"-What happened to this technology in the years after WW2?"
good question. it all went black when kennedy was killed. we get frauds based on fantasy science but no real new technology since nov of 63. i found one exception - velcro. we are still using 19th century technology everywhere in our everyday lives. everything else is secretly being used, many times against us in some kind of fraudulent power play. if not already, if and when they perfect free energy they will never tell us a thing, except maybe they are raising our rates again (for greater profit, of course).