This question came to me last night while I was meditating and watching my candles burn out on their own:
Physics says that energy cannot be created or destroyed, right? (Help me out here, I dropped high school physics) If that’s true, then where did the energy from those flames go? I watched them eat up all the wax that the candles had, then seeminly “die” on the burnt remains of the wicks.
What happened?
No disrespect, but that quote is inaccurate.
Everything around you basically involves conversion of an energy source or fuel into another form. The solid wax and wick are slowly consumed, all the while being converted into heat, light, and a small amount of gaseous emissions.
When the flame went out, the chemical reaction ceased.
Which quote would that be?
Yeah I’m not sure what quote he means either.
Basically the chemical reaction expends fuel (wick + wax) and releasing energy (heat + light) and some other by products.
When the candle goes out the chemical process stops and there is no more enrgy to give off. The little energy remaining is given off as heat and light. Nothing is created or destroyed, just transformed.
It went into heating the air in the room, which heated the walls and ceiling which ultimately heated the atmosphere which radiated it into space because you, believe it or not, did your bit to increase earth-warming. In addition, the light and the invisible, to us, infra red was aborbed by you, and the walls and the ceiling raising their temperatures which heated the adjacent air which, etc. etc, etc.
Hold your hand over the candle (not too close) and you will feel the energy leaving the flame via the air.
When a candle burns, the molecules of wax (after being vaporized) are recombined with molecules from oxygen in the air. Since the energy in the chemical bonds after the reaction is less than that before, the excess is released as photons. Some of these are in the red to orange region of wavelengths (seen as the flame) and many of them are infrared (“heat”). Incidentally, the ones emitted towards the candle melt and vaporize more wax to feed the reaction.
Anyhow, the flame more or less a side-effect of energy being released from the wax rather than a “thing” in and of itself to be “eating” the wax. When there is no more wax to vaporize and feed the reaction (or there is no more oxygen to combine with wax vapor), the reaction comes to a halt, no more photons are released, and the flame “goes out”.
That’s the quote I think he’s talking about. To a physics person, it generally means something a little different than what the layman might think. Most physicists know that matter is just a kind of energy, but others might misinterpret the quote.
As for the candle, the burning is just a sustained chemical reaction, I think. So…, it’s consuming wick + air and producing heat + light + waste air. When the inputs run out, the reaction ends; no energy conservation involved.
On the other hand, if you mean how come the flame burned for a while and then went out, the the other posters’ answers apply.
The wax in the candle contains molecules having a certain latent chemical energy. When the wax is heated by applying a flame to the wick those molecules are raised to a temperature that melts the wax and starts a self-sustaining reaction that converts the wax molecules to different molecules using the oxygen in the air and these new molecules have a lower energy than the wax. That difference in the molecules’ energy appears as heat which melts more wax and keeps the reaction going.
So the original energy in the wax molecules appears in two forms. New molecules having a lower energy than the wax and heat which heats the air etc. etc. etc. as I wrote in my previous post.
And, of course, you eventually run out of wax and the reaction stops.
By the way, those new molecules are mostly carbon dioxide and water since the wax is a hydrocarbon, i.e. containing hydrogen and carbon. There are also other things in the wax that forms molecules that float around and stick to the walls, mirrors, silverware and so on and a little of the original energy is carried off by them.
And by the way, the igniting flame and the heat from the candle burning not only melts the wax, it evaporates it turning it into a gas at high temperature and it is the molecules of that gas that react with the oxygen in the air.