I doubt anybody will ever see this response, but about the Hoverboard, here it is:
Hoverboards are originally from China [1] however, most of us have likely learned about them from Kickstarter etc. I think the users of HN would agree that "invention is never a sudden thing". The process for hoverboards has been iterative, of course. I have heard claims of having commercial hoverboards as much as five years before they became household names in the US.