This is true not only for sand but also for wet paper or fabrics. It all has to do with the phenomenon of scattering, that is, the number of collisions that the light beam undergoes before surfacing again.
Bathing in the sea during a storm with electrical equipment carries some risk, since there is the possibility of being electrocuted by a lightning strike.
Danni Büchner is invited to Sam Dylan's Halloween party. But the "Goodbye Germany" emigrant has no desire for many other party guests. And find clear words.