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.
Famous quotes containing the word cold:
“If her horny feet protrude, they come
To show how cold she is, and dumb.”
—Wallace Stevens (18791955)
“Peter is poor, said noble Paul,
And I have always been his friend:
And, though my means to give are small,
At least I can afford to lend.
How few, in this cold age of greed,
Do good, except on selfish grounds!
But I can feel for Peters need,
And I WILL LEND HIM FIFTY POUNDS!”
—Lewis Carroll [Charles Lutwidge Dodgson] (18321898)
“O Captain! my Captain! our fearful trip is done,
The ship has weatherd 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 (18191892)