Planck scale

In particle physics and physical cosmology, the Planck scale (named after Max Planck) is an energy scale around 1.22 × 10¹⁹GeV (the Planck energy, corresponding to the mass–energy equivalence of the Planck mass, 2.17645 × 10⁻⁸ kg) at which quantum effects of gravity become strong. At this scale, present descriptions and theories of sub-atomic particle interactions in terms of quantum field theory break down and become inadequate, due to the impact of the apparent non-renormalizability of gravity within current theories.

At the Planck scale, the strength of gravity is expected to become comparable with the other forces, and it is theorized that all the fundamental forces are unified at that scale, but the exact mechanism of this unification remains unknown. The Planck scale is therefore the point where the effects of quantum gravity can no longer be ignored in other fundamental interactions, and where current calculations and approaches begin to break down, and a means to take account of its impact is required.