Scientists report the successful creation of a glowing ball of electromagnetic energy in the lab, which they say could offer clues to how mysterious ball lightning forms in nature.
Among the rarest and most puzzling electrical phenomena, ball lightning has fascinated researchers for centuries, although the exact mechanisms behind its formation remain elusive. Generally described as luminous spheres of self-contained electricity that float through the atmosphere, these rare manifestations can sometimes last for several seconds.
Now, the research by a Chinese team, reported in Nature Photonics, demonstrates a similar electromagnetic phenomenon that could point to new possibilities for the storage of electrical energy, as well as generating forms of radiation for various applications.
Capturing Ball Lightning in a Bottle
Although ball lightning has been reported for centuries, scientists still struggle to explain the exact cause behind the spontaneous formation of spherical glowing electrical structures, as opposed to more common forms of lightning.
To create a similar effect in the lab, a team of researchers at the Shanghai Institute of Optics and Fine Mechanics was able to produce a concentrated arrangement of relatively stable electromagnetic fields. To achieve this, the team leveraged terahertz radiation, which occupies a specific region of the electromagnetic spectrum between microwaves and infrared light.
Generating extremely powerful terahertz electromagnetic fields, the researchers created a spherical soliton—essentially a kind of quasiparticle which is propagated as a non-dissipative wave—measuring only a few meters across. Despite its small size in comparison to natural manifestations of ball lightning, the sphere remained detectable for approximately 100 nanoseconds, or around one ten-millionth of a second.
Although this duration would seem extremely brief to most of us, it represents an unusually long period for such an electromagnetic structure to remain sustained under the kinds of extreme conditions of the team’s experiment.
Terahertz EM Fields Resembling Ball Lighting at Larger Scales
During the lab experiments, the research team found that the phenomenon they observed also exhibited characteristics that could correspond to theoretical manifestations of ball lightning at larger scales, similar to how it has often been described appearing in nature. These include observations of ball lighting structures up to around a meter or more in size, which in some instances can last for up to several seconds.
The smaller-scale lab-grown ball lightning was also observed producing light across a range of wavelengths from ultraviolet up to visible light, and even into the infrared. Spectral signatures observed by the research team also revealed the presence of ionization, which suggests that the intense electromagnetic fields were capable of interacting with surrounding matter, offering a possible clue to how such phenomena may occur in nature.
By tracking the changing size and changes in light emissions their sphere exhibited, the researchers reported that it appeared to expand in ways that were also consistent with current theoretical models regarding the interaction between energetic fields and their surrounding matter.
The sustained glow that the ball lightning produced also suggested that the lab-induced electromagnetic structure was able to confine its energy, rather than immediately dispersing it.
Unlocking the Secrets of Concentrated Structures
Overall, the team’s findings provide new experimental approaches for the investigation of powerful electromagnetic fields and how they can produce remarkably stable concentrated structures.
The research goes beyond just understanding how ball lightning forms and maintains its shape: the researchers say their findings may eventually help shed light on high-energy photon storage technologies, as well as advanced technologies that harness powerful radiation.
While the team’s findings do not offer a conclusive explanation for how and why natural ball lightning forms, their experiments do demonstrate that a long-duration electromagnetic structure resembling this long-held natural mystery can be produced and studied under controlled conditions, thereby bringing scientists closer to unraveling the mysteries of a phenomenon that has remained mysterious for generations.
The recent study, “Ball-lightning-like relativistic terahertz solitons,” appeared in Nature Photonics.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.