maxwell@speedy.DEC (07/27/85)
As I recall, there have actually been tests to see what happens to a burning candle in Zero-G. Although I don't remember the source, I do recall reading about a test in a plane 'falling' through a parabola for 30 seconds or so, just before which the pilot had lit a candle. During the beginning of the Zero-G period, the candle's flame rounded into a sphere, which got smaller and smaller. The flame soon went 'out'. When gravity 'returned' however, the flame returned, for all appearances reversing its disappearing act. The offered explanation of the phenomenon (as I recall, don't hold me to this) was that the absence of gravity prevented the differentation of the gasses involved (both fuel and by products); gravity allows hotter, lighter gasses to leave (CO2, H2O, etc.), and cooler, denser gasses to enter (vaporized fuel). Unable to rid itself of the useless byproducts, and unable to get enough fuel, the flame dies. However, during the buring, a number of free radicals (transition products) are produced that, when gravity returns, can 'continue' combustion. -+- Sid Maxwell