A mainstay of classic science fiction is the flying saucer, the universal icon for extraterrestrial alien space vehicles. The problem is, no species capable of constructing ships to traverse the stars would ever go with a saucer design that involved spinning, as astrophysicist Neil deGrasse Tyson explains here.
He goes over the basic issues with the design on his regular radio show, Star Talk, snippets of which are available on YouTube. In one dated May 2, deGrasse Tyson starts off by humorously pointing out a visual faux pas with old Hollywood:
Anytime I saw flying saucers in movies spinning, yet the people in the flying saucer just look out of a window that has a constant facing direction, I couldn't reconcile [that].
deGrasse Tyson then moves onto the science:
There are some fundamental problems with an entire rotating ship. If you set it into rotation, something else has to be rotating in the opposite direction ... you learn it in the second week of physics — these are laws that apply to the entire universe — it's the conservation of angular momentum.
So, for a saucer to just spin up, I just don't see the point ... those are the stupid aliens.
Of course, there's a bit more too it, so if you'd like to listen watch the clip above or head over to YouTube below.