What does this mean?
That, my friend, is exactly the question you have to ask.
It means that this is one of the best ways to pile up rocks and not have them fall down for a long time.
omg, it’s almost like 3 separate cultures figured out physics.
omg, it’s like you don’t have to be white to figure out physics!
Could also lend evidence to a long forgotten empire or…yeah…that’s just how you build stuff.