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Floating egg

  1. Oct 12, 2003 #1

    Everyone of you must have done the following experiment while you prepare your breakfast.

    Put an egg (boiled or not) in a glass or brig then put the glass under a tab and release the water, you will notice that seconds later the egg will slowly arise to the top of the water surface and will remain there until you stop the water.

    If we were living in middle ages this would be a miracle but since we are living in 21st century I would like to hear you opinions about this phenomenon.
  2. jcsd
  3. Oct 12, 2003 #2


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    Have you ever seen the trick of the ball "floating" in a stream of moving in air? I wonder if this is something similar.
  4. Oct 12, 2003 #3
    Some kind of Venturi effect? Higher velocity, lower density symmetric fluid flow situates around object exterior, creating a stable partial vacuum.
  5. Oct 13, 2003 #4
    Thanks for replaying guys,
    but I want also to add (I am sorry I did not give this information in my first mail) that the phenomenon must have something to do with the size of the vessel we are using.

    Especially with the width and not the height of the vessel because if you use a little wider vessel the egg does not move and remains at the bottom of the vessel.

    And something more the egg is rotating (has spin) around its big axis.
  6. Oct 13, 2003 #5


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    It is not necessary for the egg to spin, I observed this in a glass to narrow to allow that. The egg elevated to a midpoint in the glass, well above the bottom, but not quite to the top. There was no perceivable spin.
  7. Oct 13, 2003 #6
    The dimensions of the vessel would help determine size, number, symmetry and orientation of "convection" currents.
  8. Oct 15, 2003 #7
    The EGG...


    The answer to ur question is very simple. It is just that narrower the vessel, the more the force with which water moves into the vessel. So The more the force, the more will be the upward motion of the water as it hits the bottom. Which means that the egg is going to float. But as soon as you close the tap, this upward force stops due to the stop in the flow of water and hence the egg again sinks due to its weight.

    (PS: It would be easier to understand if you can visualise this...)

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