Most noise-blocking headphones fall into two categories: they use some kind of material to absorb or scatter noise, or they use active cancellation that creates a signal to oppose the noise signal. As you’ve probably noticed, both of these approaches have limitations. Now, Swiss scientists think they have a new method that will work better. In Nature Communications, they describe a noise cancellation system that moves air by using ionization instead of a conventional transducer.
With the cool name plasmaacoustic metalayers, the technique uses a controlled corona discharge to create very thin layers of plasma between a metal grid and thin wires. With no voltage, sound passes freely. Applying a voltage across the assembly produces ions and moves air with very low inertia, unlike a typical speaker. By controlling the reverse pressure of air, the system can cancel incoming noise picked up by a microphone.
Doing something for the first time is tough. Yet to replicate the nuclear fusion process that powers the very stars, and do it right here on Earth in a controlled and sustained fashion is decidedly at the top of the list of ‘tough’ first times. What further complicates matters is when in order to even get to this ‘first’ you also add in a massive, international construction project and a heaping of geopolitics, all of which is a far cry from past nuclear fusion experiments.
With the International Thermonuclear Experimental Reactor (ITER) as the most visible part of nuclear fusion research, it is perhaps little wonder that the recent string of delays and budget increases is leading some to proclaim doom and gloom over the entire sector. This ironically in contrast with the recent news from the US’s NIF and its laser-based inertial confinement fusion, which is both state-funded and will never produce commercial power.
In light of this, it feels pertinent to ask the question of whether ITER is the proverbial white elephant, or even the mausoleum of international science that a recent article in Scientific American makes it out to be. Is fusion research truly doomed to peter out amidst the seemingly never-ending work on ITER?
Mining projects are approved or disapproved based on all kinds of reasons. There are economic concerns, logistical matters, and environmental considerations to be made. Mining operations can be highly polluting, or they can have outsized effects on a given area by sheer virtue of the material they remove or the byproducts they leave behind.
The block contains beams, and by controlling how the block is compressed, the vertical beams shift in a stable and consistent way, acting as a mechanical counter. It’s a straightforward implementation of the work of two physicists from the Netherlands: [Martin van Hecke] and [Lennard Kwakernaak].
You can check out the research paper for more details on the rubber beam counter. [Kwakernaak] aims to create a much more complex structure with elements that interact across a plane instead of in a single direction. Such a device would, in effect, be a simple computer.
Watch the beam counter in action in the short video embedded below. See how the elements of the green rubber block move while constrained by an outer frame that helps control the force that is applied. The thin beams flip from left to right, one at a time with each press.
The term ‘quantum computer’ gets usually tossed around in the context of hyper-advanced, state-of-the-art computing devices. But much as how a 19th century mechanical computer, a discrete computer created from individual transistors, and a human being are all computers, the important quantifier is how fast and accurate the system is at the task. This is demonstrated succinctly by [Davide ‘dakk’ Gessa] with 200 lines of BASIC code on a Commodore 64 (GitHub), implementing a range of quantum gates.
Much like a transistor in classical computing, the qubit forms the core of quantum computing, and we have known for a long time that a qubit can be simulated, even on something as mundane as an 8-bit MPU. Ergo [Davide]’s simulations of various quantum gates on a C64, ranging from Pauli-X, Pauli-Y, Pauli-Z, Hadamard, CNOT and SWAP, all using a two-qubit system running on a system that first saw the light of day in the early 1980s.
Naturally, the practical use of simulating a two-qubit system on a general-purpose MPU running at a blistering ~1 MHz is quite limited, but as a teaching tool it’s incredibly accessible and a fun way to introduce people to the world of quantum computing.
[NightHawkInLight] has been working on radiative sky paint. (Video, embedded below.) That’s a coating that radiates heat in the infrared spectrum at a wavelength that isn’t readily absorbed or reflected by the atmosphere. The result is a passive system that keeps materials a few degrees cooler in direct sunlight than an untreated piece in the shade. That sounds a bit like magic, but apparently the math checks out.
A research paper titled Biological Organisms as End Effectors explores the oddball approach of giving small animals jobs as grippers at the end of a robotic arm. Researchers show that pill bugs and chitons — small creatures with exoskeletons and reflexive movements — have behaviors making them useful as grippers, with no harm done to the creatures in the process. The prototypes are really just proofs of concept, but it’s a novel idea that does work in at least a simple way.
Pill bugs reflexively close, and in the process can grasp and hold lightweight objects. The release is simply a matter of time; researchers say that after about 115 seconds a held object is released naturally when the pill bug’s shell opens. While better control over release would be good, the tests show basic functionality is present.
The chiton — a small mollusk — can grip underwater.
Another test involves the chiton, a small mollusk that attaches to things with suction and can act as an underwater end effector in a similar way. Interestingly, a chiton is able to secure itself to wood and cork; materials that typical suction cups do not work on.
A chiton also demonstrates the ability to manipulate a gripped object’s orientation. Chitons seek dark areas, so by shining light researchers could control in which direction the creature attempts to “walk”, which manipulates the held object. A chiton’s grip is strong, but release was less predictable than with pill bugs. It seems chitons release an object more or less when they feel like it.
This concept may remind readers somewhat grimly of grippers made from dead spiders, but researchers emphasize that we have an imperative to not mistreat these living creatures, but to treat them carefully as we temporarily employ them in much the same manner as dog sleds or horses have been used for transportation, or carrier pigeons for messages. Short videos of both pill bug and chiton grippers are embedded below, just under the page break.
