# Would blowing someone else's candle out make mine shine brighter?

Is the claim in this sign correct? Would a candle shine slightly brighter with slightly more oxygen in the room?

And what do you mean "The candles aren't literal."?

The claim is certainly true for candles in different rooms. Even in the same room, the effect of one candle on another in terms of oxygen consumption is with all likelihood completely negligible, and the candles could thus be treated as completely separate systems.

As to your question about how the candles are not literal: The sign is a metaphor for how sabotaging someone else does not make you absolutely better, only relatively, which is not the kind that matters (and makes the total situation worse, since you now have less total light / talent / whatever).

Note that if oxygen is a very limited resource, blowing out one candle would make the others burn longer. In much the same way the metaphor does not work in a competition over limited resources. But in the physical situation, infinite oxygen is usually a good approximation.

• Although if the candles are in a very small box, blowing out one could definitely make the other brighter... I guess the metaphor doesn't have the intended effect when you can say "If competition for resources is tight, eliminating competitors will enhance you..." Mar 1, 2019 at 13:18
• That is true. Edited the answer to reflect this. Mar 1, 2019 at 13:26
• Actually it doesn't burn brighter but rather longer. Given the desity of air in that system remain constant, the amount of oxygen consumed by the candle per unit time is constant and consistent regardless of the number of candles in the system. Mar 1, 2019 at 13:50
• @TechDroid You should make that an answer. Mar 1, 2019 at 14:18
• @tfb, how bright a candle burn isn't a function of how much ambient heat is available. The candle flame works by phase transition of wax from solid to liquid and to gas which burns as it rises into the flame. Oxygen determines how hot or bright something burns. The soot from the candle is due to insufficiency in the available oxygen surrounding the flame and ready to grab leading to incomplete combustion of wax vapor. Burning candle is as simple as physics can be, so catch up bro. Mar 1, 2019 at 14:36

It doesn't burn brighter but rather longer. Given the desity of air in that system remain constant, the amount of oxygen consumed by the candle per unit time is constant and consistent regardless of the number of candles in the system. To put that into perspective, blowing on a flame brightens it because setting air in motion requires compressing it forward layer by layer of molecules, it's this dense cloud of air that provides more oxygen per unit volume to the fuel increasing the combustion rate. So I'll advise not to blow out someone else's candle coz yours won't budge because of that, and you'll never know if you'll live long enough to witness yours burnout.

• If we define 'brightness' as 'power output' then if it burns for longer it must necessarily be dimmer since there is a given amount of energy in the candle wax, assuming the combustion is as complete in both cases. If the combustion is less complete in one case than the other (which would be the case if the oxygen level got low enough).
– user107153
Mar 1, 2019 at 16:12
• Brightness I believe is the amount of the visible part of the electromagnetic spectrum a light source is giving out. Like I said, you've got to get more combustion going per unit time to get more visible radiation emitted. The only way that happens is by density change. It's not the unavailability of oxygen that makes the combustion incomplete, it's how much the wax vapor can get oxidized at a time, some would, some won't, some partially. Mar 1, 2019 at 16:46
• Using that definition of brightness then for a given flame temperature it is proportional to the power output. So if it burns for a longer time, then either it is dimmer (in your sense) or, if it has the same brightness, the flame temperature must change to yield more energy in the visible spectrum (which I think would need it to be hotter, since there's pretty much no energy in the UV for a candle flame). You've not provided any explanation as to why that should be.
– user107153
Mar 1, 2019 at 17:41
• Let me make it simple. As long as the air density around the flame is constant, and the amount of oxygen in the air is also constant, the candle flame will illuminate with the same brightness for most of the time. Take out one candle in a system of two doesn't make the other burn brighter at all if all conditions remain the same. So if you want a brighter flame, either burn the candle in a pressurized chamber or create momentary compression disturbance by blowing on the flame (you only get momentary brightness as well). Mar 1, 2019 at 18:25
• Exactly. And that means it won't burn for longer, because it can't both burn with the same brightness and burn for longer without some additional source of energy (ie more wax). This answer, therefore, is incorrect: you should either delete it or modify it to be correct. You might also want to be a bit less patronising.
– user107153
Mar 2, 2019 at 14:26

I think it would look as though it would shine more brightly and this is more to do with the eyes response to light stimuli.

For example, a candle in daylight doesn’t seem as bright as a candle in the dark.

The quote is TRUE for most candles, in most conditions, for most people. Both the literal and the philosophical can use this quote, as the candle is a candle AND the candle is a metaphor for the light that shines within each of us.

The quote is NOT true for people living in their own darkness of immaturity or an inflated delicate ego. This person believes - If there are 2 identical candles in the darkness, they will appear equally bright. And - If this person blows out my candle, only their candle will be shining in the darkness. Therefore - Their candle will shine brighter than mine, as my candle no longer shines in their darkness.

Sadly this person is trapped in their own darkness, too afraid their light is gone if it’s no longer the brightest light they see.