# Planck Length

on . Posted in Quantum Mechanics

Planck length, abbreviated as $$l_p$$, is a fundamental unit of length in the system of natural units known as Planck units.  It is denoted by and is derived from fundamental physical constants such as the speed of light, the gravitational constant, and the reduced Planck constant.  It is thought to be the smallest possible length in a section on spacetime.

The Planck length is significant because it represents the scale at which quantum gravitational effects become important and at which classical notions of space and time might break down.  It is often used in theoretical physics, especially in attempts to understand the behavior of space-time at very small distances or in the context of theories of quantum gravity.

### Planck Length Formula

$$l_p = \sqrt{ h\;G \;/\; c^3 }$$     (Plank Length)

$$h = l_p^2 \; (c^3 \;/\; G)$$

$$G = l_p^2 \; c^2 \;/\; h$$

$$c = \sqrt[3]{ h\;G \;/\; l_p^2 }$$

Symbol English Metric
$$l_p$$ = Planck length (See Physics Constants) $$ft$$ $$m$$
$$h$$ = Planck constant $$lbf-ft\;/\;sec$$ $$J-s$$
$$G$$ = gravitational constant $$lbf-ft^2\;/\;lbm^2$$  $$N - m^2\;/\;kg^2$$
$$c$$ = speed of light in vacuum  $$ft\;/\;sec$$  $$m\;/\;s$$

Tags: Magnetic Plank