This book is devoted to interfaces between two fluids, that is, between a liquid and a gas (such as water and air) or between two liquids (such as water and oil). The main motivation for the book is twenty years of experimentation in the microgravity environment of space, and the associated theory. This unique environment has made possible numerous qualitative and quantitative observations of effects that are masked by gravity on earth. Large liquid surfaces have been created and their stability and dynamics have been studied. The experimental insights gained have, in turn, strongly stimulated further theoretical and mathematical investigations. Advancing and receding contact angles, wetting barriers, pinning of contact lines, oscillations of capillary surfaces and fluid sloshing are also discussed.
