ABOVE — Artist’s impression of an asymmetric toroidal vortex (a “heart”).
The shape of the healthy heart is optimized for vortex ring formation
Fusion energy research has in the past 40 years focused primarily on the tokamak concept, but recent advances in plasma theory and computational power have led to renewed interest in stellarators. The largest and most sophisticated stellarator in the world, Wendelstein 7-X has just started operation, with the aim to show that the earlier weaknesses of this concept have been addressed successfully, and that the intrinsic advantages of the concept persist, also at plasma parameters approaching those of a future fusion power plant. Here we show the first physics results, obtained before plasma operation: that the carefully tailored topology of nested magnetic surfaces needed for good confinement is realized, and that the measured deviations are smaller than one part in 100,000. This is a significant step forward in stellarator research, since it shows that the complicated and delicate magnetic topology can be created and verified with the required accuracy.
Let’s translate aerodynamic terms from the following illustration into electrodynamic terms:
MOTION — time-dependent magnetic field;
ROTATION AXIS — angular momentum (spin) of elementary particles and atoms;
PRESSURE — electric field’s charge density.
The Magnus force points in the direction from the high to the low pressure, so the Abraham-Magnus force should point from the high electric field’s charge density to the low one.
The Magnus force is a macroscopic aerodynamic phenomenon; the Abraham force is a quantum (microscopic) electrodynamic phenomenon.
Would it be possible to combine a macroscopic aerodynamics phenomenon with a quantum (microscopic) electrodynamic phenomenon, into one Abraham-Magnus force in one electromechanical experiment?
Perhaps we could try to spin a macroscopic object, like a gyro, inside Earth’s magnetic and electric fields?
Instead of a ball moving through stationary air, we have time-dependent magnetic field moving through stationary spinning gyro (relative motion).
Earth is a spherical, asymmetric electric capacitor, and that would provide for inhomogeneous electric charge density distribution, i.e. the high-low pressure difference:
and therefore the force should point from the high electric charge density to the low one, as indicated by red arrows above.
” It followed from the Special Theory of Relativity that mass and energy are both but different manifestations of the same thing, a somewhat unfamiliar conception for the average mind.” — Albert Einstein
The Magnus force and the Abraham force are both but two manifestations of the same, deeper, scale-invariant principle.
THE Abraham-Magnus FORCE FOR SPACE PROPULSION:
According to experiments performed by Dr. Takaaki Musha, the dynamic Biefeld-Brown effect is stronger than the static one. According to my understanding, the static Biefeld-Brown effect is in fact quasi-static, i.e. less dynamic than the dynamic one.
Even though the Abraham force produces electromagnetotoroids, in case of a typical table-top Abraham force experiment, this happens at the quantum scale only.
Because the Biefeld-Brown effect is a modified instance of the Abraham force, there are both, the quasi-static and dynamic Abraham-Magnus effect. To distinguish between the two, for the static one I propose to use the term magnetotoroid, and for the dynamic one to use the term electromagnetotoroid.
Now, where is electromagnetotoroid in the Abraham-Magnus force? Because the Sun spins:
- its magnetic field becomes twisted (like a vortex?);
- due to the tilt of the magnetic axis in relation to the Sun’s spin axis, the heliospheric electric current sheet (and also its associated electric field?) flaps like a flag in the wind.
Therefore, a macroscopic material body, like a tennis ball, or a gyro, while spinning in Earth’s magnetic and electric fields, will form toroidal vortex structures in magnetic field, i.e. magnetic vortex tubes (this would be in regard to the quasi-static Abraham-Magnus effect). This applies also to moons, planets, stars, solar systems, and galaxies.
If a spinning macroscopic material body can form toroidal vortex structures in magnetic field, then I would also expect to observe magnetic vortex tube produced by one body influence another body in such a way that the vortex tube will enclose it (something like a vacuum-cleaner hose sucking at a ping-pong ball) and makes it start spinning. It should all naturally work both ways, like electricity with magnetism. For example, toroidal vortex tube connects two spinning bodies, Jupiter and its moon:
In regard to the dynamic Abraham-Magnus effect, electromagnetic toroidal vortex structures could, by analogy, look like the one on the following illustrations below.
The Fedorov-Imbert controversy
An example of the transverse helicity-dependent momentum in an evanescent field was first found by F.I. Fedorov in 1955. Incidentally, this discovery caused a half-century-long controversy in the physics of light reflection and refraction. Analysing the total internal reflection of a polarized plane wave, Fedorov found a helicity-dependent transverse component of the Poynting vector in the transmitted evanescent field. Fedorov concluded that ‘the lateral energy flux should lead to a specific light pressure’, and by an analogy with the Goos–Hänchen effect, that ‘the reflected beam in the case of total reflection must be displaced in the lateral direction’. Later, C. Imbert indeed observed such helicity-dependent beam shift experimentally, and the effect is now known as the Imbert–Fedorov transverse shift, or spin Hall effect of light.
Giving Light a New Twist
Physicists have known for a century that a light beam can carry angular as well as linear momentum, but about 15 years ago they learned that this rotation comes in two distinct forms. In the 28 April PRL, researchers describe an optical device that cleanly converts one kind of angular momentum into the other, a demonstration that may ultimately find applications in communication and computing.
Imagine that a wide beam of so-called circularly polarized light is pointed at you. As you look at the beam, the electric field vectors across its face would all appear to sweep around like a set of synchronized clock hands. Now imagine that the clock hands move at the same rate but are out of phase. Freezing the motion, a clock at the top of the beam might point to three o’clock, whereas one to the right of center might point to six o’clock, and so on around the beam.
In quantum terms, the beam consists of photons, each one imbued with the properties of the beam as a whole. “Synchronized clocks” corresponds to photons with one unit of intrinsic spin, positive or negative according to the sense of the rotation. In the “clocks out-of-phase” case, the photons also possess so-called orbital angular momentum. A single photon can in principle carry any whole-number amount of this rotation, from minus to plus infinity.
Orbital angular momentum is hard to visualize, admits Lorenzo Marrucci of the University of Naples, Italy, but it interacts with matter differently than spin does. If a particle sitting off-axis in a light beam absorbs a photon with orbital angular momentum, it responds by circulating around the beam, not by spinning on its axis.
Marrucci and his colleagues have built a device that reverses the spin of photons while transferring the change of angular momentum into the orbital kind. For example, a photon entering with plus one unit of spin and no orbital momentum will leave with minus one unit of spin and two units of orbital angular momentum, keeping the total constant. Similar arithmetic holds true for any incoming combination of spin and orbital angular momentum.
The design of the converter begins with a standard optical device known as a half-wave plate, made of a material in which light moves at different speeds depending on the direction of its electric field relative to the crystal lattice. Ordinarily, a half-wave plate converts right-handed (“clockwise”) circularly polarized light into left-handed, and vice versa, equivalent to changing the sign of the photon spin. But the Neapolitan physicists created a more sophisticated converter by arranging that one of the crystal axes of the optical material is not aligned the same throughout the device. Instead, its orientation changes with location on the plate. With the right choice of this variation, the device doesn’t absorb spin angular momentum when it reverses a photon’s spin but instead switches it into orbital angular momentum of the outgoing photon.
A proposed scheme for generating torus-shaped light pulses called flying doughnuts utilizes a metamaterial “sprinkled” with tiny resonators in a concentric ring pattern.
Textbook electromagnetic waves are typically transverse, which means their electric and magnetic fields point perpendicularly to the direction of wave propagation. However, certain electromagnetic waveforms have longitudinal field components that are parallel to the propagation direction. One example is the flying electromagnetic doughnut, whose fields wrap around in a torus pattern. Such pulses could potentially transfer information, accelerate particles, or perform spectroscopy, but so far they have never been observed. A new scheme by Nikolay Zheludev from the University of Southampton, UK, and colleagues shows how flying doughnuts might be generated using a metamaterial based on a circular array of resonators.
Proposed over 20 years ago, flying doughnuts are one-cycle pulses, meaning the fields go up and down just once as the wave packet passes through a point in space. Such a compact pulse would be ideal for delivering energy or information. The problem is that the complicated spatiotemporal structure of a flying doughnut cannot be generated by a single antenna but requires an array of antennae emitting waves at different frequencies and with different phases. Coordinating electrical inputs to the antennae to produce such an emission pattern at optical wavelengths is beyond current technology.
The strategy of Zheludev and colleagues allows conversion of an ordinary light pulse into a flying doughnut by using a polarization converter and a specially designed metamaterial. The proposed metamaterial is a flat sheet containing a pattern of small dipole resonators arranged in concentric rings. When excited by the incoming light pulse, the resonators individually emit pulses—like an array of coordinated antennae. The resonators have different shapes, which affects their emission: the resonators near the center emit shorter, higher-frequency pulses than those on the periphery. The team performed numerical simulations showing that the metamaterial can produce flying doughnuts, and they are now working on an experimental prototype.
Knotted vortex ring
Two US researchers have effectively created “smoke rings” in water and knotted them together for the first time. The development, reported in Nature Physics, opens the path to new understandings in fields as diverse as cosmology, meteorology, fluid dynamics and turbulence. Australian physicists praised the work and said the ability to now create knotted vortices would allow researchers to study properties such as their structure and stability.
The creation of vortex rings, such as a smoke ring, is common, but tying one into a knot has eluded researchers for the past 50 years.
“Whereas tying a shoelace into a knot is a relatively simple affair,” write researchers Dr Dustin Kleckner and Professor William Irvine of Chicago University in their paper, “tying magnetic field into a knot is a different story. The entire knot must be twisted everywhere to match the knot being tied at the core.”
To create the knotted vortex the team used a three-dimensional printer and high-speed cameras filming at 100,000 images per second allowed them to observe the behaviour of linked and knotted vortex loops.
Traditionally to create vortex in water scientists have forced a burst of fluid through a hole. In this paper, the researchers used a round wing structure with angled edges that when accelerated through water generates linked rings or a “trefoil” – a single ring that ties itself into a knot.
Irvine says until now energy and momentum have been considered the key to understanding fluid dynamics but there is a “lot of interest and suggestion that the degree of knottedness in fluids will help us understand fluid flow”.
Associate Professor Matthew Davis, of the University of Queensland agrees, adding that vortices are the “building blocks” of turbulence in fluids. “Understanding the general properties of turbulence is a big deal – for example in aerodynamics and designing more efficient planes/cars. “But despite being able to solve equations for fluid flow, we still don’t have that much insight into the generic properties of turbulence.
“What they have been able to do is to generate the most basic structures of knotted vortices, and study how they break up in a fluid experimentally. I think this is important because it could well help provide some insight into turbulence.”
Kleckner says creating the knotted vortices is an “important first step”. However he says they are now looking at the finer structure of the knots such as whether they can untie and how they interact.
“In particular, linked and knotted vortices both spontaneously self-interact through a series of local reconnections: sections of the vortex collide, break, and reconnect in such a way that the knots become a series of separate, contorted, rings,” he says.
“The possibility of finding analogous structures in vastly different physical systems ranging from cosmology to string theoretical models makes these experiments in classical fluids really exciting because the motion of these water vortices can be seen just by looking at them. It is this kind of first-hand experience which may turn out to be tremendously important when trying to understand the knotted vortices in more exotic contexts where direct visual observations are not available.”
Optical diametric drive acceleration through action–reaction symmetry breaking
A team of physicists working at the University of Erlangen-Nuernberg in Germany has built a working optical diametric drive. Scientists have toyed with the idea of diametric drives for quite some time, hoping to overcome the obvious limitation that it goes against Newton’s third law of motion that every action must have an equal and opposite reaction.
Even though ideas of this sort have been around for several years, they have never been successfully pursued because mass in nature is always a positive quantity. The principles behind this breakthrough are ideas like “negative mass,” but the results are simple enough, and speak for themselves.
A diametric drive is basically an antigravity system that uses a block of material with negative mass to create a negative gravitational field that would endlessly repel an object with actual mass, a spaceship.
Diametric drive refers to the possibility of a self-contained, space propulsion engine that operates without the need for any external fuel. Though nothing remotely like an antigravity material has yet been found, light can have a negative effective mass if manipulated just right — and that’s what this team’s device is designed to do, because the concept of negative mass is not restricted to photons.