The invisible shield is the result of very low frequency radio communications interacting with particles in space.
The barrier, which comes and goes, is the result of very low frequency radio communications interacting with particles in space, which results in a sort of shield protecting Earth from high energy radiation in space.
A number of experiments and observations have figured out that, under the right conditions, radio communications signals in the VLF frequency range can in fact affect the properties of the high-energy radiation environment around the Earth,” Phil Erickson, one of the scientists involved, said in a statement.