Ylijäähtynyt

Ylijäähtynyt is a Finnish term that translates to "supercooled" in English. It describes a liquid that has been cooled below its freezing point without solidifying. This metastable state occurs when the liquid lacks sufficient nuclei or disturbances to initiate the crystallization process.

Supercooled liquids are inherently unstable. The presence of a tiny crystal, a solid particle, or even a sudden shock can trigger rapid solidification. This phenomenon is commonly observed with water, which can remain liquid at temperatures below 0 degrees Celsius under specific conditions. When a supercooled liquid finally freezes, it can do so with considerable speed and heat release.

In nature, supercooling plays a role in atmospheric processes, particularly in the formation of precipitation. Cloud droplets can exist in a supercooled state even at temperatures well below freezing. When these droplets encounter ice nuclei or collide with existing ice crystals, they can freeze and grow, contributing to the formation of snow and hail.

The concept of supercooling also has applications in various scientific and technological fields, including cryogenics, materials science, and food preservation. Understanding and controlling supercooling is crucial for processes that involve phase transitions of liquids.