These parameters are named after the German physicist Max Planck, the founder of quantum physics.
The parameters are derived from the three most fundamental constants of nature:
- Planck's constant h, a universal constant which depends on Planck's law and has the value 6.626 076 x 10-34
J s
the speed of light c in a vacuum which is defined as 2.997 924 58 x 108 ms-1 (exactly)
the universal gravitational constant G, which has the value 6.672 59 x 10-11m3 kg-1 s-2
Derived from these three constants are:
- Planck time The time (Gh/2p c5)1/2, taken for a photon travelling at the speed of light to travel a distance equal to the Planck length. It is equal to 1.708 63 X 10-43 s.
- Planck length The length (Gh/2p c3)1/2, where G is the gravitational constant, h is the Planck constant, and c is the speed of light. It is equal to 1.615 99 X 10-35 m.
- Planck mass The mass (hc/2p G) 1/2, where h is the Planck constant, c is the speed of light, and G is the gravitational constant. It is equal to 2.176 84 x 10-8 kg.
- Planck energy, which equals 1018 GeV.
- Planck's law The law that forms the basis of quantum theory. The energy of electromagnetic radiation is confined to small indivisible packets or photons, each of which has an energy hf, where f is the frequency of the radiation and h is the Planck constant.
To find out more about Planck go to links.
|
