Recently, the science section of leading Dutch newspaper NRC ran a story – in response to reader questions – on “why are dust flakes grey?” (click sorry if there’s a paywall). The question notably addresses dust as flakes”, in Norway also known as “hybelkaniner” (~student dorm rabbits :-))  and in Britain as “dust bunnies”. In search of answers, reporter Nienke Beintema found out that the major fraction of dust is composed of … skin flakes, both from the local human inhabitants as well as associated fauna.

Nienke contacted COPS scientist Willem Vos, to discuss notably if Mie scattering could play a role. In the end, it does not seem likely that the particles inside the hybelkaniner are spherical – as described by Gustav Mie’s brilliant theory – and it is more likely that dust is random light scattering entity where an intermediate fraction of the incident light is absorbed (if it would not absorb, one’d expect it to be white, and if it absorbs all, one’d expect it to be completely black.)

Unless one of our dear visitors informs us of already published papers (most studied dust seems to be interstellar!), we suppose that to really settle the question, we may have to set up a research project to investigate this major societal question. Anyone who may volunteer interesting sample material? (Preferably well characterized :-))