Translations:Funzionamento di una penna stilografica/2/en

In fact, the forces involved are different: the gravity that pushes the ink to escape from any downward oriented opening, the atmospheric pressure, which prevents any tank with a single outlet hole to empty if there is no way of access that allows the air to enter instead of the liquid (what makes it difficult to quickly empty a bottle when you turn it over), the surface tension", i.e. the characteristic tension of liquids that climb up the walls of a container (the same tension that causes drops to remain attached to the tap or on the surface of a glass).