1916: Rediscovering the ZENNECK Surface Wave

In 1916 while speaking of his system for global transmission, Nikola Tesla cited the analysis of mathematician Arnold N. Sommerfeld as verification of his explanations of observed radio phenomena. Tesla was referring to his system in which 90% to 95% of the electrical energy was manifested at the transmitter’s output as “current waves” with the remainder directed to the antenna structure, resulting in dissipating EM radiation. In 1909 another investigator by the name of Johann Zenneck, while working to explain Marconi’s trans-oceanic results, showed that a unique type of surface wave could travel along with the interface between the ground and the air. In the words of Dr. James Corum, “The distinguishing feature of the Zenneck wave was that the propagating energy didn’t spread like radiation, but was concentrated near the guiding surface. Sommerfeld had shown that an electromagnetic wave could be guided along a wire of finite conductivity, […] Read More