Nah, more like wrinkled gauze. In fact there is a photo of a beautifully low-tech model at the bottom: two styrofoam balls, one with a few loops of plastic thre

Nah, more like wrinkled gauze. In fact there is a photo of a beautifully low-tech model at the bottom: two styrofoam balls, one with a few loops of plastic thread stuck in it, one with a loop of a wrinkled, gauzy fabric. Both are casting a shadow on the wall; the gauzy fabric's shadow has a lot of subtleties of translucency that the thread doesn't, and does indeed look more like all the sun photos above it.