There is a mystic cult which has grown around the name of Nicola Tesla, which credit him with all manner of inventions which defy the laws of physics, using some form of hidden knowledge which is suppressed by various nefarious and powerful forces. Indeed, the absence of documentary evidence seems to be taken as proof, not of its non-existence, but of the determination and thoroughness with which it has been suppressed. I must admit to being at a loss when it comes to debating such views.