Tesla called the idea of atomic energy "illusionary." In a 1931 New York Times interview he said: "The idea of atomic energy is illusionary but it has taken so powerful a hold on the minds, that although I have preached against it for twenty-five years, there are still some who believe it to be realizable."
He stated he had shattered atoms with high voltages yet saw no usable energy release, and that any process would require more energy input than it could return.