A Dance of the DoomedMingchi MathurAward: Top 100
School: minnetonka high school This image shows a water droplet on an exceedingly hot pan, simultaneously generating a bubble and undergoing the Leidenfrost effect. The Leidenfrost effect is a phenomenon where the bottom part of liquid on a hot enough surface vaporizes instantly, creating a vapor layer that insulates the liquid from the hot surface. This vapor layer suspends the droplet above the surface, preventing direct contact. Since heat transfers slower through vapor than liquid water due to its lower thermal conductivity, the rest of the liquid ends up heating up much more slowly. For water on a smooth surface, the Leidenfrost point typically occurs around 193°C. I was originally going to take a photo of the Leidenfrost effect with a few droplets in the frame skittering around the pan, but I noticed that after a few droplets of water merged into one larger droplet, the larger droplet began to look as if it were boiling. Curious, I looked further into the Leidenfrost effect and learned that because such a symmetrical larger droplet's mass is concentrated at its center, the vapor layer beneath must exert a higher pressure to balance the downward force of gravity acting on the center. Combined with the vapor itself being lighter than water, the vapor's upward push against the water triggers Rayleigh-Taylor instability, so that with a large enough droplet of water, the pressure builds up enough to let a jet of vapor punch through the droplet. For a few seconds, water and fire conspire in this fleeting ballet. 
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