I am suspicious about the part where the density decreases. That means, the air expands to a larger volume. But larger in which dimension: horizontally or vertically? I suppose it cannot be horizontally, because next to it there is air in exactly the same situation, which also tries to expand with equal pressure. But if vertically, then what is the difference between being in a (vertical) chimney or being outside of it?
I am suspicious about the part where the density decreases. That means, the air expands to a larger volume. But larger in which dimension: horizontally or vertically? I suppose it cannot be horizontally, because next to it there is air in exactly the same situation, which also tries to expand with equal pressure. But if vertically, then what is the difference between being in a (vertical) chimney or being outside of it?
These superchimneys are pure nonsense. Don’t bother.