The innovations of the past century were easier for amateur inventors to build without capital. Think of the Wright Brothers - a couple of bicycle makers built the first powered aircraft.

Could the equivalent pair of bicycle mechanics build the first reusable spaceship or electric flying car? Building a new space launch system will cost $500m+. Neither governments nor large aerospace firms are willing to take large risks with this amount of money. Incremental improvements to proven systems are much easier to justify.

I think crowd-funding and the Internet will lead to a new boom in innovation. The Pebble watch is a good example. The VC's turned them down, and now the public has pre-purchased $7m of Pebble watches in two weeks.

We need new forms of risk capital for inventors. VCs and governments are not going to fund enough high risk innovation. They both rejected my pitch for electric aviation saying it was "too ambitious for a startup" (http://electrictakeoff.com).