In his 1891 public lecture on the structure of the aether and electromagnetism, given at a time when the since discredited notion of the luminiferous aether was still scientifically respectable, Tesla claimed that there exists an infinitesimal world, with molecules and their atoms spinning and moving in orbits, in much the same manner as celestial bodies carrying with them static charges. Tesla further claimed that carriers exist transmitting "tensions or electrostatic strains".