CAUTION: DO NOT ATTEMPT THIS AT HOME
Here is an experiment that even the professionals at AstroCamp will not dare to perform. Water can become superheated in a closed system, like that in a microwave, and become extremely dangerous. Superheated water is liquid water under pressure at temperatures between the usual boiling point, 100 °C, and the critical temperature, 374 °C.
Superheated water can be stable because the liquid water is in equilibrium with the vapor. However, if water becomes superheated due to this equilibrium and a lack of bubbles or impurities, then it will all of a sudden boil if there is a change in the system. This could be a simple as jostling the liquid, introducing something like a spoon, tea bag, or even a tiny piece of dust!
Smooth containers do not have bubbles of air clinging to their sides. Rough or scratched containers may hold microscopic bubbles in their cracks, becoming nuclei for boiling. These nuclei provide a source for the water to release heat and energy in a safe way. But with a smooth container, when a nuclei is added, the superheated water will explode!
Written by: Mimi Garai
