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Prototype · Front Line Assembly.
Echoes.
℗ 2014 Metropolis Records.
How infinity threatens cosmology
Posted in cosmology, mathematics, physics
Infinity is back. Or rather, it never (ever, ever…) went away. While mathematicians have a good sense of the infinite as a concept, cosmologists and physicists are finding it much more difficult to make sense of the infinite in nature, writes Peter Cameron.
Each of us has to face a moment, often fairly early in our life, when we realize that a loved one, formerly a fixture in our life, was not infinite, but has left us, and that someday we too will have to leave this place.
This experience, probably as much as the experience of looking at the stars and wondering how far they go on, shapes our views of infinity. And we urgently want answers to our questions. This has been so since the time, two and a half millennia ago, when Malunkyaputta put his doubts to the Buddha and demanded answers: among them he wanted to know if the world is finite or infinite, and if it is eternal or not.
Why do some materials carry electrical currents without any resistance only when cooled to near absolute zero while others do so at comparatively high temperatures? This key question continues to vex scientists studying the phenomenon of superconductivity. Now a team of researchers from Andrea Cavalleri’s group at the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) in Hamburg has provided evidence that electron “stripes” in certain copper-based compounds may lead to a break in the material’s crystal symmetry, which persists even in their superconducting state. Their work has been published in PNAS.
Focusing on a range of cuprates, the team investigated the coexistence and competition of their superconducting state with other quantum phases. Such interactions are believed to be crucial to the development of high-temperature superconductivity—a process which remains one of the most important unsolved problems in condensed matter physics today.
The researchers exposed several cuprate crystals, grown and characterized at Brookhaven National Labs, to ultrashort laser light pulses. They observed how the materials began to emit a particular type of terahertz (THz) light—a technique known as THz emission spectroscopy.
Nanobubbles are extremely small (i.e., nanoscopic) gaseous cavities that some physicists observed in aqueous solutions, typically after specific substances were dissolved in them. While some studies reported the observation of these incredibly tiny bubbles, some scientists have argued that they are merely solid or oily residues formed during experiments.
Researchers at Centro de Investigación y de Estudios Avanzados Unidad Monterrey and Centro de Investigación en Matemáticas Unidad Monterrey in Mexico have recently carried out an experiment aimed at further investigating the nature of these elusive and mysterious objects, specifically when xenon and krypton were dissolved in water. Their study, featured in Physical Review Letters, identified the formation of what the team refers to as “nanoblobs,” yet found no evidence of nanobubbles.
“Our aim was to create xenon and krypton nanobubbles using a clean method,” Carlos Ruiz Suarez, one of the researchers who carried out the study, told Phys.org. “I must say that many scientists claim that nanobubbles, despite their use in many applications, do not exist. Rather, it is thought that they are oil/solid contaminants formed during the experiments.”
Skoltech scientists modeled the behavior of nanobubbles appearing in van der Waals heterostructures and the behavior of substances trapped inside the bubbles. In the future, the new model will help obtain equations of state for substances in nano-volumes, opening up new opportunities for the extraction of hydrocarbons from rock with large amounts of micro-and nanopores. The results of the study were published in the Journal of Chemical Physics.
The van der Waals nanostructures hold much promise for the study of tiniest samples with volumes from 1 cubic micron down to several cubic nanometers. These atomically thin layers of two-dimensional materials, such as graphene, hexagonal boron nitride (hBN) and dichalcogenides of transition metals, are held together by weak van der Waals interaction only. Inserting a sample between the layers separates the upper and bottom layers, making the upper layer lift to form a nanobubble. The resulting structure will then become available for transmission electron and atomic force microscopy, providing an insight into the structure of the substance inside the bubble.
The properties exhibited by substances inside the van der Waals nanobubbles are quite unusual. For example, water trapped inside a nanobubble displays a tenfold decrease in its dielectric constant and etches the diamond surface, something it would never do under normal conditions. Argon which typically exists in liquid form when in large quantities can become solid at the same pressure if trapped inside very small nanobubbles with a radius of less than 50 nanometers.
Insights into how minute, yet powerful, bubbles form and collapse on underwater surfaces could help make industrial structures such as ship propellers more hardwearing, research suggests.
Supercomputer calculations have revealed details of the growth of so-called nanobubbles, which are tens of thousands of times smaller than a pin head.
The findings could lend valuable insight into damage caused on industrial structures, such as pump components, when these bubbles burst to release tiny but powerful jets of liquid.
My 1.5KJ Home-Built Gauss Rifle!
Posted in engineering, habitats
I’ve finally finished my gauss rifle! This is about four months in the making. I may improve on it in the future, or build an entirely new and better one! But I want to take a break from coil guns for a while.
Disclaimer:
I’d consider myself to be a pacifist, and don’t intend to use this on any person or animal. This project has merely acted as an outlet for my interest in electronics and electromagnetism. My aim has also been to create something cool to get others interested in science and engineering.
Coil Gun Design Guide:
https://docs.google.com/document/d/1QH2dbDUKwIGOhsAcvSpi7IVG…sp=sharing.
Circuit Schematic:
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Quantify Discount Link (At-Home Blood Testing)
https://getquantify.io/mlustgarten.
TruDiagnostic Discount Link (Epigenetic Testing)
CONQUERAGING!
https://bit.ly/3Rken0n.
Bristle Discount Link (Oral microbiome quantification):
Do humanoid robots have a future? As Elon Musk demonstrates a humanoid robot, we explore Engineered Arts — a humanoid robot factory with the creator of a highly realistic looking robot. Experts analyse Musk’s proposals so far, looking at how these robots could become a reality.
#humanoid #humanoidrobot #robotics #robot #technology #tech.
Produced and directed by Tom Hannen. Additional filming by Richard Topping, Nicola Stansfield, and Horacio Jones.
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The science fiction icon who coined and popularized the term “metaverse” is pausing his literary career to build his own.
As revealed by Wired, “Snow Crash” author and cyberpunk pioneer Neal Stephenson is working with a crypto bro to create an open metaverse platform that will, its creators hope, be a more decentralized version of the types of Big Tech metaverses like those run by Fortnite and Facebook.
“It’s like Neal is coming down out of the mountains like Gandalf, to restore the metaverse to an open, decentralized, and creative order,” said robotics and augmented reality entrepreneur Rony Abovitz, who is also acting as a strategic advisor to Lamina1, the company Stephenson is cofounding with Bitcoin Foundation head Peter Vessenes.