Plants may use newly discovered molecular language to communicate

A Virginia Tech scientist has discovered a potentially new form of plant communication, one that allows them to share an extraordinary amount of genetic information with one another.

The finding by Jim Westwood, a professor of plant pathology, physiology, and weed science in the College of Agriculture and Life Sciences, throws open the door to a new arena of science that explores how plants communicate with each other on a molecular level. It also gives scientists new insight into ways to fight parasitic weeds that wreak havoc on food crops in some of the poorest parts of the world.

His findings were published on Aug. 15 in the journal Science.

"The discovery of this novel form of inter-organism communication shows that this is happening a lot more than any one has previously realized," said Westwood, who is an affiliated researcher with the Fralin Life Science Institute. "Now that we have found that they are sharing all this information, the next question is, 'What exactly are they telling each other?'."

Westwood examined the relationship between a parasitic plant, dodder, and two host plants, Arabidopsis and tomatoes. In order to suck the moisture and nutrients out of the host plants, dodder uses an appendage called a haustorium to penetrate the plant. Westwood has previously broken new ground when he found that during this parasitic interaction, there is a transport of RNA between the two species. RNA translates information passed down from DNA, which is an organism's blueprint.

His new work expands this scope of this exchange and examines the mRNA, or messenger RNA, which sends messages within cells telling them which actions to take, such as which proteins to code. It was thought that mRNA was very fragile and short-lived, so transferring it between species was unimaginable.

But Westwood found that during this parasitic relationship, thousands upon thousands of mRNA molecules were being exchanged between both plants, creating this open dialogue between the species that allows them to freely communicate.

Through this exchange, the parasitic plants may be dictating what the host plant should do, such as lowering its defenses so that the parasitic plant can more easily attack it. Westwood's next project is aimed at finding out exactly what the mRNA are saying.

Using this newfound information, scientists can now examine if other organisms such a bacteria and fungi also exchange information in a similar fashion. His finding could also help solve issues of food scarcity.

"Parasitic plants such as witchweed and broomrape are serious problems for legumes and other crops that help feed some of the poorest regions in Africa and elsewhere," said Julie Scholes, a professor at the University of Sheffield, U.K., who is familiar with Westwood's work but was not part of this project. "In addition to shedding new light on host-parasite communication, Westwood's findings have exciting implications for the design of novel control strategies based on disrupting the mRNA information that the parasite uses to reprogram the host."

Westwood said that while his finding is fascinating, how this is applied will be equally as interesting.

"The beauty of this discovery is that this mRNA could be the Achilles hill for parasites," Westwood said. "This is all really exciting because there are so many potential implications surrounding this new information."

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The above story is based on materials provided by Virginia Tech . Note: Materials may be edited for content and length.

Early antibiotic exposure leads to lifelong metabolic disturbances in mice

A new study published in Cell suggests that antibiotic exposure during a critical window of early development disrupts the bacterial landscape of the gut, home to trillions of diverse microbes, and permanently reprograms the body's metabolism, setting up a predisposition to obesity. Moreover, the study shows that it is altered gut bacteria, rather than the antibiotics, driving the metabolic effects.

The new study by NYU Langone Medical Center researchers reveals that mice given lifelong low doses of penicillin starting in the last week of pregnancy or during nursing were more susceptible to obesity and metabolic abnormalities than mice exposed to the antibiotic later in life.

Most intriguing, in a complementary group of experiments, mice given low doses of penicillin only during late pregnancy through nursing gained just as much weight as mice exposed to the antibiotic throughout their lives.

"We found that when you perturb gut microbes early in life among mice and then stop the antibiotics, the microbes normalize but the effects on host metabolism are permanent," says senior author Martin Blaser, MD, the Muriel G. and George W. Singer Professor of Translational Medicine, director of the NYU Human Microbiome Program, and professor of microbiology at NYU School of Medicine. "This supports the idea of a developmental window in which microbes participate. It's a novel concept, and we're providing direct evidence for it."

The researchers stress that more evidence is needed before it can be determined whether antibiotics lead to obesity in humans, and the present study should not deter doctors from prescribing antibiotics to children when they are necessary. "The antibiotic doses used in this study don't mirror what children get," says Laura M. Cox, PhD, a postdoctoral fellow in Dr. Blaser's laboratory and the lead author of the study. "But it has identified an early window in which microbes can influence metabolism, and so further studies are clearly warranted."

In one experiment in the study, Dr. Cox administered water with low doses of penicillin to three groups of mice. One group received antibiotics in the womb during the last week of pregnancy and continued the medication throughout life. The second group received the same dose of penicillin after weaning and, like the first group, continued it throughout life. The third received no antibiotics. "We saw increased fat mass in both penicillin groups, but it was higher in the mice who received penicillin starting in the womb," Dr. Cox says. "This showed that mice are more metabolically vulnerable if they get antibiotics earlier in life."

The treated mice also grew fatter than the untreated mice when both were fed a high-fat diet. "When we put mice on a high-calorie diet, they got fat. When we put mice on antibiotics, they got fat," explains Dr. Blaser. "But when we put them on both antibiotics and a high-fat diet, they got very, very fat." Normally, adult female mice carry three grams of fat. The animals in the study fed the high-fat diet had five grams of fat. By comparison, the mice who received antibiotics plus the high-fat chow packed on 10 grams of fat, accounting for a third of their body weight. The treated rodents were not only fatter but also suffered elevated levels of fasting insulin, and alterations in genes related to liver regeneration and detoxification -- effects consistent with metabolic disorders in obese patients.

This work confirms and extends landmark research published by Dr. Blaser's lab in 2012 in Nature. That research showed that mice on a normal diet who were exposed to low doses of antibiotics throughout life, similar to what occurs in commercial livestock, packed on 10 to 15 percent more fat than untreated mice and had a markedly altered metabolism in their liver.

Among the unanswered questions in that study was whether the metabolic changes were the result of altered bacteria or antibiotic exposure. This latest study addresses the question by transferring bacterial populations from penicillin-exposed mice to specially bred germ-free, antibiotic-free mice, starting at three weeks of age, which corresponds to infancy just after weaning. The researchers discovered that mice inoculated with bacteria from the antibiotic-treated donors were indeed fatter than the germ-free mice inoculated with bacteria from untreated donors. "This shows us that the altered microbes are driving the obesity effects, not the antibiotics," says Dr. Cox.

Contrary to a longstanding hypothesis within the agricultural world that holds that antibiotics reduce total microbial numbers in the gut, therefore reducing competition for food and allowing the host organism to grow fatter, the team found that the penicillin did not, in fact, diminish bacterial abundance. It did, however, temporarily suppress four distinct organisms early in life during the critical window of microbial colonization: Lactobacillus, Allobaculum, Candidatus Arthromitus, and an unnamed member of the Rikenellaceae family, which may have important metabolic and immunological interactions. "We're excited about this because not only do we want to understand why obesity is occurring, but we also want to develop solutions," says Dr. Cox. "This gives us four potential new candidates that might be promising probiotic organisms. We might be able to give back these organisms after antibiotic treatments."

The researchers worked with six different mouse models over five years to obtain their results. To identify bacteria, they used a powerful molecular method that involves extracting DNA and sequencing a subunit of genetic material called 16S ribosomal DNA. Altogether, the scientists evaluated 1,007 intestinal samples, which yielded more than 6 million sequences of bacterial ribosomal genes, the order of the nucleotides that spell out DNA. Studies like these are possible because of technological advances in high-throughput sequencing, which allows scientists to survey microbes in the gut and other parts of the body. The Genome Technology Center at NYU Langone Medical Center played a key role in identifying the genetic sequences in the study.

Long antibiotic treatments: Slowly growing bacteria to blame

Whether pneumonia or sepsis -- infectious diseases are becoming increasingly difficult to treat. One reason for this is the growing antibiotic resistance. But even non-resistant bacteria can survive antibiotics for some time, and that's why treatments need to be continued for several days or weeks. Scientists at the Biozentrum of the University of Basel showed that bacteria with vastly different antibiotic sensitivity coexist within the same tissue. In the scientific journal Cell they report that, in particular, slowly growing pathogens hamper treatment.

Many bacteria are principally susceptible to treatment, but can still survive for some hours to days in adverse environmental conditions, such as exposure to antibiotics. It is commonly assumed that these pathogens are in a type of "dormancy" state. They don't grow and thus become invulnerable against the effects of many antibiotics. However, Prof. Dirk Bumann and his team at the University of Basel's Biozentrum, demonstrated that dormant pathogens play only a minor role in Salmonella-infected tissue. Instead, abundant slowly growing bacteria are the biggest challenge for treatment.

Salmonella Grows at Different Rates

Genetically identical bacteria can grow at very different rates, even within the same test tube. Is this also true for pathogens in infected host tissues? Bumann used a new method based on fluorescent colors, to measure the proliferation of individual Salmonella. The results revealed that in host tissues some Salmonella grow very rapidly, producing many daughter cells, which cause increasingly severe disease. Most bacteria, however, reside in tissue regions with limited nutrient supply, in which they grow only slowly.

Slow Growth Ensures Survival

How do these diverse growth rates impact on the success of antibiotic therapy? Therapy of infected mice quickly ameliorated disease signs, but even after five days of treatment, some bacteria still survived in the tissues, posing a risk for relapse. "We could kill already 90 percent of the Salmonella with the first antibiotic dose, particularly those that grew rapidly," reports Bumann, "but non-growing Salmonella survived much better. Treatment success thus depended on the Salmonella replication rate."

This observation could support the current research focus on "dormant" bacteria. However, Bumann was surprised that such bacteria were actually not the biggest challenge for treatment. "Instead, slowly growing Salmonella are more important. They tolerate antibiotics less well compared to dormant bacteria, but they are present in much larger numbers, and readily restart their growth once antibiotic levels in the tissue drop, thus driving infection and relapse. As a result, slowly growing pathogens dominate throughout the entire therapy. A better understanding of bacterial physiology of such slowly growing bacteria, could help us to shorten the duration of treatment with a more specifically targeted antibiotic therapy." This is particularly interesting for infectious diseases that currently require medication over several weeks or even months, to prevent a recurrence of the infection.

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The above story is based on materials provided by University of Basel . Note: Materials may be edited for content and length.

Treatment with lymph node cells controls dangerous sepsis in animal models

An immune-regulating cell present in lymph nodes may be able to halt severe cases of sepsis, an out-of-control inflammatory response that can lead to organ failure and death. In the August 13 issue of Science Translational Medicine, a multi-institutional research team reports that treatment with fibroblastic reticular cells (FRCs) significantly improved survival in two mouse models of sepsis, even when delivered after the condition was well established. Even after treatment with antibiotics, sepsis remains a major cause of death.

"Our findings are important because, to our knowledge, no experimental therapeutic has shown such a significant survival benefit after the disease has progressed so far -- in our study up to 16 hours after a sepsis-inducing injury," says Biju Parekkadan, PhD, of the Center for Engineering in Medicine at Massachusetts General Hospital (MGH), senior author of the Science Translational Medicine report. "The effectiveness of late treatment is essential because septic patients often do not receive treatment until hours or days after the original injury occurred."

Usually set off when bacteria or other infectious agents invade the bloodstream, sepsis involves an over-reaction of the immune system in which signaling molecules called cytokines attract excessive numbers of immune cells to the site of an infection or injury. Those cells secrete more cytokines, which recruit even more immune cells leading to a vicious cycle called a cytokine storm. Instead of stopping the initial infection, immune factors attack the body's tissues and organs, potentially leading to organ failure. Worldwide, more than 140,000 people die from sepsis each week.

Potential sepsis treatments targeting the activity of single molecules have not been successful, the authors note, probably because the condition involves complex interactions among many inflammatory pathways. Treatments using cells, however, can target the action of several molecules, influencing multiple disease pathways and potentially responding to changes in a patient's disease state. Since FRCs are known to regulate many aspects of the immune response within lymph nodes, the researchers investigated whether introducing FRCs to the site of a sepsis-inducing infection could modulate the inflammatory response.

The first experiments used two mouse models -- one that uses a bacterial toxin associated with some forms of sepsis, the other in which an injury to the large intestine exposes the abdominal cavity to intestinal contents. The researchers showed that infusing FRCs into the abdominal cavity significantly improved survival in both young and aged mice with toxin-induced sepsis. FRC administration also led to greatly increased survival in the intestinal injury model, which produces a more severe form of sepsis, even though both FRC-treated mice and saline-treated control animals also were treated with antibiotics.

Since the FRCs used in those experiments were cultured from the lymph nodes of the animals to which they were administered, the researchers repeated the experiments using FRCs cultured from an unrelated strain of mice. The increased survival of animals receiving FRCs -- with 89 percent surviving versus 14 percent of those treated with saline -- implied that cells from healthy human donors could be cultured, stored and used without the need to match immune or other factors in the recipients. The test of treatment delivered well after sepsis was established showed that FRCs delivered 16 hours after a sepsis-inducing injury -- instead of 4 hours in the other experiments -- also produced a significant survival advantage.

Experiments investigating the mechanism behind the treatment indicated that FRC administration prevented both damage to the spleen -- which filters pathogens from the blood -- and the death of several types of immune cells normally present in the organ. Preservation of spleen function probably explains the reduced levels of bacteria in the bloodstream of FRC-treated animals, even though bacterial levels in the abdominal cavity, where sepsis was induced and into which FRCs were infused, remained unchanged. Additional evidence suggested that activity of the signaling molecule nitric oxide may be essential to the effects of FRC treatment.

"The development of FRC therapy for testing in human patients is the critical path we plan to follow, and this study is a good first step," says Parekkadan, an assistant professor of Surgery at Harvard Medical School.

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The above story is based on materials provided by Massachusetts General Hospital . Note: Materials may be edited for content and length.

Injected bacteria shrink tumors in rats, dogs and humans

A modified version of the Clostridium novyi (C. novyi-NT) bacterium can produce a strong and precisely targeted anti-tumor response in rats, dogs and now humans, according to a new report from Johns Hopkins Kimmel Cancer Center researchers.

In its natural form, C. novyi is found in the soil and, in certain cases, can cause tissue-damaging infection in cattle, sheep and humans. The microbe thrives only in oxygen-poor environments, which makes it a targeted means of destroying oxygen-starved cells in tumors that are difficult to treat with chemotherapy and radiation. The Johns Hopkins team removed one of the bacteria's toxin-producing genes to make it safer for therapeutic use.

For the study, the researchers tested direct-tumor injection of the C. novyi-NT spores in 16 pet dogs that were being treated for naturally occurring tumors. Six of the dogs had an anti-tumor response 21 days after their first treatment. Three of the six showed complete eradication of their tumors, and the length of the longest diameter of the tumor shrunk by at least 30 percent in the three other dogs.

Most of the dogs experienced side effects typical of a bacterial infection, such as fever and tumor abscesses and inflammation, according to a report on the work published online Aug. 13 in Science Translational Medicine.

In a Phase I clinical trial of C. novyi-NT spores conducted at MD Anderson Cancer Center, a patient with an advanced soft tissue tumor in the abdomen received the spore injection directly into a metastatic tumor in her arm. The treatment significantly reduced the tumor in and around the bone. "She had a very vigorous inflammatory response and abscess formation," according to Nicholas Roberts, Vet.M.B., Ph.D. "But at the moment, we haven't treated enough people to be sure if the spectrum of responses that we see in dogs will truly recapitulate what we see in people."

"One advantage of using bacteria to treat cancer is that you can modify these bacteria relatively easily, to equip them with other therapeutic agents, or make them less toxic as we have done here, " said Shibin Zhou, M.D., Ph.D., associate professor of oncology at the Cancer Center. Zhou is also the director of experimental therapeutics at the Kimmel Cancer Center's Ludwig Center for Cancer Genetics and Therapeutics. He and colleagues at Johns Hopkins began exploring C. novyi's cancer-fighting potential more than a decade ago after studying hundred-year old accounts of an early immunotherapy called Coley toxins, which grew out of the observation that some cancer patients who contracted serious bacterial infections showed cancer remission.

The researchers focused on soft tissue tumors because "these tumors are often locally advanced, and they have spread into normal tissue," said Roberts, a Ludwig Center and Department of Pathology researcher. The bacteria cannot germinate in normal tissues and will only attack the oxygen-starved or hypoxic cells in the tumor and spare healthy tissue around the cancer.

Verena Staedtke, M.D., Ph.D., a Johns Hopkins neuro-oncology fellow, first tested the spore injection in rats with implanted brain tumors called gliomas. Microscopic evaluation of the tumors showed that the treatment killed tumor cells but spared healthy cells just a few micrometers away. The treatment also prolonged the rats' survival, with treated rats surviving an average of 33 days after the tumor was implanted, compared with an average of 18 days in rats that did not receive the C. noyvi-NT spore injection.

The researchers then extended their tests of the injection to dogs. "One of the reasons that we treated dogs with C. novyi-NT before people is because dogs can be a good guide to what may happen in people," Roberts said. The dog tumors share many genetic similarities with human tumors, he explained, and their tumors appeared spontaneously as they would in humans. Dogs are also treated with many of the same cancer drugs as humans and respond similarly.

The dogs showed a variety of anti-tumor responses and inflammatory side effects.

Zhou said that study of the C. novyi-NT spore injection in humans is ongoing, but the final results of their treatment are not yet available. "We expect that some patients will have a stronger response than others, but that's true of other therapies as well. Now, we want to know how well the patients can tolerate this kind of therapy."

It may be possible to combine traditional treatments like chemotherapy with the C. novyi-NT therapy, said Zhou, who added that the researchers have already studied these combinations in mice.

"Some of these traditional therapies are able to increase the hypoxic region in a tumor and would make the bacterial infection more potent and increase its anti-tumor efficiency," Staedtke suggested. "C. novyi-NT is an agent that could be combined with a multitude of chemotherapy agents or radiation."

"Another good thing about using bacteria as a therapeutic agent is that once they're infecting the tumor, they can induce a strong immune response against tumor cells themselves," Zhou said.

Previous studies in mice, he noted, suggest that C. novyi-NT may help create a lingering immune response that fights metastatic tumors long after the initial bacterial treatment, but this effect remains to be seen in the dog and human studies.

Science Graphic of the Week: Map Shows Western U.S. May Suffer Huge Reductions in Snow

P. Zion Klos et. al./Geophysical Research Letters

The western United States is undergoing a major shift in precipitation patterns. Large swaths of the West that have historically been dominated by snow in the winter months are starting to see a lot more rain instead. A new study that maps out the predominant form of precipitation shows that this trend could result in an average reduction in snow-dominated area of around 30 percent by the middle of this century.

P. Zion Klos et. al. / Geophysical Research Letters

The western US depends heavily on snowpack to sustain its water supply through the dry summertime, but the new research, published in Geophysical Research Letters in July suggests this may have to change.

The map above shows the current extent of snow-dominated (shown in white and grey) and rain-dominated (shown in blue) areas during the winter months of December, January and February based on data from 1979–2012. Red and pink areas typically have a mix of rain and snow during these months, with redder areas being wetter. The grey areas are projected to transition from 100 percent snow to a mix of rain and snow over the next few decades.

Even more striking is the projection for the shoulder months in the spring and fall as shown on the series of maps to the right. These maps show the probability of snow and rain for each month based on climate models, with 100 percent probability that any precipitation will be rain shown in blue, mixed rain and snow shown in red and pink, and 100 percent snow shown in white. Huge areas that typically have a lot of snow during October and November and March and April could have only rain during those months in the future.

The local details are even more depressing. Areas that could see a complete loss of area that is dominated by snow during the winter months include: the northern Rockies, the Cascades, Puget Sound, the Blue Mountains, the northern Basin and Range, and the Colorado Plateau. And other snowy areas will see drastic reductions, including the Sierra Nevada, the Wasatch and Uinta Mountains in Utah and the Snake River plain.

Overall, the study projects the West could see an average monthly reduction of snow dominated area from historical levels of 53 percent down to 24 percent by mid-century, as shown in the graph below. Much of the strongly snow-dominated area of the West could go from five snowy months down to three.

P. Zion Klos et. al./Geophysical Research Letters

For more details and data check out the website of lead author Zion Klos of the University of Idaho.

Reference: Klos, P. Z., T. E. Link, and J. T. Abatzoglou (2014), Extent of the rain-snow transition zone in the western U.S. under historic and projected climate, Geophys. Res. Lett., 41, doi:10.1002/2014GL060500.

Scientists Program Largest Swarm of Robots Ever

A Kilobot swarm up close. Michael Rubenstein, Harvard University

Alone, the simple little robot can’t do much, shuffling around on three vibrating tooth-pick legs. But working with 1,000 or more like-minded fellow bots, it becomes part of a swarm that can self-assemble into any two-dimensional shape.

These are some of the first steps toward creating huge herds of tiny robots that form larger structures—including bigger robots. Building swarming robots can also help scientists understand collective behavior seen in nature, from bird flocks and fish schools to networks of cells and neurons.

In the past, researchers have only been able to program at most a couple hundred robots to work together. Now, researchers at Harvard University have programmed the biggest robot swarm yet.

“It’s really a big accomplishment,” said roboticist Hod Lipson of Cornell University, who wasn’t involved in the work. “It’s the first demonstration of this swarm robotic behavior at the scale of 1,000 physical robots.” Getting even tens or a hundred robots to work together is difficult, with a lot of algorithmic and technical challenges, he says.

Fancy robots with wheels, odometers, orientation sensors, and cameras can make self-assembly easier, said Mike Rubenstein, the roboticist who led the research team. “But if it’s too complicated, you can’t build a thousand robots.” That would be too expensive and difficult. At the same time, if you make your robots too simple, their capabilities become too limited. “So there’s a difficult trade-off.”

A “K” shape self-assembled by 1024 Kilobot robots. Michael Rubenstein, Harvard University

The researchers used robots they designed and built called Kilobots, which aren’t much bigger than a penny. Each one costs $14 in parts and only takes a few minutes to put together—you can even order some for yourself. To program them all at once, the researchers beam down instructions via an infrared light from an overhead controller. The robots communicate with one another by sending and receiving infrared signals. The team programmed 1,024 of these robots to gather into the shape of a star, the letter “K,” and a wrench (watch the robots at work in the video below).

The shape formation begins with four seed robots that act as the origin of a two-dimensional coordinate system. The other robots scurry one-by-one along the edge of the group toward the seed robots. Once the robots sense they’re behind another robot or at the boundary of the shape they’ve been programmed to form, they stop. The newly positioned robots then broadcast their locations so that their bot brethren know where to go. Each robot keeps track of its location and orientation relative to its neighbors.

These kinds of self-organizing algorithms have many applications, such as in driverless cars, Lipson says. Sooner or later, driverless cars will chauffeur us around, he says, and they’re going to need sophisticated algorithms to ensure smooth traffic flow and to avoid collisions.

Eventually, swarming robots could even lead to what’s called programmable matter. Imagine thousands of tiny robots forming whatever three-dimensional structure you want, whether it’s a hammer or a cell phone—a kind of 3-D printing that works like programmable, self-molding clay. “That’s the dream,” Lipson said.

Or, Rubenstein says, these tiny robots can act as biological cells, forming the building blocks for bigger, shape-shifting robots. The idea is that such a robot could take whatever shape is best suited for a particular task. It could assume the shape of a snake to slither across sand, form legs to crawl over rock, or even a wheel to roll up and down a hill. A swimming robot could become more aerodynamic to slice through water. It could even split into two if the task requires it. And, these collective robots would be easily fixed, since ideally every one of the tiny robots would be cheap and replaceable.

Of course, that’s still a long way away, Rubenstein says. For now, he’d like to design robots that can actually attach to one another and form rigid structures. Another area of improvement would be to refine the algorithm so that robots can arrange themselves more quickly. Right now, the robots scuttle around one at a time, taking hours to form a shape. But with an algorithm that allows them to assemble in parallel, then they can shape up faster.

A faster algorithm would also enable even larger swarms of 10,000 robots to self-assemble, which could otherwise take days. But first, there are practical issues. “I would need a bigger table,” Rubenstein said.

Killer Software That Finally Stabilizes Shaky GoPro Videos

Wearable cameras like GoPro and Google Glass will only become more common in years to come. The only problem? Latched to our dumb bodies, they make everything look like it was shot during the Running of the Bulls, just without any of the excitement of, you know, running with bulls. Microsoft’s got some wild new software to fix that.

A team of researchers recently demoed an application that smooths out jerky, first-person video into fantastically smooth hyperlapse clips. The results look like something you’d expect from a camera attached to a drone, not a clumsy biped.

The software finds a virtual camera path through the original clip. Microsoft

As the researchers show in this clip, standard image stabilization doesn’t work when you speed up first-person videos. The new approach is much more sophisticated. First, an algorithm looks at the frames from the original video and reconstructs the photographer’s path through three-dimensional space. Then it derives a new, smooth camera path that can be created from it. By warping the perspective on some of the original shots and stitching and blending them together, it ends up with a fluid, fast-paced new clip. The researchers say they’re working on packaging it up for the public as a Windows application.

It’s all very impressive stuff. But it’s also kind of strange, in the sense that these algorithms are transforming a very real, first-person document of an experience into something wholly artificial. The results may feel more “natural” than the original, unstabilized videos, but they’re not. In fact, they’re the opposite. Here we’re not seeing our world so much as a rigorous reconstruction of it, with familiar sights stretched around and stitched back together as subjects for a virtual camera. The software algorithmically crunches ho-hum GoPro footage into dreams that we can send to our friends and upload to YouTube.

How Dodge Made Its New Sedan Even Faster Than Its Beastly Coupe

The 2015 Dodge Charger SRT Hellcat is “less of a brick” and faster than the Challenger Hellcat. Chrysler

Earlier this year, Dodge wowed car lovers with the 2015 Dodge Challenger SRT Hellcat, which delivered a completely ludicrous 707 horsepower and could hit 199 mph. This engineering coup was well received, so it’s no surprise Dodge then decided to stuff the same 6.2-liter HEMI V8 engine into the two-door Challenger’s bigger brother, the Charger sedan.

What did catch our attention is the fact that even though the four-door Charger is 136 pounds heavier, it’s the faster of the two cars. On street tires, it can run the quarter mile in 11 seconds, compared to 11.2 for the Challenger. Its top speed is a whopping 204 mph, enough for Dodge to call it the “quickest, fastest, most powerful sedan in the world.” (Other high-end sedans can likely best the Hellcat, but their manufacturers electronically limit their top speed. And there are specially customized rigs like the Brabus Mercedes E63 that can go faster. Still, 204 mph is really, mind-blowingly fast.)

So how can the four-door Charger outrun the lighter Challenger, if they share an engine? It’s all about aerodynamics. The Challenger has the look of an iconic muscle car, but that style doesn’t do well in the wind tunnel. It “has this big front end which is more vertical,” says Mark Trostle, head of design for Dodge’s SRT division. “The mass that breaks through the air is larger.” More wind resistance, less speed.

The Charger is heavier than the two-door Challenger, but it’s also quicker thanks to “less of a brick” aerodynamics. Chrysler

The Charger, on the other hand, is “less of a brick.” It’s more swept back at the front, Trostle says, “a little more soft.” The Charger’s drag coefficient is .335, making the sedan much, much more slippery than the Challenger’s .380. That’s not particularly impressive compared to the Tesla Model S’s 0.24 or the Toyota Prius’ 0.25, but the huge improvement helps buy that extra 5 mph at top speed.

Looking at the front of the two cars, the Charger is (a little) more subtle, with a smaller, understated front splitter. The Challenger is much more aggressive and muscular, an intentional choice by the design team. The look of the Charger is “a little more sophisticated,” Trostle says.

Let’s note that the difference between 199 mph and 204 mph is more about bragging rights than actual usefulness (and that getting caught driving anywhere near those speeds on the street will get you a free trip to jail in most states). But bragging rights matter, especially when it comes to muscle cars. The fact that you’ll be able to fit actual adults into the backseat of the Charger is an extra bonus. We imagine there will be more than a few folks heading to Dodge dealerships next year with just one question to answer: two doors or four?

Lord of the Rings Physics Homework

Gandalf vs. the Balrog. Illustration: Rhett Allain

I don’t think I am going to give any Lord of the Rings spoilers here. The books are over 50 years old and even the first movie (the Peter Jackson version) was released in 2001. So let me just say that at one point, Gandalf fights a monster and essentially dies. That sucks for Gandalf (although I think he leveled-up in the process) but it is a great opportunity for some physics homework.

Just so that we all start with the same material, I am going to use the Gandalf vs. Balrog scene from the Peter Jackson version of Fellowship of the Ring and The Two Towers. The fight actually happens during Fellowship of the Ring but there are pieces of it shown in The Two Towers. If you do a quick search for “Gandalf vs Balrog”, you should be able to find the video of it without too much difficulty.

No one is happy if I just give out homework questions. What about an example from the textbook? Well, there isn’t a textbook. This is real world stuff. But ok, I’ll start off with an example.

How Long is the Balrog’s Whip?

Here’s the scene. Gandalf and the rest of the party are trying to escape from Moria. They cross a narrow bridge and then Gandalf makes a stand agains the Balrog. In order to prevent the Balrog from crossing, Gandalf breaks the bridge and the monster falls. But wait! At the last second, the Balrog’s whip grabs a hold of Gandalf and pulls him into the chasm.

Let’s get data from the video to estimate the length of the Balrog’s whip. But first, a couple of assumptions.

• Even though this is Middle Earth, I will assume that the local gravitational field is just like on Earth. That means that a free falling object will have an acceleration of 9.8 m/s².


• During this initial falling motion of the Balrog, I am going to assume that the air resistance is negligible so it accelerates with a constant acceleration.

Now for the only measurement from the video – time of fall. It’s difficult to pinpoint exactly when the Balrog was in free fall as well as the time the whip hits Gandalf. I can use Tracker Video Analysis and mark a beginning and ending frame for the fall (with a conservative estimate of the start and stop times). This gives a falling time of about 13.8 seconds.

How far did the Balrog fall during this time interval? Well, if I stick with my original assumption that there isn’t any air resistance I can use the following kinematic equation:

I can set the initial position at 0 meters and if the Balrog starts from rest, the initial velocity is 0 m/s. Putting in a time of 13.8 seconds and a value of g at 9.8 m/s², I get a final position of -933 meters. That’s just crazy.

The real crazy thing is my assumption that there is no air resistance. Without air resistance the Balrog would have a constant acceleration during this time. I can find the vertical velocity at the end of the 13.8 seconds with the definition of acceleration.

If I again assume the Balrog starts from rest, I get a final velocity of 135 m/s (over 300 mph). This is a problem. If the Balrog was moving this fast, then there should be a significant air resistance force. Suppose that I use the following model for the air resistance:

In this expression, ρ is the density of air. A is the cross sectional area of the object and C is a drag coefficient that depends on the shape of the object. Of course I don’t really know C or even A for a Balrog. However, I do think that the Balrog has a terminal speed similar to that of Gandalf (who is human-like). At terminal speed, the air resistance force is equal to the weight of the object such that the net force is zero. When the net force is zero, the object doesn’t change speed – thus the term “terminal velocity”. If I guess a terminal velocity of 54 m/s (approximately true for humans) then I can solve for the things I don’t know. Since I am assuming the Balrog falls the same way a human would, I am going to use a human mass of 68 kg (otherwise I would have to guess at the area and mass of a Balrog).

All the stuff on the left side of the equation is mostly unknown (I know the value of 1/2 and I can guess at the density of air). Since this stuff doesn’t change, I am just going to call it K. Putting in my values for the terminal velocity and the mass, I get a value of K = 2.24 kg/m.

What now? Now, I can make a numerical calculation. If look at a falling Balrog in small time steps, I can approximate the forces as constant. With constant forces, I can calculate the change in velocity and change in position during this time interval. A new velocity means a new air resistance forces for the next time interval. So, I just keep doing this stuff over and over. Here is an older post with more details of a numerical calculation.

I’ll skip all the details in the calculation – but, it’s here if you want it. Here is a plot of the vertical position of a Balrog falling for 13.8 seconds.

You can see that the Balrog reaches a terminal velocity fairly quickly (after just about 3 seconds). Also, the falling distance with air resistance is 215 meters (700 feet).

So, how long is the Balrog’s whip? Maybe my time is off for the start and finish of this falling motion. Maybe my air resistance model is wrong – or maybe the Balrog actually flies a little bit. I feel comfortable saying that the whip is at least 100 meters long and maybe as long as 200 meters.

Let me just look in the back of the book and check my answer for this homework problem. Oh snap. Only the even number problems have answers. I guess we will never know if I am correct.

More Homework

Now it is your turn to answer some questions.

• If you look at the fight scene between Gandalf and the Balrog as they fall, it takes about 69 seconds for the two to fall from the bridge to the underground lake. Estimate the height of this fall.


• Suppose that when the Balrog grabbed a hold of Gandalf, it temporarily stopped falling at a position of 200 meters below Gandalf. When they are both falling, it take Gandalf 15 seconds to catch up to the falling Balrog. Assuming the Balrog has a terminal speed of 54 m/s, what terminal speed would Gandalf need to catch the Balrog? Use this to estimate Gandalf’s percent decrease in cross sectional area multiplied by drag coefficient (AC).


• While falling, Gandalf catches up with his falling sword – Glamdring. Estimate the density of this sword (assumptions and estimations required).


• Assume the Balrog has a terminal speed of 54 m/s. If the Balrog has the same proportions as a human (roughly true) but a height 3 times larger than a human, what is the density of a Balrog? (hint: you can estimate the increase in cross sectional area for the Balrog and assume the drag coefficient is the same for a human).


• Near the end of the fight, Gandalf and the Balrog fall into an underground lake. I went ahead and used Tracker Video to mark the position of the falling duo as a function of time. Here is that data.

• If you assume that Gandalf and the Balrog are falling at a terminal speed of 54 m/s, how tall is the ceiling in this cavern. The units for the distance in this plot are in units of cavern height (since there was nothing obvious to scale the video). What is the tallest underground cavern known to humans? How does this cavern compare to the known caverns?

That’s the homework. None of these questions have answers in the back of the book (because there is no textbook).

BitTorrent Sync Apps Offer Escape from Big Brother

BitTorrent Sync. Ariel Zambelich/WIRED

Big app-makers are grabbing all the personal data they can these days. But a small cadre of developers is building decentralized, privacy-conscious apps on the fast-growing BitTorrent Sync platform, creating everything from a more resilient version of the web to a peer-to-peer version of Facebook. They’re betting people are tired of seeing private information Hoovered up by the likes of the National Security Agency, online advertisers, or rogue hackers.

These developers are riding the same wave that carried BitTorrent Sync, a file-syncing system similar to Dropbox but heavily encrypted and without a central server. Sync now counts more than 2 million users only 16 months after launching.

The growth of Sync apps is in the early, fragile stages. None of the software is even at the so-called “beta” stage of development, where wider testing can begin. And all of the apps could be scuttled by one false move at BitTorrent Inc., the file-sharing company that developed Sync and controls the platform interfaces on which Sync developers build. But the emerging Sync ecosystem offers an intriguing example of how corporate prerogatives can help promote, rather than undermine, pro-privacy practices like encryption and decentralization. It also offers evidence that some developers want to avoid or escape the Apple and Google app stores, which tend to reward apps with invasive ads and tricks to sell digital goods within the apps. If one or two Sync apps take off, it could bolster the entire business of selling privacy-friendly software.

“Can the internet be structured in such a way that you don’t risk sharing your information with the government or an intruder?” asks Jon Seymour, one of the two people behind Peers, a rudimentary social network built on top of Sync. “With BitTorrent technology… you could reset people’s worries and take some of the edge off sharing personal information.”

Sync Gets ‘Tons of Resources’

BitTorrent says it is just getting started building out the crucial infrastructure for an app ecosystem around Sync. It has yet to release a formal software developer kit, or SDK, which would provide code libraries and documentation to help programmers quickly and more easily communicate with Sync from within their apps. It has only begun to formally describe Sync’s application-programming interface, or API, which provides a rougher way of working with Sync.

But the company, which until now has made much of its money installing spammy search toolbars alongside BitTorrent file-sharing software, clearly sees a big future in the Sync platform. It has hired a VP, a developer evangelist, and a PR manager focused entirely on Sync; it is preparing a big software update; and it is developing a plan to monetize Sync—though the company is keeping mum on specifics. Still, BitTorrent claims that Sync is more about promoting a decentralized vision of the internet than making money. That’s the pitch it’s started making at security- and privacy-oriented conferences like DefCon and Chaos Communication Congress.

BitTorrent

“We have many developers and engineers working on this, we have tons of resources and brand marketing,” says Aaron Liao, BitTorrent’s developer evangelist for Sync. “Sync is a large team… How often do you get to work on something like that without money as the main driver?”

Sync does have critics, who note it’s impossible to fully verify the security and privacy of the system without access to the source code. Runa Sandvik, a security researcher and longtime developer of the private web surfing tool Tor, says users likely will be better off with “open-source clones.” But Sync’s big strength is that it has some of the polish of other commercial software, including rival Dropbox, a centralized system with full access to the data it syncs on behalf of users. That should win it wider adoption.

Small Beginnings for Sync Apps

A wide audience is precisely what the first batch of Sync apps is missing. But they offer intriguing glimmers of what’s to come.

Seymour’s app Peers—developed with co-founder Paul Daly—allows people to connect socially with one another by sharing 32-character keys. Once you follow someone, you get access to their contact information, work history, education, other interests, and media files, like images. It’s sort of Facebook meets LinkedIn meets a shared address book like Plaxo. You also get the same information for all people they follow. But, crucially, all this information is downloaded to your own Windows or Mac computer, so you have a local copy, available even if you later decide to leave the network. (A mobile version is coming.)

The software, now at version 0.2.3 after eight months, is at a pre-release stage, and the lack of polish shows. But the software already is far more durable than the centralized social network, which makes it hard to get data out of the system and can cut off access or lop off features without notice. Peers is more like a physical Rolodex—simple and powerful.

“This is how contact info used to spread,” Seymour says of Peers. “You gave someone your info and inherently gave them the power to pass it along and pass it along.”

Another early Sync app, known as SyncNet, a version of the World Wide Web in which the content of the sites is distributed among the readers of the sites. So when you visit a site on SyncNet, a copy of the whole site is downloaded to your computer. The next user to visit the site will download part of the site from you, and part of the site from the original location. As the site gets more popular, the burden of serving its content is spread among more computers, a feature that comes from the underlying BitTorrent protocol.

The end result is a system that is much more resilient against traffic spikes and censorious governments and web hosts.

Jack Minardi, who does 3-D printing research at Harvard Medical School, put together SyncNet as part of a crusade to make it easier to publish a website. Minardi remembers wanting to make a website as a child and having to first learn about to configure a Linux server and establish an FTP connection before he could put any content online.

“It shouldn’t be that hard, and with SyncNet, if you can put files in a folder, you can have a web page,” Minardi says. “Anybody can do that. That was the main motivation for me.”

Right now, SyncNet is just a pile of python code sitting on GitHub, albeit one that’s been getting lots of programmer attention.

Whether it and Peers and Sync itself can find maintream adoptions remains to be seen. Maybe, in the end, people want decentralized systems like BitTorrent just so they can flout copyright law from time to time and download new episodes of Downton Abbey. But maybe, just maybe, they are tired of having their personal information brokered and stored and sifted by large companies and government agencies, and ready for the fresh start developers are trying to give them.

Lord of the Rings Physics Homework

Gandalf vs. the Balrog. Illustration: Rhett Allain

I don’t think I am going to give any Lord of the Rings spoilers here. The books are over 50 years old and even the first movie (the Peter Jackson version) was released in 2001. So let me just say that at one point, Gandalf fights a monster and essentially dies. That sucks for Gandalf (although I think he leveled-up in the process) but it is a great opportunity for some physics homework.

Just so that we all start with the same material, I am going to use the Gandalf vs. Balrog scene from the Peter Jackson version of Fellowship of the Ring and The Two Towers. The fight actually happens during Fellowship of the Ring but there are pieces of it show in The Two Towers. If you do a quick search for “Gandalf vs Balrog”, you should be able to find the video of it without too much difficulty.

No one is happy if I just give out homework questions. What about an example from the textbook? Well, there isn’t a textbook. This is real world stuff. But ok, I’ll start off with an example.

How Long is the Balrog’s Whip?

Here’s the scene. Gandalf and the rest of the party are trying to escape from Moria. They cross a narrow bridge and then Gandalf makes a stand agains the Balrog. In order to prevent the Balrog from crossing, Gandalf breaks the bridge and the monster falls. But wait! At the last second, the Balrog’s whip grabs a hold of Gandalf and pulls him into the chasm.

Let’s get data from the video to estimate the length of the Balrog’s whip. But first, a couple of assumptions.

• Even though this is Middle Earth, I will assume that the local gravitational field is just like on Earth. That means that a free falling object will have an acceleration of 9.8 m/s².


• During this initial falling motion of the Balrog, I am going to assume that the air resistance is negligible so it accelerates with a constant acceleration.

Now for the only measurement from the video – time of fall. It’s difficult to pinpoint exactly when the Balrog was in free fall as well as the time the whip hits Gandalf. I can use Tracker Video Analysis and mark a beginning and ending frame for the fall (with a conservative estimate of the start and stop times). This gives a falling time of about 13.8 seconds.

How far did the Balrog fall during this time interval? Well, if I stick with my original assumption that there isn’t any air resistance I can use the following kinematic equation:

I can set the initial position at 0 meters and if the Balrog starts from rest, the initial velocity is 0 m/s. Putting in a time of 13.8 seconds and a value of g at 9.8 m/s², I get a final position of -933 meters. That’s just crazy.

The real crazy thing is my assumption that there is no air resistance. Without air resistance the Balrog would have a constant acceleration during this time. I can find the vertical velocity at the end of the 13.8 seconds with the definition of acceleration.

If I again assume the Balrog starts from rest, I get a final velocity of 135 m/s (over 300 mph). This is a problem. If the Balrog was moving this fast, then there should be a significant air resistance force. Suppose that I use the following model for the air resistance:

In this expression, ρ is the density of air. A is the cross sectional area of the object and C is a drag coefficient that depends on the shape of the object. Of course I don’t really know C or even A for a Balrog. However, I do think that the Balrog has a terminal speed similar to that of Gandalf (who is human-like). At terminal speed, the air resistance force is equal to the weight of the object such that the net force is zero. When the net force is zero, the object doesn’t change speed – thus the term “terminal velocity”. If I guess a terminal velocity of 54 m/s (approximately true for humans) then I can solve for the things I don’t know. Since I am assuming the Balrog falls the same way a human would, I am going to use a human mass of 68 kg (otherwise I would have to guess at the area and mass of a Balrog).

All the stuff on the left side of the equation is mostly unknown (I know the value of 1/2 and I can guess at the density of air). Since this stuff doesn’t change, I am just going to call it K. Putting in my values for the terminal velocity and the mass, I get a value of K = 2.24 kg/m.

What now? Now, I can make a numerical calculation. If look at a falling Balrog in small time steps, I can approximate the forces as constant. With constant forces, I can calculate the change in velocity and change in position during this time interval. A new velocity means a new air resistance forces for the next time interval. So, I just keep doing this stuff over and over. Here is an older post with more details of a numerical calculation.

I’ll skip all the details in the calculation – but, it’s here if you want it. Here is a plot of the vertical position of a Balrog falling for 13.8 seconds.

You can see that the Balrog reaches a terminal velocity fairly quickly (after just about 3 seconds). Also, the falling distance with air resistance is 215 meters (700 feet).

So, how long is the Balrog’s whip? Maybe my time is off for the start and finish of this falling motion. Maybe my air resistance model is wrong – or maybe the Balrog actually flies a little bit. I feel comfortable saying that the whip is at least 100 meters long and maybe as long as 200 meters.

Let me just look in the back of the book and check my answer for this homework problem. Oh snap. Only the even number problems have answers. I guess we will never know if I am correct.

More Homework

Now it is your turn to answer some questions.

• If you look at the fight scene between Gandalf and the Balrog as they fall, it takes about 69 seconds for the two to fall from the bridge to the underground lake. Estimate the height of this fall.


• Suppose that when the Balrog grabbed a hold of Gandalf, it temporarily stopped falling at a position of 200 meters below Gandalf. When they are both falling, it take Gandalf 15 seconds to catch up to the falling Balrog. Assuming the Balrog has a terminal speed of 54 m/s, what terminal speed would Gandalf need to catch the Balrog? Use this to estimate Gandalf’s percent decrease in cross sectional area multiplied by drag coefficient (AC).


• While falling, Gandalf catches up with his falling sword – Glamdring. Estimate the density of this sword (assumptions and estimations required).


• Assume the Balrog has a terminal speed of 54 m/s. If the Balrog has the same proportions as a human (roughly true) but a height 3 times larger than a human, what is the density of a Balrog? (hint: you can estimate the increase in cross sectional area for the Balrog and assume the drag coefficient is the same for a human).


• Near the end of the fight, Gandalf and the Balrog fall into an underground lake. I went ahead and used Tracker Video to mark the position of the falling duo as a function of time. Here is that data.

• If you assume that Gandalf and the Balrog are falling at a terminal speed of 54 m/s, how tall is the ceiling in this cavern. The units for the distance in this plot are in units of cavern height (since there was nothing obvious to scale the video). What is the tallest underground cavern known to humans? How does this cavern compare to the known caverns?

That’s the homework. None of these questions have answers in the back of the book (because there is no textbook).

WTF Just Happened: My Computer Monitor Looks Awful on Camera

Your film, 1994 Computer Lab, is in post-production. While reviewing the dailies, you’ve noticed a big problem. The CRT monitors in every shot have fat, dark lines scrolling vertically on their screens. No worries: You have a billion-dollar budget to work with, so you’ll simply rename the film 2014 Computer Lab and reshoot all those scenes with LCD monitors.

But what’s this? There are no lines on the screens anymore, but the LCD monitors look like they’re flickering in your footage. Will you need to rename the movie 2034 Computer Lab and develop futuristic monitor technology to use in the film? And why don’t any of these monitors look right when you point a camera at them?

Different Monitors, Similar Problems

Although the technologies inside CRT and LCD monitors are quite different, what’s happening in each scenario has a similar underlying cause: Your camera’s frame rate doesn’t match up with the monitor’s refresh rate. What adds to the problem is that human beings process moving images in a very different way than video cameras do.

Unless you also use a kerosene-powered camcorder, you probably don’t use a CRT monitor anymore. That’s a shame, because the underlying technology is cool. An electron gun in the back of the monitor blasts electrons toward the screen. Before they get there, they are precision-routed by magnets, line by line, in a sweeping motion from the top to the bottom of the screen. The final stage of the electron beam’s journey involves hitting a phosphor coating on the inside of the screen that lights up and emits color.

That whole top-to-bottom, line-by-line process happens 60 times a second with a CRT TV, equivalent to a refresh rate of 60Hz to match up with TV broadcast standards. But with a CRT computer monitor, the refresh rate is often variable, and it’s usually between 60Hz and 85Hz.

Unless your camera’s frame rate matches up with a CRT monitor’s refresh rate, you’ll see those dark bands scrolling vertically on the screen. That’s because the camera is capturing the electron gun in mid-sweep, when parts of the screen are still fresh with brightly glowing phosphors but others aren’t. Our eyes don’t pick up those fading phosphors on certain portions of the screen, but the camera does.

A lot of that has to do with the differences between human and machine vision. A camera simply takes rapid-fire shots of specific moments in time and stitches them together. Our eyes and brains don’t work like that. There’s a constant flow of communication between our eyes and our visual cortex, crunching data, providing context, and making split-second adjustments. When we’re looking directly at a source of light—a monitor, for example—an afterimage hangs around on our retina due to our eyes’ sensitivity to light. This afterimage can bridge the gap between individual screen refreshes, making on-screen motion look fluid and preventing us from seeing a strobe or striping effect. Cameras aren’t so easily fooled.

LCDs (including LED-backlit LCD monitors) don’t have the same banding problems as CRTs, because they create images in an entirely different way. There’s a constant source of backlight behind the screen, and the entire image doesn’t have to be “redrawn,” line by line, at a cyclical rate.

However, you may still see a bit of flicker when an LCD monitor is recorded on video. Much of this has to do with the pulse width modulation used to regulate the brightness of many LED-backlit displays. Pulse width modulation is essentially like flicking a power switch on and off at a very fast rate: It pulses the amount of power supplied to the backlight system based on the selected brightness level. Even though it’s rarely visible to the naked eye, some people report getting headaches from it.

How to Fix It

In each of these cases, fixing the odd effects of shooting a monitor on video is easy to fix. Simply match the frame rate of your video camera to the refresh rate of the monitor. In Windows, right-click the desktop, select “Screen Resolution,” click “Advanced Settings,” and select a refresh rate from the Monitor settings menu. In Mac OS X, click the Apple icon, click “System Preferences,” click “Displays,” and select a refresh rate (the default for all Macs will be 60Hz).

Sixty frames per second for a 60Hz monitor is ideal, and 30fps for a 60Hz monitor should also work. If you’re shooting any monitor at 24fps, you may see some weirdness—it’ll just be far more subtle with an LCD display. If you’ve already synced up the frame rate and the refresh rate but you’re still seeing flickering on an LED-backlit monitor, try turning its brightness all the way up. That should mitigate any pulse width modulation madness.

The 10 Best Non-Jaws Movies to Round Out Your Shark Week

Four years before Jaws turned the great white into the world’s most feared predator, documentarian Peter Gimbel and his team of fearless divers and photographers set out to film the first footage of the species in its natural habitat. The crew—which included shark experts Ron and Valerie Taylor, who would go on to shoot much of the underwater footage for Jaws—spent nine months at sea, traveling from South Africa to South Australia, where they finally managed to capture their target. Their time on the water had clearly emboldened them. The divers risk their lives as the film progresses, at one point shooting footage of a feeding frenzy without the benefit (and/or protection) of a cage. In another scene, photographer Peter Lake keeps his camera steady while his cage is attacked—and it’s that moment that inspired Peter Benchley to write Jaws. Blue Water, White Death is everything a great shark movie should be: entertaining, frightening, suspenseful, and scientifically sound.

How to watch it: Vudu, iTunes

Open Water (2004)

Open Water‘s greatest success just may be the fact that—unlike so many other movies of this ilk—it wasn’t trying to be Jaws. More of a psychological drama than a straight-up shark movie, it tells the story of an American couple who get left behind on a scuba diving expedition in the Caribbean and must wait out a rescue in shark-infested waters. Shot on a budget of just $500,000, the movie’s handheld digital style and frequent use of submerged POV shots help to achieve an unusually visceral effect. That the film is loosely based on the true story of Tom and Eileen Lonergan—an American couple who were stranded on the Great Barrier Reef in 1998—and produced and directed by a husband and wife team (Chris Kentis and Laura Lau, who are both veteran scuba divers) also adds an authenticity to the relationship aspect of this on-the-water drama.

How to watch it: Vudu, iTunes

Sharkwater (2006)

Underwater photographer-turned-filmmaker Rob Stewart goes rogue for much of this documentary, which seeks to expose the inhumane practices utilized in the shark-hunting industry. Tracing the shark’s evolution from predator to prey, Stewart teams up with Paul Watson, a conservationist from the Sea Shepherd Conservation Society, to reveal the true (and not-so-scary) nature of these wrongfully maligned animals and how easily their population could be extinguished by shark poachers. The undercover nature of their mission makes this one action-packed documentary, too. (Which isn’t an adjective that is frequently applied to the genre.)

How to watch it: Vudu, iTunes

The Reef (2010)

Yes, The Reef is pretty similar to Open Water, right down to the movie poster. But somehow writer-director Andrew Traucki makes it work. In the case of this Australian production, a group of friends turn a yacht delivery to Indonesia into an open water party … until said yacht capsizes. Oops! Their best chance for survival, according to their friend/captain, is to make a 12-mile swim to a nearby island—which seems like a great plan to the great white shark that’s intent on eating them. Tensions run high as the group attempts its journey onward, and only time will tell how many—if any—of them survive to tell the tale.

How to watch it: Netflix

Deep Blue Sea (1999)

Don’t get us wrong: We’re not saying that Renny Harlin’s improbable tale of super-smart sharks run amok was snubbed by the Academy. But as far as entertainment for entertainment’s sake goes, Deep Blue Sea more than delivers. The movie makes the most of its ridiculous plotline—a team of scientists genetically modify a couple of Mako sharks in the search for a cure for Alzheimer’s—and has a large enough budget ($78 million) to serve up some impressive special effects and decent talent, including Stellan Skarsgård, Thomas Jane, LL Cool J, and Saffron Burrows, who spends a seemingly inordinate amount of time in a half-zipped wetsuit or less. Best of all, Deep Blue Sea plays like a pre-Snakes on a Plane dry run for Samuel L. Jackson to chew up as much scenery as the bloodthirsty fish.

How to watch it: Vudu, iTunes

Sharks 3D (2004)

Not to be confused with Shark Night 3D, Sharks 3D makes the most of the stereoscopic experience by going underwater with explorer/filmmaker Jean-Michel Cousteau, son of the legendary Jacques Cousteau. The film is the culmination of nine months of shooting and 500 dive hours in shark-infested waters around the world including Guadalupe Island, the Red Sea, Sodwana Bay, and Rangiroa Atoll, where the filmmakers’ Imax cameras capture a variety of shark species—from great whites to hammerheads—up-close and interacting on their home turfs.

How to watch it: Blu-ray/DVD

Bait (2012)

If one were to read the box synopsis alone—a grocery store robbery is interrupted by a freak tsunami which waterlogs the store and traps a hungry great white shark in there with the survivors—he or she would likely move on to the next movie in the pile. And understandably so. But Bait manages to rise above its schlocky-sounding premise with a series of subplots that keep the story moving along and (fortunately) not solely focused on the 12-foot maneater that’s lurking beneath the surface. The film did well enough at the box office to warrant a sequel, Deep Water, which was officially put on hold in March due to what were described as “uncomfortable similarities” to the disappearance of Malaysia Airlines flight MH370.

How to watch it: Vudu, iTunes

Mission of the Shark: The Saga of the U.S.S. Indianapolis (1991)

Any Jaws aficionado will remember the scene in which Quint reveals himself as a survivor of the U.S.S. Indianapolis, the Navy ship that was torpedoed in 1945 after delivering pieces of the first atomic bomb to a U.S. air base in Tinian. This made-for-television movie—starring Stacy Keach and David Caruso—recounts the actual events (sorry, Quint!) of one of the Navy’s greatest tragedies, in which only 317 of the ship’s 1,196 crewmen survived. Being that it was made for television, the gore factor is low (which can be a pro or con, depending on your horror threshold). But it packs a lot of history into its 100-minute running time, and is impressively directed by Robert Iscove, who—fun fact—would go on to direct She’s All That and From Justin to Kelly.

How to watch it: Netflix

Blood in the Water (2009)

If you can get past the cheesy reenactments, this made-for-television documentary, which kicked off Shark Week in 2009, is rather fascinating from an informational perspective. It tells the story of a series of shark attacks that took place over 12 days on the Jersey Shore in 1916 and put a nation of water-dwellers on high alert. Namely because the latter attacks were perpetrated on children playing in a shallow creek, located roughly 75 miles from where the initial attack (in Beach Haven) occurred.

How to watch it: Vudu

Shark! (1969)

Weren’t aware that Samuel Fuller directed Burt Reynolds in a movie about treasure hunters diving into shark-infested waters in the Red Sea? That’s exactly the way the legendary action director wanted it. Originally titled Caine, the film’s title—and main marketing tactic—changed when one of the movie’s stuntmen was actually killed by a shark during filming, all of which was caught on camera, then subsequently exploited by the studio in order to drum up interest in the film with a new title (Shark!) and tagline (“Will rip you apart”). Fuller was not on board and pleaded with the powers-that-be to remove his name from the project. They refused. And while the final film is far from a cinematic masterpiece, its behind-the-scenes controversy make it worth a watch.

How to watch it: DVD

The Gyroscopes in Your Phone Could Let Apps Eavesdrop on Conversations

Getty

In the age of surveillance paranoia, most smartphone users know better than to give a random app or website permission to use their device’s microphone. But researchers have found there’s another, little-considered sensor in modern phones that can also listen in on their conversations. And it doesn’t even need to ask.

In a presentation at the Usenix security conference next week, researchers from Stanford University and Israel’s defense research group Rafael plan to present a technique for using a smartphone to surreptitiously eavesdrop on conversations in a room—not with a gadget’s microphone, but with its gyroscopes, the sensors designed measure the phone’s orientation. Those sensors enable everything from motion-based games like DoodleJump to cameras’ image stabilization to the phones’ displays toggling between vertical and horizontal orientations. But with a piece of software the researchers built called Gyrophone, they found that the gyroscopes were also sensitive enough to allow them to pick up some sound waves, turning them into crude microphones. And unlike the actual mics built into phones, there’s no way for users of the Android phones they tested to deny an app or website access to those sensors’ data.

“Whenever you grant anyone access to sensors on a device, you’re going to have unintended consequences,” says Dan Boneh, a computer security professor at Stanford. “In this case the unintended consequence is that they can pick up not just phone vibrations, but air vibrations.”

For now, the researchers’ gyroscope snooping trick is more clever than it is practical. It works just well enough to pick up a fraction of the words spoken near a phone. When the researchers tested their gyroscope snooping trick’s ability to pick up the numbers one through ten and the syllable “oh”—a simulation of what might be necessary to steal a credit card number, for instance—it could identify as many as 65 percent of digits spoken in the same room as the device by a single speaker. It could also identify the speaker’s gender with as much as 84 percent certainty. Or it could distinguish between five different speakers in a room with up to 65 percent certainty.

But Boneh argues that more work on speech recognition algorithms could refine the technique into a far more real eavesdropping threat. And he says that a demonstration of even a small amount of audio pickup through the phones’ gyroscopes should serve as a warning to Google to change how easily rogue Android apps could exploit the sensors’ audio sensitivity.

“It’s actually quite dangerous to give direct access to the hardware like this without mitigating it in some way,” says Boneh. “The point is that there’s acoustic information being leaked to the gyroscope. If we spent a year to build optimal speech recognition, we could get a lot better at this. But the point is made.”

Modern smartphones use a kind of gyroscope that consists of a tiny vibrating plate on a chip. When the phone’s orientation changes, that vibrating plate gets pushed around by the Coriolis forces that affect objects in motion when they rotate. (The same effect is why the Earth’s rotation causes the ocean’s water to swirl or air currents to form into spinning hurricanes.)

But the researchers found that the same tiny pressure plates could also pick up the frequency of minute air vibrations. Google’s Android operating system allows movements from the sensors to be read at 200 hertz, or 200 times per second. Since most human voices range from 80 to 250 hertz, the sensor can pick up a significant portion of those voices. Though the result is unintelligible to the human ear, Stanford researcher Yan Michalevsky and Rafael’s Gabi Nakibly built a custom speech recognition program designed to interpret it.

The results, says Boneh, aren’t anywhere close to the kind of eavesdropping possible from the phone’s microphone–he describes the software in its current state as picking up “a word here and there.” But he says the research is only intended to show the possibility of the spying technique, not to perfect it. “We’re security experts, not speech recognition experts,” Boneh says.

Both iOS and Android devices use gyroscopes that can pick up sound vibrations, Boneh says. And neither requires any apps to seek permissions from users to access those sensors. But iOS limits the reading of the gyroscopes to 100 hertz, which makes audio spying far harder to pull off. Android allows apps to read the sensor’s data at twice that speed. And though Chrome or Safari on Android limit websites to reading the sensor at just 20 hertz, Firefox for Android lets websites access the full 200 hertz frequency. That means Android users visiting a malicious site through Firefox could be subject to silent eavesdropping via javascript without even installing any software.

Boneh says that Google has likely been aware of the study: The company’s staffers were included on the Usenix program committee. A Google spokesperson wrote in a statement that “third party research is one of the ways Android is made stronger and more secure. This early, academic work should allow us to provide defenses before there is any likelihood of real exploitation.”

The research isn’t actually the first to find that phones’ gyroscopes and accelerometers pose a privacy risk. In 2011, a group of Georgia Tech researchers found that a smartphone could identify keystrokes on nearby computers based on the movement of the phone’s accelerometers. And in another paper earlier this month, some of the same Stanford and Rafael researchers found that they could read a smartphone’s accelerometers from a website to identify the device’s “fingerprint” out of thousands.

In this case, the researchers say mobile operating system makers like Google could prevent the gyroscope problem by simply limiting the frequency of access to the sensor, as Apple already does. Or if an app really needed to access the gyroscope at high frequencies, it could be forced to ask permission. “There’s no reason a video game needs to access it 200 times a second,” says Boneh.

In other words: Don’t worry. With a small Android tweak from Google, it’s possible to keep DoodleJump and your privacy too.

How to Create a Logo for a Space Engine That Physicists Can’t Explain

A speculative spaceship with the Cannae logo. House Industries

A speculative spaceship with the Cannae logo.

House Industries

House Industries created the brand for the Cannae Drive several years back. But these glossy visuals are helping to pitch the product today. House Industries

House Industries created the brand for the Cannae Drive several years back. But these glossy visuals are helping to pitch the product today.

House Industries

"When you go in front of these funding bodies, like DARPA or the Air Force or private equity guys, you’ve gotta have a brand name for this thing,” says House Industries cofounder Rich Roat. House Industries

"When you go in front of these funding bodies, like DARPA or the Air Force or private equity guys, you’ve gotta have a brand name for this thing,” says House Industries cofounder Rich Roat.

House Industries

“They’ve seen a lot of snake oil over the years, so you have to look professional. And they said over and over again, this stuff got the foot in the door.” House Industries

“They’ve seen a lot of snake oil over the years, so you have to look professional. And they said over and over again, this stuff got the foot in the door.”

House Industries

An earlier concept when the device was called the "Q-Drive." House Industries

An earlier concept when the device was called the "Q-Drive."

House Industries

A microsatellite with Cannae branding. House Industries

A microsatellite with Cannae branding.

House Industries

“It’s kind of a wacky intro, but stick with me, it gets good.”

Thus Andy Cruz begins the tale of how his design studio and type foundry, House Industries, ended up creating a brand identity for a futuristic space engine called the Cannae Drive—technology that could potentially cut travel time to Mars from months to mere weeks, overturning the law of conservation of momentum along the way.

The unlikely project came by way of an even less likely referral. It was holiday season 2010, and Cruz and House Industries co-founder Rich Roat were at an event in New York. They ran into Joel Hodgson, creator of Mystery Science Theater 3000. He was familiar with their work, which includes the typefaces used for the Lucky Charms logo and Green Day’s Dookie album cover, to name a few. And they were familiar with Hodgson’s work, which includes Mystery Science Theater 3000. Everyone got to chatting, and eventually Hodgson made an unusual request: He wanted the designers to meet his neighbor.

A breakdown of a microsatellite using the Cannae Drive. House Industries

That neighbor turned out to be Guido P. Fetta. Over the course of several years, Fetta had developed what he considered a revolutionary engine technology. (Fetta’s background is in marketing for pharmaceutical companies, though he studied chemical engineering in college). He dubbed it the Cannae Drive.

Instead of relying on fuel or nuclear reactors, Fetta’s design bounces microwaves around a specially-shaped container, creating changes in radiation pressure that ultimately generate thrust. It could have all sorts of applications, including vastly reducing the waste involved in launching satellites into orbit. And while it’s true that futuristic space drives and independent inventors generally are viewed with skepticism, the Cannae Drive got a fairly huge endorsement last week when NASA published the results of its own tests: Inexplicably, it worked. (Granted, this may still be an experimental glitch. Only time will tell.)

Just because Cannae isn’t consumer tech

doesn’t mean it’s not a product being sold.

At that point in 2010, however, the Cannae Drive was just a wild idea by a math-obsessed salesman. Hodgson, savvy in the ways of pitches and presentations, knew his neighbor’s technology needed a proper public face if it was going to sell. Thus the introduction to Cruz and Roat.

The final Cannae logo. House Industries

It didn’t take long to settle on a direction. “When you’ve got your creative meeting with Joel and Guido and the knuckleheads at House Industries, of course we head toward the world of science fiction,” Cruz says. They spent hours talking about their favorite sci-fi films and their visual languages. Ultimately, the challenge was creating a brand identity that alluded to familiar ideas futuristic technologies without feeling like a parody of them. It needed to look like something that would be emblazoned on a rocket, not an arcade machine.

There were other ingredients in the mix. The designers looked at existing brands that were both timeless and forward-looking, drawing inspiration from the automotive industry and specifically airlines like Pan Am and Continental. They experimented with typography inspired by Ancient Rome, a nod to the Battle of Cannae after which the drive is named (Fetta is also a Roman warfare buff).

Sketches for the Cannae logo. House Industries

The thing that makes the final logo immediately feel futuristic is the absence of crossbars on the A’s, Cruz explains. “That’s one of those elements that’s sort of an emotional or thematic touchpoint, based on things we’ve seen.” But the designers gave the rest of the mark just as much attention as they do with all their typefaces. “Once we’ve established something that does trigger that ‘this is the future’ feeling, then we come back and say, ‘OK, let’s take what we’ve learned in the world of typography on Earth and apply some of those principles,’” Cruz says. An orbital loop around the last letter lends the mark a nice graphic touch, evoking space and visually suggesting a breakthrough technology.

It needed to look like something that would be

emblazoned on a rocket, not an arcade machine.

It isn’t immediately obvious why a breakthrough technology would need a “brand identity” in the first place. But as Roat points out, just because Cannae isn’t consumer tech doesn’t mean it’s not a product being sold. “When you go in front of these funding bodies, like Darpa or the Air Force or private equity guys, you’ve gotta have a brand name for this thing,” he says. “They’ve seen a lot of snake oil over the years, so you have to look professional. And they said over and over again, this stuff got the foot in the door.”

Creating the Cannae identity was the first step. Recently, House Industries has worked on illustrations and videos of the types of spacecrafts Cannae might work with. If a professional brand is what gets you in the door, these sorts of visual assets are what help open the pocket books. “That’s why I think Joel immediately said, ‘Oh I’ve gotta talk to House Industries,’” Roat says. “We need these guys to make this thing look real.’”