Schwinger limit
... that light can elastically scatter other light if the electric field strength exceeds the Schwinger limit?
... that light can elastically <a href="./Scattering" id="mwEbY" rel="mw:WikiLink" title="Scattering">scatter</a> other light <i id="mwEbc">(<a href="./Feynman_diagram" id="mwEbg" rel="mw:WikiLink" title="Feynman diagram">Feynman diagram</a> pictured)</i> if the electric field strength exceeds the <b id="mwEbk"><a href="./Schwinger_limit" id="mwEbo" rel="mw:WikiLink" title="Schwinger limit">Schwinger limit</a></b>?