I believe the point is that they made the math to match the observations.
Maths that accurately describes the physical world is DISCOVERED not "made up". Seriously, read a fucking text book and immunise yourself against that populist nonsense.
So they bilt this not only in one day but the very day after the earth was craterd? I don't think.
Haven't read TFA but I do know Roman battalions advanced by marching for a few days, stopping at a strategic point, and proceed to turn a nearby forest into a 3 storey fort in a single day. The forts were all of the same design and required ~5,000 trees to build, each man was an expert at a specific task. Reinforcements moved from fort to fort and signal towers were set up in between so that there was a visual link along the entire path. Today, we call this strategy a "supply line".
The Romans did a similar thing building up their Navy with spectacular speed when circumstances required, it was a classic "assembly line production" that existed 2000yrs before Henry Ford "invented" it. They also stole the boat design from the Carthaginians who had kindly numbered all the individual planks for them (no IP lawyers back then).
For a modern army or even a well organised militia, erecting a fake ruin in a day is definitely doable, so it boils down to motivation, which both sides have in spades.
To reach the hall, you could navigate the roof and descend from the awnings
Coincidentally, the earliest known stone villages appeared in Turkey ~12,000 years ago, they had no streets and the houses had no doors, they were all squashed together as one big flat building, people entered individual homes by navigating the roof and descending through a hole into their "cubicle". They also had a habit of burying dead relatives in the living room. Similar architecture and burial practices were common across the N. Hemisphere for the next 10,000yrs.
And it should be the law: If you use the word `paradigm' without knowing what the dictionary says it means, you go to jail. No exceptions. -- David Jones