Study and use of low-temperature phenomena.
The cryogenic temperature range is from -238kF (-150kC) to absolute zero . At low temperatures, matter has unusual properties. Substances that are naturally gases can be liquefied at low temperatures, and metals lose electrical resistance as they get colder (see superconductivity ). Cryogenics dates from 1877, when oxygen was first cooled to the point at which it became a liquid (-297kF, or -183kC); superconductivity was discovered in 1911. Applications of cryogenics include the storage and transport of liquefied gases, food preservation, cryosurgery, rocket fuels, and superconducting electromagnets .