If there are two constants we face as New Yorkers, one is change and the other, our hunger for pizza. It was only a matter of time then before someone combined the two — in this case, five friends who over the past four years documented a changing New York through the time-weathered eyes of 120 of the “most authentic slice joints.” The result of there efforts: The New York Pizza Project book, which launched last week. In the excitement of the long-awaited release, we caught up with project member Ian Manheimer to find out more about the project, his thoughts on the precarious concept that is authenticity, and what makes the perfect pizzeria.