How to float your coffee creamer
When a drop is released close to a bath of liquid (e.g. water or oil), our common sense tells us that the two should coalesce almost immediately. However when we pour drops of cold cream on our hot coffee or we observe raindrops over a puddle, we can often see the droplets floating on the surface for much longer than expected...so what happens? In this video we show that a temperature difference between a droplet and a bath can help levitate droplets without any direct contact! For more details, see our paper @JFluidMech "Thermal delay of drop coalescence", by M. Geri, B. Keshavarz, G. McKinley and J. Bush.