1. The problem statement, all variables and given/known data (Sorry if this topic belongs to another forum.) The definition of surface tension is the force exerted parallel to the surface of a liquid along a line of unit length, perpendicular to the line. So if, hypothetically, when you place a needle on the surface of water, the water does not depress, how is the needle's weight being supported at all? Would the surface tension be completely parallel to the surface of the water, but in no way perpendicular to the line?