I do think the smaller-scale studio works have that incredible love of data crunching, whereas I would say the large-scale earthworks tend to be much more stripped-down. With the mappings, as connected as they are to a much more analytical idea, what's a map? And can I make a map about time? I think the first time was Hurricane Sandy, the flood plane; a moment in time, but indelibly marked on any of us who were in the city. Mapping time is something that I'm really interested in.

Math, it's a puzzle to me. I love figuring out puzzles.

I saw the Vietnam Veterans Memorial not as an object placed into the earth but as a cut in the earth that has then been polished, like a geode.

My dad was dean of fine arts at the university. I was casting bronzes in the school foundry. I was using the university as a playground.

I think I needed to really move past my first public work as memorialist, and be equally balanced. It's a bit unusual, to be working between the architecture, the art, and what I would say is a synthesis, the memorials - they're problem solving, but it's very symbolic. You get this triangle; I need to be balanced with those three. They're all equally a part of who I am. I love how different they are, and yet they're coming out the same thing, whatever it is.

If you don't remember history accurately, how can you learn?

I always give the analogy of the Earth at Night picture, of 7.3 billion of us, right? And everyone says, "Well, that's population." Well, if you took the entire world's population and you lived at the density of Manhattan proper - not a bad place to live - how much space do 7.3 billion people take up? The state of Colorado. At which point I end my lectures, because I want you to be thinking ... is this really a question of population, or is this a question of land use and resource consumption? And let's face it, the top 1.3 billion of us are doing all the damage. Sorry.