That's all it takes.

The entire Earth's magnetic field is waiting to be tapped by a properly atteneuated inductance coil, creating, for all intents and purposes, limitless electrical power.

However, gifts of bright minds to those who cannot elevate themselves culturally to the point they create these things for themselves is historically a very bad idea. Like medicine or food, they almost always become tools of the reigning tyrant to further enslave the masses and tighten their grip of control.

And the more powerful the gift, the more dangerous, and all too often one has to bite one's tongue and keep it under wraps - because, ironically, that's what's in the best interests and welfare of the recipients.