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:
“Old age grows cold to love.”
—Virgil [Publius Vergilius Maro] (70–19 B.C.)
“If you stand right fronting and face to face to a fact, you will see the sun glimmer on both its surfaces, as if it were a cimeter, and feel its sweet edge dividing you through the heart and marrow, and so you will happily conclude your mortal career. Be it life or death, we crave only reality. If we are really dying, let us hear the rattle in our throats and feel cold in the extremities; if we are alive, let us go about our business.”
—Henry David Thoreau (1817–1862)
“Willows last to relinquish a leaf,
curious, patient, lion-headed, tense
with energy, watching
the serene cold through a curtain
of tarnished strands.”
—Denise Levertov (b. 1923)