First known magnetic wormhole created

Could make MRIs more comfortable for patients and improve magnetic imaging
September 7, 2015

(Left) 3-D diagram of the magnetic wormhole shows how the magnetic field lines (in red) leaving a magnet on the right side of the sphere pass through the wormhole. (Right) As seen by a magnet, the magnetic field seems to disappear on the right side of the sphere only to reappear on the left in the form of a magnetic monopole. (credit: Jordi Prat-Camps/Universitat Autònoma de Barcelona)

A wormhole* that can connect two regions of space magnetically has been created in the laboratory and experimentally demonstrated by physicists at Universitat Autònoma de Barcelona in Spain.

This is not a wormhole in space, as in the movie Interstellar. It’s a special design that transfers a magnetic field from one location in space to another in such a way that the process is magnetically undetectable and invisible (only visible by light). This is explained in the diagrams above.

The researchers used metamaterials and metasurfaces to build the tunnel experimentally. The magnetic field from a source, such as a magnet or an electromagnet, appears at the other end of the wormhole as an isolated magnetic monopole (a magnet with only one pole, whether north or south, which does not exist in nature).

That causes the magnetic field to appear to magically travel from one location to another through a dimension that appears to (or actually?) lies outside the conventional three dimensions.

How to build a wormhole

The magnetic wormhole device is composed of (from left to right) an outer spherical ferromagnetic metasurface, an inner spherical superconducting layer, and inside that, an inner spirally wound ferromagnetic sheet (credit: (credit: Jordi Prat-Camps/Universitat Autònoma de Barcelona)

To create the wormhole used in this experiment, the researchers designed a sphere made of three layers: an external layer with a ferromagnetic (as in a standard iron magnet) surface, a second inner layer made of superconducting material, and a ferromagnetic sheet rolled into a cylinder that crosses the sphere from one end to the other and conducts the magnetic field.

The magnetic wormhole is analogous to a gravitational wormhole — it “changes the topology of space, as if the inner region has been magnetically erased from space,” explains Àlvar Sánchez, the lead researcher.

Practical applications

The study was published in an open-access paper in Scientific Reports, but the researchers first published the fundamental concept in a paper in Physical Review Letters, where they described it as a “magnetic hose.”

Experimental magnetic wormhole (credit: Jordi Prat-Camps/Universitat Autònoma de Barcelona)

The researchers built a magnetic “hose” capable of channeling a magnetic field from a source to a distance more than 10 centimeters away. (However, that version was detectable magnetically.)

As Steven Anlage, a professor of Physics at the University of Maryland, explains in this open-access article in the journal Physics, channeling magnetic fields could improve the spatial resolution of magnetic-field images, for example.

“Another application would be magnetic resonance imaging, in which the patient and superconducting magnet required to generate the magnetic field could be physically separated, and the intense magnetic field could be applied locally to the patient” (instead of having to enter an MRI machine).

Or it could allow MRI images of different parts of the body to be obtained simultaneously.

There may be other possible uses. Any ideas? Please comment below.

* Wormholes are cosmic tunnels that can connect two distant regions of the universe, popularized by science fiction like Stargate, Star Trek or, more recently, Interstellar. Using present-day technology, it would be impossible to create a gravitational wormhole because the field would have to be manipulated with huge amounts of gravitational energy, which no one yet knows how to generate. In electromagnetism, however, advances in metamaterials and invisibility have allowed researchers to put forward several designs to achieve this.

Abstract of A Magnetic Wormhole

Wormholes are fascinating cosmological objects that can connect two distant regions of the universe. Because of their intriguing nature, constructing a wormhole in a lab seems a formidable task. A theoretical proposal by Greenleaf et al. presented a strategy to build a wormhole for electromagnetic waves. Based on metamaterials, it could allow electromagnetic wave propagation between two points in space through an invisible tunnel. However, an actual realization has not been possible until now. Here we construct and experimentally demonstrate a magnetostatic wormhole. Using magnetic metamaterials and metasurfaces, our wormhole transfers the magnetic field from one point in space to another through a path that is magnetically undetectable. We experimentally show that the magnetic field from a source at one end of the wormhole appears at the other end as an isolated magnetic monopolar field, creating the illusion of a magnetic field propagating through a tunnel outside the 3D space. Practical applications of the results can be envisaged, including medical techniques based on magnetism.