Cold refers to the condition or subjective perception of having low temperature, the opposite of hot.
A lower bound to temperature is the absolute zero, defined as 0 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 °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 this classical sense. The object would 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.
Read more about Cold: Mammalian Perception, Cooling, Notable Cold Locations and Objects, See Also
Famous quotes containing the word cold:
“Of how he loved high laughter and the lonely
Heart, and cursed a dissipated rime
Of weariness in a golden morning, only
To rouse a cold Helen where the dawn distils
Her bewildered beauty on feet-forgotten hills.”
—Allen Tate (1899–1979)
“Continuous eloquence wearies.... Grandeur must be abandoned to be appreciated. Continuity in everything is unpleasant. Cold is agreeable, that we may get warm.”
—Blaise Pascal (1623–1662)
“Professor: War is hell, Mr. Thornhill, even if it’s just a cold one.
Roger Thornhill: If you fellows can’t lick the Vandamms of this world without asking girls like her to bed down with them, and fly away with them, and probably never come back, perhaps you ought to start learning how to lose a few cold wars.
Professor: I’m afraid we’re already doing that.”
—Ernest Lehman (b.1920)