[meteorite-list] Slightly OT...but sttill space related!

[Chris Peterson]

In microgravity, oil and water still won't mix, but they won't separate 
the way they do under gravity. The reason they don't mix is because oil 
has very low solubility in water. When you mix them vigorously, you get 
what's called an emulsion- in this case very small droplets of oil 
floating in the water. Unless you use special ingredients (as in mayo) 
to maintain the emulsion, the droplets will separate because of their 
buoyancy (which is meaningless in microgravity).

What I'd expect to happen in space is that the individual oil droplets 
will gradually coalesce as they collide (a statistical process). 
Eventually, you'll have a single blob of oil drifting around in (or on) 
a single blob of water.

Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com


----- Original Message ----- 
From: "Dave Harris" <entropydave at ntlworld.com>
To: "metlist" <meteorite-list at meteoritecentral.com>
Sent: Saturday, November 11, 2006 3:04 PM
Subject: [meteorite-list] Slightly OT...but sttill space related!


> Hullo,
> Well, I am a bit stumped by a question I was asked by one of my 
> sons...and I
> couldn't answer it for certain - I've asked one chap, a good mate of 
> mine,
> who has an astrophysics masters degree, and he proposed an answer to 
> my
> query but I am not sure he's right...
>
> SO, we all know that oil and water don't mix - the oil will float on 
> the
> water.  What about in zero-g?
> Would they mix? (think how easy it'd be to make mayo!) or would they 
> still
> separate out if shaken together?
>
> It obviously has a relationship between certain meteorite classes (ie 
> mesos)
> ie, whether molten silicates would float on molten iron...
> but I just cannot visualise whether oil on water would still float.
>
> Seems a really silly question now I;ve written it down - but nope, 
> just
> cannot figure what an oil/water mix would do.
>
> Any ideas (Bernd.....??)
>
> Dumbly....
>
> dave