I meant space stations with population. I am not personally going to do research on it because I don't think it's a problem. Best example I can think of is the Death Star and it has under the 2.1million that Absalom has soo...
The thing you have to look at is what it takes to run a ship that could house that many people. I think people who really get this concept are people who work in construction or engineering. Not saying you can't understand it's just people who are in those fields have to think about it on a daily basis.
The Death Star was a rather different animal, though. It was a military vessel that used up a large portion of its volume on a planet-killing superweapon. Strip that thing out, dump the space spent on housing legions of stormtroopers, thousands of turbolasers, thousands of fighters, shuttles, ground combat vehicles, the hyperdrives, etc, and you could fit a hundred million more people in there no problem. The thing’s 75 Miles in diameter, for goodness sake. The superlaser’s focusing dish alone has a diameter greater than Absalom Station. It doesn’t have a complement in the tens of millions because it was meant to support a superweapon, not a civilian population.