Waves in the Earth: Tesla's Earth Resonance Patent (U.S. 787,412)

2 minute read. Published October 17, 2026.

In short: U.S. Patent No. 787,412, Art of Transmitting Electrical Energy Through the Natural Mediums, was granted to Nikola Tesla in 1905. It proposes treating the earth as a giant conductor that can be set into electrical resonance, so that energy sent into the ground at one place could be received at another, potentially very far away.

Tesla's 1905 earth resonance patent drawing printed in amber on a black T-shirt — The drawing from U.S. Patent 787,412, restored and printed in amber on black.

What is the idea behind it?

Strike a bell and it rings at its natural frequency. Tesla believed the earth could behave in a similar way electrically. If a transmitter pumped energy into the ground at just the right frequency, the planet would respond with standing electrical waves, and receivers tuned to the same frequency could tap into them.

Where did Tesla get the idea?

During his 1899 experiments in Colorado Springs, Tesla studied the electrical disturbances caused by distant lightning storms. He became convinced that he was observing waves travelling through the earth and reflecting back, evidence, in his view, that the planet could act as a resonant circuit.

Did it work?

Tesla never built a working system that sent usable power around the world this way, and the theory is still debated by historians of science. What's beyond dispute is how far ahead of its time the thinking was: it treats the whole planet as part of an electrical system.

What does the drawing show?

The drawing is wide and spare: apparatus connected between the ground and an elevated terminal, laid out horizontally. On a shirt, it sits as a clean band of linework across the chest.