The basic concepts of ULF and VLF transmissions aren't new. They've been used in the military for decades for contacting submarines and otherwise impractical feats. The challenge here is packing the necessary electromagnetic power into a relatively small space, since you're physically moving materials with strong electrical or magnetic fields instead of relying on circuits and amps. Cold War-era VLF stations required vast amounts of land as well as towers hundreds of feet tall. The AMEBA group is counting on breakthroughs in design, insulators, magnets and engineering to make its vision a reality.

The ball will get rolling soon, at least. DARPA is talking to idea proposers on January 6th, and recent science has shown that there's definitely room for more discoveries in magnetism. The project is unsurprisingly focused on military uses -- special forces in particular could use it in situations where they'd otherwise have to go silent. However, it's not a stretch to imagine these transmitters being useful in any situation where it would be virtually impossible to get in touch.