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Violation of second law ? help me

  1. Jan 27, 2006 #1
    I've thinked an experiment.
    We have two containers that contain two liquids.
    One container contains a liquid that have small molecules and with high specific weight.
    The second container contains a liquid that have molecules greater and low specific weight.
    Now we connect the two container making a hole in the two container at an half of the height of the containers (the two container are close).
    The hole allow only the passage of the smaller molecules.
    What happen now ?
    I think that some molecules (the smaller molecules) move from a container to the other container (I think that for the movement of the molecules some molecules can pass from the first container to the second and ,because are heavier, they fall on the bottom of the second container ). In this way the level of the liquid in the second container is higher than before.
    Now, the liquid of the first container that is passed in the second container is on the bottom of the second container.
    If we install a tube that connect the bottom of the containers, the liquid that is passed return to the original position. (It moves for the higher pressure).
    In this way we can use the movement of the liquid in the tube to create energy.
    What do you say about this ?

    Thanks Ocunue
  2. jcsd
  3. Jan 27, 2006 #2
    What you've described is essentially osmotic pressure.

    What you're missing is that very soon you'll have the same concentrations in each container, and it will be an equilibrium system - the smaller molecules can move freely both ways, so there is no net osmotic pressure difference.
  4. Jan 31, 2006 #3
    On a hand you have reason ..:rolleyes:
    I've forgot to say that the two liquid are not soluble as oil and water !!...
    In this way when a molecule of water pass in the second container fall down on the bottom.
    The molecules pass only from the first container to the second container until the level of the water (on the bottom of second container ) is at the height of the hole. The oil can not pass through the hole (the molecules are greater than the hole), in equilibrium the level of the water is the same in both container .... but the oil is elevated from the water in second container .......
    We have elevated the oil free ..
    We can repeat this .. passing the water from the second to the first container
    I hope I've explained well...

    good thinking ..

  5. Jan 31, 2006 #4


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    Staff: Mentor

    If they are not soluble, then osmosis will not occur.
  6. May 10, 2009 #5
    At the molecular scale (i.e., velocity, momentum, etc. or at the value close to Boltzmann Constant), it is very difficult for gravity to be influential. The system will be homogeneous. Hence, the specific weight is not relevent. Consequently, another perpetual machine is proposed and described. In the history of mankind, no perpetual machine (of any kind) has been achieved. Energy cannot be obtained for free.
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