Project Silica proof of concept stores Warner Bros. ‘Superman’ movie on quartz glass
> It was the first proof of concept test for Project Silica, a Microsoft Research project that uses recent discoveries in ultrafast laser optics and artificial intelligence to store data in quartz glass. A laser encodes data in glass by creating layers of three-dimensional nanoscale gratings and deformations at various depths and angles. Machine learning algorithms read the data back by decoding images and patterns that are created as polarized light shines through the glass.
How to wring power from the night air
> Solar power is all very well, but it is available only during daylight hours. If something similarly environmentally friendly could be drawn on during the hours of darkness, that would be a great convenience. Colin Price, an atmospheric scientist at Tel Aviv University, in Israel, wonders if he might have stumbled across such a thing. As he told a meeting of the International Union of Geodesy and Geophysics, held in Montreal in July, it may be possible to extract electricity directly from damp air—specifically, from air of the sort of dampness (above 60% relative humidity) found after sundown, as the atmosphere cools and its ability to hold water vapour diminishes.
Survey of Alternative Displays
> The purpose of this article is to collect and consolidate a list of these alternative methods of working with displays, light and optics. This will by no means be an exhaustive list of the possibilities available — depending on how you categorize, there could be dozens or hundreds of ways. There are historical mainstays, oddball one-offs, expensive failures and techniques that are only beginning to come into their own.
There’s more to life than the LCD.
Advanced Nuclear Power
> The basic idea of a nuclear reactor is really simple. In fact, you could make a toy to explain it to kids.
Wireless nanowire lasers absorb infrared, emit blue light
> So, where will these be used? I’ve no idea at this point, and I don’t really care—I just love the physics. More seriously, it takes a very bright light to turn a laser on like this (think ~1TW/cm2), so the applications will certainly be niche.
> Nano Letters, 2019, DOI: 10.1021/acs.nanolett.9b00510
X-ray imaging reveals the secrets of termite mounds
> Turner found that the assumptions of Pearce and others that the mounds’ complex tunnel systems serve to circulate air and remove heat to regulate interior temperatures isn’t accurate. The air mixing isn’t the result of the colony’s internal heat but air pressure from outside the mound. The termites build the mounds so tall to catch the wind, and their porous outer surface is what allows the air to move into and through the colony. Turner likens the effect to the alveoli in human lungs: the mound almost “breathes.”
Just going to link to the whole blog.
Mammalian Near-Infrared Image Vision through Injectable and Self-Powered Retinal Nanoantennae
> Vision is an essential sensory modality for humans. Our visual system detects light between 400 and 700 nm (Dubois, 2009, Wyszecki and Stiles, 1982, Schnapf et al., 1988), so called visible light. In mammalian photoreceptor cells, light absorbing pigments, consisting of opsins and their covalently linked retinals, are known as intrinsic photon detectors. However, the detection of longer wavelength light, such as near-infrared (NIR) light, though a desirable ability, is a formidable challenge for mammals. This is because detecting longer wavelength light, with lower energy photons, requires opsins (e.g., human red cone opsins) to have much lower energy barriers. Consequently, this results in unendurable high thermal noise, thus making NIR visual pigments impractical (Ala-Laurila et al., 2003, Baylor et al., 1980, Luo et al., 2011, St George, 1952). This physical limitation means that no mammalian photoreceptor can effectively detect NIR light that exceeds 700 nm, and mammals are unable to see NIR light and to project a NIR image to the brain.
> To this end, the successful integration of nanoparticles with biological systems has accelerated basic scientific discoveries and their translation into biomedical applications (Desai, 2012, Mitragotri et al., 2015). To develop abilities that do not exist naturally, miniature nanoscale devices and sensors designed to intimately interface with mammals including humans are of growing interest. Here, we report on an ocular injectable, self-powered, built-in NIR light nanoantenna that can extend the mammalian visual spectrum to the NIR range. These retinal photoreceptor-binding upconversion nanoparticles (pbUCNPs) act as miniature energy transducers that can transform mammalian invisible NIR light in vivo into short wavelength visible emissions (Liu et al., 2017, Wu et al., 2009). As sub-retinal injections are a commonly used ophthalmological practice in animals and humans (Hauswirth et al., 2008, Peng et al., 2017), our pbUCNPs were dissolved in PBS and then injected into the sub-retinal space in the eyes of mice. These nanoparticles were then anchored and bound to the photoreceptors in the mouse retina.
How an Explosion (Not Aliens) Turned New York’s Night Sky an Electric Blue
> The bizarre illumination was sparked by an “electric arc flash” tied to faulty equipment at a Con Edison substation, a spokesman for the utility, Bob McGee, said early Friday. The equipment, located about 20 feet above the ground, contained cables that transmit 138,000 volts of electricity — a staggering amount compared with the 120 volts supplied to American households.
A better way to calculate pitch range
> Today’s topic is a simple solution to a complicated problem. The complicated problem is how to estimate “pitch range” in recordings of human speakers. As for the simple solution — wait and see.
> You might think that the many differences between the perceptual variable of pitch and the physical variable of fundamental frequency (“f0“) arise because perception is complicated and physics is simple. But if so, you’d be mostly wrong. The biggest problem is that physical f0 is a complex and often fundamentally incoherent concept. And even in the areas where f0 is well defined, f0 estimation (usually called “pitch tracking“) is prone to errors.
iPhones are Allergic to Helium
> This piqued my interest, and I reached out to some friends that make ‘MEMS’ silicon. These microelectromechanical systems are some of the smallest mechanical apparatuses in the world. Every phone has gyroscopes and accelerometers with micrometer-thin elements. My initial theory, shared by some on Reddit, was that the helium molecules were small enough to get inside these chips and interfere with the mechanical workings.
Mystery of the cargo ships that sink when their cargo suddenly liquefies
> When a solid bulk cargo liquefies, it can shift or slosh inside a ship’s hold, making the vessel less stable. A liquefied cargo can shift completely to one side of the hold. If it regains its strength and reverts to a solid state, the cargo will remain in the shifted position, causing the ship to permanently tilt or “list” in the water. The cargo can then liquefy again and shift further, increasing the angle of list.
FIU had grand plans for 'signature' bridge. But the design had a key mistake, experts say
> The unconventional placement of diagonal supports in an uneven zig-zag pattern along the bridge produced a complex structural web with a glaring weakness at a key connection point, apparently overlooked by designers at FIGG Bridge Group, say three independent structural engineers who reviewed nearly 2,000 pages of calculations for the bridge at the Miami Herald’s request.
Follow up: https://www.nytimes.com/2019/10/22/us/bridge-collapse-florida-international-university-NTSB.html
A physical constant’s value shouldn’t depend on how you measure it
> Measurements in physics are funny things. You’d hope that attempts to quantify some of the fundamental properties of the Universe would follow a simple pattern: they’d start with large error bars, but, over time, measuring technology improves and the error bars shrink. Ideally, the value would then remain nicely within the previous error.
> It almost never really works like that.
Giant atom hides its neighbors under a single-electron skirt
> So, how did the researchers manage this feat of atomic woodwork? To get a grip on that, we need to introduce three concepts: the Bose Einstein Condensate, which forms the crowd of very cold atoms; a polaron, which is the mechanism that traps the atoms inside the outer shell of the doll; and finally, Rydberg atoms, a way to make an atom very large and very empty.
Two Chaotic Motion Demos
> I’ve put together two online, interactive, demonstrations of chaotic motion. One is 2D and the other is 3D, but both are rendered using WebGL — which, for me, is the most interesting part. Both are governed by ordinary differential equations. Both are integrated using the Runge–Kutta method, specifically RK4.
Olympic Curling Doesn’t Only Stump Viewers—It Confuses Scientists, Too
> The stone, a hefty piece of granite sent careening across the ice, doesn’t behave the way scientists expect, and no one knows exactly why
> Spin an overturned glass clockwise on a smooth countertop and it drifts to the left. Spin it counterclockwise and it drifts to the right. A curling stone in play does the opposite. Spin that glass harder and it makes a sharper turn. In curling, the faster the stone spins, the more straight it goes.
A Water-based Solution of Polynomial Equations
Super-Black Is the New Black
> Feathers on birds of paradise contain light-trapping nanotechnology that makes some of the deepest blacks in the world.
A Pragmatic Introduction to Signal Processing
> An illustrated essay with free software to download