I believe in a somewhat modified version of 'think it and it happens'. There are probably a few absolute geniuses who, in their minds, have invented something that will not see the light of day for another 10 years. At the moment there is a practical problem such as the lack of a particular raw material or the horrendous expense of a v­ital part. So, those very few people can think it and it is as good as invented, just delayed by the current lack of the particular raw material or the expense of a v­ital part.

The IDMS database software was invented in the 1960s but not implemented because memory and disc space was expensive. IDMS used a vast amount of both and nobody could believe that both would ever drop in price and increase in capacity such that IDMS would ever run. By the late 1970s IDMS was the most used mainframe database software worldwide because memory and disc space was no longer a problem.

New developments are merely incremental to current scientific knowledge and possibly inhibited by current cost. They do not challenge the fundamentals of physics. Such developments are probably happening at DARPA and the Lockheed Martin 'Skunk Works' all the time. They can access incredible amounts of money, which may bring forward such developments to make a prototype now. But this is merely about money, not challenging the known fundamentals of physics.