Instant

An instant is a infinitesimal moment in time, a moment whose passage is instantaneous.

The continuous nature of time and its infinite divisibility was addressed by Aristotle in his Physics where he wrote on Zeno's paradoxes. The philosopher and mathematician Bertrand Russell was still seeking to define the exact nature of an instant thousands of years later.

In physics, a theoretical lower-bound unit of time called the Planck time has been proposed, that being the time required for light to travel a distance of 1 Planck length. The Planck time is theorized to be the smallest time measurement that will ever be possible, roughly 10−43 seconds. Within the framework of the laws of physics as we understand them today, for times less than one Planck time apart, we can neither measure nor detect any change. As of May 2010, the smallest time interval that was directly measured was on the order of 12 attoseconds (12 × 10−18 seconds), about 1024 times larger than the Planck time. It is therefore physically impossible, with current technology, to determine if any action exists that causes a reaction in "an instant", rather than a reaction occurring after an interval of time too short to observe or measure.

Famous quotes containing the word instant:

    Take the instant way,
    For honor travels in a strait so narrow,
    Where one but goes abreast. Keep then the path,
    For emulation hath a thousand sons
    That one by one pursue. If you give way,
    Or hedge aside from the direct forthright,
    Like to an entered tide, they all rush by
    And leave you hindmost.
    William Shakespeare (1564–1616)

    No, I have never found
    The place where I could say
    This is my proper ground,
    Here I shall stay;
    Nor met that special one
    Who has an instant claim
    On everything I own
    Down to my name....
    Philip Larkin (1922–1986)

    we two
    With life forever old yet new,
    Changed not in kind but in degree,
    The instant made eternity—
    Robert Browning (1812–1889)