What I don't understand about this experiment (and every show I've seen describing it) is how they can say that the single photon they think they are firing is a particle. Yes it's spooky that an interference pattern appears when not observed and only two lines when observed but if you are truly...
So it's the fact that the air's volume is not constrained which allows it to expand it's volume and being less dense it rises above the colder denser air.
I would assume then however that if two volumes of air were contact rained in equal sized separate vessels, the hotter air vessel would be...