Pressure Gradients: No Sucking Involved
Tuesday, September 20, 2011 - 13:10
in Physics & Chemistry
The word "suck" sucks in science. Although much has been written about this misconception, I'll try to string together several everyday examples to further tackle a sucking illusion that persists despite the nearly four hundred year discovery of atmospheric pressure.If you place one end of a straw into a juice and its other end loosely into your mouth, and you do nothing, the juice does not rise into your mouth. The only reason there's a bit of liquid in the straw is because the tube is narrow enough and capillary action acts against gravity. If you had inverted a glass in water, however, the inside of the glass would only contain air.read more