Planck time

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In physics, the Planck time (t_P), is the natural unit of time. Eponymously termed for Max Planck, it is considered to be the smallest possible interval of time.

[t_P = \sqrt} \approx] 5.39121(40) × 10⁻⁴⁴ seconds

where:

[\hbar] is the reduced Planck constant (h / 2π which is also called Dirac's constant)

G is the gravitational constant

c is the speed of light in a vacuum

The two digits between the parentheses denote the uncertainty (standard deviation) in the last two digits of the value.

The Planck time is the time it would take a photon travelling at the speed of light to cross a distance equal to the Planck length, and is thus considered to be a "quantum of time".

The estimated age of the Universe in the big-bang theory (4.3 × 10¹⁷ s) would be roughly 8 × 10⁶⁰ Planck times.

External links

[Shortest time interval measured] - coverage of 2004 event on BBC news.
[Fastest view of molecular motion] - BBC news.

Planck time

External links

See also