It’s the second Tuesday of the month, which is when we hear from our commentators in the field. This week, Gretchen Gerrish of UW-Madison’s Trout Lake Station tells us about darkness as a resource. Sitting on a boat in the middle of Crystal Lake under a full moon, I can see a few stars around the sky’s perimeter, clearly see the outline of trees, differentiate the light-colored concrete of the boat landing and see the details of my student intern’s face as she rows us out to the deep spot to