There are too many. It happens all the time, every day. To choose just one I would say chaos theory. The basic idea is that there really may not be any long-term predictability in any of the things that we usually talk about. One of the major goals of science is to say that things are predictable and deterministic; by finding the real law and associated data you can describe the future.
In chaos theory if you know what is going on today, you may be able to say something about a short period in the future, but after that, no. With even fairly simple systems you can start to lose predictability and all you may be able to say is something about the likelihood of certain types of events. Today, many scientists focus on linking large, complex climate models to water and ecology models, and may not have clear thinking as to what they can and cannot reliably expect to predict. At the same time, in a complex system, you may end up with interactions that lead to near regular recurrence of the same type of events, e.g., floods and droughts, in a certain region. That was fascinating and I spent quite a bit of time on it. I looked at it not just from a water or climate point of view, but at all kinds of systems in nature.
Who are three people or organizations that you would put in a Hall of Fame for your field?
First, the South Florida Water Management District, with Jayantha Obeysekera, and Tampa Bay Water, because academia creates knowledge, but one has to decide whether or not that knowledge is useful and how best to correctly apply it. These two organizations have done an amazing job in the U.S. They have been extremely forward-looking using academic tools and emerging ideas in the real world.
Second, the Harvard Water Program in the 1960s. They came up with principles for public sector investment in water. Today these principles are not considered to be functioning very well and in fact to be responsible for some of the ills, but at the time it was a benchmark.
Third, I'll say Leonardo da Vinci. He explored two main theories of how fluids flow and what can be done with them. Many of the things he worked on became the principles for design during that period.
What other field or occupation did you consider going into?
English literature, physics, and psychology.
What website or app most helps you do your job on a daily basis?
Gmail. It's available wherever you are. It's actually something that wastes most of my life. It's the communications piece of my life. I get papers to read, I send papers out.
What song's been stuck in your head lately?
Rat-a-tat. OK, that's not a song, but that's what I hear all day long from the keyboard