Airborne house dust
by Konstantinos Kourtidis, Demokritus University of Thrace, Xanthi, Greece
Airborne dust particles. The movie was shot at my home (not a very dusty place!). The room was in shadow while a narrow beam of sunlight from a window was illuminating the dust on its path. You can see larger particles settling gravitationally. The iridescent colors originate from light scattering.
Konstantinos Kourtidis (distributed via imaggeo.egu.eu)