# Convection under gravity?

**URL:** <https://boards.straightdope.com/t/convection-under-gravity/136416>\
**Category:** Factual Questions\
**Created:** [November 12, 2002, 10:42am UTC](https://boards.straightdope.com/t/convection-under-gravity/136416 "2002-11-12T10:42:22Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![starman](https://avatars.discourse-cdn.com/v4/letter/s/8c91f0/32.png) [@starman](https://boards.straightdope.com/u/starman)\
**Post date:** [November 12, 2002, 10:42am UTC](https://boards.straightdope.com/t/convection-under-gravity/136416/1 "2002-11-12T10:42:22Z")

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What effects does gravity (or the lack thereof) have upon the convection of gasses, for example in a candle flame? I know that under microgravity, a flame takes the shape of a sphere, so what would a flame look like under high gravity conditions?  
-Oli

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**Author:** ![scotth](https://avatars.discourse-cdn.com/v4/letter/s/b9e5f3/32.png) [@scotth](https://boards.straightdope.com/u/scotth)\
**Post date:** [November 12, 2002, 3:02pm UTC](https://boards.straightdope.com/t/convection-under-gravity/136416/2 "2002-11-12T15:02:13Z")

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It would be more elongated under heavy gravity.

Convection gets stronger with more gravity.

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**Author:** ![micco](https://avatars.discourse-cdn.com/v4/letter/m/5f8ce5/32.png) [@micco](https://boards.straightdope.com/u/micco)\
**Post date:** [November 12, 2002, 3:02pm UTC](https://boards.straightdope.com/t/convection-under-gravity/136416/3 "2002-11-12T15:02:59Z")

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Many convection effects are entirely driven by bouyancy, which is dependent on gravity. In these cases, velocities are induced in a fluid by a temperature difference which causes density gradients which induce a flow, and the density gradients would have no effect if there were no gravity to define which direction lighter materials should “float”. Low gravity tends to suppress the flow and high gravity increases it, so I’d expect a candle flame in high gravity to be more narrow and elongated as the hot gasses rose away from the flame more quickly and induced higher velocities in ambient air.

Note that some convection effects are not dependent on gravity. For example, convective heat transfer happens any time there is a velocity across a body, so this can be caused by the body moving through a fluid rather than having the temperature difference induce a flow in the fluid by itself.