Day: 09/06/2012

Black Hole Radiation Simulated in Lab.

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For the first time, scientists have been able to simulate the type of radiation likely to be emitted from black holes.

A team of Italian scientists fired a laser beam into a chunk of glass to create an analogue (or simulation) of the Hawking radiation that many physicists expect is emitted by black holes.

A spokesperson for the research group said: “Although the laser experiment superficially bears little resemblance to ultra-dense black holes, the mathematical theories used to describe both are similar enough that confirmation of laser-induced Hawking radiation would bolster confidence that black holes also emit Hawking radiation.”

The renowned physicist Stephen Hawking first predicted this sort of radiation in 1974 but it has proved elusive to detect, even in the lab. This research group was able to use a “bulk glass target” to isolate the apparent Hawking radiation from the other forms of light emitted during such experiments.

Black holes are region in space where nothing can escape, not even light. However, and despite their name, they are believed to emit weak forms of radiation (such as Hawking radiation). Physicists expect that this radiation may be so weak as to be undetectable.

Source: http://www.communicatescience.eu

New horizons for Hawking radiation.

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In 1974, Steven Hawking predicted that black holes were not completely black, but were actually weak emitters of blackbody radiation generated close to the event horizon—the boundary where light is forever trapped by the black hole’s gravitational pull [1]. Hawking’s insight was to realize how the presence of the horizon could separate virtual photon pairs (constantly being created from the quantum vacuum) such that while one was sucked in, the other could escape, causing the black hole to lose energy. Hawking’s idea was significant in suggesting a possible optical signature of a black hole’s existence. Yet, even though the prediction created an extensive theoretical literature in cosmology, calculations have since shown that Hawking radiation from black holes is so weak that it would be practically impossible to measure.

It turns out, however, that the physics of how waves interact with a horizon does not depend in a fundamental way on the presence of gravity at all. In principle, an analogous Hawking radiation should occur in other systems [2, 3]. The key requirement is simply that the interaction between waves and the medium in which they propagate causes there to be a boundary between zones where the wave and the medium have different velocities [4, 5]. In a paper in Physical Review Letters [6], Francesco Belgiorno at the Università degli Studi di Milano, in collaboration with researchers at several other institutes, also in Italy, describe a series of experiments where high-intensity filaments of light in glass perturb the optical propagation environment in an analogous manner to the way a gravitational field affects light near a black hole horizon. This perturbation creates the optical equivalent of an event horizon that allows Belgiorno et al. to make convincing measurements of analog Hawking radiation at optical frequencies [7]. These results are highly significant in suggesting a system in which Hawking’s prediction can be fully explored in a convenient laboratory environment.

A really useful way to visualize an analog event horizon is to imagine a fish swimming upstream in a river flowing towards a waterfall [4, 5]. The point at which the current flows faster than the fish can swim represents a boundary at which fish cannot escape and they are swept over the waterfall. This “point of no return” for the fish is equivalent to a black hole horizon. A similar analogy exists for white holes, associated with horizons that fish can never enter, namely, if they were attempting to swim upstream towards the bottom of a waterfall. This simple picture is surprisingly powerful at capturing the physics of horizons, and can be extended rigorously to describe horizon physics in diverse systems including acoustics, cold atoms, and gravity-capillary waves on water [8, 9, 10, 11]. Indeed, horizon effects and a stimulated form of Hawking radiation have recently been explicitly observed in the vicinity of an obstacle placed in an open channel flow [12]. However, the question has remained open as to whether these analog gravity systems also generate the spontaneous thermal radiation Hawking predicted.

Belgiorno et al.’s experiments suggest that the answer is yes. They created an optical event horizon by using intense, ultrashort light pulses that change the refractive index of the glass in the vicinity of the moving pulse [13]. The change in the refractive index modifies the effective propagation “geometry” (Fig. 1, left) as seen by copropagating light rays such that a trapping horizon forms and, in principle, Hawking radiation should occur. The changing index is an effect called a Kerr nonlinearity, whereby a pulse modifies the refractive index of glass such that it is higher at the center of the pulse than the wings. Because wave speed depends on refractive index, the propagating pulse induces an effective velocity gradient in the material such that horizons can appear at points on the pulse leading and trailing edges.

It is important to note here that Kerr-induced trapping in itself is not a new effect, but rather one that is well known in nonlinear fiber optics [14, 15, 16]. In fact, the Raman frequency shifting on solitons (where the spectrum of short pulses moves to longer wavelengths) is a deceleration effect that was even shown to lead to an equivalent gravitational potential [16, 17], but it was only recently that scientists appreciated the possibility of extending the gravitational analogy to test predictions of Hawking radiation [13]. The particular attraction of experiments in optics is that the intensity and wavelength of the Hawking radiation depends on the induced refractive index gradient, and pulses containing only a few optical cycles or a steep shock front would be expected to generate measureable emission of visible light. Unfortunately, although it is straightforward to demonstrate the existence of an event horizon in an optical fiber [13], dispersive and dissipative effects present in the fiber appear to prevent the clean formation of the particular pulse profiles needed for the spontaneous generation of Hawking radiation.

The experiments of Belgiorno and co-workers attempt to overcome this problem in a novel way. In fact, they move away from the fiber environment altogether, performing experiments in bulk glass, using laser pulses in the form of needlelike beams known as optical filaments (Fig. 1, right) to generate the nonlinear refractive index perturbation [18]. Optical filament pulses generally have a complex spatiotemporal structure, but it is possible to experimentally synthesize them so that their internal group and phase velocity gradients can be controlled. This is what Belgiorno et al. did in their experiments, using properties of what are called Bessel beams, where the filament is preshaped so as to control its group velocity relative to the velocity change induced by the refractive index perturbation. This is a crucial aspect of their experiments because it allows them to fine tune the window of Hawking radiation emission into the near infrared, around away from any other possible contaminating signals. With a cooled CCD camera, they detect a clear signal above background that they associate with Hawking radiation, and the spectral shift of this signal with incident energy is in good agreement with the predictions of theory. They also performed experiments where the filaments were formed from Gaussian pulses, and although the dynamics are more complicated here, the spectral emission window of the spontaneous radiation is again in agreement with theory.

Overall, this work provides significant evidence for the observation of Hawking radiation in an analog gravity system. The results must nevertheless be interpreted carefully. For example, it is essential to state very plainly that measuring analog Hawking radiation gives no direct insight into quantum gravity because there is no physical gravitational potential involved. Indeed, one might even argue that the description of this emission as “Hawking” radiation is inappropriate, but this seems an unnecessary restriction because the study of analog horizon systems was clearly motivated by Hawking’s work over years ago. Of course additional experiments still remain to be carried out. Specifically, the spontaneous photon pairs emitted on either side of the horizon may be detectable with suitable angular resolution [18], and measurements of their entanglement and correlation will be an essential next step. Moreover, the polarization properties of filaments are very subtle and may need to be taken into account more fully in a complete interpretation of the experiments.

This field of research is at the interface of several areas of physics, and “standardizing” the terminology would be welcome. For example, effects related to Cerenkov radiation are seen both in filament and fiber soliton propagation [15, 16], and distinguishing similarities and differences is important to avoid confusion. On the other hand, Belgiorno et al.’s results now point out the clear need to study the quantum electrodynamics of soliton radiation, as this may have direct bearing on their experiments. This work is also likely to be far reaching in other ways. By showing how tailored spatiotemporal fields provide a high degree of control over the interaction geometry of propagating light pulses, they may represent a new example of experiments in “ultrafast transformation optics,” where geometrical modifications of an optical propagation environment can be induced on ultrafast timescales. This may allow a much wider study of other analog physical effects, using a convenient benchtop platform.

Corrections (6 December 2010): Paragraph 3, sentence 5, “capillary waves” changed to “gravity-capillary waves.” References 2, 3, 10, 13 and 18, changed/updated.

References

  1. S. W. Hawking, Nature 248, 30 (1974).
  2. W. G. Unruh, Phys. Rev. Lett. 46, 1351 (1981).
  3. P. C. W. Davies and S. A. Fulling, Proc. R. Soc. London A 356, 237 (1977); M. Visser, Classical Quantum Gravity 15, 1767 (1998).
  4. U. Leonhardt and T. G. Philbin, Philos. Trans. R. Soc. A 366, 2851 (2008).
  5. W. G. Unruh, Philos. Trans. R. Soc. A 366, 2905 (2008).
  6. F. Belgiorno, S. L. Cacciatori, M. Clerici, V. Gorini, G. Ortenzi, L. Rizzi, E. Rubino, V. G. Sala, and D. Faccio, Phys. Rev. Lett. 105, 203901 (2010).
  7. D. Faccio, S. Cacciatori, V. Gorini, V. G. Sala, A. Averchi, A. Lotti, M. Kolesik, and J. V. Moloney, Europhys. Lett. 89, 34004 (2010).
  8. P. Ball, Nature 411628 (2001).
  9. Artificial Black Holes, edited by M. Novello, M. Visser, and G. E. Volovik (World Scientific, Singapore, 2002)[Amazon][WorldCat].
  10. G. Rousseaux, C. Mathis, P. Maïssa, T. G. Philbin, and U. Leonhardt, New J. Phys. 10,053015 (2008); R. Schützhold and W. G. Unruh, Phys. Rev. D 66, 044019 (2002).
  11. G. Rousseaux, P. Maïssa, C. Mathis, P. Coullet, T. G. Philbin, and U. Leonhardt, New J. Phys. 12,095018 (2010).
  12. S. Weinfurtner et al., Phys. Rev. Lett. (to be published); arXiv:1008.1911v2 (gr-qc).
  13. T. G. Philbin, C. Kuklewicz, S. Robertson, S. Hill, F. König, and U. Leonhardt, Science 319, 1367 (2008); R. Schützhold and W. G. Unruh, Phys. Rev. Lett. 95, 031301 (2005).
  14. N. Nishizawa and T. Goto, Opt. Express 10, 1151 (2002).
  15. J. M. Dudley, G. Genty, and S. Coen, Rev. Mod. Phys. 78, 1135 (2006).
  16. D. V. Skryabin and A. V. Gorbach, Rev. Mod. Phys. 82, 1287 (2010).
  17. A. V. Gorbach and D. V. Skryabin, Nature Photon. 1, 653 (2007).
  18. F. Belgiorno, S. L. Cacciatori, G. Ortenzi, V. G. Sala, and D. Faccio, Phys. Rev. Lett., 104,140403 (2010).

Source: http://physics.aps.org

Technology Fuels Cyberbullying and Cheating in Teens.

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McAfee’s study “The Digital Divide: How the Online Behavior of Teens is Getting Past Parents” shows an alarming 70% of teens have hidden their online behavior from their parents, up from 45% in 2010. And yet half of parents live under the assumption that their teen tells them everything he/she does online.

The school year is now upon us. If you haven’t already, you will soon start packing up the kids to send them off to school. Outfitting your kids with new clothes are new technologies is often a big part of back to school preparations.

However, these technologies can have drawbacks and even some dangers that parents need to address: cyberbullying and cheating.

Cyberbullying

  • Almost 25% of teens claimed to be targets of cyber bullying and 2/3 of all teens have witnessed cruel behavior online
  • Only 10% of parents are aware of their teens are targets of cyber bullying
  • Facebook has become the new school yard for bullies with 92.6% of teens saying that cruel behavior takes place on Facebook, and 23.8% on Twitter, 17.7% on MySpace and 15.2% via Instant Messenger
  • When witnessing others being attacked, 40% of teens have told the person to stop, 21% have told an adult and 6% joined in
  • When being attacked themselves, 66% of teens responded to the attacker (with 35% responding in person), 15.4% avoided school, and an alarming 4.5% have been in a physical fight with their attacker

 

Cheating

  • Only 23% of parents express concern about their teen going online to cheat in school, yet nearly half of all teens (48%) admit they’ve looked up answers to a test or assignment online
  • 22% cheated specifically on a test via online or mobile phone; while only 5% of parents believed their children did this.
  • 15.8% of teens have admitted to cheating on a test by looking up answers on their phone yet only 3.2% of parents thought their teens cheated this way
  • 14.1% of teens admitted to looking up how to cheat on a test online
  • Overall, 77.2% of parents said they were not worried about their teens cheating online

Parents, you must stay in-the-know. Since your teens have grown up in an online world, they may be more online savvy than you, but you can’t give up. You must challenge yourself to become familiar with the complexities of the teen online universe and stay educated on the various devices your teens are using to go online.

As a parent, I proactively participate in my kids’ online activities and talk to them about the “rules of the road” for the Internet. I’m hoping that this report opens other parent’s eyes so they’ll become more involved in educating their teens with advice and tools

 

Source: http://blogs.mcafee.com

 

The story of the Compact for Safe Cosmetics and the growth in demand for safe cosmetics.

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The Campaign for Safe Cosmetics’ report Market Shift describes the seven-year project during which the Campaign worked with companies through the Compact for Safe Cosmetics, the voluntary pledge to avoid chemicals banned in other countries, avoid harmful ingredients whenever possible and fully disclose product ingredients.

Market Shift highlights the 322 cosmetics companies (we call them “Champions”) that met the goals of the Compact. Another 110 companies (we call them “Innovators”) made significant progress toward those goals.* This is great news for you, the consumer, and for the Campaign, the cosmetics industry and the lawmakers working to pass the Safe Cosmetics Act. These 432 companies are leading the industry toward safety, showing it’s possible to make products without using the hazardous chemicals that are all too common in conventional personal care products.

More than 1,500 companies signed the Compact from its inception in 2004 until 2011. The Campaign for Safe Cosmetics closed the Compact in August 2011. The research team at Environmental Working Group’s Skin Deep database developed tools for tracking each company’s compliance with the goals of the Compact. Through these tools the Campaign determined that 322 companies achieved “Champion” status by fulfilling the goals of the Compact, and another 110 companies reached “Innovator” status by getting most of the way there.

The report describes how these companies – from small mom-and-pop businesses to some of the largest businesses in the natural products sector – are setting a new high-bar standard for personal care products. The Champions are demonstrating best practices by:

  • Making effective products without using ingredients linked to cancer or birth defects.
  • Disclosing all their ingredients, including those that make up “fragrance,” showing that it’s not necessary to hide these ingredients from the public.
  • Working together with nonprofit health groups to increase market demand for safe, sustainable products and practices.

Please read and share the Market Shift report with your friends and family, and vote with your dollars to support companies that are doing the right thing- keeping toxic chemicals out of people and the environment.

*Due to an error in data analysis, one company was moved from Innovator to Champion status after the initial report release.

Source: safeccosmetics.org

Dream Chaser: A ‘family car’ for space.

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To get a sense of what it would be like to fly the Dream Chaser space plane hop into the front seat of a car – ideally a large SUV (Sports Utility Vehicle) or minivan – preferably with six friends. Instead of a steering wheel in front of you, picture a joystick. Instead of a dashboard, a row of flatscreen displays. Now shut and lock the doors, fasten your seatbelts and we’re ready to go. Next stop, the International Space Station (ISS).

Dream Chaser is being built by the Sierra Nevada Corporation (SNC) in the US mid-western state of Colorado. It is one of three concepts backed by Nasa to replace the retired Space Shuttle and is designed to carry crew and cargo to and from orbit. The other two concepts – SpaceX’s Dragon and Boeing’s, uninspiringly named CST-100 – are both capsules, not much different in appearance to the Apollo spacecraft that took men to the Moon.

But even Dream Chaser’s designers liken the space plane to a large family car, and sitting at the controls it’s easy to see why. The mock-up cabin is certainly no wider and the windows surrounding the two pilots offer similar visibility. Behind the front seats, there’s room for five more astronauts with a small area at the back for luggage. On the outside, it resembles a shoe with two wings poking out diagonally at the back.

The space plane’s squat, compact shape was inspired by a fuzzy 1970s spy photograph of an experimental Soviet aircraft. Nasa engineers spent more than a decade reverse engineering and developing the concept.  They even built a full-sized mock-up before the project was quietly shelved. SNC has now been working on Dream Chaser for the last nine years and, with a recent extra $212 million from NASA, is getting close to finally turning the dream into reality.

“It started as a dream,” admits Mark Sirangelo, head of SNC Space Systems. “It was a very small group of people that looked to the future and said we think that when the Shuttle retires, that there’s a place for a modern version of that shuttle.”

“The reality is quite real now. We have built our vehicle, we have actually conducted our first test flight, the vehicle will do its first autonomous [atmospheric] flight later this year…and we’re now in the final three companies who are going to be looked towards to produce a vehicle that can take people and cargo back and forth to the space station.”

Blurred vision

Comparisons with a mid-sized family hatchback even extend to the factory, on the outskirts of Denver, where the first space plane is taking shape. It resembles a garage workshop, where you expect to see mechanics tinkering with cars; instead they’re preparing the first Dream Chaser for flight.

The plane sits in a bay at the end of the room beneath a vast Stars and Stripes flag. Constructed primarily of carbon fibre, the first impression of Dream Chaser is that it’s, well…small. With no massive engines or cargo bay, and only a couple of metres off the ground, it is quite unlike any other space plane design. And whereas the Space Shuttle was, notoriously, the most complicated machine ever built, Dream Chaser is much simpler.

“We look at it what jobs are needed,” says Sirangelo. “We’re not taking big pieces to and from the Space Station any more, we’re taking people and critical cargo back and forth and it’s designed in size for that purpose.”

Dream Chaser will be launched on the top of an Atlas 5 rocket (although it could be launched on Europe’s Ariane rocket), with the astronauts lying on their backs looking through the front windows at the sky. Although not yet rated for manned spaceflight, Atlas 5 is one of the most reliable US launchers ever built. The space plane’s engines would only be fired in space to change orbit, catch up and dock with the ISS and de-orbit before returning to Earth.

Similar SNC engines have already flown in space on the first privately operated human spacecraft, Spaceship One, and are being built for Virgin Galactic’s Spaceship Two. Like the Shuttle, and these other designs, Dream Chaser would glide back to Earth – a feature its designers are keen to highlight.

“Within eight to 10 hours of leaving the station, we’re on the ground on a runway,” says Sirangelo. “We come home with less than 2Gs – twice the force of gravity – unlike most capsules, which come down to an ocean landing or a desert landing and come down at a much higher rate of descent. That could damage the experiments and could make it much more difficult for the people coming home.”

The ability to return fragile equipment or experiments from the space station is one of the big selling points of the Dream Chaser concept. The only return option at the moment is a cramped and bumpy landing in a Russian Soyuz capsule, which barely accommodates its three astronauts. There’s certainly room for cargo in the Dream Chaser (depending on how many astronauts are being flown) but where space planes really have the edge over capsules is their versatility.

The Shuttle was so much more than a space cargo hauler. It allowed, for example, astronauts to fix satellites and telescopes in orbit. Without it, the Hubble Space Telescope would still have blurry vision (and would probably have failed by now). But with the demise of the Shuttle, that ability was lost.

Now, Dream Chaser could bring it back. Like the Shuttle (and unlike most capsules)it has an airlock enabling astronauts to leave the plane for space walks. “The missions … could be to go out and repair things in space [or] help with the large and growing problem of space debris – how could we move a satellite out of the way before it causes a problem?,” says Sirangelo.

As a transport craft to and from the ISS, Dream Chaser faces stiff competition from SpaceX and Boeing. But Sirangelo believes, once the considerable development and construction work is done, it will find lots of different roles….just like any good family car.

“As with most SUVs, you haul your family around,” he says. “But sometimes you take supplies around, sometimes you go camping, sometimes you fix things with it and that’s what we’re trying to do with this vehicle.”

Source: BBC

 

 

 

 

Upgrading the dogs of war.

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In a secluded section of Raleigh, North Carolina live 16 carefully selected recruits for a high-priority Pentagon project that could play a life or death role in Afghanistan.

None of them have any previous military experience, so their training is necessarily disciplined – if they get through the programme their work could pave the way for others, like them, who will be called on to make life-saving decisions in high-stress environments. As a result, nothing is left to chance.  Their days involve intense physical and mental training to see if they are able to cope with the rigors of war.

Outside, a trainer introduced me to one recruit, Jimmy, who is outfitted with a telemetry vest, which can measure his physiological changes, such as heart rate, breathing, and skin temperature. It gives him an almost Olympian look, like an athlete whose every breath is measured by a team of coaches.

But you also get a sense that Jimmy gets a kick out of it. As he is ordered forward, he is panting and his tail is wagging with the enthusiasm of youth.

The good-natured black Labrador retriever is the Jason Bourne of dogs – part of a specialised Navy programme designed to select and train the most highly skilled members of his breed for a high-priority mission: finding improvised explosive devices (IEDs) on the battlefield. While prototypes of the dogs have already been deployed, research on Jimmy and his colleagues is part of a “2.0” version of the programmme, which is based on formal science studies being conducted here at North Carolina State University’s College of Veterinary Medicine, and other universities.

Over the past six years, the Pentagon has spent over $18 billion trying to find ways to detect and neutralise roadside bombs – the leading killer of US troops in Afghanistan –by investing in everything from better mine detectors to newfangled devices that shoot beams of energy. But in North Carolina, a state that is home to a 300-year hunting dog tradition, everyone seems to agree on the best technology for the job.

In the lab, I’m introduced to Dakota, one of Jimmy’s colleagues. In front of Dakota are two small containers, one scented with vanillin and the other with ethanol. Dakota, who is learning to signal when she detects a scent, is supposed to select the vanillin, a training aid that will later be switched to ammonium nitrate used in explosives. If she selects correctly, she’ll be rewarded with a treat. She gets the first one right, choosing vanillin, misses the next two, but then got the fourth one right. At that point, she was averaging 50-50, which is not good, but she was still a beginner with time to learn.

Biting machine?

Though war dogs may be high profile these days – thanks in part to Cairo, the Belgian Malinois who accompanied Navy Seals on the Osama bin Laden raid – there were virtually no deployed military bomb dogs working on battlefields when the US invaded Iraq, and hadn’t been for decades. After the Vietnam War, the military’s working dog programme was handed over to the Air Force, which used them to patrol missile fields in the United States. Those dogs were used to being guided on leashes, living in air-conditioned kennels and working limited shifts: a far cry from a war zone.

That quickly changed with the arrival of IEDs and in 2007, 13 dogs – all Labs – were deployed with the Marines to Iraq and Afghanistan. When the dogs started finding bombs, Marines asked for more, and today there are some 600 dogs.

Whilst successful, they were all essentially prototypes for the next generation of bomb dog. “After we do all this science, we’re going to rewrite the protocols,” says Lisa Albuquerque, an energetic Navy official who heads the programme, known formally as the IED Detector Dog. “It’s basically an upgrade to an existing model.”

Her starting point was talking to the Marines who would ultimately use the dogs. She recalls asking a staff sergeant: “Do you want a dog that bites,” to which he replied: “I have 13 heavily armed Marines, why do I need a dog that bites?” What they wanted, it turned out was a good-natured dog, hence the Labradors. From there, she began an extensive array of experiments with researchers at North Carolina State University, Duke University, and Oklahoma State, to develop the training and selection criteria that will make them the perfect IED detector.

Talking about dogs as a technology, like a rifle or a pair of binoculars, is part of what makes the Navy programme unique. “I think that a real key point is that the science and technology that the [Department of Defense] has funded [in the past] has never been about trying to optimise the dog,” says Albuquerque, who spent 25 years as a military dog trainer. “It’s all been about trying to make a sensor that’s as good as a dog, and so our approach, which is really very unique, is saying, ‘Wait a minute, for the near term, dogs are still going to be the best sensor.’”

Mind games

But smell is just one part of the Navy’s dog programme – a large part of the effort is animal cognition. Brian Hare, who heads Duke University’s Canine Cognition Centre, is interested in animals’ inferential abilities, or the ability to reason and problem solve. Until recently, it was something that scientists thought was impossible.

Hare demonstrates his work with a video, showing Yaya, a great ape in Uganda, who is presented with a mental puzzle: a long plastic tube that is latched down and can’t be moved. “At the bottom is the equivalent of a Peabody award,” says Hare. “It’s three peanuts.”

The question is how would Yaya get the peanuts (and could I come up with a solution before she does)? In less than 10 seconds, before I could even venture an answer, Yaya has already solved the problem. She goes to her water dish, sucks some water into her mouth, and then spits the water into the tube, allowing the peanuts to float to the top.  Pretty much all of the female apes, like Yaya, solved the nut problem the same way, according to Hare. “There’s also a male solution to this problem,” he adds. “Many of the male chimpanzees just peed in the tube.”

Hare has extended these cognition tests to dogs. In one test, for example, Border Collies were shown several objects they know by name, such as tennis balls and Frisbees. The dogs then were told to fetch the “gazzer”, a made up word for a toy car, the one object whose name they don’t know. The dogs consistently fetched the toy car, which Hare attributes to the dogs reasoning that the “gazzer” must be the one object they didn’t know: an example of inferential reasoning. “It’s even scarier than that because there’s evidence that dogs, after only two pairings of hearing the word out loud – no food rewards, no training, no nothing – remember the words for as long as four months,” says Hare. “That’s on the order of what human children do.”

Just understanding that dogs are smart isn’t enough, however. At North Carolina State University, Barbara Sherman, a specialist in animal behaviour, and David Dorman, a veterinary toxicologist, are focusing on coming up with tests that can predict which dogs will be the best bomb dogs, in the way that the SATs help predict which students will do well at college. Good attributes of a working dog might be factors such as intelligence and motivation. “Some of these factors we could try to measure directly, some we’re not able to measure directly,” says Dorman, who is wearing a red tie adorned with dogs. “It’s very similar to our student situation.”

The tests include seemingly simple tasks, such as how a dog reacts to climbing industrial stairs (many dogs don’t like staircases you can see through to the ground), or measuring their reaction to gunshots. The researchers will also soon be testing the dogs in a new lab equipped with cameras, speakers that pipe in white noise, and odour sources. The room, which includes obstacles for the dogs to work around, will test to see which dogs work best on their own, or “off leash”, and which can create a good spatial map – not something that has traditionally been looked for or rewarded in working military dogs – but could prove critical for bomb dogs.

But as researchers begin to understand more about the canine mind, there are also signs that, like humans, they are susceptible to conditions like Post-Traumatic Stress Disorder. That means that on top of all of the intelligence tests, physical training and scent trials, researchers must also try to identify dogs that are resilient, even when faced with prolonged exposure to explosions and gunfire. For example, in one test, to measure “resiliency” in a war zone, the researchers study the dogs’ reaction to the sound of a gunshot.  Why is this important? “You might be less motivated to be an enthusiastic participant in hunting for olfactants if you’re afraid you’re going to be blown up,” says Sherman.

If all goes well, the first 2.0 detector dogs will be deployed in Afghanistan early next year.  The ultimate question, however, is whether these new and improved bomb dogs are more effective. Albuquerque says that for now, the best proof lies with the troops: When Albuquerque first spoke with Marines at the beginning of the programme, they were reluctant to even consider dogs. Their attitude quickly changed when the dogs started finding IEDs, and in a show of respect, early dogs in the programmme, like Cann, were named after fallen Marines (Cann was named for Staff Sergeant Adam Cann, a dog handler killed in Iraq; Cann, the dog, is now retired and living with a former Marine).

Marines, who once doubted the utility of the dogs, also now volunteer to carry provisions for the canines. “They’re not carrying water because they like the dog; they’ll leave the dog behind,” says Albuquerque. “If they’re carrying extra water, they believe in it and it works.”

Source: BBC

 

 

Futurist fixes for fighting skyscraper fires.

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“The tallest building in the world is on fire. You are there with 294 other guests. There’s no way down. There’s no way out.” So read the poster for the 1974 disaster movie Towering Inferno, which depicts an epic tale of survival in the badly wired 138 story Glass Tower in San Francisco and the race to put the fire out.

The action plays out amidst obvious tension and dislike between the two main characters –architect Doug Roberts and Fire Chief Michael O’Halloran. In one scene, O’Halloran, played by Steve McQueen, laments: “Now, you know there’s no sure way for us to fight a fire in anything over the seventh floor, but you guys just keep building ’em as high as you can.”

In the end, his only option is blow up water tanks on the top of the building; a move that may kill those remaining trapped inside.

Off the silver screen, the choices for fighting fires in skyscrapers are not usually so stark., although they are still limited.  Automatic systems help contain smaller fires, while ground crews and helicopters are deployed to tackle bigger blazes. For example, a recent fire in the 42 story Polat Tower in Istanbul was eventually contained by helicopters and fire fighters working from the ground, as was a blaze in April at the Federation building in Moscow, when hundreds of tons of water had to be dropped to contain a blaze on the 65th floor. In both these cases, thankfully, no one was hurt. But, that is not always the case.

In the US, between 2005-2009 alone, there were an average of 15,700 reported fires in high-rise buildings (not all skyscrapers) each year, leading to an average of 53 deaths and millions of dollars of damage annually. Just last week, a [thankfully] false report of a fire on the 88th floor of a skyscraper on the Ground Zero site, caused flashbacks to the tragedy of 9/11.

As the world’s cities have grown into the skies, we’ve had to confront the question of what to do when something goes terribly wrong and we are forced to fight fires in the cities of tomorrow. It has proved a fertile ground for futurists, designers and scientists.

‘Eating smoke’

For example, the cover of the March 1927 issue of Science and Invention magazine included a look at the “aerial fire fighters” of the future. The article, Fighting Flames from the Air by Joseph H Kraus, shows how an invention by Edward P Conlin might one day be used to reach the highest skyscrapers ever built in the event of a fire: “Mr Conlin employs the pressure of the water [in a long hose] to operate or energize two lifting propellers, the purpose of which is to carry the hose to heights unattainable with present apparatus…”

The March 1931 issue of Modern Mechanics was perhaps more realistic – and closer to what we see today. It quotes New York City Fire Chief John Kenlon as saying, “I expect to see the day when fires in lofty skyscraper quarters will be fought with special types of airplanes. They will operate on the system of the helicopter so that they can remain stationary in a desired and advantageous spot. Special chemicals would be used by firemen in their airplanes for putting out the blaze. We have seen the police departments take up aviation. I believe the firefighters will go a long way in that direction.”

Kenlon wrote a book a couple of decades earlier in 1913 called Fires and Fire Fighting which explained even then just how daunting the fires of the future will be when skyscrapers dominate our urban landscape.

But it was perhaps the 2 July 1961 edition of Arthur Radebaugh’s Sunday comic strip Closer Than We Think that took the idea of sky-high firefighters to an optimistic extreme. The comic took the idea of helicopters and doused it with that unique brand of flashy optimism that mid-century American designers did so well. A bright red fire engine in the sky emblazoned with NYFD (New York Fire Department) is seen hovering as it shoots water from its pressure tank. A young girl and her mother look on excitedly from an adjacent building.

The text reads: “Tomorrow’s firefighters, as a leading helicopter technician has predicted, may actually travel in airborne united, powered by “dynaprop” fans. Great advantages will be derived from the ability to hover beside conflagrations, regardless of whether the blaze is high in a skyscraper or simply smouldering in a farmer’s barn. Firefighting direction will improve, rescue work will be far more efficient than with ladders, and radio instructions from aloft will speed the subduing of flames.”

As we now know, most of these ideas have remained firmly on the drawing board. But the fear of skyscraper fires has left its mark in some cities we see today. Take Sydney, in Australia, for example. It passed an act in 1912 to limit new buildings to just 50m (150ft) tall, within reach of the fire fighting technologies of the day. As a result, Sydney became a city that spread outward rather than upward until the mid 1950s.

Other cities, like Los Angeles, have also been shaped by this fear. Its 1974 city fire code explicitly states that every building needed flat roofs to allow for helicopters landing there in case of fire. As a result, all of LA’s towers are rectangular monoliths, leading some to to describe the city as “bland” and as “stuck with high and tights, not liberty spikes”. The city is currently revisiting the code and some indications suggest that there may be a change, allowing more ornate tops to some of its buildings.

If and when they do, let’s hope they take the advice from the final lines of Towering Inferno, when O’Hallorhan is once again with the architect of the building.

“You know we were pretty lucky tonight, body count’s less then 200,” he says. “You know, one of these days, you’re gonna kill 10,000 in one of these firetraps, and I’m gonna keep eating smoke and carrying out bodies until someone asks us… how to build them.”

  • Source: BBC.

 

 

Arctic ice melt ‘like adding 20 years of CO2 emissions’.

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The loss of Arctic ice is massively compounding the effects of greenhouse gas emissions, ice scientist Professor Peter Wadhams has told BBC Newsnight.

White ice reflects more sunlight than open water, acting like a parasol.

Melting of white Arctic ice, currently at its lowest level in recent history, is causing more absorption.

Prof Wadhams calculates this absorption of the sun’s rays is having an effect “the equivalent of about 20 years of additional CO2 being added by man”.

The Cambridge University expert says that the Arctic ice cap is “heading for oblivion”.

In 1980, the Arctic ice in summer made up some 2% of the Earth’s surface. But since then the ice has roughly halved in area.

“Thirty years ago there was typically about eight million square kilometres of ice left in the Arctic in the summer, and by 2007 that had halved, it had gone down to about four million, and this year it has gone down below that,” Prof Wadhams said.

And the volume of ice has dropped, with the ice getting thinner:

“The volume of ice in the summer is only a quarter of what it was 30 years ago and that’s really the prelude to this final collapse,” Prof Wadhams said.

Parts of the Arctic Ocean are now as warm in summer as the North Sea is in winter, Prof Wadhams said.

Radiation absorbed

The polar ice cap acts as a giant parasol, reflecting sunlight back into the atmosphere in what is known as the albedo effect.

But white ice and snow reflect far more of the sun’s energy than the open water that is replacing it as the ice melts.

Instead of being reflected away from the Earth, this energy is absorbed, and contributes to warming:

“Over that 1% of the Earth’s surface you are replacing a bright surface which reflects nearly all of the radiation falling on it with a dark surface which absorbs nearly all.

“The difference, the extra radiation that’s absorbed is, from our calculations, the equivalent of about 20 years of additional CO2 being added by man,” Prof Wadhams said.

If his calculations are correct then that means that over recent decades the melting of the Arctic ice cap has put as much heat into the system as all the CO2 we have generated in that time.

And if the ice continues to decline at the current rate it could play an even bigger role than greenhouse gases.

UK weather effect

Professor Wadhams stresses that there are uncertainties – cloud cover over the Arctic could change and help reflect back some of the sun’s radiation.

But then another greenhouse gas – methane, currently trapped in the Arctic permafrost – could be released with warming and make matters worse.

The melting ice could have knock-on effects in the UK. Adam Scaife, from the Met Office Hadley Centre told Newsnight it could help explain this year’s miserable wet summer, by altering the course of the jet stream.

“Some studies suggest that there is increased risk of wet, low pressure summers over the UK as the ice melts.”

There may be an effect for our winters too: “Winter weather could become more easterly cold and snowy as the ice declines,” Mr Scaife said.

Opinions vary on the date of the demise of summer sea ice. The Met Office says it is not expecting the Arctic to be completely ice-free in summer until after 2030.

Source: BBC.

 

 

Airbus details Smarter Skies vision for planes in 2050.

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Aeroplanes that take-off and prepare to land at much sharper angles than they do at present are among Airbus‘ latest industry forecasts.

The European jet-maker made the predictions in its Smarter Skies vision for air travel in 2050.

The firm said the moves could minimise noise, reduce fuel emissions and potentially shorten flight times.

It added that shorter runways could be used, helping reduce the amount of space airports need.

That marks a contrast with the firm’s recent launch of the A380 “sumperjumbo” which – along with Boeing‘s older 747 design – stretches minimum runway length requirements in the opposite direction.

Airbus suggested a propelled platform with its own set of wheels placed beneath the aeroplane’s fuselage could help boost its acceleration before detaching just before take-off.

It said this would make a steeper climb possible, and in turn allow jets to reach cruise altitude in less time.

At the other end of the journey it suggested planes could glide towards airports using a steeper approach than is common at present as an alternative to the use of engine thrust and air brakes.

It said this could slow aircraft at an earlier stage, making shorter landing distances possible.

“As space becomes a premium and mega-cities become a reality, this approach could… minimise land use, as shorter runways could be utilised,” it added.

One analyst agreed that environmental pressures were likely to lead to change, but questioned whether Airbus’ vision would prove true.

Airbus suggests that flying in formation could cut air drag and thus boost fuel efficiency

“Shorter runways would certainly require some more radical – and likely expensive – technological developments,” said John Strickland, from JLS Consultancy.

“We have new larger aircraft like the Airbus A80 and smaller like the Boeing 787 Dreamliner. They offer longer range but that in itself tends to reduce opportunities for shorter take offs.

“I’d tend to be a bit sceptical of whether we will actually see this development as envisioned.”

Other suggestions made in the Smarter Skies document included:

  • The use of software to select routes that make the best use of weather conditions to cut fuel use.
  • Planes flying in formation to take advantage of reduced drag making them more energy efficient.
  • The use of biofuels, solar power and hydrogen as alternative sources of power.

 

  • Source: BBC.

 

Sunshine vitamin ‘may help treat tuberculosis’.

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Vitamin D could help the body fight infections of deadly tuberculosis, according to doctors in London.

Nearly 1.5 million people are killed by the infection every year and there are concerns some cases are becoming untreatable.

A study in Proceedings of the National Academy of Sciences showed patients recovered more quickly when given both the vitamin and antibiotics.

More tests would be needed before it could be given to patients routinely.

The idea of using vitamin D to treat tuberculosis (TB) harks back to some of the earliest treatments for the lung infection.

Before antibiotics were discovered, TB patients were prescribed “forced sunbathing”, known as heliotherapy, which increased vitamin D production.

However, the treatment disappeared when antibiotics proved successful at treating the disease.

Drug resistance

There is widespread concern about tuberculosis becoming resistant to antibiotics.

The World Health Organization (WHO) says 3.4% of new cases of TB are resistant to the two main drug treatments – known as multiple drug resistant tuberculosis.

That figure rises to nearly 20% for people who have been infected multiple times in their lives.

One analysis said that in some countries about half of all cases were resistant.

There is also concern about extensively drug resistant tuberculosis, which is resistant to the back-up drugs as well.

The WHO says 9.4% of all drug-resistant TB is extensively drug resistant.

In this study, patients all had non-resistant TB. The researchers said adding vitamin D to treatments may be even more valuable for patients when the drugs do not work as well.

This study on 95 patients, conducted at hospitals across London, combined antibiotics with vitamin D pills.

It showed that recovery was almost two weeks faster when vitamin D was added. Patients who stuck to the regimen cleared the infection in 23 days on average, while it took patients 36 days if they were given antibiotics and a dummy sugar pill.

Dr Adrian Martineau, from Queen Mary University of London, told the BBC: “This isn’t going to replace antibiotics, but it may be a useful extra weapon.

“It looks promising, but we need slightly stronger evidence.”

Trials in more patients, as well as studies looking at the best dose and if different forms of vitamin D are better, will be needed before the vitamin could be used by doctors.

Vitamin D appears to work by calming inflammation during the infection. An inflammatory response is an important part of the body’s response to infection.

During TB infection, it breaks down some of the scaffolding in the lungs letting more infection-fighting white blood cells in. However, this also creates tiny cavities in the lungs in which TB bacteria can camp out.

“If we can help these cavities to heal more quickly, then patients should be infectious for a shorter period of time, and they may also suffer less lung damage,” Dr Martineau said.

The doctors suggested this might also help in other lung diseases such as pneumonia and sepsis.

Prof Peter Davies, the secretary of the charity TB Alert, said the findings were “excellent” and vitamin D could play “an important role in treating tuberculosis”.

However, he thought there could be an even greater role in preventing the disease.

One in three people have low levels of tuberculosis bacteria in their lungs and have no symptoms, known as latent tuberculosis. However, this would turn to full blown TB in about 10% of people. Prof Davies’s idea is that giving vitamin D supplements, for example in milk, could prevent latent TB developing.

“That would be a massive revolution if it was shown to work,” he said.

Prof Alison Grant, from the London School of Hygiene and Tropical Medicine, said: “Drug-resistant TB is an increasing concern world-wide and so new treatments to reduce the length of TB treatment would be very welcome.

“Vitamin D supplements are often given to patients who are short of vitamin D and these low doses are generally very safe.

“In this study the researchers were giving higher doses of vitamin D, and I think we would need larger studies to be confident that there were no negative effects of this higher dose.”

  • Source: BBC.