You are right - your ignorance of the use of the quote button seems to have fooled me.
MRC Hans is the first to mention chaos theory.
Let me elaborate slightly, for those with the potential to understand chaos theory.
If you balance a needle perfectly on its point, then in theory it should keep standing, but in practice, it will always fall over. From the moment the pin deviates from perfect balance, normal physical laws apply, but what fills the gap between the perfect condition and the realm of standard physics is chaos theory.
For weather systems, the moment a bubble of air starts to rise into the cooler layers above, normal physics rule completely, but if we want to determine exactly which puff of air will start the bubble, we turn to chaos theory. However, when discussing weather systems, we don't need to, because an other aspect of chaos theory it that the bubble Will always start, if the conditions are present.
Let us also cut to the chase about gravity's role in this:
The thermal bubble rises because its lower mass gives it
buoyancy. Buoyancy is only relevant in a gravity field. However, there are no local gravity anomalies or the like in play. This is not a matter of gravity theories, it is a matter of simple logic:
In a calm mass of air, all parts of the mass are equally attracted to each other.
Even if a center of gravity should somehow exist somewhere, it cannot cause a stream of air, because there is nowhere it could go, except directly towards the gravity center, where there is already air. So all that would happen is that a slight overpressure would exist around such a gravity center.
Hans