Planck length
The Planck length (ℓP) is the fundamental unit of length in the system of Planck units, defined by ℓP = √(ħG/c³). Using the 2022 CODATA adjustment maintained by NIST, its value is 1.616255(18) × 10⁻³⁵ meters with a relative standard uncertainty of 1.1 × 10⁻⁵. It is widely treated as a characteristic scale at which quantum and gravitational effects are expected to become comparable, motivating research programs in quantum gravity.
