Throughout history, the size and grandeur of buildings -- royal palaces, medieval cathedrals, corporate skyscrapers -- have testified to their occupant's power. But modern architects predicted buildings that would not only attain mind-blowing dimensions, but also radically alter our concepts of what buildings could be. While science fiction warned that the one-percenters would retreat to supertowers and form their own corporate countries, architects like Paolo Soleri described population-dense, self-contained architectural ecologies, or arcologies, that sought to change society for the better.
Architectural wonders never cease, they just move forward a bit more slowly and more piecemeal than expected. As Dubai's 2,716-foot (828-meter) Burj Khalifa and its ilk demonstrate, architects and status seekers keep reaching for more sky to scrape, even if they have to use vast, unoccupied spires to achieve the heights their compensatory needs demand [sources: CTBUH; Lecher].
Meanwhile, green architecture and engineering have produced buildings that ventilate like termite mounds, sport rooftop gardens and solar farms, and manage sunshine like a vampire bungalow. Unfortunately, current arcologies remain half-realized showpieces, sufficient only to inspire further development of green technologies that may or may not prove sufficient to power a future world [sources: Biomimicry Institute; Goodman; Kingsley].