Huge fluctuations in Gradflex experiment

Gradflex experiment, flown aboard the umanned Foton-M3 capsule in 2007 was about the fundamental science beneath mixing two liquids. Mixing is accompanied by large fluctuations consisting of localised motions that move the two liquids into each other. This effect occurs when liquids with different compositions diffuse into each other or even in a liquid subjected to a temperature difference that causes heat to diffuse. It was found that during the diffusion of tiny, nano-metre-sized molecules in a liquid, their concentration exhibits fluctuations with sizes ranging up to millimetres, and lifetimes as long as almost 17 minutes.The thickness of the fluid layer is in the end what limits any further growth of these fluctuations. The initial results were published on 19 April in the journal Nature Communications