Researchers have recently discovered unusual thermal convection in a uniform mixture of high and low viscosity liquids. They found that concentration fluctuations are enhanced by thermal convection when the two liquids have a large viscosity difference. Such mixtures are ubiquitously observed in nature, daily life, and manufacturing processes, e.g. mantle convection, syrup, polymer products. These results promise further insight into non-equilibrium phenomena in fluid mixtures with contrasting 'thickness.'