Editing Length scale (section)

== Examples ==
* The atomic length scale is {{nowrap|&ell;<sub>a</sub> ~ {{val|e=-10|u=m}}}} and is given by the size of hydrogen atom  (''i.e.'', the [[Bohr radius]], approximately {{val|53|ul=pm}}).
* The length scale for the [[strong interaction]]s (or the one derived from [[Quantum chromodynamics|QCD]] through [[dimensional transmutation]]) is around {{nowrap|&ell;<sub>s</sub> ~ {{val|e=-15|u=m}}}}, and the "radii" of strongly interacting particles (such as the [[proton]]) are roughly comparable.  This length scale is determined by the range of the [[Yukawa potential]].  The lifetimes of strongly interacting particles, such as the [[rho meson]], are  given by this length scale divided by the speed of light: {{val|e=-23|u=s}}.  The masses of strongly interacting particles are several times the associated energy scale ({{val|500|u=MeV/c2}} to {{val|3000|u=MeV/c2}}).
* The [[electroweak]] length scale is shorter, roughly {{nowrap|&ell;<sub>w</sub> ~ {{val|e=-18|u=m}}}} and is set by the rest mass of the [[W and Z bosons|weak vector bosons]], which is roughly {{val|100|u=GeV/c2}}.  This length scale would be the distance where a Yukawa force is mediated by the weak vector bosons. The magnitude of weak length scale was initially inferred by the [[Fermi's interaction|Fermi constant]] measured by [[neutron]] and [[muon]] decay.
* The [[Planck length]] (Planck scale) is much shorter yet – about {{nowrap|&ell;<sub>P</sub> ~ {{val|e=-35|u=m}}}}, and is derived from the [[Newtonian constant of gravitation]].
* The [[mesoscopic scale]] is the length at which quantum mechanical behaviours in liquids or solid can be described by [[macroscopic]] concepts.