Named after physicist Max Planck, considered to be the father of quantum mechanics. There are two different calculations used for Planck time, which give different values:
  1. $t_p = sqrt(G\hbar/c^5)$, which is approximately 5.391E-44 seconds.
  2. $t_p = sqrt(Gh/c^5)$, which is approximately 1.351E-43 seconds.
G = 6.672E-11 N m**2/kg**2
h = 6.6262E-34 J s
\hbar = h / (2pi)
c=2.9979 m/s