Re: The upside-down Enterprise
And if you have a single spaceship, then Up is simply where the ceilings are. And nobody would design a spaceship with an interior where there is no recognizable up and down, because humans would go crazy. Every module of the ISS has a ceiling and a floor, despite zero gravity.
Actually, they did. The MDA section of Skylab was deliberately designed with no up or down, and consoles on any surface they would fit, in contrast to the more conventional design of the main section, so NASA could see which approach suited the crew best. As 8 of the 9 Skylab astronauts preferred the up-down approach, that's the one that's been used ever since.
"Some days are better than others. They say that where I come from."
"Loudly, I imagine, on the day you left."
(Blake's 7 - Rumours of Death)