Lifeboat Foundation

U.S. fighter jets intercepted Russian bombers twice on Wednesday off the coast of Alaska, the North American Aerospace Defense Command said Wednesday. The intercepts come less than two weeks after U.S. bombers were met by Russian jets over the Black Sea.

NORAD said US F-22 Raptors intercepted a Russian bomber formation early Wednesday that came within 20 nautical miles of the Alaskan coast. NORAD posted images of the incident on Twitter.

The formation consisted of two TU-95 bombers, two SU-35 fighter jets and an A-50 airborne early warning and control aircraft, NORAD said. The second formation consisted of two TU-95 bombers and an A-50 and came within 32 nautical miles of Alaskan shores.

The discovery that at least some Fast Radio Bursts (FRBs) repeat has ruled out cataclysmic events as the progenitors of these particular bursts. FRB 121102 is the most well-studied repeating FRB but despite extensive monitoring of the source, no underlying pattern in the repetition has previously been identified. Here, we present the results from a radio monitoring campaign of FRB 121102 using the 76 m Lovell telescope. Using the pulses detected in the Lovell data along with pulses from the literature, we report a detection of periodic behaviour of the source over the span of 5 yr of data. We predict that the source is currently ‘off’ and that it should turn ‘on’ for the approximate MJD range 59002–59089 (2020 June 2 to 2020 August 28). This result, along with the recent detection of periodicity from another repeating FRB, highlights the need for long-term monitoring of repeating FRBs at a high cadence. Using simulations, we show that one needs at least 100 h of telescope time to follow-up repeating FRBs at a cadence of 0.5–3 d to detect periodicities in the range of 10–150 d. If the period is real, it shows that repeating FRBs can have a large range in their activity periods that might be difficult to reconcile with neutron star precession models.

Color is a foundational aspect of visual experience that aids in segmenting objects, identifying food sources, and signaling emotions. Intuitively, it feels that we are immersed in a colorful world that extends to the farthest limits of our periphery. How accurate is our intuition? Here, we used gaze-contingent rendering in immersive VR to reveal the limits of color awareness during naturalistic viewing. Observers explored 360° real-world environments, which we altered so that only the regions where observers looked were in color, while their periphery was black-and-white. Overall, we found that observers routinely failed to notice when color vanished from the majority of their visual world. These results show that our intuitive sense of a rich, colorful world is largely incorrect.

Color ignites visual experience, imbuing the world with meaning, emotion, and richness. As soon as an observer opens their eyes, they have the immediate impression of a rich, colorful experience that encompasses their entire visual world. Here, we show that this impression is surprisingly inaccurate. We used head-mounted virtual reality (VR) to place observers in immersive, dynamic real-world environments, which they naturally explored via saccades and head turns. Meanwhile, we monitored their gaze with in-headset eye tracking and then systematically altered the visual environments such that only the parts of the scene they were looking at were presented in color and the rest of the scene (i.e., the visual periphery) was entirely desaturated. We found that observers were often completely unaware of these drastic alterations to their visual world. In the most extreme case, almost a third of observers failed to notice when less than 5% of the visual display was presented in color.

Brilliantly colored chameleons, butterflies, opals—and now some 3D-printed materials—reflect color by using nanoscale structures called photonic crystals.

A new study that demonstrates how a modified 3D-printing process provides a versatile approach to producing multiple colors from a single ink is published in the journal Science Advances.

Continue reading “Researchers mimic nature for fast, colorful 3D printing” »

Electrons are very much at the mercy of magnetic fields, which scientists can manipulate to control the electrons and their angular momentum—i.e. their “spin.”

A Cornell team led by Greg Fuchs, assistant professor of applied and engineering physics in the College of Engineering, in 2013 invented a new way to exert this control by using acoustic waves generated by mechanical resonators. That approach enabled the team to control electron spin transitions (also known as spin resonance) that otherwise wouldn’t be possible through conventional magnetic behavior.

The finding was a boon for anyone looking to build quantum sensors of the sort used in mobile navigation devices. However, such devices still required a magnetic control field—and therefore a bulky magnetic antenna—to drive certain spin transitions.

Although many animals have evolved intrinsic transparency for the purpose of concealment, the development of dynamic, that is, controllable and reversible, transparency for living human cells and tissues has remained elusive to date. Here, by drawing inspiration from the structures and functionalities of adaptive cephalopod skin cells, we design and engineer human cells that contain reconfigurable protein-based photonic architectures and, as a result, possess tunable transparency-changing and light-scattering capabilities. Our findings may lead to the development of unique biophotonic tools for applications in materials science and bioengineering and may also facilitate an improved understanding of a wide range of biological systems.

Researchers at the University of Colorado Boulder’s Soft Materials Research Center (SMRC) have discovered an elusive phase of matter, first proposed more than 100 years ago and sought after ever since.

The team describes the discovery of what scientists call a “ferroelectric nematic” phase of liquid crystal in a study published today in the Proceedings of the National Academy of Sciences. The discovery opens a door to a new universe of materials, said co-author Matt Glaser, a professor in the Department of Physics.

Nematic liquid crystals have been a hot topic in materials research since the 1970s. These materials exhibit a curious mix of fluid- and solid-like behaviors, which allow them to control light. Engineers have used them extensively to make the liquid crystal displays (LCDs) in many laptops, TVs and cellphones.

An international collaboration of scientists has recorded the most accurate confirmation to date for one of the cornerstones of Einstein’s theory of general relativity, ‘the universality of free fall.”

The new research shows that the theory holds for strongly self-gravitating objects such as neutron stars. Using a radio telescope, scientists can very accurately observe the signal produced by pulsars, a type of neutron star and test the validity of Einstein’s theory of gravity for these extreme objects. In particular, the team analyzed the signals from a pulsar named “PSR J0337+1715’ recorded by the large radio telescope of Nançay, located in the heart of Sologne (France).

The universality of free fall principle states that two bodies dropped in a gravitational field undergo the very same acceleration independently of their composition. This was first demonstrated by Galileo who famously would have dropped objects of different masses from the top of Pisa’s tower to verify that they both reach the ground simultaneously.

At Imperial College we’ve been comparing psilocybin to conventional antidepressants – and the results are likely to be game-changing, says Robin Carhart-Harris.