Nature · Study 036
Dandelion Clock
A dandelion seed head waits for a breeze. Sweep your pointer past it to blow the seeds loose and watch each parachute drift away.
What you're looking at
Each seed hangs from the head on a thin stalk topped with a tuft. Moving the pointer nearby counts as wind: seeds close to the gust let go, pick up its direction, and then float on a slow, noisy breeze with a little lift. When the head is bare for a few seconds, a fresh one grows.
The idea behind it
A dandelion seed stays aloft thanks to its pappus, a disc of about a hundred fine bristles. Air passing through the gaps forms a stable ring shaped vortex just above it, which slows the fall enough for wind to carry the seed long distances.
Try this
Sweep the pointer across the seed head, gently for a few seeds or fast for the lot.
