[QUOTE=Slick Cam;183535]They say technological advancement is exponential. Our conception of the expected timeframe, based on past experience, may not be valid… We’ll see
However, we still don’t have hover-boards, or flying cars.[/QUOTE]
Hover board does exist: http://www.wired.com/2015/10/how-the-most-promising-hoverboards-actually-work/
Even kids can build them: https://www.youtube.com/watch?v=4HI137m7XA4