Nikola Tesla theorized that the Earth possessed "fluid electrical charges" beneath its surface, and that disrupting these with a series of precisely timed electrical discharges could unlock a limitless power supply by generating immense low-frequency electrical waves.
This theory, while innovative, is not scientifically accepted. Tesla's ideas surrounding wireless power transmission and resonance were groundbreaking, but his specific concept of tapping into a boundless energy source within the Earth remains largely unproven and controversial within the scientific community.
Essentially, Tesla envisioned a way to resonate with the Earth's natural electromagnetic frequencies to transmit power wirelessly over long distances. He believed that by injecting electrical energy into the Earth at specific frequencies, he could create standing waves that could be tapped into anywhere on the globe. The Wardenclyffe Tower, his unfinished project, was intended to test and potentially implement this concept.
While Tesla's work inspired significant advancements in alternating current (AC) electricity and wireless communication, his theories about free energy from the Earth have not been validated through empirical evidence or rigorous scientific testing.