Interaction networks can describe many interesting things – human social systems, like facebook, but also complex engineered systems like the internet, or animal societies. The past century has seen the development of an area of mathematics called graph theory, which can be used to describe the structure of these networks. There are statistics that describe…

Walk through the Rocky Mountains in the summer, and you will be immersed in a sea of green, and will hear the soft rustling sound of millions of leaves. These are quaking aspen (Populus tremuloides) trees, and they dominate the landscape. When I first came to Colorado in late-fall 2009, I was captivated by the…

Living in the Arizona desert, clouds are a rare occurrence. But in the Andean highlands, they are everything. The cloud forest (bosque nublado) that dominates these mountains can change its character rapidly, and so imposes its rhythms on its inhabitants. The first thing to understand is where cloud forest comes from. Clouds form as moist…

A field campaign is not very different than a space launch. After seven weeks of fieldwork in Peru, I’ve returned from our expedition and have been contemplating the long journeys we made, laden with supplies and scientists. Like a space mission, we aim for inhospitable destinations in far-away places. The steep slopes of the cloud…