Jump to content


From Wikipedia, the free encyclopedia

An iceberg, which is commonly associated with cold
Signal "cold" – unofficial (except recommended by CMAS), it is nonetheless used by many schools of diving and propagated through diving websites as one of the more useful additional signals[1]
Goose bumps, a common physiological response to cold, aiming to reduce the loss of body heat in a cold environment
A photograph of the snow surface at Dome C Station, Antarctica. A part of the notoriously cold Polar Plateau, it is representative of the majority of the continent's surface.

Cold is the presence of low temperature, especially in the atmosphere. In common usage, cold is often a subjective perception. A lower bound to temperature is absolute zero, defined as 0.00 K on the Kelvin scale, an absolute thermodynamic temperature scale. This corresponds to −273.15 °C on the Celsius scale, −459.67 °F on the Fahrenheit scale, and 0.00 °R on the Rankine scale.

Since temperature relates to the thermal energy held by an object or a sample of matter, which is the kinetic energy of the random motion of the particle constituents of matter, an object will have less thermal energy when it is colder and more when it is hotter. If it were possible to cool a system to absolute zero, all motion of the particles in a sample of matter would cease and they would be at complete rest in the classical sense. The object could be described as having zero thermal energy. Microscopically in the description of quantum mechanics, however, matter still has zero-point energy even at absolute zero, because of the uncertainty principle.


Cooling refers to the process of becoming cold, or lowering in temperature. This could be accomplished by removing heat from a system, or exposing the system to an environment with a lower temperature.

Coolants are fluids used to cool objects, prevent freezing and prevent erosion in machines.[2]

Air cooling is the process of cooling an object by exposing it to air. This will only work if the air is at a lower temperature than the object, and the process can be enhanced by increasing the surface area, increasing the coolant flow rate, or decreasing the mass of the object.[3][better source needed]

Another common method of cooling is exposing an object to ice, dry ice, or liquid nitrogen. This works by conduction; the heat is transferred from the relatively warm object to the relatively cold coolant.[4]

Laser cooling and magnetic evaporative cooling are techniques used to reach very low temperatures.[5][6]


Early history[edit]

In ancient times, ice was not adopted for food preservation but used to cool wine which the Romans had also done. According to Pliny, Emperor Nero invented the ice bucket to chill wines instead of adding it to wine to make it cold as it would dilute it.[7]

Some time around 1700 BC Zimri-Lim, king of Mari Kingdom in northwest Iraq had created an "icehouse" called bit shurpin at a location close to his capital city on the banks of the Euphrates. In the 7th century BC the Chinese had used icehouses to preserve vegetables and fruits. During the Tang dynastic rule in China (618–907 AD) a document refers to the practice of using ice that was in vogue during the Eastern Chou Dynasty (770–256 BC) by 94 workmen employed for "Ice-Service" to freeze everything from wine to dead bodies.[7]

Shachtman says that in the 4th century AD, the brother of the Japanese emperor Nintoku gave him a gift of ice from a mountain. The Emperor was so happy with the gift that he named the first of June as the "Day of Ice" and ceremoniously gave blocks of ice to his officials.[7]

Even in ancient times, Shachtman says, in Egypt and India, night cooling by evaporation of water and heat radiation, and the ability of salts to lower the freezing temperature of water was practiced. The ancient people of Rome and Greece were aware that boiled water cooled quicker than the ordinary water; the reason for this is that with boiling of water carbon dioxide and other gases, which are deterrents to cooling, are removed; but this fact was not known till the 17th century.[7]

From the 17th century[edit]

Shachtman says that King James VI and I supported the work of Cornelis Drebbel as a magician to perform tricks such as producing thunder, lightning, lions, birds, trembling leaves and so forth. In 1620 he gave a demonstration in Westminster Abbey to the king and his courtiers on the power of cold.[8] On a summer day, Shachtman says, Drebbel had created a chill (lowered the temperature by several degrees) in the hall of the Abbey, which made the king shiver and run out of the hall with his entourage. This was an incredible spectacle, says Shachtman. Several years before, Giambattista della Porta had demonstrated at the Abbey "ice fantasy gardens, intricate ice sculptures" and also iced drinks for banquets in Florence. The only reference to the artificial freezing created by Drebbel was by Francis Bacon. His demonstration was not taken seriously as it was considered one of his magic tricks, as there was no practical application then. Drebbel had not revealed his secrets.[9]

Shachtman says that Lord Chancellor Bacon, an advocate of experimental science, had tried in Novum Organum, published in the late 1620s, to explain the artificial freezing experiment at Westminster Abbey, though he was not present during the demonstration, as "Nitre (or rather its spirit) is very cold, and hence nitre or salt when added to snow or ice intensifies the cold of the latter, the nitre by adding to its own cold, but the salt by supplying activity to the cold snow." This explanation on the cold inducing aspects of nitre and salt was tried then by many scientists.[10]

Shachtman says it was the lack of scientific knowledge in physics and chemistry that had held back progress in the beneficial use of ice until a drastic change in religious opinions in the 17th century. The intellectual barrier was broken by Francis Bacon and Robert Boyle who followed him in this quest for knowledge of cold.[11] Boyle did extensive experimentation during the 17th century in the discipline of cold, and his research on pressure and volume was the forerunner of research in the field of cold during the 19th century. He explained his approach as "Bacon's identification of heat and cold as the right and left hands of nature".[12] Boyle also refuted some of the theories mooted by Aristotle on cold by experimenting on transmission of cold from one material to the other. He proved that water was not the only source of cold but gold, silver and crystal, which had no water content, could also change to severe cold condition.[13]

19th century[edit]

Out In The Cold, Léon Bazille Perrault

In the United States from about 1850 till end of 19th century export of ice was second only to cotton. The first ice box was developed by Thomas Moore, a farmer from Maryland in 1810 to carry butter in an oval shaped wooden tub. The tub was provided with a metal lining in its interior and surrounded by a packing of ice. A rabbit skin was used as insulation. Moore also developed an ice box for domestic use with the container built over a space of 6 cubic feet (0.17 m3) which was filled with ice. In 1825, ice harvesting by use of a horse drawn ice cutting device was invented by Nathaniel J. Wyeth. The cut blocks of uniform size ice was a cheap method of food preservation widely practiced in the United States. Also developed in 1855 was a steam powered device to haul 600 tons of ice per hour. More innovations ensued. Devices using compressed air as a refrigerants were invented.[14]

20th century[edit]

Iceboxes were in widespread use from the mid-19th century to the 1930s, when the refrigerator was introduced into the home. Most municipally consumed ice was harvested in winter from snow-packed areas or frozen lakes, stored in ice houses, and delivered domestically as iceboxes became more common.

In 1913, refrigerators for home use were invented. In 1923 Frigidaire introduced the first self-contained unit. The introduction of Freon in the 1920s expanded the refrigerator market during the 1930s.[15] Home freezers as separate compartments (larger than necessary just for ice cubes) were introduced in 1940. Frozen foods, previously a luxury item, became commonplace.

Physiological effects[edit]

Cold has numerous physiological and pathological effects on the human body, as well as on other organisms. Cold environments may promote certain psychological traits, as well as having direct effects on the ability to move. Shivering is one of the first physiological responses to cold.[16] Even at low temperatures, the cold can massively disrupt blood circulation. Extracellular water freezes and tissue is destroyed. It affects fingers, toes, nose, ears and cheeks particularly often. They discolor, swell, blister, and bleed. Local frostbite leads to so-called chilblains or even to the death of entire body parts. Only temporary cold reactions of the skin are without consequences. As blood vessels contract, they become cool and pale, with less oxygen getting into the tissue. Warmth stimulates blood circulation again and is painful but harmless. Comprehensive protection against the cold is particularly important for children and for sports. Extreme cold temperatures may lead to frostbite, sepsis, and hypothermia, which in turn may result in death.[17][18]

Common myths[edit]

A common, but false, statement states that cold weather itself can induce the identically named common cold.[19] No scientific evidence of this has been found, although the disease, alongside influenza and others, does increase in prevalence with colder weather.

Notable cold locations and objects[edit]

Boomerang Nebula
Neptune's moon Triton

Mythology and culture[edit]

  • Niflheim was a realm of primordial ice and cold with nine frozen rivers in Norse Mythology.[40]
  • The "Hell in Dante's Inferno" is stated as Cocytus a frozen lake where Virgil and Dante were deposited.[41]

See also[edit]

  • Technical, scientific
    • Chiller – Machine that removes heat from a liquid coolant via vapor compression
    • Cryogenics – Study of the production and behaviour of materials at very low temperatures
    • Cryosphere – Earth's surface where water is frozen
    • Freezing point – Temperature at which a solid turns liquid
    • Negative temperature – Physical systems hotter than any other
    • Coldness – Measure of the coldness of a system
    • Ultracold atom – Atoms kept at temperatures close to absolute zero
  • Entertainment, myth
    • Ice cream – Frozen dessert
    • Indrid Cold
    • Snowball – Spherical object made from compacted snow
    • Snowman – Figure sculpted from snow
    • Winter sport – Sports or recreational activities which are played on snow or ices
  • Meteorological:
    • Atmospheric inversion – Deviation from the normal change of an atmospheric property with altitude
    • Cold front – Leading edge of a cooler mass of air
    • Freezing rain – Rain maintained at temperatures below freezing
    • Frost – Coating or deposit of ice
    • Hail – Form of solid precipitation
    • Sleet – Form of precipitation consisting of rain and melting snow
    • Snow – Precipitation in the form of ice crystal flakes
  • Geographical and climatological:
    • Glacier – Persistent body of ice that is moving downhill under its own weight
    • Ice cap – Ice mass that covers less than 50,000 km² of land area
    • Ice cap climate – Polar climate where no mean monthly temperature exceeds 0 °C (32 °F)
    • Ice sheet – Large mass of glacial ice


  1. ^ Scuba Diving – Hand Signals Archived 14 April 2009 at the Wayback Machine
  2. ^ "An Introduction to Coolant Technology". coolantexperts.com. Archived from the original on 23 February 2016. Retrieved 15 February 2016.
  3. ^ "Air Cooling". techopedia.com. Archived from the original on 2 March 2016. Retrieved 16 February 2016.
  4. ^ "When you add energy to an object and the object warms, what exactly is happening inside the object?". atmo.arizona.edu. Archived from the original on 16 September 2015. Retrieved 16 February 2016.
  5. ^ "Laser Cooling". hyperphysics.phy-astr.gsu.edu. Archived from the original on 31 January 2016. Retrieved 15 February 2016.
  6. ^ "The basic idea of the evaporative cooling is simple". cold-atoms.physics.lsa.umich.edu. Archived from the original on 9 December 2015. Retrieved 15 February 2016.
  7. ^ a b c d Shachtman 2000, p. 17.
  8. ^ Shachtman 2000, p. 4.
  9. ^ Shachtman 2000, pp. 8–9.
  10. ^ Shachtman 2000, pp. 12–13.
  11. ^ Shachtman 2000, pp. 18–25.
  12. ^ Shachtman 2000, pp. 25–26.
  13. ^ Shachtman 2000, p. 28.
  14. ^ Flynn 2004, p. 23.
  15. ^ "The Story of the Refrigerator". aham.org. Association of Home Appliance Manufacturers. Archived from the original on 5 March 2016. Retrieved 16 February 2016.
  16. ^ Mayo Clinic staff. "Hypothermia: Symptoms". Mayo Clinic. Archived from the original on 4 February 2016. Retrieved 15 February 2016.
  17. ^ Ellen Goldbaum (2 February 2016). "Shocked by frostbite amputations, med students take action". UB Reporter. Archived from the original on 4 March 2016. Retrieved 15 February 2016.
  18. ^ This is how cold protection works in winter (German) - Alpin 01/2007
  19. ^ Zuger, Abigail (4 March 2003). "'You'll Catch Your Death!' an Old Wives' Tale? Well . ." The New York Times.
  20. ^ Clark, Jeremy B.; Lecocq, Florent; Simmonds, Raymond W.; Aumentado, José; Teufel, John D. (11 January 2017). "Sideband cooling beyond the quantum backaction limit with squeezed light". Nature. 541 (7636): 191–195. arXiv:1606.08795. Bibcode:2017Natur.541..191C. doi:10.1038/nature20604. PMID 28079081. S2CID 4443249.
  21. ^ "The Nobel Prize in Physics 1997". Archived from the original on 24 September 2015.
  22. ^ "Mysterious Sedna | Science Mission Directorate". science.nasa.gov. Archived from the original on 16 May 2017. Retrieved 28 February 2023.
  23. ^ Amos, Jonathan (16 December 2009). "'Coldest place' found on the Moon". BBC. Retrieved 17 December 2009.
  24. ^ "Boomerang Nebula boasts the coolest spot in the Universe". NASA's Jet Propulsion Laboratory. 20 June 1997. Archived from the original on 27 August 2009. Retrieved 8 July 2009.
  25. ^ "By the Numbers | Haumea".
  26. ^ Staff (7 July 2009). "Coldest Known Object in Space Is Very Unnatural". Space.com. Archived from the original on 3 July 2013. Retrieved 3 July 2013.
  27. ^ Hinshaw, Gary (15 December 2005). "Tests of the Big Bang: The CMB". NASA WMAP. Archived from the original on 20 March 2008. Retrieved 9 January 2007.
  28. ^ "Voyager the Interstellar Mission". NASA: Jet Propulsion Laboratory, California Institute of Technology. Archived from the original on 20 December 2007. Retrieved 15 February 2016.
  29. ^ "Uranus Fact Sheet". Archived from the original on 21 June 2013. Retrieved 2 August 2012.
  30. ^ "Saturn Fact Sheet". Archived from the original on 18 August 2011. Retrieved 2 August 2012.
  31. ^ "Mercury: In Depth". NASA. Archived from the original on 2 February 2016. Retrieved 15 February 2016.
  32. ^ "Jupiter Fact Sheet". Archived from the original on 13 April 2011. Retrieved 2 August 2012.
  33. ^ "Mars Fact Sheet". Archived from the original on 23 November 2013.
  34. ^ "Melting Ice in Antarctica : Image of the Day". 25 September 2007. Archived from the original on 19 January 2009.
  35. ^ Bignell, Paul (21 January 2007). "Polar explorers reach coldest place on Earth". The Independent. London. Archived from the original on 8 January 2012. Retrieved 30 April 2010.
  36. ^ Budretsky, A.B. (1984). "New absolute minimum of air temperature". Bulletin of the Soviet Antarctic Expedition (in Russian) (105). Leningrad: Gidrometeoizdat. Archived from the original on 27 February 2009.
  37. ^ Weidner, George; King, John; Box, Jason E.; Colwell, Steve; Jones, Phil; Lazzara, Matthew; Cappelen, John; Brunet, Manola; Cerveny, Randall S. (23 September 2020). "WMO evaluation of northern hemispheric coldest temperature: −69.6 °C at Klinck, Greenland, 22 December 1991". Royal Meteorological Society.
  38. ^ Lawrence 2012, p. 16.
  39. ^ Negi 2002, p. 9.
  40. ^ Toole 2015, p. 118.
  41. ^ Fowlie 1981, p. 198.


External links[edit]