By my count at least four of the researchers are employed by American universities and therefore most likely live somewhere in the United States. And "this stu

By my count at least four of the researchers are employed by American universities and therefore most likely live somewhere in the United States. And "this stuff" to which you refer is the intended output of their full time jobs*. So presumably, they find time to work on it in the same way a software developer finds time to write code. You just sit down and do it, because you are being paid to do it. *Did I miss something about how these papers were developed in their spare time?