I know this is like a hindsight 20/20 thing, but it would seem to me the only 'problems' left to solve are just the really hard ones (even on the scale of a dec

I know this is like a hindsight 20/20 thing, but it would seem to me the only 'problems' left to solve are just the really hard ones (even on the scale of a decade): fusion, unified field theory, intelligent / extraterrestrial life, becoming multi-planetary species, etc. My feeling is that biotech or nanotech have the most room for something revolutionary or unforseen to be produced