Collection, not dew

In the morning fog, a Goldeneye Duck rests atop a piling.

After a few weeks of low cloud and rain, the skies cleared overnight. The inevitable result of moist ground, moist air, and radiative cooling was valley fog. Fog blanked the Lake. It gently drifted over the water and along the shore.

The droplets in the drifting fog do not collide with large objects; rather, the air and the drops gently flow around them.

But, small objects—that is different. The droplets just collide with the tiniest objects, and collect on them. And the tiniest of the objects the fog drifts toward are the threads of a spider’s web.

This is why droplets festoon a web and make it look like pearls on a necklace: the droplets collide with the threads and stay there.

I cannot count how many times a picture such as the one below has been glibly passed off as: dew on a spider’s web. No, it is not; it is the result of the collection of fog dropplets. While collection favours tiny objects, dew favours larger ones, and on this occasion, there was no dew on the big objects.

Collected fog drops are draped along a spider’s web. This picture does not show dew!