The maximum diameter of a falling liquid drop that will not disintegrate in a gas is influenced by several variables, including interfacial energy and viscosity. Drop breakup occurs primarily due to the forces acting on the drop as it falls, with larger drops being more susceptible to fragmentation. The discussion highlights the importance of understanding the balance between these forces to predict drop behavior. Additionally, the timescale of disintegration is closely related to the viscosity of the liquid. Overall, the dynamics of drop disintegration are complex and depend on multiple physical properties.