Dynamics of a drop floating in vapor of the same fluid

Evaporation of a liquid drop surrounded by either vapor the same fluid, or and air, is usually attributed to diffusion -- which, however, does not apply former setting, as pure fluids do diffuse. The present paper puts forward an additional mechanism, one that applies both settings. It shown disparities between in terms their pressure chemical potential give rise flow. Its direction depends on density drop's size. In undersaturated saturated vapor, all drops evaporate but oversaturated (yet thermodynamically stable) there exists critical radius: smaller evaporate, larger act centers condensation grow. developed model used estimate evaporation time floating vapor. that, if vapor-to-liquid ratio small, so evaporative flux result, millimeter-sized water at temperatures lower than $70^{\circ}\mathrm{C}$ survive for days. If, temperature comparable (but necessarily close) its value, such within minutes. Micron-sized drops, turn, seconds triple points.