Can anyone explain why occasionally, when filling a bottle with a funnel, despite the rate of pour remaining steady, you get a sort of backsplash which seems to create a barrier in the neck of the bottle, and the liquid then comes out and over the top of the bottle, spluttering.
I have tried to watch when it happens - it's *not* because the rate of flow exceeds the rate the neck can take liquid in. Even lifting the funnel slightly (so there's a gap all the way round) doesn't guarantee it won't happen.
Would this be classed as hydrostatics ?