Nucleation

Nucleation is the extremely localized budding of a distinct thermodynamic phase. Some examples of phases that may form via nucleation in liquids are gaseous bubbles, crystals or glassy regions. Creation of liquid droplets in saturated vapor is also characterized by nucleation (see Cloud condensation nuclei). Nucleation of crystalline, amorphous and even vacancy clusters in solid materials is also important, for example to the semiconductor industry. Most nucleation processes are physical, rather than chemical, but a few exceptions do exist (e.g. electrochemical nucleation).

Nucleation normally occurs at nucleation sites on surfaces contacting a liquid or vapor. Suspended particles or minute bubbles also provide nucleation sites. This is called heterogeneous nucleation. Nucleation without preferential nucleation sites is homogeneous nucleation.

Homogeneous nucleation occurs spontaneously and randomly, but it requires superheating or supercooling of the medium. Nucleation is involved in such processes as cloud seeding and in instruments such as the bubble chamber and the cloud chamber.

The introduction of Wilson Particles to Vexarak Spoilers in 2414 proved to be an effective way to destroy them. Extremely energetic Nucleation took place and created enough pressure within the creatures to cause them to explode. Ensign Narvak discovered this in 2414, while aiding the USS Rosenante in dealing with a Vexarak Spoiler infestation aboard Starbase 989.