Siphoning off the last word
DOI: 10.1063/PT.3.1315
Before the whole siphon issue goes away (see PHYSICS TODAY, August 2011, page 10 , and previous comments cited therein), I thought I’d point out why people often think that siphons depend on atmospheric pressure. In the most familiar examples, atmospheric pressure is required to set up the siphon, as one “sucks the liquid up” into the pipe, hose, or other conduit.
Once the siphon is set up, of course, the tensile strength of the liquid itself is what keeps it going. Liquid tensile strength is something that a lot of people don’t understand, however, and they confuse the setup condition with the continuous operation of the siphon.
More about the authors
Glen Davidson, (interelectromagnetic@yahoo.com) College Place, Washington.
