A photo of something I hopefully won't ever see!
This is me and a colleague inspecting a radioactive source for damage or corrosion, but using a mirror.
It's not a particularly hazardous source, we can allow 16yr old students to work with it under close supervision, but "do not point it at your eyeballs" is one of the main rules.
@_thegeoff I never thought about this: do radiations reflect on dense enough surfaces?
On shallow enough angles you get more reflection (and maybe even more reflection than scattering). This gets exploited by https://en.wikipedia.org/wiki/Wolter_telescope
I actually realised now that I don't understand why the angles need to be shallower for gamma (Fresnel equations imply that reflectivity for a given direction and polarisation of beam depends only on refractive index -- with no reflection at all for equal refractive indices -- and in the around-visible range refractive indices tend to grow with decreasing wavelength).
