Science fiction novels, television and movies are riddled with wormholes, places where a spaceship can fly through a mysterious field and wind up in a completely different place. While physicists have proposed theories for how we might generate such gravitational wormholes, current technology does yet not allow for the creation of the massive energy required to create such a phenomenon.
In 2007, a group of mathematicians offered suggestions for how to create a “magnetic wormhole” that would begin with a magnetic field in one place and end with the field in another location. To be classified as a wormhole, the space between the beginning and end of the fields would need to be undetectable. Until recently, these theories proved to be unworkable because the space between magnetic fields was not hidden, or cloaked, effectively.
But on September 3, physicists Jordi Prat-Camps, Carles Navau, and Alvaro Sanchez from the Autonomous University of Barcelona published the results of their successful creation of a magnetic wormhole. To mount the impossible, they built a separate area of three-dimensional space using three layers of metamaterials and metasurfaces. Because of the difficulties with previous attempts, the researchers focused their efforts on finding a way to cloak the space between fields. Metamaterials and metasurfaces are created when two existing natural elements are combined and the new hybrid materials act in ways that the existing elements are not capable of on their own. They can even alter physical phenomena such as light and sound.
Recent research into metamaterials conducted at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and the University of California Berkeley has resulted in the creation of invisibility cloaks that hide small objects by distorting light, making them look
flat, or masking a heat signature. Prat-Camps et al used metamaterials and metasurfaces to build a device outside of normal space to carry and hide a magnetic field.
The magnetic wormhole was created with three layers: a ferromagnetic sheet, made from materials that are unusually easy to make into strong magnets, was wound into a spiral, surrounded by a superconducting sphere, enclosed by a ferromagnetic metasurface similar to the ones used to manipulate light. Ferromagnetic materials are among the best at supporting a magnetic charge within themselves (highly permeable), while superconductors have low permeability.
via Nature (a) The field of a magnetic source (right) is appearing as an isolated magnetic monopole when passing through the magnetostatic wormhole; the whole spherical device is magnetically undetectable. (b) The wormhole is composed of (from left to right) an outer spherical ferromagnetic metasurface, a spherical superconducting layer, and an inner spirally wound ferromagnetic sheet.
Each section was unsuccessful in masking the magnetic field on its own, but when combined as shown, the authors were unable to detect any magnetic activity between the fields on the outside of the sphere. Additionally, the magnetic field on the far end of the sphere is monomagnetic and attracts in only one direction, something that does not happen in nature.
This magnetic wormhole isn’t just a fun bit of science fiction come to life. Prat-Camps et al suggest that it has the potential to change medicine. The magnetic fields projected through it could eventually allow doctors to perform simultaneous MRIs on a patient since the magnetic fields used in the imaging would not intersect. The authors also believe magnetic wormholes could be used in engines or electric energy generators. As research continues, scientists and researchers may find more practical applications.
Featured image via Flickr user Dennis van Zuijlekom