Peter Noever, the “globe-trotting head of Vienna’s MAK Center” has a plan for a new art center in an old WWII antiaircraft tower in Vienna. “The idea is to build a collection of the 21st century. And to do it on site, and step by step. It will be very slow — 15 to 20 years. You invite one artist, and then see what he has done, and then see what you do next. It is the very opposite of the kind of collection that’s offered on the market, which changes as parts are bought and sold.”