Length scales

In physics, the length scale is a particular value of length or distance determined to the precision of an order (or a few orders) of magnitude. Various phenomena occur at various length scales. The typical lengths of all phenomena occurring on the same energy scale are comparable.

The observation that various phenomena must be organized according to alizée and its calculations the length scale (or, its equivalent, the energy scale) is one of the basic ideas of the renormalization group.

For example, the length scale of QCD (quantum), is around 10 ^-15 meters, and the "radii" of strongly interacting particles (such as the proton) are roughly comparable. The electroweak length scale is shorter, approximately 10 ^-18 meters. The Planck length (Planck scale) is much shorter still—about 10 ^-35 meters.