Accident may be the wrong word, but he author doesn't give a better one. Why is English the language of commerce, or the dollar so popular? If it's not an accident of history, then what's the right word?

Most scientific advancement is not on time and on schedule though; it's a conflux of the right people standing next to the right problem. Gutenberg's press would have been almost worthless without cheap rag for making cheaper paper, which was available through another accident of history. I'm sure Gutenberg didn't know that movable type would lead to mass media and the protestant reformation. It's all accidents.