First i thought that smoke used to rise upwards due to a 'projection' created by a chimney.. but lately when I was looking at an essence stick.. the smoke could literally go anywhere. Even the same with a burning piece of coal. Even the smoke generated at the bottom part of the coal 'envelopes' around the piece of coal and rises upwards. No matter what orientation we select, the smoke always rises upwards. By 'upwards' I mean 'opposite and along the line of force of gravity'. So.. what exactly is the reason of this happening? My best guess is that this is due to another fluid surrounding the burning object as well as acting as a medium for the travel of smoke [i.e. air]. So.. if i burn a piece of coal in vacuum [just believe that for know we have some oxygen bubbles in the coal itself or something].. will the smoke move around in all directions despite the effect of gravity?