The Fragile Beauty of Frozen SpheresMaxim LoAward: First Place Contrived
School: bloomington high school south As a kid, the simple joy of blowing soap bubbles and watching them float away, shimmering under the sunlight, was magnificent. These delicate spheres have always fascinated me. Recently the harsh, cold weather of winter reignited my curiosity: what exactly occurs when a bubble freezes? To find out, I ventured into my backyard, blew bubbles, and took pictures in order to capture the phenomenon. Setting the bubbles on the snow at a temperature of -16 to -20 degrees Celsius and under the same frigid air, almost instantly, the magic begins as the bubble freezes from the bottom up due to the rapid heat transfer. Within seconds, small ice crystals form at the bottom, detaching and swirling around the bubble due to a phenomenon called the Marangoni flow, which is caused by surface tension gradients influenced by temperature variations. This is a result of the different thermal conductivity and specific heat capacity of the soap solution, causing convection currents within the bubble. This beautiful dance continues for around 23 seconds until the bubble is completely frozen. The final picture I was able to capture shows the bubble fully frozen, showing the intricate patterns formed by crystallization. However, if the surrounding temperature is warmer, the bubble will only partially freeze, as the upper region remains too warm. This creates a dynamic equilibrium where the heat from the warmer air prevents complete solidification of the bubble. In this case, the bubble stays partially frozen until the liquid top pops. 
|
|