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Why do fluid drops are sperical?

  1. Mar 19, 2009 #1

    fluidistic

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    Hi,
    I'm almost sure that this question frequently appears and have been asked thousands of times and if so, then excuse me and I'll be OK if you give me a link to such a thread.
    I don't understand why fluid drops in air are not ellipsoidal since the air makes pressure vertically on everything submerged in it. The same apply for air's bubbles in water. Water makes pressure vertically and so the bubble should get an ellipsoidal form, but it doesn't.
    Thank you!
     
  2. jcsd
  3. Mar 19, 2009 #2

    mgb_phys

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    Surface tension balances the aerodynamic forces - mostly surface tension wins so the drops are almost spherical.
     
  4. Mar 19, 2009 #3

    fluidistic

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    Thanks SO much!
    If I find a fluid that has a little surface tension and I put it say in deep ocean (more than 10km under water surface) then I'd likely get an ellipsoidal bubble. :smile: if I understand well.
     
  5. Mar 19, 2009 #4

    mgb_phys

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    Well there is still the surface tension of the water because there is a surface around the bubble.
    It would be interesting to know what shape 'raindrops' of other materials formed in air - say organic solvents or superfluid helium!
     
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