Started writing in 2005, after 20 years working for a living...In fact, writing is work, of course, but I mean that I like it a lot more than the 9-to-5 grind of my office job (research engineer for a multinational aerospace corporation).
Ingenium was my first book, and I guess it shows, but I still have a great fondness for it. I was approached out of the blue by the editor of Johns Hopkins University Press who had seen a bunch of my published papers on historically important machines--he thought they could form the basis of an interesting popular science book. So I wrote it; the reviews were kind. I've recently completed my tenth book.