It's time to build: a New World's Fair
The last really prophetic world's fair was New York, 1939. That's famous for GM's vision of the future of 1960, the original "Futurerama" . Freeways everywhere.  RCA had television. AT&T let you make free long distance calls. All that stuff happened.<p>The 1964 World's Fair had another GM exhibit. Colonization of the Moon. Underwater cities. None of that happened.<p>What could we have in a World's Fair now that looks ahead? Colonization of Mars? Mars sucks as real estate. There may be research bases there someday, but as a self-sufficient area, it would be tougher than Antarctica or a continental shelf. Robots may some day be a thing, but they still don't work well in unstructured environments.