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:
“O Captain! my Captain! our fearful trip is done,
The ship has weather’d every rack, the prize we sought is won,
The port is near, the bells I hear, the people all exulting,
While follow eyes the steady keel, the vessel grim and daring;
But O heart! heart! heart!
O the bleeding drops of red,
Where on the deck my Captain lies,
Fallen cold and dead.”
—Walt Whitman (1819–1892)
“I have been told, that in some public discourses of mine my reverence for the intellect has made me unjustly cold to the personal relations. But now I almost shrink at the remembrance of such disparaging words. For persons are love’s world, and the coldest philosopher cannot recount the debt of the young soul wandering here in nature to the power of love, without being tempted to unsay, as treasonable to nature, aught derogatory to the social instincts.”
—Ralph Waldo Emerson (1803–1882)
“In your Salvation shelter I saw poverty, misery, cold and hunger. You gave them bread and treacle and dreams of heaven. I give from thirty shillings a week to twelve thousand a year. They find their own dreams; but I look after the drainage.”
—George Bernard Shaw (1856–1950)