"Saturn’s rings are a conveniently located dynamical laboratory," says the opening sentence of a new paper. The convenient part may be debatable, but the dynamism isn't. The rings are filled with gaps and wiggles, created by interactions among their particles and a collection of small moons that act as shepherds, their gravity ushering the rings' particles into distinctive orbits.
Now researchers have identified a series of bright objects embedded in the outer edge of Saturn's A Ring. The largest of these, which has been nicknamed "Peggy," may be as much as a kilometer across. The objects may represent a moon that is disintegrating after contact with the outer edge of the A Ring. But it could also be one in the process of formation—a process that may have played out many times in Saturn's past.
The initial observation of Peggy, shown above, came in a photograph taken a year ago yesterday by the Cassini orbiter. That prompted a dive into the image archive. Prior to May of 2012, the orbiter didn't have a good perspective for imaging the rings for over a year, but Peggy was visible in over 100 detections between then and November of 2013.
Right now, photovoltaic devices are the cheapest, most efficient way to harvest the energy in sunlight. The problem is that this energy ends up in the form of electricity, which we have difficulty storing in a cost-effective manner. An alternative approach, solar thermal energy, converts solar energy to heat and can use that heat to continue generating power for several hours after the Sun goes down. But that's not enough to make solar an around-the-clock energy source.
Researchers are apparently working on a third option, one that could potentially store energy indefinitely. It goes by the name of "solar thermal fuel," but it's not a fuel in the traditional sense. Rather than breaking apart the fuel molecule through combustion, solar thermal fuels release heat by rearranging bonds within a molecule, leaving all the atoms in place. As a result, they can be recycled repeatedly—in the example that introduced me to solar thermal fuels, a research team ran theirs through more than 2,000 cycles with no loss in performance.
How do you get energy into and out of a molecule without breaking any bonds? In this case, the authors worked with derivatives of a chemical called azobenzene, shown below. The double bond between the two nitrogens forces the remaining bonds into one of two forms: either both of the rings can be on opposite sides of the molecule (top, called the "trans" form) or they can be on the same side (bottom, called "cis").
It's no secret that biology research in the US is facing a number of challenges. After years of rapid growth, the funding for biomedical research has dropped by 25 percent in real dollar terms since 2003, leaving researchers scrambling to keep their labs running. Meanwhile, the system is still training far more graduates than there are faculty positions to fill. But it's tempting to think that taking care of the first by increasing the funding would help take care of the second.
"Don't kid yourself" seems to be the message of a perspective published this week by PNAS. The authors, Bruce Alberts, Marc Kirschner, Shirley Tilghman, and Harold Varmus (most of whom helped create or expand the current system), say its current course is unsustainable without some deep-rooted reforms. The ones they suggest would produce far fewer graduates and research labs, but they're courses better equipped to keep biomedical research sustainable even without a large budget increase.The grad student problem
The researchers identify a couple of major structural problems that have made the current system unsustainable. One is simply that graduate students represent the cheapest form of labor, and so graduate programs have expanded to keep researchers well supplied. The end result is that 8,000 people get a PhD in the biological sciences each year, far more than can ever hope to find faculty positions. Only about 20 percent of them end up staying in research positions, yet graduate education generally provides training in nothing but research.
For years, the “have you seen this child?” part of missing persons’ reports has been the most difficult one. Not just emotionally but literally. How can someone be recognized based on a childhood photo—often a low-detail one, at that—along with an awkward-looking artist's estimate of their current appearance?
Ira Kemelmacher-Shlizerman, an assistant computer science professor at the University of Washington, stumbled upon this challenge after roughly a decade of research in similar fields. Kemelmacher-Shlizerman and her colleagues have worked for years to accurately re-render photos, mostly in converting 2D faces to 3D models.
The results of her teams’ studies thus far have been intriguing—and even hilarious. In 2010, for example, her team made it possible to be John Malkovich, translating live facial movement onto another face on a screen. Her most recent project was a little different, as it began with a nudge from the National Center for Missing and Exploited Children to find out what more could be done with so much facial data.
Bacterial diseases cause millions of deaths every year. Most of these bacteria were benign at some point in their evolutionary past, and we don’t always understand what turned them into disease-causing pathogens. In a new study, researchers have tracked down when this switch happened in one flesh-eating bacteria. They think the knowledge might help predict future epidemics.
The flesh-eating culprit in question is called GAS, or Group A β-hemolytic streptococcus, a highly infective bacteria. Apart from causing the flesh-eating disease necrotizing fasciitis, GAS is also responsible for a range of less harmful infections. It affects more than 600 million people every year, and it causes an estimated 500,000 deaths.
These bacteria appeared to have affected humans since the 1980s. Scientists think that GAS must have evolved from a less harmful streptococcus strain. The new study, published in PNAS, reconstructs that evolutionary history.
If you were collecting sections of the new report from the Intergovernmental Panel on Climate Change, you can now complete your set. Following the release of the section on the physical science of climate change in September and the section on the impacts of, and adaptations to, climate change just two weeks ago, the section on how to avoid future warming was finally released over the weekend in Berlin.
This section was written by 235 scientists from 58 countries and cites almost 10,000 studies. The final publication of the entire report will take place in October, along with a short synthesis report summarizing the key findings in simpler, less-technical terms.How we got here
If you add up all the human-caused greenhouse gas emissions around the world in 2010, it was equivalent to 49 billion tons of CO2. That number isn’t just growing, its growth is accelerating. Over the previous decade, it increased by about one billion tons each year, while the average from 1970-2000 was about 0.4 billion tons more each year. More than three-quarters of these emissions come from fossil fuels, and the rest come from things like deforestation, livestock production, and industrial pollutants.
Titan Aerospace—the drone-maker that was previously pegged as a Facebook acquisition—has been snapped up by Google, according to a report from the Wall Street Journal (subscription required). Titan creates “atmospheric satellites,” solar-powered drones that can fly for five years without landing.
According to the report, Google says the Titan team will be headed to Project Loon, Google's balloon-based Internet project. Loon also uses solar-powered drones in the form of balloons instead of airplanes, so the two teams seem like a good match. The Journal also says the team might help out Manaki, a Google-owned company working on an airborne wind turbine (basically a drone plane on the end of a power cable). Atmospheric satellites could also be a big help to Google Maps and Google Earth since they both use satellite imagery. A fleet of camera-packing drones could take all the photos Google needs.
One of Titan's "smaller" drone models, called the "Solara 50," has a wingspan of 164 feet. That's larger than a Boeing 767. Before the acquisition, the Titan Aerospace's drone Internet project expected to hit "initial commercial operations" in 2015. By using specialty communications equipment, the company claimed it could get Internet speeds of up to one gigabit per second.
The latest SpaceX resupply mission to the International Space Station is set to lift off at 6pm US Eastern Time today. The Falcon 9 launch vehicle will be sending a Dragon capsule into orbit to bring over 5,000 lbs of supplies and science experiments to the ISS. If all goes according to plan, the Dragon will rendezvous with the Station early Wednesday morning (also US Eastern).
This is SpaceX's third resupply mission, so parts of the liftoff and rendezvous are likely to be routine. Lately, however, SpaceX has been doing interesting things with its Falcon boosters after payload separation. Back in September, the Falcon flipped around in flight and fired its engines to reverse direction, the first step toward a controlled return to the atmosphere.
This time around, the company is planning on expanding on that test. "During today’s launch SpaceX will attempt to recover the first stage of the Falcon 9 launch vehicle as part of SpaceX’s reusability program," a SpaceX spokesperson told Ars. "It’s important to note this is not a primary mission objective and the probability of recovering the first stage is low, maybe 30-40 percent."
Computers, cell phones, and any other device being used to read this article rely on a three-century-old approach to computation that represents data with a binary system. However, it’s possible that some computations will shift to a different system entirely thanks to developments in the field of quantum computing.
Classical computing uses logic gates with a 1 or 0 value. Quantum bits, or qubits, can represent a 1, 0, or any state achieved by a mixture of these two through their quantum superposition. Single qubits can be linked to create a single computer that can perform parallel calculations that are out of the reach of today’s hardware.
Studies conducted at the Max-Planck-Institut in Germany may help enable these sorts of parallel computations. In their studies, published in Nature, researchers have used the two spin orientations of an atom, along with two polarization states of a photon, to represent a 0 or 1.