Abstract
According to Laplace's equation, a bubble becomes stable when the pressure difference between inside and outside of the bubble is equilibrated with the surface tension of the surrounding liquid. However, this equation has not been tested for its validity from microscopic viewpoint. In this study, we focused on the pressure part of Laplace's equation using molecular dynamics simulation. A bubble was formed by removing a part of liquid droplet and inserting a part of low density fluid in the vacancy. The following behavior of the bubble, expansion or shrinkage, was observed by changing the pressure inside the bubble.