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Does the strength of gravity on a planet limit a species ability to create temperatures high enough to melt metals?

I read that at low gravity fire burns at cooler temperatures and reduced convection leads to reduced inflow of oxygen but I believe most of this is based on how fire behaves in microgravity. If true this makes me wonder if species on low gravity planets could advance to bronze or iron age level, being able to create high enough temperatures to melt metals? assuming their atmosphere has a similar amount of oxygen as our planet.

If there is a limitation to how low the gravity can be to create the high temperatures does that mean that high gravity planets will be able to achieve high temperatures much easier?

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    $\begingroup$ I am absolutely certain that the same bellows used by Earthian blacksmiths would work equally well on a world with somewhat lower or somewhat higher gravitation. Would it be possible that you are confusing gravitation and atmospheric pressure, or partial pressure of oxygen? $\endgroup$
    – AlexP
    May 17, 2022 at 21:50
  • $\begingroup$ @AlexP I meant just gravity but I was confusing its effect on ambient oxygen rather than controlled airflow which would be used in metallurgy. $\endgroup$
    – user96146
    May 17, 2022 at 22:02

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No.

The rate of convection depends on the acceleration of heated air. Air heated to a given temperature is of reduced density, and buoyancy causes it to rise. Less gravity reduces the buoyancy, reducing its rising rate, so less cold air (containing unburned oxygen) is sucked in to replace it. This does reduce the rate that a natural fire burns in a lower atmosphere environment, all else (air composition etc) being equal.

However, even primitive metallurgy rarely uses a natural fire. Early furnaces like the bloomery AlexP mentions can use clever geometry to accelerate convection to generate enough heat to smelt iron; but in general forced air flow is used. Bellows are a basic technology used for forcing fresh over a fuel at a controllable rate, allowing increased burn rate and temperature. Even before developing the "modern" bellows a metalworker will realize that waving a fan over his coal bed will increase the temperature and make smelting easier. And once you're using forced air flow, whether with a fan, a bellows, or something more modern, gravity matters not at all.

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    $\begingroup$ "Smelting iron definitely requires forced air flow": citation needed. Directed airflow, yes; but bloomery furnaces with natural draft were used to smelt iron for more than a millennium. $\endgroup$
    – AlexP
    May 17, 2022 at 21:55
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    $\begingroup$ Thanks for the correction, AlexP. (I shouldn't have made this mistake, I've even used a bloom furnace to smelt iron for my waffle iron!) I've made my answer more accurate; I don't think the essential message changes. $\endgroup$
    – addaon
    May 17, 2022 at 23:10
  • $\begingroup$ Yes, minor nitpick. I had even upvoted before commenting. $\endgroup$
    – AlexP
    May 17, 2022 at 23:24

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