I was at a strip club called Bristol's in Monroe, Ohio back in 1992 or so. My buddy had a little too much to drink and got pissed off because a dancer wasn't paying enough attention to him (so he said.) He started yelling "I SEE A STRING!!! I SEE A MOTHERFUCKIN' STRING!!!" over and over again until the bouncers came over and escorted him out. My friend died shortly thereafter and they tore down the club about 10 years later; now Larry Flynt's Hustler Hollywood occupies an adjacent lot.
If the sphere in the middle is supposed to be the Battle Room then they've definitely mucked up.. the fact there are multiple Battle Rooms, all spherical, and all null-G (which only happens dead-center in a rotating station/ref. frame), is how Ender realizes that the IF has some control over gravity/inertia.