A Drop in the BucketOliver HomanAward: Top 100
School: bethesda-chevy chase high school What I demonstrated in my photo is the fluid dynamics and miscibility of dye in a separated mixture. The photo is one of a separated mixture of oil and water, where the less dense oil formed a thin film at the top of the water, then a drop of dye was dropped into the water and its interactions captured. When the dye first meets the oil it does not mix as it is immiscible in oil due to the oil being a non-polar fluid and the dye being polar. It forms small nodules of dye that slowly fall through the oil film into the rest of the water, the surface tension present keeping it in a rather coherent droplet. Once the sinking droplet reaches the water, water's polar nature allows it to disperse through complex processes. Passive diffusion of the dye from areas of higher to lower densities while convection currents due to the differences in temperature also cause movement and general dispersion away from a singular droplet. But the more complicated and active process is Rayleigh-Taylor Instability which is the dispersion that occurs when two fluids of different densities meet, such processes leads to the plumes seen in the photo and elaborate mixing. Rayleigh-Taylor Instability is seen across the natural world as well, in volcanos and mushroom clouds, all of which involve a similar mixing of different density fluids. These hydrodynamics are an extremely important physical science, plumbing the depths of the natural world, and allowing us to understand such a diverse array of phenomena as aerodynamics to interstellar nebulae. 
|
|