RELATIONSHIP BETWEEN PENETRATION AND SHAPE OF FALLING DROP
穿透现象和液滴形状的关系

Photos of falling drops in proccess of periodical deformation are presented. The penetration (it means the falling drop becomes a ring after colliding with surface of water and then it penetrates into water until the bottom is reached) happens after the drop with the shape of flat ellipse or its resemblance collides with the surface of water. Surface tension of drop water acts to deform the shape of falling drop.