Note the large water droplets in the photo to the right.
It is often caused by water droplets in the sky.
Light from the sun hits the little water droplets after a rain.
The main advantage of this system is that it has no moving parts except the water droplets.
Picture waves; water droplets by the thousands come in contact with air.
A thick cloud of water droplets fell to the ground.
With the exception of the water droplets they all allow visible light energy to reach the earth.
Too large a water droplet means less oxygen is available to the root system.
These help create a nucleus for the water droplets to bond to.
As particles group together to form water droplets, they will quickly be pulled down to earth by the force of gravity.