Thursday 27 August 2015

Metamaterial wormhole Teleports Magnetic Fields across Space

Metamaterials are the stuff futurists dream of: painstakingly engineered materials of conventional origin (plastics, metal, etc.) that display properties not found in nature, enabling things like invisibility (also sometimes called ‘cloaking’), imaging beyond the diffraction limit of light and dissipating seismic waves.

Metamaterials differ with conventional materials

In that they display significant interaction with the magnetic component of electromagnetic waves. It is this property that has been exploited by Alvaro Sanchez et al. at the Universitat Autònoma de Barcelona (Autonomous University of Barcelona), in Spain, who claim to have built the world’s first magnetic wormhole. Unlike the wormhole of the popular lexicon however, this is no portal in space-time that allows travelling over great distances almost instantaneously; it is simply a device that allows a magnetic field originating in one region to emerge elsewhere, the device itself remaining magnetically undetectable. Simply put: an invisible (so to speak) device that absorbs a magnetic field at one end and emits the field, unchanged, at the other, much like an invisible garden hose that apparently causes water to vanish at the tap and spontaneously rematerialize at the other end.

This “pipe of magnetism” seems fairly insignificant at first glance, until you consider that when a magnetic field disappears at a point, it effectively is a magnetic monopole.

More about the idea

The idea was first put forth in a 2008 paper “Electromagnetic wormholes and virtual magnetic monopoles” by Allan Greenleaf et al. According to Matti Lassas at the Helsinki University of Technology in Finland, co-author of the 2008 paper, some clever manipulations of the mathematical constructs in that paper, by the scientists at the Autonomous University of Barcelona, have enabled the “wormhole device” to finally fall within the scope of present engineering techniques.

The device has at its core a magnetised nickel-iron tube, coated with “metasurfaces” that actually transmits the magnetic field. It is surrounded by a spherical mesh of superconducting alloy (made of yttrium barium copper oxide) that helps with both repelling the field inside the tube as well as protecting it from distortion due to incoming external fields. Now to completely make the arrangement magnetically undetectable, the sphere is further enclosed in a ferromagnetic metal array that disguises the superconductor’s magnetic signature. The entire arrangement is dipped in liquid nitrogen to bring the temperature down to where the yttrium barium alloy becomes superconducting.

The result is simply that a magnetic field disappears into one end of the apparatus and appears out the other end. No field is detected between the two ends. This is effectively a pair of monopoles, one at each end of the device.

This ‘cloaking’ of magnetic fields as they travel has significant advantages, the most obvious of which, at least at the present, is in the field of medicine. The MRI machine has revolutionised medical care by providing doctors the ability to fully image the entire human body, a very tedious and slow process with x-rays, which also posed the risk of radiation overexposure, in very little time. With this device multiple imagers could work simultaneously without mutual distortion. The ‘cloaking’ effect could also be implemented in that it would be possible to use metal implements, viz. surgical equipment, in the vicinity of an MRI machine. Presently, the strong fields emanated by an MRI machine can cause unsecured metal to fly across the room. Metal also interferes with the imaging.

Another scenario is one in which the patient does not have to lie inside a loud claustrophobic machine for a scan; the fields generated by the actual machine could simply be “teleported” around the patient.

Most of all though, this device actually presents us with a functional magnetic monopole, the likes of which have eluded us, despite theoretical evidence, for decades. New research will definitely open avenues to as-of-yet unknown applications for the magnetic wormhole.

Assuming this holds up to third-party confirmation and is peer reviewed for accuracy, it really might be a real game changer.

Next stop, real matter?

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