Planck Time

In physics, the Planck time, (t_P), is the unit of time in the system of natural units known as Planck units. It is the time required for light to travel, in a vacuum, a distance of 1 Planck length. The unit is named after Max Planck, who was the first to propose it.

The Planck time is defined as:

≈ 5.39106(32) × 10−44 s

where:

is the reduced Planck constant (sometimes is used instead of in the definition)

G = gravitational constant

c = speed of light in a vacuum

s is the SI unit of time, the second.

The two digits between parentheses denote the standard error of the estimated value.