Lifeboat Foundation

Monitoring the fissile material aboard nuclear-powered submarines is notoriously difficult. Researchers may now have a way to safeguard this weapons-grade substance.

Last year, the United Kingdom and the United States agreed to transfer some of their nuclear-powered submarines to Australia, a country that, at that time, possessed none. On hearing the announcement, Bernadette Cogswell and Patrick Huber of Virginia Tech in Blacksburg say that they were immediately concerned as there is currently no easy way to safeguard a nuclear reactor aboard a submarine. Now, the duo has come up with a technique that could solve that problem [1]. They say that the method could be used to confirm the presence of a submarine’s nuclear core without the need for onboard monitoring.

Most naval nuclear reactors employ uranium that is highly enriched fissile uranium-235 (235U 2 3 5 U 235U), a material also used to make nuclear weapons. For land-based reactors, inspectors keep track of 235U 2 3 5 U 235U using neutrino detectors placed close to an operating core (see Feature: Neutrino Detectors for National Security). But this technique doesn’t work for the water-submerged cores in submarines at sea. It also fails for the weak signals from powered-down cores, allowing operators to subvert checks of docked submarines.

Defining a fermionic lattice using spin and momentum instead of spatial coordinates opens the door for interacting-fermion simulations with more complex lattice geometries.

Amazon Linux server can be hacked easily. Critical Privilege Escalation vulnerability in Log4j Hotpatch released to fix Log4j vulnerabilities — Vulnerabilities — Information Security Newspaper | Hacking News.

Electrons are some of the most basic building components of matter that we are familiar with. They have several distinguishing characteristics, including a negative charge and the existence of an exact intrinsic angular momentum, often known as spin. Each electron, as a charged particle with spin, has a magnetic moment that aligns in a magnetic field as a compass needle does.

Quantum electrodynamics can forecast the strength of this magnetic moment, which is given by the so-called g-factor, with incredible accuracy. This computation agrees to within 12 digits with the empirically determined g-factor, making it one of the most precise theory-experiment matches in physics to date. The magnetic moment of the electron, on the other hand, changes when it is no longer a “free” particle, that is, when it is linked to an atomic nucleus, for example. QED, which defines the interaction between electrons and nucleus in photon exchange, can be used to determine minor changes in the g-factor. This notion can be sensitively tested thanks to high-precision measurements.

In a new study, scientists at the Max Planck Institute for Nuclear Physics (MPIK) in Heidelberg successfully investigated QED predictions with unprecedented resolution. They used a newly developed technique to measure a very small difference in the magnetic properties of two isotopes of highly charged neon in an ion trap with previously inaccessible accuracy.

Imagine a road with two lanes in each direction. One lane is for slow cars, and the other is for fast ones. For electrons moving along a quantum wire, researchers in Cambridge and Frankfurt have discovered that there are also two “lanes,” but electrons can take both at the same time!

Current in a wire is carried by the flow of electrons. When the wire is very narrow (one-dimensional, 1D) then electrons cannot overtake each other, as they strongly repel each other. Current, or energy, is carried instead by waves of compression as one particle pushes on the next.

It has long been known that there are two types of excitation for electrons, as in addition to their charge they have a property called spin. Spin and charge excitations travel at fixed, but different speeds, as predicted by the Tomonaga-Luttinger model many decades ago. However, theorists are unable to calculate what precisely happens beyond only small perturbations, as the interactions are too complex. The Cambridge team has measured these speeds as their energies are varied, and find that a very simple picture emerges (now published in the journal Science Advances). Each type of excitation can have low or high kinetic energy, like cars on a road, with the well-known formula E=1/2 mv², which is a parabola. But for spin and charge the masses m are different, and, since charges repel and so cannot occupy the same state as another charge, there is twice as wide a range of momentum for charge as for spin.

Stanene is a topological insulator comprised of atoms typically arranged in a similar pattern to those inside graphene. Stanene films have been found to be promising for the realization of numerous intriguing physics phases, including the quantum spin Hall phase and intrinsic superconductivity.

Some theoretical studies also suggested that these films could host topological superconductivity, a state that is particularly valuable for the development of quantum computing technology. So far, however, topological edge states in stanene had not been reliably and consistently observed in experimental settings.

Researchers at Shanghai Jiao Tong University, the University of Science and Technology of China, Henan University, Zhengzhou University, and other institutes in China have recently demonstrated the coexistence of topological edge states and superconductivity in one to five-layer stanene films placed on the Bi(111) substrate. Their observations, outlined in a paper published in Physical Review Letters, could have important implications for the development of Stanene-based quantum devices.

Adam FordAdmin.

I disagree with Ross Dawson here… it’s not ultimately a matter of belief or faith, it’s a matter of understanding our existing knowledge about the physiology of sentience, and of furthering the relevant research agendas. Questions of sentience in h… See more.

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ANOTHER solar flare has a chance of hitting Earth today.

A huge expulsion of particles from the Sun hit Earth yesterday and we could see a similar geomagnetic storm causing event today.

The experts at SpaceWeather.com explained: NOAA forecasters say there is a 25% chance of M-class solar flares today.

Using a newly developed technique, scientists at the Max Planck Institute for Nuclear Physics (MPIK) in Heidelberg have measured the very small difference in the magnetic properties of two isotopes of highly charged neon in an ion trap with previously inaccessible accuracy. Comparison with equally extremely precise theoretical calculations of this difference allows a record-level test of quantum electrodynamics (QED). The agreement of the results is an impressive confirmation of the standard model of physics, allowing conclusions regarding the properties of nuclei and setting limits for new physics and dark matter.

Electrons are some of the most fundamental building blocks of the matter we know. They are characterized by some very distinctive properties, such as their negative charge and the existence of a very specific intrinsic angular momentum, also called spin. As a charged particle with spin, each electron has a magnetic moment that aligns itself in a magnetic field similar to a compass needle. The strength of this magnetic moment, given by the so-called g-factor, can be predicted with extraordinary accuracy by quantum electrodynamics. This calculation agrees with the experimentally measured g-factor to within 12 digits, one of the most precise matches of theory and experiment in physics to date. However, the magnetic moment of the electron changes as soon as it is no longer a “free” particle, i.e., unaffected by other influences, but instead is bound to an atomic nucleus, for example.

Lasers produce coherent waves of light: All the light inside a laser vibrates completely in sync. Meanwhile, quantum mechanics tells us that particles like atoms should also be thought of as waves. As a result, we can build “atom lasers” containing coherent waves of matter. But can we make these matter waves last, so that they may be used in applications? In research that was published in Nature this week, a team of Amsterdam physicists shows that the answer to this question is affirmative.

Getting bosons to march in sync

The concept that underlies the atom laser is the so-called Bose-Einstein Condensate, or BEC for short. Elementary particles in nature occur in two types: fermions and bosons. Fermions are particles like electrons and quarks—the building blocks of the matter that we are made of. Bosons are very different in nature: they are not hard like fermions, but soft: for example, they can move through one another without a problem. The best-known example of a boson is the photon, the smallest possible quantity of light. But matter particles can also combine to form bosons—in fact, entire atoms can behave just like particles of light. What makes bosons so special is that they can all be in the exact same state at the exact same time, or phrased in more technical terms, they can “condense” into a coherent wave. When this type of condensation happens for matter particles, physicists call the resulting substance a Bose-Einstein Condensate.