St. Louis found they could determine 10 percent of individual differences in intelligence by determining the strength of neural pathways, specifically those branching out from the left lateral prefrontal cortex to the rest of the brain. That part, their research suggests, acts as a director for the rest of the brain, overseeing how the individual pieces work in tandem and tweaking the process when necessary.

For the study, researchers set participants in fMRI machines, then had them perform tasks designed to measure fluid intelligence, like showing them a series of images and asking if one of them had appeared earlier. The results that came out of the scans allowed them to make individual maps of participants' "Global Brain Connectivity"--how well those parts of the brain work together.

Objective tests of intelligence are difficult to come by, and even though the researchers say there's a lot more to learn about how the left lateral prefrontal cortex works, it's another bit of knowledge about the hunk of gray matter we're all carrying around.

[Journal of Neuroscience via Washington University in St. Louis]

Researchers at CERN and the world over were already sure they had found the Higgs Boson--five-sigma sure--but in case there were any lingering doubts a new round of results coming out of Geneva further backs the earlier findings. One team there now reports a 5.9 sigma level of certainty that the Higgs exists. That equates to a one-in-550 million chance that the results are incorrect reflections of statistical errors.

The agreed-upon sigma level for a proper discovery is a 5-sigma result, which only requires a one-in-3.5 million chance of statistical fluke. That's what both the ATLAS and CMS teams were claiming back in July when the initial discovery was reported (technically CMS was reporting a result between 4.9 adn 5 sigma). The ATLAS team has now submitted additional data on the "decay channels" by which the Higgs breaks down into lighter particles a fraction of a second after being created by high energy particle collisions. The CMS reiterated its 5-sigma certainty in the same journal (Physics Letters B).

What does that mean? Well, it means that we were already really sure about the Higgs, and now we're even more sure. But there's still a lot we're not sure about, like whether the Higgs that we've found is actually the Higgs that we've theorized about, the one that fits perfectly into our Standard Model of the universe. That's going to take a lot more science. But at least we can be nearly 6-sigma sure that we've found something very interesting.

[BBC]

While we in the U.S. wait with bated breath for Mars Rover Curiosity's August 5 landing on the red planet, India's space program, the Indian Space Research Organisation, has confirmed that it plans to send an orbiter to Mars in 2013. It's one small step in a program that's been making giant leaps in recent years, including multiple satellite launch missions.

The total price tag for the project could wind up between $70 and $90 million, a source told AFP, which would go toward a 320-ton rocket carrying the orbiter. Once in place, it would study the planet's climate and geology. That would already be a pretty big success for the program, but the ISRO is trying to go even further, planning to launch a fully manned mission by 2016.

India's space program has been in place since the '60s, but it's in more recent years that its gained notoriety. In 2009, the country successfully launched seven satellites on a single rocket and it has been providing a cost efficient means of transporting satellites into space, but it was the Chandrayaan-1 lunar probe that brought the program global attention. Officials took criticism for spending on the space program, which intensified when the ISRO lunar probe lost radio contact with the probe after ten months. But Chandrayaan-1 was deemed a major success when it discovered water and a protective magnetic field on the moon.

Of course, a mission to Mars is a whole new beast, and they'll be up against a lot of rough history when it launches.

[AFP]

Russia just set a speed record for a sprint that took place a long way from London. An unmanned Russian Progress cargo ship launched from Baikonur Cosmodrome in Kazakhstan yesterday and docked with the International Space Station just six hours later, marking the first same-day docking ever performed at the ISS.

Launched aboard a Russian Soyuz rocket, the robotic Progress 48 performed additional firings of its own onboard engines early in the mission to boost it toward the ISS in a shorter period of time. This isn't a completely novel maneuver--back in the Gemini days NASA docked spacecraft together on obit on the same day they were launched, and Russia has done the same. But it does require more precise calculations and a tighter margin of error.

Spacecraft usually spend two days catching up to the ISS in orbit, making the approach much slower (and safer). For same-day docking, spaceflight engineers have to execute that famous "striking a speeding bullet with a speeding bullet" math and physics. But it does come with unique benefits, especially if the maneuver is extended to manned Soyuz capsule missions as it is expected to be.

With manned missions, docking at the station within hours reduces the amount of food and water that must be packed aboard a spacecraft and provides for far greater crew comfort (spacious the Soyuz capsule is not). And of course, while no one is saying it out loud, it also could prove an important capability if something should go wrong aboard the station. Though there's really no such thing as an emergency space launch--it takes time to fuel up a rocket and place a mission on a launchpad--the ability to shave two days off the arrival time of people or supplies at the ISS could make a difference should things ever get hairy up there.

[SPACE]

When we feel there's a situation out of our control, we often fall back on superstition to account for it. ("Nothing else is working, why not blame it on that black cat?") But when enough of us rely on superstition, it's not just an individual comfort; it starts to have real repercussions. Now a designer has created an algorithm trades stock superstitiously, and it's going to see if gambling based on full moons and thirteens can pay off.

Sid the Superstitious Robot (for which you can see the open-sourced code if you're so inclined) is governed by a set of rules programmed by 25-year-old Shing Tat Chung. Among them are a phobia of the number thirteen that prevents it from trading stocks on the thirteenth day of the month. On the other side of the scale, it has an affinity for new moons, but will sell during a full moon. It's a rewiring of other trading systems that make decisions based on more rational changes, such as costs of certain goods or other expected outcomes.

But those beliefs aren't concretely set; Sid incorporates new ones based on feedback from his performance. That doesn't equate to rationality: a certain pattern can be observed but also be imaginary, and the algorithm will incorporate it based on a superstitious "feeling" that it evokes.

We've seen some amazing-sounding algorithms even recently, but so far this one's just doing OK. It's at -5 percent of its original amount of cash, compared to a relative rise of about 4 percent on the market. But it does seem like the stock market is the place to try this; superstitions probably affect it at least somewhat, and an algorithm trading based on that could give us a glimpse into the rules of risk we subconsciously follow. The experiment will continue using real people's money, and at the end of the year we'll get to see what betting on full moons can buy.

[BBC]

As much as we love our silicon semiconductors, quantum computers are very much a technology of the future. Instead of the usual string of 1s and 0s, they'll be able to send both types of information at the same time, dwarfing their traditional counterparts. But one major problem is that they can only move through one optical fibre. To push more information through, they need a router, and Chinese physicists have unveiled the first one.

In a quantum computer, photons ferry information to other sources. It's possible to send the photons directly through one fibre, but routing comes in when another fibre is needed. Like the router you probably own, a control signal reads the data then sends it to its destination. But dealing with unruly quantum particles is a little more complicated; when a signal is read it's also destroyed. So even though the data can be transferred with traditional methods, that doesn't offer the kind of data-transferring power quantum computing offers.

This new quantum router proves it's possible to truly guide a quantum signal. The information used is encoded in two different types of polarized photons (like 1s and 0s). Scientists then create a single photon that acts as both (the combined 1s and 0s). That photon is then broken down into two photons that share the combined state. The router picks up one to determine the route, then the other photon is used to transfer the information. A simple series of half mirrors guides the photons along the correct route.

Does this mean we're now well on our way to a globally connected, super-fast stream of information? No. The scientists say it's just a proof of concept--we know it's at least theoretically possible to send quantum information through a router, but it's still a limited way of doing it. In other words, when this sort of technology is usable (and it will be), it won't look like this.

[Technology Review via Gizmodo]

The dust has settled on the final round of NASA's Commercial Crew integrated Capability program project, and three winners have been given funding for the next round of American-made space taxis: Boeing, who received $460 million; SpaceX with $440 million; and the Sierra Nevada Corporation, with a paltry $212.5. The companies will use it as seed money to create commercial spacecraft that U.S. astronauts will fly aboard.

With NASA's space shuttle program shelved, it's had to compensate for all of the spacecraft it won't be making itself, instead investing in companies that have shown promise in creating commercially viable, safe spacecraft. Once those companies have created one, NASA can put their astronauts on board (maybe even alongside civilian space tourists).

In May, SpaceX made news by launching a privately built craft to the international space station. Boeing has developed a low-Earth orbit space capsule. Sierra Nevada has a somewhat similar Dream Chaser spaceplane project.

Between now and the end of May 2014, the companies will continue working on their spacecraft designs, and if they reach the milestones set by NASA, crewed missions will be underway soon after.

[NASA]

We're big fans of innovative gameplay here at PopSci, and the web browser can provide the perfect, simple canvas for that. For example: You may be familiar with the game QWOP, created by Oxford professor Bennett Foddy, whom we featured in our PopSci Arcade earlier this year. In QWOP, you frustratingly try to direct a person through a race by moving their limbs using the Q-W-O-P keys. It's almost impossible to beat and almost impossible to put down. Now, from the same productivity vampire comes CLOP. This time you're a unicorn.

Bennett Foddy, also the creator of PoleRiders, is the one behind it. He's also one of the most visible in a new line of indie creators working in the web browser. The design of CLOP, like some of its counterparts, is simple, but it's slightly more polished than QWOP. There are landscapes in the background, and you actually get to see those landscapes because it's much more forgiving. Quadrupeds just have better balance, it seems.

[Foddy.net]

Cornell University researchers used porn and measures of pupil dilation to study arousal in straight-, gay- and bisexual-identifying men and women, reports a study published April 3 in PLoS ONE. The results, which point to surprising differences in arousal based on a person's sex and sexual orientation, corroborate previous research using measures of genital response, opening up a less-invasive method of studying arousal and orientation.

Human development experts Gerulf Rieger and Ritch Savin-Williams measured pupil dilation in 325 people as they watched two 30-second videos -- one of a woman masturbating and one of a man -- as well as a 1-minute clip of a neutral landscape that served as a palate-cleanser and a control between the porn clips. Participants in a pilot study chose the clips based on the attractiveness of the models, and the order they were shown in (man first versus woman first) was selected randomly during the dilation study.

Unsurprisingly, "heterosexual men dilated most to the other sex, homosexual men dilated most to the same sex, and bisexual men dilated more equally than other men to both sexes," the authors wrote. The same wasn't true for straight women, though. On average, heterosexual women dilated more to images of a man than to a landscape, but they also responded more strongly to images of a woman masturbating compared to heterosexual men watching a man. Lesbians and bisexual women in the study more closely followed the male patterns.

The finding that straight women more so than straight men are likely to get turned on by both sexes could be explained by evolutionary theory, Rieger says. In 2000, Roy Baumeister, a psychologist then at Case Western Reserve University, proposed that the female sex drive evolved to be more malleable than the male sex drive. Then, in 2007, Canadian researchers studying the genital response to watching videos of human and animal sex suggested that whereas the biological function of arousal in men is to become erect and penetrate women, in women it has historically been to self-protect (with lubrication) during forced sex, which ostensibly required them to be more automatic and flexible in their arousal to any stimuli. "Forced copulation in several species and in most human societies indicate that it may have occurred throughout human evolution," Rieger and Ritch Savin-Williams write.

Here's how the Canadian authors explained it in 2007: "Reflexive vaginal responding may have had fitness benefits for our female ancestors because vaginal vasocongestion produces lubrication, which reduces the likelihood of injury and subsequent infection during vaginal penetration. Ancestral women who did not reflexively lubricate would have been more likely to experience injuries or infections that could have rendered them reproductively sterile or resulted in their deaths."

Rieger says a less plausible theory that has been suggested is that "because women are less exposed to pornography than men, they might respond strongly to anything erotic they see. It could be a novelty effect. I do not buy it, but it is possible."

The results of the study are in line with previous research that measured arousal based on penis circumference in men and vaginal pulse amplitude, which reflects changes in vaginal engorgement, in women. Genital response studies have found that, "the relationship of genital arousal to either male or female sexual stimuli with self-reported sexual orientation is considerably stronger in men than in women," the authors write. "Most men are exclusively aroused to the sex consistent with their reported sexual orientation; for example, most heterosexual men are almost exclusively aroused to women and most homosexual men are almost exclusively aroused to men. In contrast, women's sexual orientation is poorly reflected in their genital response because they respond with substantial arousal to both sexes."

Pupil dilation has been used before in sex research-in Canada in the 1950s through '70s to weed out gays, "who were at the time considered a national risk"-but those studies were riddled with problems, like failing to factor in bisexuality and measuring dilation by hand rather than with a camera and a computer program (an infrared gaze tracker automatically recorded pupil size and dilation in the new study). The agreement between genital response and pupil dilation results bolsters the reliability of the less-used method.

Switching to measuring pupil dilation in arousal studies has several benefits, Rieger says, starting with using the same method for both sexes. Some people can suppress genital arousal, but because pupil dilation is controlled by the automatic nervous system, study participants can't affect the measurements. Plus, the less-invasive method will be palatable to more study participants, allowing researchers to learn about arousal and orientation in traditional cultures and even children -- using less sexy images, of course.

Jennifer Abbasi is a science and health writer and editor living in Portland, OR. Follow Jen on Twitter (@jenabbasi) and email her at popsi.thesexfiles@gmail.com.