Frozen

Physical process and natural occurrences

Freezing is a phase change in which liquids become solids as molecular motion decreases. In nature this produces ice, frost and permafrost. Permafrost is ground that remains at or below 0 degrees Celsius for multiple consecutive years and influences ecosystems, engineering and climate feedbacks in polar and subpolar regions.

Applications and technologies

Freezing is widely applied to preserve food and biological material. Flash or quick freezing, pioneered commercially in the early 20th century, limits ice crystal growth and helps retain texture and nutrients in food. Cryopreservation extends the idea to cells, tissues and embryos using controlled cooling and sometimes cryoprotectants to enable long term storage at very low temperatures.

Legal, financial and technical senses

In law and finance the term frozen describes assets or accounts rendered inaccessible by court order, regulatory action or sanctions. In computing a frozen program is one that has become unresponsive and may require termination and restart. In psychology the term freeze refers to an involuntary immobility response that can accompany fight or flight.

Cultural works and notable uses

The single word Frozen is also a common title for films, songs and other works. Most widely known is the 2013 Disney animated feature Frozen and its 2019 sequel Frozen II. The 2013 film achieved major commercial success and won Academy Awards including Best Animated Feature and Best Original Song for Let It Go.

Distinctions and notable facts

• Frozen in everyday speech often implies preservation for later use, as in frozen food.
• Freezing differs from refrigeration in temperature and in how it slows microbial activity.
• Care is required when freezing living tissues because ice crystals can damage cells unless special methods are used.