MIT Technology Review: Microsoft's HoloLens combines a video studio with 100 cameras, processing software, and a headset with sensors that detect the surroundings of the wearer. The result is a photorealistic holographic display that is projected into the user's present reality; the headset wearer can interact with the images as if they were solid and real. The headset uses sensor systems to determine how to fit the images to the user's surroundings. This approach is different from most other virtual displays, which block off the outside world. The images can also be presented on two-dimensional displays, and users can interact with them via touchscreens. Microsoft is trying to determine how to reduce the cost of the recording studio to make it more accessible.
The filamentary discharge seen within commercial plasma globes is commonly enjoyed yet not well understood. Here, we investigate the discharge properties of a plasma globe using a variable high voltage amplifier. We find that increasing voltage magnitude increases the number of filaments while leaving their individual structure basically unchanged, a result typical of dielectric barrier discharges. The frequency of the voltage also affects filament population but more significantly changes filament structure, with more diffuse filaments seen at lower frequencies. Voltage polarity is observed to be important, especially at lower frequencies, where for negative-gradient voltages the discharge is more diffuse, not filamentary. At late stages of the discharge circular structures appear and expand on the glass boundaries. We find no trend of discharge speed with respect to voltage variables, though this may be due to manufacturer sample-to-sample variation. Each voltage cycle the discharge expands outward at ∼10–15 km/s, a speed significantly higher than the estimated electron drift yet considerably lower than that observed for most streamers. We discuss the physics of these observations and their relation to similar discharges that can be found within nature and industry.
Nature: The Open Researcher and Contributor ID (ORCID) scientist registry system has announced that it will include peer-reviewer information in its database. The system will use a standard developed in partnership with the Consortia Advancing Standards in Research Administration Information and publisher Faculty of 1000. The system, which is voluntary, will allow researchers to add to their ORCID profile information about their peer review activities. For journals that participate in the standard, the reviewer's report itself can be added to the profile. For other journals, all that would be stored would be the number of reviews the researcher has completed for the journal in a certain period of time. The American Geophysical Union has already announced that it will use the new standard for its publications.
New Scientist: Vesta is the second most massive and third largest asteroid in the main belt and is classed as a minor planet. Like Ceres and Pallas, the other two most massive and largest asteroids, it doesn't have any natural satellites. That the three largest asteroids don't have any moons is curious because more than 100 main-belt asteroids are known to have other bodies in orbit around them. Vesta in particular looks like it ought to have a moon because its surface shows two large craters whose formation by impact should have created enough debris to form satellites. Lucy McFadden of NASA's Goddard Space Flight Center in Greenbelt, Maryland, and her colleagues examined flyby images from the Dawn spacecraft to confirm the absence of any bodies larger than 6 m orbiting Vesta. Nick Gorkavyi, also of NASA Goddard, suggests that Vesta's high rate of rotation could have resulted in any satellites that formed losing momentum and merging with the asteroid. Gorkavyi says such merging events could explain the large canyons on Vesta's surface.
Physicist/ Sr. Physicist - Group Leader for X-Ray Scattering - Job Id #320 | Brookhaven National Laboratory
The flow past a circular cylinder under diverse conditions is investigated to examine the nature of the different separation mechanisms that can develop. For a fixed cylinder in a uniform, steady, and horizontal stream, the alternating sheddings of vortices, characterizing the Kármán vortex street, occur from two separation points located in the rear cylinder wall. The prediction of the separation positions and profiles is examined in the light of the most recent theory of unsteady separation in two-dimensional flows. It is found that the separation points are fixed in space and located symmetrically about the horizontal axis passing through the center of the cylinder. The unsteady separation profiles are also well-predicted by the theory. If the cylinder rotates on its axis in the anti-clockwise direction, the upper and lower separation points are shifted in the upstream and the downstream direction, respectively, but are no longer attached to the wall and cannot be predicted by the theory. Instead, they are captured as saddle points in the interior of the flow without any connection to on-wall quantities, as suggested by the Moore–Rott–Sears (MRS) principle. The saddle points are detected through a Lagrangian approach as the location of maximum tangential rate of strain on Lagrangian coherent structures identified as the most attracting lines in the vicinity of the cylinder. If, in addition, the uniform stream is unsteady, the Eulerian saddle points, i.e., detected by streamlines, change position in time, but have no direct relation to the true separation points that are defined by Lagrangian saddle points, thus invalidating the MRS principle that is Eulerian by nature. Other separation mechanisms are also described and understood in view of Lagrangian identification tools.