What Causes the Hydrodynamic Paradox in Water Springs?

[Oomph!]

Hello.

Have you ever seen this experiment?
OK, i know why does the watter flows without cover and does not flows with cover.
However, what about the springs? Why they get together with horizontal hand movement and separate with vertical hand movement?
Liquid always have the possible lowest energy. It is related?

Thank you very much.

 

[A.T.]

However, what about the springs? Why they get together with horizontal hand movement and separate with vertical hand movement? Liquid always have the possible lowest energy. It is related?

Yes. It's about
http://en.wikipedia.org/wiki/Cohesion_(chemistry)
versus
http://en.wikipedia.org/wiki/Adhesion

Cohesion makes the water stick together and minimize surface area. Adhesion makes the water stick to the fingers. The vertical finger moving horizontally diverts the streams horizontally so they collide and find a new local minimum surface area. The horizontal finger provides horizontal adhesion that pulls the streams apart. The horizontal deflection after collision with the horizontal finger might also play a role in separating the streams.

 

[Oomph!]

thank you very much
well, I thought about it and now I have some question. what about Bernoulli equation? ... namely hydrodynamic paradox. it makes underpressure near strings and can connect it together. how much does this affect?