On Wed, 23 Sep 2015 02:59:18 +0000 (UTC) jim bell <[email protected]> wrote: > >Â Â But only a dweeb doesn't know that X-rays cannot be focussed. > >Â (With one very obscure exception not applicable here. Â Find it and > >get an "attaboy!". ) Isn't it possible to focus any sort(frequency) of EM wave, at least in theory? > Its called Grazing Incidence > > https://en.wikipedia.org/wiki/X-ray_optics