Not really a puzzle or anything just something i like to think about.

[Wiggle]

If you light a match in zero gravity which direction will the flame head (as in on earth it heads upwards)? Or even better if anyone knows or even has a picture. My mind say a sphere but that also doesn't make sense because of convection. Blah.

 

Admin delete this if its too daft a question, I would love to see it though.

[reverse]

no gravity ..

no thermal displacement upwards..

so an irregular star shape due to uneven burn rates and complex convection...

as a guess.

[BenSon]

Yeah, I think the flame points up because of the heat convection not gravity so I would say it would look the same.

 

~Scott

[reverse]

So without a good strong upward convection suction to keep re oxygenating the area around the flame....

 

would it even burn at all?

 

..maybe it would go out straight away...

 

Maybe it would take for ever to burn...and be really weak ?

[atinymonkey]

Yeah' date=' I think the flame points up because of the heat convection not gravity so I would say it would look the same.

 

[/quote']

 

That doesn't really make much sense. If the heat was rising away from the flame, causing the flames direction, it would be a sphere in space.

[swansont]

Yeah' date=' I think the flame points up because of the heat convection not gravity so I would say it would look the same.

 

~Scott[/quote']

 

Do you understand that convection depends upon gravity?

[swansont]

Why doesn't anyone Google anymore?

 

picture of a candle flame in microgravity

[atinymonkey]

Actually, I did. I can't remember why I decided not to post the link, I think I was holding out for someone to work it out.

 

http://www.nasa.gov/centers/marshall/multimedia/photos/2003/photos03-004.html

[why?]

google works for everything

everything i tell u.

[Draco]

The flame is actually spherical as Swansont mentions, Google has the answers !!!!

[Wiggle]

Thank guys, now i know.

[YT2095]

just an additional oddity.

 

the flame also goes out after a short time, but will re-ignite if the candle or match is moved into a fresh pocket of air

[Pat Says]

Ha, that is kind of funny. You mean if there is no air current right?

 

"would it even burn at all?

 

..maybe it would go out straight away...

 

Maybe it would take for ever to burn...and be really weak ?"

 

Thats only dependent on the amount of oxygen and fuel source available.

[ssj5harsh]

I don't EXACTLY agree with what YT2095 has said. The reason simply is because the candle needs GASEOUS wax so that it can burn. On earth, Wax near the wick is heated, turns to liquid, then gaseous state. This gaseous wax burns. The wick serves the purpose of absorbing the liquid wax so that the gaseous wax can burn. In microgravity, the wax will not rise towards the flame and hence will burn out after some time.

 

One way to check this is to notice that a vertical candle burns until the wick reaches the ground, but the same candle when held horizontally will burn out sooner and most of the candle will not be used.

[gnpatterson]

The wick effect works in micro gravity, it is due to capilarity/surface wetting effect so it will continue to "rise" to the "top". The horizontal fast burning candle phenomena you describe in gravity is due to the convection of heat from the flame into the side of the candle and the failure of the candle to form a stable pool of wax.

 

You must have observed how quickly a candle burns if you constantly drain the little pool of wax.

You may have observed how quickly you can melt one candle into the flame of another to produce a massively waxy decorated bottle with candle?

 

If not I can tell you it is great fun (well maybe once or twice after a while it gets boring and your girlfriend starts to get impatient and the waitors try to move you out)