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Oh yeah. I remember this thing now. I never bought into the explanation related to assuming that there is a negative pressure to get the fluid to rise in the pores above a hydrostatic column. I felt that there were some other more likely explanations, such as peristaltic pumping of the pore fluid by the walls of the pores (so that the system is not hydrostatic) or viscoelasticity of the pore fluid (beyond the "tensile strength" of water; actually tensile stiffness). Has anyone ever measured the rheological (viscoelastic) characteristics of the (biological) pore fluid in the laboratory? (Biological fluids are notoriously viscoelastic)jbriggs444 said:There is a good deal of relevant discussion in https://www.physicsforums.com/threads/negative-pressure.428998/
In that thread Andy Resnick provides a reference to http://www.nature.com/nature/journal/v278/n5700/abs/278148a0.html which discusses the tensile strength of water.
In any event, our excursion into the esoteric subject of the possible existence of negative absolute pressure has gone far afield of the intent of the OP's original questions. Irrespective of whether negative absolute pressure can actually exist, the formation of bubbles and the occurance of cavitation are realities that we have adequately explained in our previous responses.
Chet