This week’s challenge is all about forces of nature, so I thought I’d post something about light and its effects of animals. Here’s another Exploratorium exhibit. Basically, zooplankton can distinguish different colors of light. In the ocean, it helps them swim toward the surface, where their food is located. Blue and green lights shine deeper in the water than the other colors, hence why the plankton are attracted to these ones; they think the sun is shining through the water, and that they’re entering the photic zone for a meal. Large version available here.