Knowra Planck scale Planck scale The regime near the Planck length, time, and energy, where quantum gravitational effects are expected to matter and established theories may cease to apply.
Planck length : A length of about 1.6 × 10⁻³⁵ metres, formed from the gravitational constant, the speed of light, and the reduced Planck constant. It marks the distance scale at which quantum-gravity effects are expected to become significant.
Quantum gravity : The sought framework describing gravity using quantum principles. It is the kind of theory expected to govern physics in this regime.
String theory : A framework in which fundamental entities are one-dimensional strings rather than point particles. It offers a candidate quantum-gravity description that can incorporate Planck-scale physics.
Electroweak scale : The energy range associated with electroweak symmetry breaking, around hundreds of gigaelectronvolts. It is vastly below the Planck energy and accessible to particle accelerators.
Planck time : A time of about 5.4 × 10⁻⁴⁴ seconds, equal to the Planck length divided by the speed of light. It is the characteristic time interval associated with the Planck regime.
General relativity : Einstein’s theory describing gravity as the curvature of spacetime caused by energy and matter. Its classical description of spacetime is expected to need quantum corrections near the Planck scale.
Loop quantum gravity : A proposed theory that quantizes spacetime geometry using networks of quantum states. It investigates whether spacetime geometry itself has discrete structure at Planckian distances.
Grand unification scale : The energy range where the strong, weak, and electromagnetic interactions may unify in some theories. It is high but still generally below the Planck scale.
Planck energy : An energy of about 1.2 × 10¹⁹ gigaelectronvolts, defined from the fundamental constants of gravity, quantum mechanics, and relativity. It expresses the extreme energy associated with probing Planck-scale distances.
Quantum field theory : A framework describing particles as excitations of fields that obey quantum mechanics and special relativity. Its standard treatment of fields on a fixed spacetime does not fully account for quantum spacetime geometry.
Show all 23