By Tobias Carroll Imagine, if you will, the offpring of a luxury cruise ship and the Helicarrier from the Marvel Cinematic Universe. It would be several orders of magnitude larger than the biggest passenger jets, with viewing terraces offering guests dramatic vistas of clouds, the aurora borealis and other sights that you can’t easily get when standing on the ground. Oh, and the whole thing would rarely touch the ground, given that it’s nuclear-powered. That’s the thinking at the heart of Sky Hotel, a concept that recently made an online debut via an eye-catching video created by Hashem Al-Gha…