Synopsis (I’d copy and paste but don’t want the duplicate content penalty )

1) Jar holds a finite amount of air

2) Candle heats up air

3) PV=nRT dictates that under finite volume hotter air increases pressure

4) High pressure air bubbles out of the jar

5) Candle burns out => air cools down

6) Air pressure in jar decreases

7) Water in jar rises until the pressure difference between the jar and the atmosphere equals the height of the column of water * density of water * gravity

The basic premise is the change in air pressure. When the open end of the cup is submerged in the water it creates a type of water seal preventing additional air from entering the space. When the candle is lit it begins to heat up the air around it, burning the oxygen up and according to Boyle’s law, when a gas (air) is heated its density is reduced. (This is the motive “force” behind hot air balloons by the way). The reduced density of the hot air in a closed container creates a vacuum.

The air pressure being exerted on the water outside of the jar is greater than that being exerted inside the jar so the water moves towards the path of less resistance and pushes itself inside. Technically if there were enough water and the candle was allowed to burn itself out, the water would fill approximate 1/5th of the volume available inside the jar since air is almost 20% oxygen.

Hope that works for you. Thanks for the challenge!

Hey if I do win, I don’t really need the Dreamhost hosting but I would love to use it as a joint prize for a challenge on my blog if you agree. By joint I mean “Prize supplied by AllTipsAndTricks.Com” or something like that.

Can’t wait to see if I won!