background preloader

Sur la mort

Facebook Twitter

What signs have you noticed that you are getting older? Yitang Zhang Proves 'Landmark' Theorem in Distribution of Prime Numbers | Simons Foundation. On April 17, a paper arrived in the inbox of Annals of Mathematics, one of the discipline’s preeminent journals. Written by a mathematician virtually unknown to the experts in his field — a 50-something lecturer at the University of New Hampshire named Yitang Zhang — the paper claimed to have taken a huge step forward in understanding one of mathematics’ oldest problems, the twin primes conjecture.

Editors of prominent mathematics journals are used to fielding grandiose claims from obscure authors, but this paper was different. Written with crystalline clarity and a total command of the topic’s current state of the art, it was evidently a serious piece of work, and the Annals editors decided to put it on the fast track.

Yitang Zhang (Photo: University of New Hampshire) Just three weeks later — a blink of an eye compared to the usual pace of mathematics journals — Zhang received the referee report on his paper. “The main results are of the first rank,” one of the referees wrote. A New Kind of Invisibility Cloak Demonstrates Better Cloaking Efficiency. Top: Color online) Snap-shots of Hz distributions for fwork=8 GHz at TM wave incidence on: (a) bare metallic cylinder with the radius 0.75 λwork; (b) the same target cloaked by the shell with material parameters prescribed by Eq. (7); (c) the same target cloaked by the multi-layer dielectric shell; (d) zoomed-in view of (c).Bottom: (Color online) The TSCW spectra obtained by integrating the simulated far-fields for the cloaked and bare targets of two different sizes.

Dimensional parameters of the multi-layer dielectric cloaks in both cases were fixed for the wavelength corresponding to fwork=8 GHz. Using a new kind of cloak that uses a very thin multilayer dielectric coating made of natural material, not metamaterial, researchers at Michigan Technological University demonstrated better cloaking efficiency than a similarly sized metamaterial cloak designed by using the transformation optics relations. Michigan Technological University’s invisibility cloak researchers have done it again. Study of the Day: Soon, You May Download New Skills to Your Brain - Hans Villarica. New research suggests it may be possible to learn complex tasks with little to no conscious effort, just like in The Matrix.

Whoa, indeed. PROBLEM: Unlike Neo in The Matrix or the titular superspy in the comedy series Chuck, we can't master kung fu just by beaming information to our brain. We have to put in time and effort to learn new skills. METHODOLOGY: Researchers from Boston University and Japan's ATR Computational Neuroscience Laboratories designed a decoded functional MRI neurofeedback method that induces a pre-recorded activation pattern in targeted early visual brain areas that could also produce the pattern through regular learning. They then tested whether repetitions of the fMRI pattern caused an improvement in the performance of that visual feature. RESULTS: The experiments successfully demonstrated that, through a person's visual cortex, decoded fMRI could be used to impart brain activity patterns that match a previously known target state. Image: VLADGRIN/Shutterstock. Amazing Resonance Experiment! The Future of Design.

The Invisible Hand Illusion. Hold your hand up in front of your face. It is patently obvious that the five-fingered thing in front of you is your hand, and the empty space next to it is not. But this ability to recognise your own body is more complicated than it first appears, and can be fooled through a surprisingly simple trick. Henrik Ehrsson from the Karolinska Institute is a master of such illusion. When I visited his lab in 2011, he used little more than virtual reality headsets, mannequins and batons to convince me that I had left my body, shrunk to doll-size, and gained a third arm. Now, his team member Arvid Guterstam has devised a way of convincing people that they’ve got an invisible hand.

The team’s work was inspired by the classic rubber-hand illusion, devised by two Princeton scientists in the 1990s. It suggested to him that even though we have a lifetime’s experience of owning our bodies, this seemingly ingrained feeling is actually very fragile. The illusion has its limits, though.