I maintain that not only they can, but that observations illustrating the phenomena are common. To keep the thread from fragmenting too badly, I should like to propose the following rules of discussion: 1) Liquids shall be limited to water and air. 2) Only natural flows may be offered. Nothing initiated, modified, or influenced by man or his works. 3) The flows must be unconstrained: no channels, pipes, or containers. 4) A flow from low pressure to high pressure shall be deemed to have occurred if the internal pressure (as measured by an imaginary manometer at the midpoint of the parcel of fluid) is higher at the finish of the flow than it was at the beginning. 5) Acceptable evidence shall consist of scientifically-accepted citations and/or compelling argument. What are your thoughts?