If there is an infinite column of air, the air entering or leaving the pit should be more or less constant, all else being equal outside the pit. But if there is a finite column of air falling into a vacuum, then there is an infinite vacuum, and I think the pit starts sucking air at the speed of sound.
Actually, there’s a finite amount of air in the pit, but it’s not falling. It’s already settled around the planet’s midpoint. The pit keeps going forever, but gravity starts pulling the other way after a while
A hole through a planet is not a bottomless pit. Like any normal hole, it is bounded on both ends. A bottomless pit has one bounded end and one unbounded end.
If there is an infinite column of air, the air entering or leaving the pit should be more or less constant, all else being equal outside the pit. But if there is a finite column of air falling into a vacuum, then there is an infinite vacuum, and I think the pit starts sucking air at the speed of sound.
Actually, there’s a finite amount of air in the pit, but it’s not falling. It’s already settled around the planet’s midpoint. The pit keeps going forever, but gravity starts pulling the other way after a while
A hole through a planet is not a bottomless pit. Like any normal hole, it is bounded on both ends. A bottomless pit has one bounded end and one unbounded end.